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USMLE Step 1 Micro review

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Ryan Dosumu-Johnson

on 7 April 2011

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Transcript of USMLE Step 1 Micro review

Direct Invasion/Toxin
1. Pharyngitis

2. Skin infections

3. Scarlet fever

4. Toxic Shock Syndrome

Antibody mediated
1.Rheumatic Fever

2. Acute post-streptococcal glomerulonephritis Microbiology Review Gram + Gram - Coccus Staphylococcus Streptococcus Neisseria Aureus Epidermidis Coagulase - Coagulase + Saprophyticus Novobiocin sensitive Novobiocin Resistant α hemolytic β hemolytic γ hemolytic Pneumoniae Viridans
(e.g. mutans) Capsule (quellung +)
Optochin Sensitive
Bile Soluble No Capsule (quellung -)
Optochin Resistant
Bile insoluble Enterococcus

Non-enterococci Partial Hemolysis (Green) Complete Hemolysis (clear) Group A Bacitracin Sensitive Group B Bacitracin Resistant no change Pyogenes Agalactiae Bacillus Clostridium Corynebacterium Bacillus Listeria Mycobacterium Enterics Escherichia Coli Shigella Salmonella Yersinia Klebsiella Proteus Enterobacter Heliobacter Pseudomonas Bacteriodes Haemophilus Legionella Bordetella Yersinia Francisella Pasteurella Bartonella Garderella Branching
Filaments Actinomyces Nocardia Weakly Acid Fast Gram Variable
Does not require X or V factor Acid Fast Pleomorphic Rickettsia Chlamydiae No Cell Wall Mycoplasma Intracellular Clusters
Breaks down H202 Clusters
Breaks down H202 Meningiditis Virulence Factors
1) Capsule:Prevents opsonization
2) Endotoxin (LPS): Hemorrhage and sepsis
causes petechiae
3) IgA protease
4) Extract Iron Lance Shaped
Virulence Factors
IgA protease

Otitis media
Some Penecillin resistance Yellow (gold) Pigment aeruginosa blue-green pigment influenzae Diseases
1) Meningitis
lymph nodes to blood to meningies
Change in mental status
Long term (retardation seizures, language delay, deafness) due to bacterial lysis (LPA)
2) Acute epiglottitis
rapid swelling after sore throat w/ fever
cherry red at the base of the tounge
3) Septic arthritis
infants (Most common causes)
4) Sepsis 6 months to 3 years old Virulence Factors:
facultative intracellular
Motile (H2S +)
Vi antigen makes antibodies unable to bind O antigen (lke k antigen)
Exotoxin (cholera-like toxin Virulence factors:
facultative intracellular
Non-motile (no H2S) Virulence Factors:
facultative intracellular
Heat Stable - bind brush border inhibits NaCl reabsorbtion Virulence Factors
facultative intracellular - Macrophages Virulence Factors
facultative intracellular
Fraction 1 - antigen that is antiphagocytic
V and W antigens - protein and lipoprotein (unk function facultative intracellular Virulence Factors
facultative intracellular (Immune cells)
Exotoxins facultative intracellular facultative intracellular Brucella Virulence factors
Anaerobic Virulence factors
Capsule (AAs)
Exotoxin Gonorrhea 2nd most common STD
Virulence Factors
Pili: bind mucosal cells and protect from phagocytosis
Some are penicillin resistant Virulence Factors
1) Pili (binds to intestinal epithelium)
P-Pili, Type 1 Pili
2) Exotoxins
Heat labile-like choleragen

Heat Stable - bind brush border inhibits NaCl reabsorbtion
3) Endotoxin: Lipid A portion of LPS
4) Iron-binding siderophore: binds iron from human transferrin or lactotransferrin
Aerobactin, hemolysin Virulence Factors
Pili (binds to intestinal epithelium)
Exotoxin Bacteria Monocytogenes Tetani Botulinum Tetanus toxin
Spores found in animal feces
Caused by puncture wounds from rusty nails
Grow in anaerobic necrotic tissue
Tetanus Toxin
H (Heavy) subunit: binds to neuronal gangliosides
L (Light) subunit: blocks release of inhibitory neurotransmitters (glycine, GABA) from Renshaw inhibitory interneurons
Continous motor neuron activity,
uncontrolled muscle contractions
lockjaw with Risus Sardonicus (constant smiling, indicates high mortality
Respiratory involvement Botulinum Toxin Inhibits acetylcholine release from motor neurons endplates at neuromuscular junctions
Spores found in jars and home-canned foods
Symptoms from neurotoxin (adult)
Double vision (diplopia)
Difficulty swallowing (dysphagia)
Flaccid muscle paralysis w/ respiratory muscles
Symptoms of neurotoxin (infants)
Floppy baby no need for antitoxin
From honey Vibrio Bacteriodes Campylobacter Serratia Cholera Virulence factor:
Choleragen (eterotoxin)
Five B subunits: GM1 Gangliosides on intestinal cell membranes
Two A subunits: Decreases NaCl (induces secretions and decreased reabsorbtion) reabsorbtion increases cAMP
Dehydration Anthracis Cereus Virulence factors
1) Spores
2) Resistant to Penicillin
Enterotoxin (causes disease no antibiotics)

Heat-stable Like-Choleragen (eterotoxin)
Five B subunits: GM1 Gangliosides on intestinal cell membranes
Two A subunits: Decreases NaCl (induces secretions and decreased reabsorbtion) reabsorbtion increases cAMP
Dehydration Jejuni Virulence Factor:
Like - Choleragen (eterotoxin)
Five B subunits: GM1 Gangliosides on intestinal cell membranes
Two A subunits: Decreases NaCl (induces secretions and decreased reabsorbtion) reabsorbtion increases cAMP
Dehydration enterocolitica Disease
Acute Gastroenteritis
Abdominal pain lower right quadrent (like apendicitis) terminal ileum
Mucosal ulceration Virulence factors
Anti immune proteins

Anti tissue proteins

Weaponry Virulence Factors
Cell Wall components

Enzymes Exotoxin activates endogenous sepsis (e.g. IL-1) Pyrogenic toxin Fever
Hypotension (shock) dysentariae Shiga Toxin
Released inside cells
Results in cell distruction
B-subunit binds
A-subunit inactivates 60s ribosome (Inhibits protein synthesis)
Shiga-like toxin Enterotoxin Clinical Presentation
Toxin mediated
Bloody Diarrhea (w/ white and red blood cells)
Inhibits protein synthesis
Shallow ulcers
FEVER! (not in ETEC)
abdominal pain
Decreased fluids and electrolytes (unable to reabsorb) Superantigen
Causes scarlet fever Symptoms
Red, swollen tonsils
Purulent exudate on tonsils
Swollen lymph nodes A) Folliculitis - infection of hair follicles
B)Cellulitis -deep infection of skin (red and swollen)
C) Impetigo - Vesicular blistered eruption around
mouth crusty and flaky (children) Sore throat, fever, and scarlet red rash on body spares face requires pyrogenic exotoxin Tx: Penicillin Group A D) Necrotizing Fasciitis - Flesh eating infection between subcutaneous tissue and muscle fascia
with color change red to purple to blue and bullae caused by M proteins. (50% mortality) TX: Dicloxacillin
(penicillinase resistant) TX: Surgery
Penicillin G
Clindamycin stops metabolism and shuts
down toxin production Onset 5-15 yrs old
Can happen after pharyngitis (not skin)
Myocarditis (heart inflammation) - due to antigenic similarities
Joint swelling (arthritis)
Subcutaneous nodules (rubbery nodules under skin)
Rash - erythema marginatum (rash w/ red margin that spreads from center) Leads to aortic/mitral rheumatic heart disease TX: Prophylactic penicillin (life) TX: Amoxicillin before dental/surgical procedures Symptoms
Puffy Face (Facial edema)
Tea colored urine/coca cola urine (hematuria)
Week after sore throat
Caused by antigen antibody complexes in the basement membrane Group B Babies! <3months
25% of women carry vaginally
Neonatal Meningitis (fever, vomiting, poor feeding irritabiliity, not neck stiffness)

Sepsis Also think E. Coli and L. Monocytogenes Big Group
Can cause
1. Dental Infections

2. Endocarditis

3. Abscesses Commonly S. Mutans causes cavities Usually after Dental manipulations
Bacteria bind to damaged heart (MVP, CHD, RF)
Grow on dextran
Subacute bacterial endocarditis Valve destruction low-grade fever
heart murmurs Caused by subgroup S. intermedius
S. intermedius, S. constellatus, and S. angiosus
If positive blood order CT w/ contrast to find abscess Enterococci (faecalis and faecium) in GI (bile)
Ampicillin, Vancomycin resistant
2nd most common cause of nosocomial infections
UTI- Nitrite negative urine S. bovis and equinus
associated with bowel cancer Sudden shaking chills (rigors)
High Fever
chest pain w/ respirations
white exudate in lungs
yellow-green sputum Children Vaccines
Done in vulnerable adults

25 capsule proteins w/o spleen
HIV disease TX: High dose penecillin G w/ cephalosporins
Hih resistance requires Vancomycin Penecillin G resistant! C carbohydrate: divides into groups
M Protein: Protects from phagocytosis provides antibody target Streptolysin O: Oxygen labile ASO titer = recent infection
Pyrogenic exotoxin Protein A: Protects opsonization/phagocytosis (binds Fc)
Coagulase: Forms fibrin protects from phagocytosis
Hemolysin (4 types): Destroy RBCs, PMNs, Macrophages, and Plts
Leukocidins: Destroy WBCs
Penicillinase secreted verion of beta-lactam inactivates antibiotics
Novel Penicillin Binding Protein(transpepsidase): Necessary for cell wall peptidoglycan formation Hyaluronidase ("spreading factor"): breaks down proteoglycans in connective tissue
Staphylokinase: lyses fibrin clots
Lipase: degrades fats/oils (allows infection of sebacous glands)
Protease Exfolatin: diffusable exotoxin causes scalded skin syndrome

Enterotoxins Toxic Shock syndrome
Hypotension (shock) if severe organ failure
TX:: antibitoics not currative Toxic shock syndrome toxin (TSST-1)
Associated with super absorbent tampons/surgical wounds
Binds MCH class II on APCs causes massive T cell responses activates IL-1 and TNF Contained in food
Enterotoxin stimulates peristalsis
Vomiting, nauseau, diarrhea, abdominal pain 12 - 24 hrs Gastroenteritis Scalded Skin Syndrome Neonates (often at umbilicus)
Cleavage of middle epidermis revealing red moist skin
Destroys keratinocyte attachments
Must rule out Drug Allergy Organ Specific infections





Skin Pneumonia (rare)
causes severe Community-acquired bacterial pneumonia
Follows after viral upper respiratory illness
Causes: Effusions empyma (pus in pleural space)Virulence factors Meningitis, Cerebritis, Brain Abscess
High fever
Stiff neck
Obtundation (decreased mental capacity)
Coma Focal
Focal Neurological signs Osteomyelitis
Boys <12
Blood to bone
Warm swollen tissue over bone w/ systemic fever and shakes Acute endocarditis
IV drug users
Violent destruction of heart valves
Sudden high fever, chills, myalgias
Brain or lung involvement Sepetic Arthritis
Invasion of synovial membrane
Acutely painful red swollen joint w/ decreased range of motion
Pediatric and <50 Cellulitis
deep infection of skin (red and swollen)
Vesicular blistered eruption around mouth crusty and flaky (children)
Local Abscesses, Furuncles(hair), and Carbuncles (communicating)
Collection of pus
Wound Infections
Abcess cellulitis or both
Blood and Catheter infections TX: Methicillin, Nafcillin,
and other penicillinase-resistant penicillins Methicillin-Resistant Staphylococcus aureus (MRSA)
Aquired via plasmid TX: Vancomycin Found on skin (contaminantes blood)
Infects compromised patients
Foley urine catheters
Intravenous lines
Prosthetic devices(valves, joints, dialysis) via capsule UTI in community settings
UREASE !!!! - staghorn caliculi (Amonium magnesium phosphate
TX: Penicillin TX: Vancomycin Found on goats, sheep and cattle
Pulmonary anthrax lethal
Spore grow in macrophages Skin
forms a malignant pustule that grows without antibitoics (via exotoxin)
Taken in lungs transported to hilar lymph nodes
Mediastinal hemorrhage
Lesion due to exotoxin Encoded on pXO1 plasmid
Edema factor (EF): Increases cAMP -> decreases neutrophil function causes edema
Protective Antigen (PA): Allows EF entry
Leathal Factor (LF): Zinc metalloprotease --| protein kinase -> macrophages release TNF and IL-1 TX: Penicillin, Doxycyclin, Ciprofloxacin, or Levofloxacin
Vaccine against PA Like-Choleragen (eterotoxin)
Five B subunits: GM1 Gangliosides on intestinal cell membranes
Two A subunits: Decreases NaCl (induces secretions and decreased reabsorbtion) reabsorbtion increases cAMP
abdominal pain diarrhea nauseau (12-24 hrs) Like-Staph aureus
short incubation
followed by severe nauseau and vomiting with little diarrhea TX: Ig anti-toxin, booster vaccine w/ toxin, debridement, antibitotics, muscle relaxants

Perfringens Dificile Gas Gangrene 1) Cellulitis/wound infection
Moist, spongy, crackling consistency (Crepitus)
2) Clostridial myonecrosis
Exotoxin destroys adjacent muscle (w/ gas pocket)
Diagnose via CT
Fatal! Unless detected early TX: Hyperbaric oxygen
Antibiotics (e.g. penecillin)
Removal of necrotic tissue Psuedomembranous Enterocolitis Causes white exudate w/ necrosison large intestine
Associated with broad spectrum antibiotics (ampicillin, clindamycin and cephalosporins)
Takes over after normal intestinal flora are destroyed
A causes diarrhea
B is cytotoxic
Severe Diarrhea
Abdominal cramping
Diagnose via stool TX
Stopping antibiotics
Metronidazole (oral) or Vancomycin (oral)
Not absorbed in blood Diphtheriae Colonizes pharynx on a psuedomembrane (fibrin, leukocytes, necrotic epithelial cells)
Darker and thicker than strep throat
Exotoxin released into blood via pharynx (Erythrogenic toxin)
Causes heart and neural damage
B binds A stops protein synthesis
Diagnosis via potassium tellurite agar and Loeffler's coagulated blood serum culture (gray to blac) Erythrogenic toxin TX
1) Anti-toxin
2) Penicillin or erythromycin
3) DPT Vaccine Causes Meningitis
neonates (3rd most common cause)
Destroyed via cell-mediated immunity
Destroyed when macrophages are activated TX:
Ampicillin or
Trimethoprim-sulfmethazole Diplococcus Clinical
High-risk groups
Infants 6 months -2 years (antibody free window)
Army recuits (weakened immune system lots of people)
Resides in nasopharynx
1) Meningococcemia: spiking fevers, chills, arthralgia (Joint), and Muscle pain
2) Fulminant meningococcemia (Waterhouse-Friderichsen syndrome)
3) Meningitis: Fever, vomiting, irritability, and/ or lethargy
Affects infants (bulging fontanelle
Positive Kernig and Brudzinski's signs
Diagnose: Thayer-Martin VCN media TX
Penicillin G
Prophylaxis (close contacts)
Rifampin Clinical
Urethra inflammation/ painful urination
Reddened friable purulent exudative discharge
Lower abdominal discomfort with intercourse
Pelvic Inflammatory Disease
Inflammatory disease of endometritis (uterus), salpingitis(fallopian tubes), oophoritis (ovaries)
Complications of PID
1) Sterility
Scarring of the fallopian tubes
2) Ectopic pregnancy
Scarring prevents normal flow
3) Abscesses
4) Peritonitis
5) Peri-hepatitis (Fitz-Hugh-Curtis syndrome):
upper quadrant pain and tenderness
Gonococcal Disease Men and Women
1) Gonococcal Bacteremia: Fever, Joint pain, skin lesions,
Complications- Pericarditis, endocarditis, and meningitis
2) Septic Arthritis
Acute onset 1-2 joints
Most common in sexually active adults TX: Ceftriaxone w/(doxycycline or azithromycin) Diseases
1) Diarrhea (Montezuma's Revenge/Traverler's Diarrhea)
Adults and infants
A) Enterotoxigenic E. Coli (ETEC)
Heat labile Toxin (LT): Like cholera
Heat stable toxin (ST):
Inhibits Na Cl absorbition and stimulates Cl and HCO3
B) Enterohemorrhagic E. Coli (EHEC)
Secrete Shiga-like toxin: inhibit 60s protein synthesis
Bloody diarrhea
Associated with Hemolytic uremic syndrome (HUS): anemia, thrombocytopenia, and renal failure
C) Enteroinvasive E. Coli (EIEC)
Causes fever!, bloody diarrhea, and white blood cells in stool
Some shiga-like toxin (like shigellosis)
2) Urinary Tract Infections - Nitrite positive urine
Most common cause
Infects bladder, kidney (pyeloneprhitis-IL-1,IL-6, TNF), and urethra
Dysuria (painful urination), increased frequency, and fullness feeling
3) Mengitis
Second most common cause in neonates (<1st month)
4) Sepsis
Most common cause of gram-negative sepsis
Hospitalized patients
5) Pneumonia
Common cause of hospital aquired pneumonia pneumoniae Virulence factors
Encasulated (O antigen) w/o H non-motile
Found in the hospital
2nd most common cause of sepsis
Common cause of UTI ( foley) - nitrite positive urine Virulence Factors
1)Urease-breaks down Urea into NH3 and CO2 TX: Fluroqunolone or TMP/Sulfa X 3 days non pregnant women and men
Pregnant women- Cephalexin avoid TMP/Sulfa 3rd trimester X7 days mirabilis Breaks down urea (NH3 + CO2) and does not grow in colonies (motile)
Common cause of hospital aquired UTI - Nitrite positive/ alkaline urine Normal Flora can cause intestinal tract infections in a Hospital
Can cause UTI (Nitrite positive urine) Has a bright red pigment
Wound Infection
Pneumonia Infection
Via fecal-to-oral transmission Infection
Via fecal-to-oral transmission
Animals - uncooked chicken, eggs, pet turtles typhi Typhoid Fever/Enteric fever (EIEC)
Intestine to lymph nodes to multiple organ systems
Facultative intracellular parasite
Disease (Salmonellosis)
Abdominal pain (right lower quadrant)
Rash (rose spots on abdomen)
Diagnosis via blood, urine, or stool cultures
Can remain chronically infected in gallbladder TX: Ciprofloxacin or Ceftriaxone choleraesuis Sepsis
usually does not involve GI
Happens in patients for splenectomy (Salmonella osteomyelitis) Enteritidis Gastroenteritis
Diarrhea (blood and mucous-ileal inflammation)
Abdominal pain
50% fever
Prolonged recovery w/ antibiotics Exotoxin
Cholera-like toxin (watery)
lasts for a week w/ shedding TX: Fluids and electrolytes Infection
Via fecal-to-oral transmission (animals)
Contaminated foods (milk, water) Infection
Via fecal-oral route
common in travelers/ Disease
Watery diarrhea (loss of 1L per hour)
Shock from severe hypovolemia
diminished pulses
sunken eyes
poor skin turgor TX:
1)Fluids and electrolytes
2) Doxycycline Illness
Fecal-oral route Disease
Extremely common cause of diarrhea (Bloody and loose)
Abdominal cramps pylori Disease
most common cause of duodenal ulcers
chronic gastritis (inflamed stomach) TX:
Bismuth salts
Tetracycline Virulence Factors
Facultative anaerobe (non-lactose fermenter)
Exotoxins - blocks protein synthesis
Antibiotic resistance Diseases
1) Pneumonia
Cystic Fibrosis (chronic) - Caspule related
Immunocompromised patients ( cancer and intensive care unite patients)
2) Osteomyelitis
Diabetic foot ulcers
IV drug users (vertebrae or clavicle)
Children foot puncture
3) Burn-wounds infections
often leads to terminal sepsis
4) Sepsis
High mortality rate
5) Urinary Tract infections/Pyelonephritis
Hospital aquired (foley catheters)
6) Endocarditis
Right heart valve endocarditis
7) Malignant external otitis
External ear canal infection (mastoid bone)
Particularly in diabetic patients
8) Corneal infections
contact lens wearers
9) Hot tub Folliculitis Fragilis No endotoxin (but does have capsule) Disease
Abscess in (trauma/apendicitis, PID, IUD)
fever melaninogenicus TX: Clindamycin, metronidazole, chormphenicol Black pigment Necrotizing anaerobic pneumonia Pertussis Pneumophila Virulence Factor
Capsule (B=bad)
Antibiotic resistance
Grows on chocolate agar (Requires factor V and X) Infection
Lack of antibodies (6 months to 3 years of age) TX: N antibiotics (2nd or 3rd generation cephalosporins) w/ sterioids to prevent long term changes
Vaccine <24 months Hi B vulgaris UTI causes kidney stones (staghorn caliculi because of urease) ducreyi Disease
Chancroid - Painful genital ulcer w/ unilateral painful swollen inguinal lymph nodes (can rupture causes pus)
DDx exclude
Syphilis (T. pallidum) no pain and no pus,
Herpes (HSV 1, 2) vesicles w/ myalgias
Lymphogranuloma venereum (C. trachomatis) - painless inguinal lymph nodes (ulcer disappears before lymphnodes) TX: Erythromycin or trimethoprim/sulfamethoxazole Vaginalis Diseases
Vaginitis - w/ coinfecting anaerobes
Pruritis (itching) of labia
dysuria (burning on urination)
Foul-smelling vaginal discharge (Fishy odor)
Clue Cells!!! - vaginal epithelial cells w/ tiny pleomorphic bacilli TX: Metronidazole Pertussis Virulence Factors:
1) Exotoxin
A) Pertussis Toxin -B and A subunit -> increases cAMP -> activates protein kinase
Histamine sensitization
Increase in insulin synthesis
Promotion of lymphocyte productio
inhibition of phagocytosis
2) Extra cytoplasmic adenylate cyclase - released when phagocytosed
Inhibits phagocytosis (H202) and chemotaxsis
3) Filamentous Hemagglutinin (FHA)
Pili that binds ciliated epithelium
4) Tracheal cytotoxin - destroys the ciliated epithelium
Decreased clearance of bacteria/mucus/inflammatory exudate
Causes cough Diseases
Whooping Cough
most common in children <1 yr
1) Catarrhal stage
1-2 weeks URI w/ sneezing, runny nose, cough, low-grade fevers
most contagious
2) Paroxysmal Stage
No fever w/ characterisitc bursts of nonproductive cough (5-20)
Inspiration whoop sound
Can have vomiting after a coughing attack
Lasts about a month
Increased lymphocytes w/o much increase in neutrophis
3) Convalescent stage TX: Erythromycin
Vaccine (FHA/AC) >2 Illness
Transmitted w/ still water aerosolized (AC, Cooling otwer, whirlpools) Diseases
1) Pontiac Fever
Headaches, muscle aches, and fatigue
Fever and chills
2) Legionnaires' disease
High fevers and severe pneumonia
>50 years old w/ smoking or sputum w/ neutrophils and few organisms TX: Erythromycin Pestis Diseases
Bubonic Plague
Carried by fleas on rats
Death w/in a few days
Think camping/fever
75% mortality
1) Invade inquinal lymph nodes (boubons)
Become swollen, red, painful and hot
2) Fever and Headache
3) Invade bloodstream, liver, lungs, and other organs
4) Hemorrhages under the skin causing blackish discoloration tularensis Tularemia
Comes from infected rabbits, ticks, and deerflies
1) Ulceroglandular tularemia
Well-demarcated hole in skin w/ black base
Fever w/ systemic symptoms
Local lymphnodes become swollen red and painful (w/ some pus)
5% mortality
can progress to lungs
2) Pneumonic tularemia
Aerosolization of bacteria during skinning/evisceration
causes pneumonia facultative intracellular Abortus (cows)/Meleitensis (goats)/ suis (pigs)/ canis (dogs) Disease
Transmitted via infected meat products/infected milk (not in US)
Think meat worker, veternarian, farmer, or traveler
Infects via skin, conjuctiva, lungs, or GI
Spreads to lymph nodes, blood and organs
Systemic symptoms (fever, chills, sweats, loss of appetite, backache, headache, sometimes lymphadenopathy)
undulate fever
slow rise in temperature during the day which declines at night

multocida Most common wound infection after cat/dog bite
Invades local joints and bones TX: Penicillin or doxycycline TX: Aminoglycoside (gentamicin or streptomycin) and/or doxycycline Virulence factors
Obligate intracellular
1) Unique life cycle
A) Elementary body - 300 nm
Metabolically inert small, round, dense infectious particle
B) Initial body (reticulate body) - 1000 nm
Blocks phagocytosis once inside cell
2) Energy parasite - Cannot make its own ATP trachomatis Disease
Chronic conjunctivitis
leading cause of preventable blindness (think native americans)
Blindness develops over 10-15 years - scars eyelid pulls lashes inward destroying cornea
2) Inclusion conjunctivitis
Delivery through infected birth canal
purulent yellow discharge and swelling of eyelids after 5-14 days
Basophilic intracytoplasmic inclusion bodies
3) Infant Pneumonia
Babies passage through an infected birth canal
4-11 weeks URI w/ rapid breathing, cough, and respiratory distress
4) Urethritis
Most common sexually transmitted disease -nongonococcal urethritits (NGU) this or ureaplasma
Dysuria (painful urination)
thin to thick mucoid discharge from urethra
Can cause Pelvic Inflamatory Disease (PID)

5) Epididymitis - men only (obviously)
6) Reiter's syndrome -inflammatory arthritis of large joints
7) Fitz-Hugh-Curtis syndrome- affects liver capsule (right upper quadrant pain)
8) Lymphomagranuloma venereum
Sexually transmitted disease
painless papule/ ulceration that heals spontaneously
Inguinal lymphadenopathy tender/painful Dyspareunia (pain w/ sexual intercourse )
Vaginal discharge
Naseau, vomiting
Lower abdominal pain (most common ) + PID shuffle +chandelier sign
Can scar fallopian tubes -> ectopic pregnancy/infertility TX: Tetracycline or Erythromycin TX: Ceftriaxone w/ doxycycline or azithromycin psittaci Psittacosis
Transmitted from bird dust (feathers/ dried-out feces)
Atypical Pneumonia
Fever, headache
dry hacking cough w/o yellow sputum
Few crackles heard
X-ray w/ patches or streaks of infiltrate
doesn't appear that sick pneumoniae
Atypical Pneumonia
Fever, headache
dry hacking cough w/o yellow sputum
Few crackles heard
X-ray w/ patches or streaks of infiltrate
doesn't appear that sick TX: Tetracycline or Erythromycin Virulence factors
Obligate intracellular
1) Size of a large virus
2) Requires a arthropod vector (except for Q fever)
Rocky mountain spotted fever -tick
Epidemic typhus - louse
Endemic typhus - flea rickettsia Wood tick/dog tick
Rocky Mountain Spotted Fever
Fever, conjunctival redness, severe headache
Rash - present on wrist, soles, and palms eventually trunk and face
More common in southeast akari Mite mediated (live on house mice)
red skin bump (papule) at bite
Fever/headache days later
vesicles all over body prowazekii Louse (human lice) and flying squirrels
Epidemic Typhus
sudden onset/rapid spread through population
2 week incubation period
Small pink macules over trunk spares palms soles face
Delerium/ stupor
Blood vessel clotting (gangrene of hands/feet) TX: Tetracycline and chloramphenicol TX: Doxycyline TX: Tetracycline and chloramphenicol typhi Rat flea
Endemic/Murine Typhus
10 day incubation period
Fever and headache
Flat bumpy maculopapular rash tsutsugamushi TX: Doxycicline or chloramphenicol Chiggers (larvae of mites) in soil
Scrub Typhus/ Tsutsugamushi fever
High fever, headach
Scab at bite site
Maculopapular rash quintana Louse borne
Trench Fever
High fever headache
severe leg and back pain
multiple recurances -relapse after 5 days henselae Motile
1) Cat-scratch Disease
regional lymphn node enlargment
low grade fever w/ malaise
resolves in a few months
2) bacillary angiomatosis
Proliferation of small blood vessels in AIDS patients coxiella burnetii Virulence Factors
Non-arthropod transmission(feces of ticks and cattle inhalation)
Q Fever
2-3 weeks after infection
Abrupt onset of fever and soakign sweats
Pneumonia Ehrlichia Chaffeensis dog tick
Like Rocky Mountain Spotted fever
High Fever and severe headache Spirochetes Treponema Borrelia Leptospira 6 thin endoflagella
cannot be cultured easily or
cannot viewed unders simple light microscopy pallidum Syphilis
Sexually transmitted via mucosal skin
Primary Syphilis
Painless chancre(firm ulcer) at site of inoculation 3-6 weeks after initial contact -sheds bacteria
Regional nontender lymph node swelling
Resolves in 4-6 weeks without a scar
Secondary Syphilis
Bacteremic >6 wks after primary chancre has healed
Rash - Macular red lesions on soles, palms, and mucous membranes (oral) can be papular and pustular
Condyloma latum - painless wart occurs on warm/moist sites (vulva or scrotum) highly contagious
Secondary organs can be involved (CNS, eyes, kidneys, and bones)
Generalized lymphadenopathy, weith loss, and fever
Latent Syphilis
serologic positive
25% negative
Tertiary Syphilis
Develops over 6-40 years slow inflammatory damage
1) Gummatous syphilis
3-10 years after primary infection in 15% of untreated
Localized granulomatous lesions -> necrose -> fibrosis
Noninfectious lesions found on skin and bones (sharp borders)
deep gnawing pain
better with antimicrobial therapy
2) Cardiovascular syphilis
Occurs at least 10 years after the primary infection in 10%
Aneurysm in ascending aorta or aortic arch
Chronic inflammatory destruction of small arterioles (vasa vasorum)
Necrosis of the media layer
May occlude coronary arteries
3) Neurosyphilis
8% of untreated
A) Asymptomatic - clinically normal but + CSF
B) subacute meningitis
Fever, stiff neck, headache,
CSF +, w/ high limphocytes, and high protein and low glucose
C) Meningovascular syphilis
Attack blood vessesl in the brain -> clot
Brain infarction
D) Tabes Dorsalis
affects spinal cord -> posterior columns -> decreased vibratory sense w/ decreased proprioception
Ataxia/ loss of reflexes/ loss of pain/temeperature
Argyll-Roberson Pupil - Prostitue pupil (accomidates but does not reac to light)
E) General Paresis
Progressive disease of nerves -> mental deterioration/ psychiatric symptoms
Argyll-Roberson Pupil - Prostitue pupil (accomidates but does not reac to light)
4) Congenital Syphilis
Fetus of infected woman
Early - within 2 years wide-spread rash w/ condyloma latum runny nose (snuffles), lymphnode, liver and spleen enlargement
Late- Similar to tertiary w/o much cardiovascular Neuro - deafness bone and teeth - destroys cartilage of palate and nasal septum (saddle nose) central notch in teeth 0hutchinson's teeth and saber shins), eye disease - corneal inflammation
TX mother before 4th month
Diagnose via increased cardiolipin/lecithin antibodies (VDRL or RPR) or indirect immuno FTA-ABS TX: Penicillin or erythromycin or doxycilin(toxic to fetus) endemicum pertenue (yaws) carateum Desert zones of africa/middle east
Sharing drinking and eating utensils
Gummas of skin and bone Yaws
Moist tropics affects someone's face Hispanic person
colored in red and blue skin lesionssecondary erruption
w/in a year lesions become depigmented burgdorferi Lyme disease
Occurs in northeast, midwest, and nortwestern US
Most common tick-borne illness in US
Carried by ixodes tick (feeds on white-footed mouse/white -tailed deer)
1) Early Stage single
10 days after and lasts 4 weeks
painless chancre at site
flulike illness w/ regional lymphadenopathy
Erythema chronicum migrans (ECM) - red bulls eye rash
2) Early disseminated
Skin/Nervous system/heart/joints (bell's palsy, AV node block, pain in joints/muscles (hot))
lots of smaller skin lesions
Late stage
10% untreated have chronic
1-2 large peripheral joints (eg. knees)
B-cell allo-antigen HLA-DR 1+ 4 (have this)
chronic neural damage (encephalopathy, memory impairment, irritability, and somnolence)
ELISA/Western TX: Doxycicline or Penicillin
Vaccines are availible recurrentis Relapsing fever
Transmitted via louse
High fever w/ chills headaches and muscle aches
drenching sweats resolves within 3-6 days then recurrs after some time due to antigenic variation TX: Doxycycline Found in the urine of dogs, rats livestock
infects via mucous membranes (swimming/ driking contaminated water)
Phase 1 (Leptospiremic phase)
Bacteria invade blood/CSF
High spiking fever
Headache, malaise, severe muscle aches
Red conjunctiva (w/ photophobia)
IgM antibodies
Phase 2 (immune Phase
Meningismus and CSF w/ increased white cell counts
Can cause Weil's disease -infectious jaundice - renal failure hepatitis, mental status changes and hemmorrhage of many organs
Diagonisis made via blood/CSF culturing in phase 1 or in urine during phase 2 TX: Doxycicline or Penicillin Mycobacterium Acid fast
Cord Factor - inhibits neutrophil migration and dmagages mitochondria alsocauses the release of cachectin and TNF
Sulfatides - inhibit phagosome fusion with lysosome
WaxD D - adjuvant (enhances antibody formation to antigen) activates protective cellular immunity
Aerobic Tuberculosis Clumped colonies on agar very slow growth
1) Facultative intracellular growth
Inhaled bacteria live in marophages
2) Cell mediated Immunity
Macrophage phagocytoses bacteria and activates T- cells in lymph nodes
Caseous necrosis
PPD is a type IV hypersensitivity reaction
1) Primary Tuberculosis
aerosolized respiratory secretions
A) Asymptomatic primary infection
tiny tubercles too small to be seen on chest x-ray (calcified called ghon w/ lymph called ranke complex)
w/ hilar lymph node involvement
B) Symptomatic primary tuberculosis
Less common and often in children/elderly/immunocompromised individulas
large caseous granulomas in lungs or other organs (eventually cavitary lesions)
2) Secondary Tuberculosis
10% chancer per year in HIV infected patients
A) Pulmonary tuberculosis
Occurs in apical areas of the lung (good oxygen tension
Caseate -> liquify -> caviate
Low-grade chronic fever
night sweats, weight loss
productive cough (w/ blood)
B) Pleural and Pericardial infection - increased fluid around lung and heart
C) Lymph node infection (scrofula)
Cervical lymph node involvement - swollen mat together and drain.
D) Kidney
Pyuria and hematuria w/ gram stain bacteria (sterile pyuria)
E) Skeletal - Thoracic and lumbar spine (Destroy's discs) Pott's disease
F) Joints - chronic arthritis of one joint
G) Central nervous system - subacute meningitis (granulomas in the brain)
H) Miliary Tuberculosis - tiny millet seed sized tubercules all over the body
Chest X-ray
Sputum acid-fast stain culture
Rule of fives
5% risk of reactivation in first 2 years and 5% lifetime risk Leprae Leprosy aka Hansen's Disease
Impossible to grow on artifical media
Damages cool areas of body (skin (spares warm areas), superficial nerves, eyes, nose, testes)
1) Lepromatous leprosy (LL) - cannot mout cell mediated immune response
Leonine facies (thinkening of facial skin)
Saddle nose (Destruction of nasal cartilage)
internal testicular damage (infertility)
Loss of sensation in feet and fingers
2) Tuberculoid Leprosy (TL)
localized superficial lesions
Enlarged nerves (ulnar, tibial, and peroneal)
similar lesions
Lepromin Skin test - only for TL Immune to Penicillin, cephalosporin and resistant to erythromycin and tetracycline penumoniae after 2-3 week incubation
Walking pneumonia
Fever, sore throat malaise
Persistent dry hacking cough
Chest x-ray w/ streaky infiltrate
Resolve in 2 months
Cold agglutinins peak after 3 weeks of onset
Complement Fixation test
Sputum Culture
Mycoplasma DNA probe TX: Erythromycin or tetracycline will limit course Ureaplasma urealyticum swims in urea part of normal flora
can cause urethritis
dysuria (burning on urination)
sometimes yellow mucoid discharge TX: Erythromycin or tetracycline Anti-Bacteria Medications Penicillins Beta lactam ring
Bacteriocidal - via inhibition of transpeptidase
Pass through porins Modes of resistance
1) Gram "-" - outer lipid bilayer
2)Beta lactamase (e.g. penicillinase "staph aureus")
3) Modify transpeptidase (MRSA) Penicillin G Original Penicillin
many are resistant
Given IM or oral
Tx: Strep pneumoniae
SE: Hypersensitivity reactions, hemolytic anemia Amino penicillins Broad spectrum
Able to affect gram "-" via better penetration
Tx: enterics
30% H. Influenzae resistant
Amoxicillin better oral absorption
Ampicillin - good for IV (used with gentamycin for UTI)
SE: Hypersensitivity reactions, ampicillin rash, pseudomembranous colitis Penicillinase-resistant penicillins Methicilin ( causes interstitial nephritis), Nacillin, and oxacillin
Tx Staph Aureus
also cloxacillin or dicoxacillin
SE: Hypersensitivity reactions Anti-Pseudomonal Penicillins Ticarcillin, carbenicillin, Piperacillin
TCP (Take care of psuedomonas)
Tx Pseudomonas aeruginosa, aslo anaerobes (b. fagilis), and many gram "+"
use w/ clavulanic acid (B-lactamase inhibitor) to provide broad coverage
SE; Hypersensitivity reactions Cephalosporin Resistant to penicillinases
each generation less effective against gram "+"
1st generation (cefazolin, cephalexin)
Tx strep/staph
also TX: p. mirabilis, E. Coli, K. pneumoniae
2nd generation (cefotetan, cefoxitin, cefaclor, cefuroxime)
Tx: H. Influenzae, E. aerogenes, Neisseria, P. mirabilis, E. Coli, K. Pneumoniae
3rd generation (ceftriaxone(gonorrhea), cefotaxime, cefoperazone, ceftazidime(psuedomonas))
Serious Gram "-" (neisseria, B. burgdorferi, enterobacter)
4th generation (cefepime)
Effective against pseudomonas and gram "+" (Best of both worlds)
SE: Hypersensitivity reactions, cross-hypersensitivity w/ penicillins 5-10 %, increased nephrotoxicity, disulfiram-like reaction w/ ethanol Carbapenem Imipenem/cilastatin, Meropenem (less seizure)
Given w/ cilastatin (inhibitor of renal dihydropeptidase I) to decrease inactivation of renal tubules
Effective against Gram + and - (pseudomonas and enterococcus included)
MRSA = resistant
Not penicillin cross reactive
SE: GI distress, skin rash, and CNS toxicity at high levels Aztreonam Monobactam
Tx: Aerobic Gram "-" including psuedomonas (tough bugs)
SE: Usually nontoxic not Penicillin cross reactive Anti-ribosomal Antibiotics Chloramphenicol Inhibits 50S peptidyltransferase activity
Tx: Gram "-" and "+", B. fragilis, Unkown Meningitis, Rickettsial infection in pregnancy
SE: Anemia, aplastic anemia, gray baby syndrome (inpremature infacts lack liver UDP-glucuronyl transferase) Clindamycin Blocks peptide bond formation at 50s ribosomal subunit
Tx: anaerobic infections, UTI
SE: Pseudomembranous colitis (C. dificile overgrowth), fever, diarrhea Linezolid Blocks peptide bond formation at 50s ribosomal subunit
Tx: Resistant Gram Positive bacteria (Vancomycin resistant enterococcus VRE)
SE: Headache and GI upset Macrolides Erythromycin, Azithromycin, Clarithromycin
blocks translocation during protein synthesis (23S rRNA of 50s)
Absorbed better by gram +
Tx: Gram "+" cocci, Mycoplasma, *legionella*, chlamydia, Community-acquired pneumonia(S. pneumoniae, M. pneumoniae, C. trachomatis)
SE: GI irritation (stimulation of peristalsis), Metalic Taste (Clarithromycin) Cholestatic hepatitis, prolonged QT interval, eosinophilia, skin rashes, Increases serum concentration of theophyllines and oral anticoagulants, Inhibits cytochrome P450 (erythromycin do not use w/ diazepam/aprazolam) Tetracyclines Tetracycline, doxycycline( fecally eliminated can be used in renal failure), demeclocycline
Binds 30S prevents aminoacyl-tRNA
limited CNS penetration
Tx: Young soldier diseases (Venereal- C. trachomatis, Pneumonia - M. pneumoniae, Animal borne- Brucella and Rickettsia, Acne) - Doxycycline, V. Cholerae, H. Pylori, Ureaplasma, Tularemia
SE: GI irritation, Phototoxic dermatitis, Renal and hepatic toxicicty, Discolored teeth (babies), depressed growth. DO NOT GIVE TO PREGNANT WOMEN Aminoglycosides Gentamicin, Neomycin (bowel surgery), Amikacin, Tobramycin, Streptomycin
Have difficulty passing through cell wall (thus often used with penicillin)
Bacteriocidal- inhibits formation of initiation complex (misreading of mRNA)
Requires 02 for uptake (only aerobes)
Tx: Severe gram-negative rods, Synergistic w/ B-lactam antibiotics
SE: Nephrotoxicity (w/ cephalosporins), Ototoxcicity (w/ loop), Teratogenic TX: Isoniazid, rifampin, pyrazinamide, ethambutol, streptomycin Anti-ribosomal Antibiotics Isoniazid (INH) Decrease mycolic acid synthesis
Tx: M. tuberculosis (solo for prophylaxis or combination for TX)
SE:Neurotoxcicity, hepatotoxicity, pyroxidine (B6) can prevent neurotoxicity Rifampin Inhibits DNA-dependent RNA polymerase
Tx: M. Tuberculosis, meningococcal prophylaxis, HiB
SE: minor hepatotoxicity, drug interactions (increased 450 (decreased coumadin, oral contraceptives, oral hypoglycemics and corticosteriods), orange bodyfluids Pyrazinamide INH-SPIRE (Inspire) Streptomycin, Pyrazinamide, Isoniazid (INH), Rifampin, Ethambutol TX: Rifampin, dapsone, clofazimine (2 years) Fluroquinolone Ciprofloxacin, norfloxacin, ofloxacin, sparfloxacin, moxifloxacin, gatifloxacin, enoxacin, nalidixic acid
Bacteriocidal - Inhibit DNA gyrase (topoisomerase II)- can mutate
must not be taken with antacids
Tx: Gram "-" rods (pseudomonas), neisseria, some gram "+"
SE: Gi upset, superinfections, skin rashes, headache, dizziness. Contraindicated w/ pregnant women and children, Tendonitis and tendon rupture, leg cramps/myalgias in kids, Photosensitivity and prolonged QT (sparfloxacin) Vancomycin IV antibiotic
Bacteriocidal - Inhibits cell wall mucopeptide formation by binding D-ala D-ala portion of cell wall
Resistance w/ mutation D-ala, D-ala to D-ala D-lac
must not be taken with antacids
Tx: All gram "+" (enterococcus, S. epidermidis, penicillin resistant bugs
SE: Nephrotoxicity, Ototoxicity, Thrombophlebitis, "red man syndrome" (diffuse flushing tx w/ antihistamines), Antimetabolite Trimethoprim and sulfamethoxazole TMP-SMX
Bacteriostatic - TMP (inhibits dihydrofolate reductase) SMX (PABA antimetabolites inhibit dihydropteroate synthetase) combined cause sequental block of folate synthesis
Tx: TX recurrent UTIs, Shigella, salmonella Pneumocystis jiroveci pneumonia
SE: Megaloblastic anemia, leukopenia, granulocytopenia (provide supplemental folinic acid), increases warfarin levels in blood Metronidazole Bacteriocidal - toxic metabolites in bacteria
Tx: Giardia, Entamoeba, Trichomonas, Gardnerella vaginalis, Anaerobes (bacteroides, clostridium), H. Pylori (w/bismuth and amoxicillin)
SE: Disulfiram-like reaction w/ alcohol; headache, metallic taste Polymyxins Polymyxin B, polymyxin E
Bind to cell membranes of bacteria and disrupt osmotic properties (acts as detergent)
Tx: Resistant gram-negative infections
SE: Neurotoxicity, acute renal tubular necrosis Fungi Virulence Factors
1) Cell Membrane - contains sterols
targeted by amphotericin B and Nystatin (creates holes)
Ketoconazole blocks ergosterol synthesis
2) Cell Wall - Potent antigen for immune system
3) Capsule - Visualized with India Ink Stain Superficial Fungal infections Pityriasis versicolor Tinea nigra Chronic superficial fungal infection leads to hypopigmented or hyperpigmented patches
Spaghetti and meatball Causes dark brown to black painless patches on soles of hands and feet Tx: Selenium sulfide or miconazole Dermatophytes Microsporum Trichophyton, and Epidermophyton
Red raised border w/ central clearing
Diagnose via KOH digest or Wood's light (UV light) Tx: Topical azoles Candida albicans Oral thrush/ diaper rash/ vagina Subcutaneous Fungal Infections Sporothrix schenckii Sporotrichosis
dimorphic fungi in rose thorns and splinters
Prick -> nodule -> necrotic -> ulcer -> new nodules Tx: Potassium iodide or itraconazole Tx: nystatin amphotericin B Systemic Fungal Infections Histoplasmosis Blastomycosis Coccidiodomycosis paracoccidioidomycosis Mississippi and Ohio river valleys
3-5 microns (hides inside macrophages) Dimorphic Fungi
In soil grow as spores
In humans grow as yeast cells States east of Mississippi River and central america
Causes inflammatory lung disease
can disseminate to skin and bone
Granulomatous nodules
5-15 microns Southwestern US
Pneumonia meningitis
disseminate to bone and skin
Increased after earthquakes
20-60 microns Latin America Tx: fuconazole or ketoconazole (local infection)
amphotericin B (systemic)
Opportunistic Cryptococcus neoformans vCryptococcal meningitis, cryptococcosis
Heavily encapsulated yeast
Found in soil (pegion droppings)
Sabouraud agar
Latex agglutination test detects polysaccharide capsule antigen
Soap bubble lesion in brain
often in AIDS patients Candida albicans Superficial infections
1) Oral thrus - patches of creamy white exudate
2) Vaginitis - Associated w/ antibiotics, oral contraceptives or menses
Vaginal itching
Thick copious discharge
3) Diaper Rash - Warm moist areas under diapers under breasts or axilla
becomes red macerated
4) Esophagitis - Extension of thrush into esophagus
burning substernal pain worse w/ swallowing
5) Disseminated - invades blood
Can affect any organ
white fluffy candidal patches may be visualized (retina) Tx: Amphotericin B and flucytosine Tx: nystatin Tx: Amphotericin B Aspergillus flavus Toxin - aflatoxin 0
Mold that branch at =< 45 degree angles
Allergic reaction Immediate Type I (bronchospasm, increased IgE and blood eosinophilia)
Ultimately type IV (delayed type cell-mediated allergic reaction)
Aspergilloma - Large ball of fungi (requires surgical removal)
Can have blood in sputum due to invasion of blood vessels by hyphae
Invasive aspergillosis -
Occurs in patinets w/ severe neutropenia, CGD, CF, Burns
Invades tissues causing hemorrhage and infarct
Nasal colonization (pneumonia or meningitis Tx: Systemic corticosteroids Mucor and Rhizopus Mold w/ irregular nonseptate hyphae branching at wide angles
Associated w/ ketoacidotic diabetic patients and leukemic patients
Rhinocerebral frontal lobe abscesses Pneumocystis jiroveci Diffuse interstitial pneumonia
Most infections are asymptomatic
Symptomatic in immunosuppresed patients (AIDS)
Diffuse bilateral CXR apearance
Dx via lung biopsy or lavage
Identified by methenamine silver stain Tx: TMP-SMX, pentamidine, dapsone Antifungal antibiotics Amphotericin B Binds ergosterol causes artificial pores (kills cells)
Wide antifungal spectrum
SE: Renal toxicity( increase BUN and Cre) revisible, Acute Febrile reaction( shaking chill rigors, somtimes after IV infusion), Anemia, Inflammation of the vein (phlebitis) Flucytosine Not used alone because rapid development of resistance
Use w/ amphotericin
Permease allows entry to 5-FU then converted to 5-FdUMP (thymidylate synthase inhibitor)
Tx: Cryptococcus, and candida albicans (systemic)
1) Bone marrow depression - Leukopenia and thrombocytopenia
2) Nausea, vomiting, diarrhea - Azole Imidazoles Triazole Inhibit cytochrome p-450 Ketoconazole, Miconazole, Clortrimazole
Tx: chronic mucocutaneous candidiasis (ketoconazole) not for systemic use
SE: GI (nauseau vomiting anorexia, common), Hepatotoxicity, inhibition of testosterone synthesis, Adrenal supression Fluconazole, Itraconazole, Voriconazole
Less toxic
1) Fuconazole
Cutaneous candida, 2nd line for systemic candidiasis or cryptococcal meningitis
2) Itraconazole
Tx: 1st line for chromoblastomycosis, histoplasmosis, coccidioidomycosis, blastomycosis, and invasive aspergillosis
Poor oral absorption requires low pH (take w/ orang juice)
3) Voriconazole
promising Nystatin Disrupts membrane by binding ergosterol
To toxic to be given via IV
No GI absorption so good for GI infections
Tx: Candida (particularly thrush)
SE: Stevens-Johnson syndrome, contact dermatitis Griseofulvin Disrupts microtubule formation
Tx: Dermatophytes in scalp and hair Terbinafine Inhibits squalene epoxidase (required for setrol biosynthesis)
Tx: Onychomycosis (nail infection) Echinocandin/caspofungin Inhibits synthesis B-1,2 glycan a component of fungal cell wall
Tx: Candida, Aspergillus
SE: Not very toxic, headacher, Infusion-related reactions Viruses RNA Viruses DNA Viruses Single Stranded Double stranded Positive-Stranded Negative-Stranded Naked Enveloped Naked Enveloped Icosohedral Complex Double-stranded (Icosohedral) Single-stranded (Icosohedral) Must have RNA-dependent RNA polymerase Directly translated HHAPPPy (herpes, hepadna, Adeno, papova, Parvo, Pox) Picornaviridae (Icosohedral) Calici (Icosohedral) Toga ( Icosohedral) Flavi (Icosohedral) Corona Retro Bunya Orthomyxoviridae Paramyxoviridae Rhabdo (Bullet Shaped) Arena Filo Reo (icosohedral) Herpesviridae Hepadna Poxviridae Papovaviridae Adenoviridae Parvo Structure
8 segmented (-) stranded RNA (HA NA on different spikes)
Proteins (nucleocapsid protein -NP)
Hemagglutinin Activity (HA)- binds sialic acid receptors
Allows for attachment to host in upper respiratory tract
Allows absorption
receptors present in URT and RBCs
Neuramidase (NA)-
breaks neuraminic acid disrupting the mucin barrier
allows access to sialic acid receptors
Both HA and NA are able to undergo antigenic shift via Disease
Causes flu
can cause seconary bacterial pneumonias (via S. aureus or S pneumoniae)
Can cause complication Reye's Syndrom (w/ fever + aspirin)
Severe liver and brain disease Tx: Amantadine and Rimantidine (Prevent uncoating of influenza A)
Sanamvir (inhaled) and oseltamivir (oral) (NA inhibitors) Structure
(-) single-stranded RNA (HA NA on same glycoprotein spike)
Hemagglutinin Activity (HA)- binds sialic acid receptors
Allows for attachment to host in upper respiratory tract
Allows absorption
receptors present in URT and RBCs
Neuramidase (NA)-
breaks neuraminic acid disrupting the mucin barrier
allows access to sialic acid receptors
Fusion protein (F)
Causes infected host cells to fuse (multinucleated giant cells)
Syncytial cells (like herpesviridae/retroviridae)
Both HA and NA are able to undergo antigenic shift via Disease
4 different types
All affect lungs URT respiratory
RSV and PIV (cause LRT infections) syncytial virus (Pneumonia kids, adults children)
Mostly in children
Viremia - dissemination of virions (mumps can produce local parotid and testes infection/measles severe febrile)
1) Parainfluenza Virus - upper respiratory infection
Adults - cold symptoma (rhinitis, pharyngitis, and sinus congestion to bronchitis and flu-like illness
Children, elderly, and immunocompromised - lower respiratory tract infections ( pneumonia)
Causes croup in childrenCroup - larynx and UR structures ( laryngotracheobronchitis) (children)
Croup results in stridor (wheezing sound) and Barking cough (seal-like)
2) Respiratory syncytial Virus
Contians F- Protein - creates syncitia
Lacks HA and NA
#1 cause of pneumonia in young children (<6 month)
Highly contagious (Usually during winter and spring)
3) Mumps Virus
URI to blood
Usually partiitis and orchitis ( parotid gland and testies inflammation)
4) Measles virus
Spread through naso pharyngeal secretions
A) Measles Prodrome - Prior to rash, conjunctivitis, swelling of eyelids, photophobia, high fever, hacking cough, rhinitis, and malaise
B) Koplik's spots (1-2 days before rash) - blue white lesions w/ red base in white centers of mouth
C) Rash- Maculopapular rash spreads from forhead down resolves in opposite direction
D) Complications - Pneumonia, Eyey damage, myocarditis, ** encephalitis **
E) Subacute sclerosing panencephalitis (SSPE) - years after infection, slowly progressing central nervous system diseas w/ mental deterioration and incoordination Tx: Palivizumab (blocks F protein) Tx: MMR vaccine = preventative I) Hepatitis B Virus (HBV)
Transmission via parenteral contact (blood-blood contact )
30% transmission risk via needle stick
Acute viral hepatitis
1) Acute viral Hepatitis
Flu like symptoms ( pharyngitis, runny nose, cough, musle/joint aches, fatigue, low-grade fever)
1-2 weeks later become jaundice (high bilirubin levels)
Elevated LFT (Aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase)
AST/ ALT very high w/ slightly elevated GGT
Painfully enlarged liver
2) Fulminant hepatitis - Severe acute hepatitis w/ rapid destruction of liver
3) asymptomatic carrier - w/o liver injury
4) Chronic -persistnat hepatitis
enlarged tender liver
mildly elevated LFTs
5) Chronic active hepatitis - acute hepatitis that doesn't recover in 6-12 months
6) co-infection w/ hepatitis delta virus
HDV - RNA virus
1) co-infection -Cause acute hepatitis
HBsAg antibodies protective to both
2) HDV after HBV
Superinfection - acute hepatitis or fulminent hepatitis
Higher chance of mortality
no cure
1)Primary hepatocellular carcinoma
200x increased risk
2) Cirrhosis
1) HBsAg= Disease
2) anti-HBsAg = cure/immune
3) IgM anti-HBcAg = New infection
4) IgG anti-HBcAG = old infection
HBeAg = highly infectivity
anti - HBeAg = low infectivity Hepatitis A
Nacked icosahedral capsid w/ a (+) single-stranded RNA
Proteins (nucleocapsid protein -NP)
Hemagglutinin Activity (HA)- binds sialic acid receptors
Allows for attachment to host in upper respiratory tract
Allows absorption
receptors present in URT and RBCs
Neuramidase (NA)-
breaks neuraminic acid disrupting the mucin barrier
allows access to sialic acid receptors
Both HA and NA are able to undergo antigenic shift via Disease
Enteroviruses 5 subgroups - most common cause of aseptic meningitis in U.S.
1) Hepatitis A (HAV) - 3 weeks of incubation
Fecal-to-oral route
Usally children more dangerous in adults
Dx - Active anti-HAV IgM, passive or active IgG
2) Poliovirus - Paralytic poliomyelitis
Infects peyer's patches of the intestine and motor neurons
Transmitted via fecal oral route (reduced via improved sanitation)
Nearly elimiated w/ vaccine
Mild illness - commly causes asymptomatic infection w/ mild febrile disease
Aseptic meningitis - fever and meningismus (recover in a week)
Paralytic poliomyelitis - virus destroys presynaptic motor neurons in anterior horn. (fever -> meningismus -> flaccid asymmetric paralyisis) Most severe in children over 15.
3) Coxsackie virus A, B, Echovirus
Aseptic meningitis - enteroviruses w/ most common cause of non-bacterial meningitis
Asymptomatic of mild febrile infections
Respieratory symptoms ("cold")
4) Rhinoviridae
Common cold Structure
Big (42 nM) enveloped icosohedral capid
Double strandid circular DNA
Dane particle - intact virus
HBsAg -grants immunity
HBcAg - antigenic core does not grant immunity
HBeAg - indicates active disease (highly contagious) Tx: Lamivudine or interferon
Disease viruses
1) Hepatitis C Virus
Parenteral transmission (3% risk by needle stick)
chronic hepatitis
50% develop cirrhosis
2) Encephalitis viruses ( japanese and russian)
3) Yellow fever
Mosquito vector
hepatitis w/ jaundice
fever, backache, nausea, vomiting
4) Dengue fever ( aka - break-fever)
Mosquito vector
Backache, muslce, and joint pain
severe headache
Severe variant Dengue hemorrhagic fever - hemorrhage or shock in children w/ 10% mortality
5) West Nile Virus
Mild flu like illness
Can cause encephalitis and death (particularly in elderly) Tx: Interferon Structure
Spherical enveloped virion
central cylindrical nucleocapsid
p24 - capsid protein (early detection)
Surface glycoproteins (envelope)
gp 120 (head), gp 41 (stalk) - extreme heterogeneity
Binds CD4 + T- helper cells via w/ fusin and CKR5 cofactors to CD4 receptor
Responsible for tearing open CD4 (specifically) during budding
Retroviral enzymes
1) Protease
2) Reverse transcriptase
3) integrase

1) LTRs (long terminal repeat sequences)
Sticky ends recognized by integrase (allow insertion into host)
Promoter/enhancer function modify viral DNA transcription
2) gag (group antigen) - code for proteins inside envelope
Nucleocapsid (NC), capsid (CA), p24, Matrix (MA)
Major antigenic proteins
3) pol - enzymes
Protease - cleaves gag and pol proteins , integrase, reverse transcriptase
4) env - forms Gp 120 (head) and gp 41(stalk) Disease
Human Immunedefficiency Virus
1) Sexual activity - women 20x more likely
2) Blood product transfusion
3) Intravenous drug use
4) Transplacental viral spread - 30%
5) Needle stick - .3%
1) p24 within weeks
2) ELISA 3-6 weeks antibodies
1) Acute viral illness - like mononucleosis
1 month after infection (80% of patients)
Fever, malaise, lymphadenopathy, pharyngitis
CD4+ T-cell 1000 (normal)
2) Clinical latency - follows for 8 years
continual distruction CD4 in lymphnodes
i) Year 7 CD4+ T-cells 400-200 - Constitutional symptoms
Weight loss, fever, night sweats, adenopathy
Oral thrush, athlete's foot (C. Albicans)
M. Tuberculosis
EBV - oral hairy leukoplakia (OHL) - hairlike projectionis on the side of tongue
3)Acquired Immuodeficiency Syndrome (AIDS)
1) Constitutional Illness
AIDS - night sweats, fevers, enlarged lymph nodes,
Severe weight loss (Wasting syndrome)
2) Malignancies
High incidence of B-cell lymphoma (via EBV)
Karposi's sarcoma ( 96% homosexual men associated w/ HHV-8) -red to purple plaques or nodules all over skin progresses to lymph nodes, lungs, and GI tract.
ii) CD4 + T-cells <200
Serious opportunistic infections
C. neoformans - Fever, nausea, vomiting, MENINGITIS (headache, mental status)
PCP (PJP) - 15%pneumothorax
T. Gondii - mass lesions in the brain
iii) CD4+ + T-cells <50
M. avium-intracellulare - usually affects birds, wasting disease, w/ fever, night sweats, weight loss, and often diarrhea (GI tract infection) elevated LFT
Cytomegalovirus - chorioretinitis and blindness, diarrhea and esophagitis Tx:
Protease inhibitors
saquinavir, ritonavir, indinavir, nelfinavir amprenavir
Reverse transcriptase inhibitors
zidovudine (ZDV aka AZT), didanosine, zalcitabine, stavudine, lamivudine, abacavir
Fusion inhibitors
Enfuvirtide General
Three subfamilies
Alpha- HSV-1, HSV-2, varicella-zoster
Beta- CMV
Gamma- Epstein-barr
1) Latent stage - hide in dorsal root ganglia reactivate after a stressor
2)Cytopathic Effects - Alpha sub family become multinucleaded giant syncytial cells w/ intranuclear inclusion bodies (detected via Tzanck test)
3) Attacked in body by cell-mediated immune response Viruses
present in 90%
1) Gingivostomatitis - painful swollen gums and mucous membranes w/ vesicles
2) Reactivation - 1/4 of people during stress (w/ aids can be severe)
3) Herpetic Keratitis - Most common cause of infectious corneal blindness in US
4) Encephalitis - Most common cause of viral encephalitis (Treatable)
focal neurological abnormail
Genetal herpes - possibly cervix vagina perineum glans and shaft.
Neonatal Herpes - transplacental viral transfer or transfer during active infection ( part of TORCH - toxoplasmosis, rubella, cytomegalovirus, Herpes/HIV, Syphilis)
Varicella - Zoster Virus (VZV)
1) Varicella
Highly contagious
Infects respiratory tract replicates for 2-week incubation period followed by viremia
Fever, malaise, headacher
Rash - start on face spread to body mucous membranes (pharynx, vagina, etc) red base w/ fluid filled vesicle
Rash ruptures and scabs then patient is no longer infections (usually 1 week)
2) Zoster (shingles)
sensory dermatonal rash result of reactivation (due to stress or lowered cell-mediated immunity)
Painful burning lesions
Cytomegalovirus (CMV)
1) Asymptomatic infection - 80% of adults have antibodies. Most are asymmptomatic.
2) Congenital disease - CMV can cross the placenta.
Common cause of mental retardation, microcephaly, deafness, seizures
3) Cytomegalovirus mononucleosis - in young adults similar to Epstein-Barr
4) CMV can reactivate in immunocompromised patients
Causes retinitis (blindness) , CMV colitis, disseminated infection, and death in HIV/AIDS
Bone marrow transplant - Pneumonitis, viremia, colitis.
Epstein-Barr Virus
Infects human B cells
Peak incidence 15-20 years of age
1) Malignancy
Through transormation can cause Burkitt's Lymphoma and Hodgkin's and nasopharyngeal carcinoma
Maybe be linked to lymphom a and other lymphoproliferative diseases
2) Mononucleosis
Younger children less severe
Fever, chills, sweats, painful pharingitis, lymphadenopathy
Dx: heterophile antibodies (monospot test)
HHV-6 - Roseola: high vevers for several days that can cause seizures, followed by a macular rash
Linked to Kaposi's sarcoma General
brick shaped box (Pox in a box)
dumb bell shaped DNA
Replicates in cytoplasm Viruses
Spread by respiratory tract
Pox skin lesions and death
Elimated by vaccine
Molluscum Contagiosum
1-2 mm white/red papule w/ central dimple Structure
Circular double-stranded DNA
Naked icosahedral capsid

Papilloma Virus-
Can cause warts ( hyperpoliferations of kertinized squamous epithelium)
cervical cancer (type 16 and 18)
1) BK virus - ubiquitous mild/asymptomatic infection
2) JC virus -
in immunocompromized caused Progressive Multifocal leukoencephalopathy (PML)
Central nervous system damage - memory loss, poor speech, and incoordination Respieratory infection in children
Infection can cause conjunctivitis, sore throat, and cough
Lower respiratory tract pneumonia Structure
smallest icosahedral virus
single strand of DNA
Erythema - in children
fectiosum (fifth disease)
Fever "slapped face" rash on the cheeks
Severe in anemics (Beta thalassemia and sickle cell) Diseases/Viruses
Alpha viruses ( western equine encephalitis (west, MA, canda) , Eastern equine encephalitis ( eastern U. Su.), venezuelan equine encephalitis ( central america/sothern U.S.)
Use the mosquito as a vector
Infect horses
Cause encephalitis, fever, and headache
Rubella (german measles) - mild febrile illness , macularpapular rash (fine truncal rash), lymphadenopathy, arthralgias
3 day illness
Part of TORCHES ( can cross the placenta) - congenital defects (heart, eyes, CNS) Heart - Patent ductus, interventricular septal defects, pulmonary atery stenosis
Eye - cataracts, chorioretinitis
CNS - mental retardation, microcephaly, deafness Arboviruses
Caliornia encephalitis
Rift Valley Fever
Hanta Virus
Transmitted via deer mouse droppings
hemorrhagic fever w/ renal failure
pulmonary syndrome - fluid filled alveoli
high fevers, muscle aches, cough, nausea, and vomiting
80% death rate 15% of the common cold Disease/Virus
Norwalk virus
viral gastroenteritis ( diarrhea and severe vomiting)
#1 cause of acute infectious diarrhea
severe dehydration Oral rehydration Rabies
Stays in negribodies
Animal transmission - warm-blooded animals (dogs, cats, skunks, coyotes, foxes, raccoons, and bats)
Infection w/ local iritation for a few days
incubation for of a few weeks to a year
when symptoms occur 1-2 weeks
1) prodrome - nonspecific symptoms of fever, headache, sore throat, fatigue, anusea, painfully sensitive nerves around healed wound site
2) Acute encephalitis - hyperactivity and agitation -> confusion, meningismus, and even seizures MADNESS
3) Classic brainstem encephalitis - brainstem infection w/ cranial nerve dysfunction, HYDROPHOBIA w/ inability to swallow saliva "FOAMING of the MOUTH"
4) Death - due to respiratory center dysfunction Ebola Virus
hemorrhagic fever Anti-viral medications Anti-Herpesviridae Acyclovir Ganciclovir monophosphorylated by HSV/VSV thymidine kinase
Guanosine analog inhibits viral DNA polymerase
Tx: HSV, VZV, EBV mucocutaneous genital lesions
SE: well tolerated monophosphorylated by HSV/VSV thymidine kinase
Guanosine analog inhibits viral DNA polymerase
Tx: CMV in immunocompromised patients
SE: Leukopenia, neutropenia, thrombocytopenia and renal toxicity Foscarnet Viral DNA plymerase inhibitor
Phosphate analog
Tx: CMV in immunocompromised patients when gancyclovir fails
SE: Nephrotoxicity Human Immunodeficiency Virus Protease inhibitors Saquinavir, ritonavir, indinavir, nelfinavir, amprenavir
Mechanism - Inhibit maturation of new viruses by blocking protease in progeny
SE: GI intolerance (nausea, diarrhea), hyperglycemia, lipodystrophy, thrombocytopenia (indinavir Normal cocktail includes
protease inhibitor w/ 2 nucleoside analogs
2nd line two nucloside analogs w/ non-nucloside analog Reverse Transcriptase inhibitors
Mechanism - inhibits reverse transcriptase of HIV. Prevents incorporation of DNA copy of viral genome into host DNA
SE: Bone marrow supression ( neutropenia, anemia), peripheral neuropathy, lactic acidosis (nucleosides), rash (non-nuclosides), megaloblastic anemia (ZDV) Nucleosides Non-nucleosides Zidovudine (ZDV/AZT), didanosine(ddI), zalcitabine (ddC), stavudine (d4T), lamivudine (3TC) ( also for HPV), abacavir Nevirapine, Efavirenz, Delavirdine Fusion inhibitors Enfuvirtide
Mechanism - Binds viral gp41 subunit; inhibits conformational change required for fusion w/ CD4 cells
SE: Hypersensitivity reactions, reactions at subcutaneous injection site, increased risk of bacterial pneumonia Interferons Glycoproteins from human leukocytes that block various stages of viral RNA and DNA synthesis. Induce ribonuclease that degrades viral mRNA
Tx: IFN-alpha Chronic hepatitis B and C, Kaposi sarcoma IFN-beta MS, IFN-gamma NADPH oxidase deficiency
SE: Neutropenia Parasites Protozoa 1-2 nuclei
eucaryotic cells
mouth = cytostome
Cyst form = infective
Trophozoite = motile form Intestinal Protozoa Entamoeba histolytica Giardia lamblia Cryptosporidium Isospora and Microsporidia ameoba uses pseudopodia for movement
fecal-oral transmission (Cysts in water)
Eats RBCs/intestinal cells (invades intestinal wall)
tetranucleated cyst
Precyst formation contains chromotoid bodies( aggregates of ribosomes)
If RBCs internalized = symptomatic infection Disease
Bloody diarrhea ( dysentery)
Liver abscess (reddish brown)
RUQ pain ( histology shows flask shapped ulcers) Tx: Metronidazole 2 forms cyst and mature motile trophozoite (kite shaped)
5% of U.S. adults harbor asymptomatically Mechanism - Toxic metabolites that damage DNA
SE: Disulfiram-like reaction w/ alcohol; headache, metalic taste Tx: iodoquinol Disease
bloating, flatulance
foul-smelling fatty diarrhea ( campers/hikers) Common 25% of american show evidence of infection
Injested as a round oocyst containing 4 motile sporozoites
Severe in immunocompromised patients Disease
Diarrhea w/ abdominal pain
Immunocompromised - Severe protracted diarrhea 'life threatening' Cause severe diarrhea in immunocompromised individuals
Transmitted via fecal-oral route Tx: TMP/SMX ( Isospora)
albendazole (microsporidia) Sexually Transmitted Protozoan Trichomonas Vaginalis Disease
Foul-smelling greenish discharge
puritis (itching), burning
Sexually transmitted - no cyst form
Extremely motile parasite in discharge/urine Tx: Metronidazole CNS infections Naegleria fowleri Acanthamoeba Disease
Rapidly fatal meningoencephalitis
95% mortality rate w/in one week
fever, headache, stiff neck, nausea, and vomiting
Related to swiming in warm water invades through cribiform plexus
CSF w/ high neutrophil count, low glucose, high protein, w/ amoebas Tx: None officially
two surviving patients were treated w/ amphotericin B Disease
Causes chronic granulomatous brain infection
In immunocompromised patients Toxoplasma gondii Transmission via undercooked meats/ household cat feces
AIDS ( CD4 <200) Disease
Brain abscess w/ ring-enhancing brain lesions on CT/MRI (seizures, gait instability, weakness, or sensory losses)
Can also cause fever and involve lymph nodes, liver, and spleen
Retina reveal yellow-white, fluffy (like cotton) patches on retina
Congenital ( part of torches)
transplacental infection
Classic triad ( chorioretinitis, hydrocephalus, and intracranial calcifications)
results in seizures, blindness, mentalretardation microcephaly, or still birth. Tx: sulfadiazine + pyrimethamine Trypanosoma ( Sleeping sickness) Disease/Virus
Enlarged lymph nodes
recurrent fevers (due to antigenic varation ( variable surface glycoproteins))
Somnolence and coma
1) Trypanosoma brucei gambiense
West african sleeping sickness
slowly progressing fevers
wasting disease
late neurological symptoms
2) Trypanosoma brucei rhodesiense
East African Sleeping Sickness
More severe than gambiense
Death occurs within weeks to months
Rapid progression from recurrent fevers
early neurological disease Transmitted by blood-sucking tsetse fly
motile flagellated Tx: Suramin ( blood borne disease)
Melarsoprol (CNS infection(TOXIC))
Melatonin (sleep) Hematologic infections Plasmodium Replicate in RBCs
lyse at the same time (causes fever)
Motile in mosquito sucker (sporozoite)
exoerythrocytic cycle
Trophozoit ->Multiucleated schizont liver
Thousands of small bodies (merozoites)
Erythrocytic cycle
merozoite->trophozoite in RBC (diamond ring)
trophozoite -> schizont -> merozoite
Free (in blood) sexually differentiated gametocytes
lack of duffy a and B is protective
Sickle cell is protective Disease/Virus
Malaria - cyclic fever, headache, anemia, splenomegaly
P. Vivax/Ovale
lyse every 48 hours (fevers ever 48 hrs)
dormant form in liver (hypnozoites) tx w/ primaquine
P. malariae
tertian malaria (bursts every 72 hrs)
3 day cycle of fevers, chills, and sweats
P. Falciparum
most common and deadly form
Quartan malria (bursts more irregularly between 36-48 hrs)
Continuous fevers and chills
occlude capillaries in brain (cerebral malaria)
Kidney and lung ischemia Babesia Microti by Ryan Dosumu-Johnson Tx: choloroquinine if resistant mefloquinine SE: GI upset, hemolysis in G6PD Replicate in RBCs
spread by tick bites ( ixodes scapularis (think lyme) -> white-footed mouse (reservoir) )
All in RBC no liver involvement
trophozoite -> 4 merozoites (X shaped tetrad "Maltese cross") Tx: quinine, clindamycin Visceral infections Leishmaniasis Reservoir rodents, dogs, and foxes
Transmitted via sandfly
Primarily south/central america, Africa, and Middle East
infects macrophages (via promastigote) ->becomes nonmotile amastigote Disease
1) Cutaneous Leishmaniasis
a) Simple
skin ulcer - 'oriental sore' (1 year to heal)
Intact immunity results in cell-mediated attack
b) Diffuse
Occurs in venezuela/ethiopia
defect in cell mediated immunity
diffuse nodular skin lesions
untreated can lasts 20 years
2) Mucocutaneous Leishmaniasis
Similar cutaneous ulcer
Ulcers in nose and mouth
can erode nasal septum, soft palate, and lips over 20-40 years
3) Visceral Leishmaniasis (Kala-azar)
Invasion of retuculoendothelial cells in liver and spleen
abdominal enlargement massive splenomegaly and hepatomegaly
Presents w/ fatigue wasting, low-grade fever, anorexia, abdominal distention/discomfort
90% fatal if untreated Trypanosoma (chagas) Affects US
transmitted via reduviid bug (kissing bug) feeds during sleep and deficates (present in feces)
Tunnels into skin taken up by macrophages and invades lymph nodes and organs Disease
Acute Chagas Disease
chagoma ( hardened red area) forms at site of entry
Fever, malaise, sowllen lymph nodes
CNS( meningoencephailtis)/Cardiac (tachycardia/EKG changes) involvment
resolves in a month
Chronic Chagas Disease
Primarily affects hollow organs
Heart - Arrythmia's and later dilated cardiomyopathy
Colon/esophagus - big dilated por functioning esophagus w/ regurgitation. Dilated colon w/ constipation and abdominal pain (Megacolon) Tx: Sodium stibogluconate Tx: Nifurtimox Helminths Nematodes (Roundworms) Ascaris lumbricoides Necator americanus Intestinal Larvae in lung
coughed up and swallowed Stronglyoides stercorous Infection occurs in sothern US (mountainous areas)
Consume food w/ eggs
Larvae pass through intestinal wall into lung alveoli
Mature in small intestine
visible eggs in feces AKA Hookworm
Larvae penetrates feet of barefoot humans travel to lung
mature in small intestine attach by mouth and suck blood
pass out of stool as larvae Larvae in soil penetrate skin
3 pathways for filaform larvae
1) Autoinfection - penetrate intestine and continue cycle
2) Direct cycle - pass outh through feces (like N. americanus)
3) Indirect cycle (sexual cycle) - pass through stool and mate in soil then differentiate sexuall and produce fertilized eggs in soil Tx: Bendazoles or Pyrantel pamoate Mebendazole, Thiabendazole, Albendazole
Paralyzes worm (pass through stool)
Paralyzes worm (pass through stool) Disease
Diarrhea w/ abdominal pain and weight loss
Iron deficiency anemia
rash inbetween toes
esosinophilia w/ chest x-ray infiltrate Disease
Vomiting, abdominal bloating, diarrhea, anemia and weight loss
puritic rash, lung symptoms (cough/wheezing) w/ eosinophilia
Steroids cause severe autoinfectio
Pneumonia, ARDS, multi-organ failure Trichinella spiralis Ingestion of raw pork Cysts found in raw pork Disease
Initially asymptomatic
Abdominal pain, diarrhea, fever
1 wk after infection larvae migrate into skeletal muscle
Results in fevers, muscle aches
Increased CPK/ increased eosinophils
If severe invades heart/brain
Can be fatal Tx: Bendazoles may help Simple life cycle Trichuris trichiura (whipworm) Enterobius vermicularis (pinworm) Slow life cycle
ingestion of infected eggs
infect cecum and ascending large intestine
eggs in fecal specimens
ingestion of infected eggs
infect cecum and ascending large intestine
female lays egg in perianal area (perianal puritis)
eggs in fecal specimens
Perianal puritis least to autoinfection
Dx via scotchtap on perianal area No invasion = no eosinophilia Tx: mebendazole Tx: mebendazole or pyrantel pamoate Blood and tissue
filarial infections onchocera volvulus Transmitted via bite of black fly
Found in central/south america and africa Disease
River blindness
Puritic skin rash w/ thickened skin leasons
can cause blindness
can cause intraepithelial granulomas
Dx via microfiliare in skin biopsies or eye examination (slit lamp) Tx: Ivermectin prevents birth of worms Wuchereria bancrofti/Brugia malayi Disease
Infection of lymphatics
swollen inguinal lymphnodes
Fiborous plugs can cause chronic leg swelling
Headaches w/ fever
Dx w/ blood drawn at night time (few organisms in blood during day) Wucheria - pacific islands/africa
Brugia - Malay peninsula and Southeast asia
Transmission via mosquito
grow/mature in lymphatic vessels of lowre extremities Tx: Diethylcarbamazine
and surgery for plugs Dracunculus mediensis (guineau worm) transmited via drinking water
Africa/Asia region in copepods(tiny crustacean)
Female grows large in host ( 100cm)
Moves to skin and presents uterus when in contact w/ water Disease
Skin inflamation and ulceration Ancylostoma duodenale Dog/cat hookworm
Slow moving cause allergic reaction
raised red itchy rash moves w/ larvae Tx: Niridazole Platyhelminthes ( flatworms) Trematodes
aka Flukes Cestodes
aka tapeworms Schistosoma (blood fluke) Clonorchis sinensis Paragonimus westermani Eggs hatch in fresh water -> infect freshwater snail
cercariae penetrate skin of humans
travel to intrahepatic portion of portal venous system
mate and mature there
lay eggs in intesine or bladder (poke holes)
Molecular mimicry Disease
1) Dermatitis
due to cercariae penetration
Intensely itchy skin
2) Katayama fever
when adults lay eggs
Fevers hives weight loss
lymph node, liver, spleen enlargment are common
3) Chronic fibrosis
due to eggs that don't enter feces or urine
Causes granulomas
Primarily in liver and spleen
Also squamous cell carcinoma of bladder Tx: Praziquantel Undercooked fish Disease
Causes inflammation of biliary tract
results in pigmented gallstones
Also cholangiocarcinoma Undercooked crab meat Disease
Causes inflammation and secondary bacterial infection of the lung causing hemoptysis Segmented worm
Segments called (proglottids)
Head called scolex Taenia solium ( pork)/saginata (beef) Dipyllobothrium latum Echinococcus granulosus Pork/Beef Tapeworm
2-8 meters
releases eggs Disease
Grows in intestine - if cyst is eaten
Neurocysticerosis - cysticeri in brain when eggs are eaten
Usually 7-10 cysts
Can cause seizures, obstructive hydrocephalus, and focal neurological deficits
grow 5-10 yrs
swiss cheese in brain (CAT scan)
Increased eosinophils Pork/Beef Tapeworm
can be 45 meters
eggs in water -> motile ->crustacean->
freshwater fish (trout, salmon, pike, etc)->human Disease
Causes vitamin B12 deficiency
Anemia Eggs in dog feces
cause cyts (5-10 cm) when ingested Disease
Cysts can grow lateral
compress organs (lungs, liver, or brain)
Cyst fluid can cause anaphylaxis (extremely allergic) Tx: bendazoles
inactivate cyst w/ ethanol Catalase + Catalase -
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