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Defense against Pathogens
Transcript of Defense against Pathogens
8th Grade Biology
Defense against Pathogens
What are they?
16th April - Mrs. Eberhardt
A disease is an abnormal condition that affects an organism's body and mind. Diseases are normally associated with distinctive symptoms and signs such as pain, dysfunction, distress and social problems. Some diseases can lead to death. They can also cause injuries, disabilities, disorders and infections. Diseases are mainly spread by the conditions people live in, conditions they are born with or hazards happening around them.
A virus is a small infectious agent, which can only duplicate within the bacterial cells of living organisms. Some viruses are transmitted by skin to skin contact and some are spread through the air we breath. Viruses are found nearly everywhere; in the soil, in the air and on animals and plants. They are mainly composed of a DNA core and a protein coat. Additionally, they can infect all types of life forms.
Influenza A is a commonly known virus, which mainly infects birds and mammals. It is also known as "the flu". It is mainly transmitted through the air and body fluid exchange. The most common symptoms caused by this severe virus are chills, fever, runny nose, sore throat, muscle pain and headache. Even though this virus has caused a lot of deaths in the past, our modern society is able to cope and treat a virus like this, due to modernized medicine and treatment. Even though Influenza may seam harmless, it can mutate itself into new, more dangerous viruses (E.g. "swine flu").
According to the American Control and Prevention Center of Diseases, measles is a highly contagious respiratory disease caused by a highly infectious virus. The most common symptoms of measles are runny noses, cough and a rash all over the body. The measles virus grows in the bacterial cells, which are located at the back of the lungs. Therefore, measles is a respiratory disease. In the year of 2012, the United States Medical Center recorded one death within 122 measle-cases.
According to the American Control and Prevention Center of Diseases, "rabies is a preventable viral disease of mammals most often transmitted through the bite of a rabid animal". The rabies virus causes disease in the brain and death, by attacking the central nervous system of the organism. The symptoms of this virus are fever, headache, and discomfort of the body. Rabies additionally causes mental disfunctions, such as confusion, anxiety and hydrophobia (fear of water).
Magnified rabies virus
Keyfacts about measles are listed below:
Measles is caused by the rubeola virus.
Diagnosis is clinical.
Both sexes are affected equally.
Measles is responsible for approxamitely one million
deaths a year in the world.
Measles is a highly contagious disease .
Species: Rabies virus
Virus Classification / Influenza A:
Species: Influenza A virus
Keyfacts about Influenza A are listed below:
Flu (Influenza) season is from Oct. to May.
Influenza A has a very similar structure to Influenza B and C.
Keyfacts about rabies are listed below:
Rabies can be transmited through from all mammals.
1/2 of the people who die from rabies, are under 15 years of age.
Rabies attacks the brain and spinal cord of the body.
Protists are eukaryotes, which means that they have a nucleus and are part of the Kingdom Protista. Protists are parasatic, meaning that they cause serious illness and damage while living in host cells. Parasatic protists are being carried by "vectors". They transmit a parasite and infect the human population. Additionally, protists can also be transmitted by direct contact with the carrier. Protists live in almost every environment that contains liquid water, as they are eukaryotic microorganisms.
Malaria is a commonly known disease, which mainly occurs in Africa and India. This disease is caused by a parasite called Plasmodium, which is being spread through the bites of infected Mosquitos. These mosquitoes can often survive their infection and then multiply, which benefits the spread of malaria in our society. Malaria parasites multiply in the liver. As they reach a certain amount of parasites, they start to attack the red blood cells of the human body. Symptoms of malaria are fever, vomiting and severe headaches. They normally occur 15 days after the infection by a mosquito.
Keyfacts about malaria are listed below:
Malaria parasites have grown resistent to a number of treatment methods.
Malaria interrupts the blood flow to life necessary organs in the body.
Malaria can also infect animals.
Giardiasis is a commonly spread disease, mainly in the United States. It is caused by the disease giardia, whose infection typically occurs from drinking contaminated water; either in a lake, stream or well. According to Elizabeth Chaplin, these protists can be ingested directly or as crysts, which will break open inside the human body, releasing the dangerous parasite. Giardia attaches itself to the wall of the human's intestines stomach pains and fatigue.
Keyfacts about giardiasis are listed below:
Also found on surfaces, soil and food.
Diarrhea and dehydration are both other symptoms caused by giardia.
The African sleeping sickness (or Trypanosomiasis) is a wide spread tropical disease. If not treated in an adequate time range, the sleeping sickness can lead to fatal sickness, pain and death. Just like malaria, it is spread by the bite of an animal; in this case, the African sleeping sickness is caused by the bite of an infected tsetse fly. The most common symptoms of Trypanosomiasis are fever, swollen lymph glands, aching muscles and joints, headaches and irritability, as the disease attacks the humans body central nervous system. This disease is found in the areas of eastern and southeastern of Africa.
Keyfacts about Trypanosomiasis are listed below:
Can also cause internal confusion, slurred speech and difficulty walking.
Symptoms normally occur in a few weeks after the infectious bite.
Amount and type of symptoms are based on the area, where one is being infected in.
Even though bacteria can often help us through our everyday life, many people only know them as "germs", which invade our body and make us sick. Bacteria are prokaryotes, which means that the cell's DNA is not enclosed in a nucleus, since they don't have a nucleus. Bacteria can endure temperature above the boiling point and below the freezing point. Bacterial diseases are virtually found everywhere and are mainly transmitted by skin to skin contact and body fluids.
Syphilis is a commonly known Sexually Transmitted disease. Syphilis is a disease, that can cause "long-term complications and/or death if not treated correctly" (Centers for Disease Control and Prevention). Additionally, the symptoms of Syphilis of Adults are divided into four stages: primary stage, secondary stage, latent stage and late syphilis. Since Syphilis is an STD, it is sexually transmitted. The most common symptoms in both sexes are sores called chancre. They painlessly develop in the genital areas of both genders. Syphilis is usually found on the surface of the genitals, the anus, the inside of the vagina and the rectum.
Keyfacts about syphilis are listed below:
A pregnant women with syphilis can pass the disease on to her unborn child.
Syphilis bacteria are extremely fragile.
A doctor mostly diagnoses Syphilis in blood tests.
According to the Center for Disease Control and Prevention, Gonorrhea is a sexually transmitted disease that can infect both women and men. Gonorrhea is most commonly asymptomatic. Since Gonorrhea is a highly infectious STD, it is transmitted through anal, vaginal, or oral sex, with someone who has this disease. The infections of Gonorrhea are found in the genital area, the rectum and the throat. Additionally, the most common symptoms of Gonorrhea are discharge, anal itching, soreness, bleeding and painful bowel movements.
Keyfacts about Gonorrhea are listed below:
You can avoid getting this disease, by having no sex, or by protecting oneself during sex. (E.g. using condoms)
A pregnant women can spread Gonorrhea to her unborn child.
Gonorrhea is most common between people from the ages 15-24 years.
Just like Gonorrhea and Syphilis, Chlamydia is a common STD, that can infect both genders. However, chlamydia is more serious, when a female person gets infected as it can cause serious damage to the female's reproductive system and it might make it almost impossible for a women to get pregnant. Since chlamydia is a STD, it is sexually transmitted. Chlamydia is most commonly found in the rectum, the genital areas, and it might develop in the eyes. The most common symptoms of chlamydia in women are abnormal vaginal discharge and burning while urinating. The most common symptoms of this disease in men are discharge from the penis, and pain and swelling on the testicles.
Keyfacts about Chlamydia are listed below:
You can avoid getting this disease, by having no sex, or by protecting oneself during sex. (E.g. using condoms)
A pregnant women can spread Chlamydia to her unborn child.
Chlamydia is most common between people from the ages 17-26 years.
Fungal diseases are mycoses, meaning they are caused by fungi growing on either the skin or hair. Additionally, systemic, or deep mycoses are able to infect internal organs of the body. According to the Center for Disease Control and Prevention, "most fungal diseases are not dangerous, but some can cause serious damage to the health". Some fungal diseases, such as fungal diseases in the lungs and the bloodstream can cause serious damage and/ or permanent damage and might lead to death. Additionally, fungal diseases can infect everyone.
Athlete's foot (or tinea pedis) is a fungal infection of the webs, of the toes and the feet of the human's body. Both athletes and nonathletes are affected alike, as athlete's foot is transmitted by person to person, and contanimated objects and floors. One one is infected by this disease, Athlete's foot is mostly found between the toes. The most common symptoms of tinea pedis are itching, pain, burning and scaling on the feet. Tinea pedis is usually a red, itchy erruption on the feet and sole of the foot. Athlete's foot is mostly found in warm and moisture environments.
Keyfacts about Tinea pedis are listed below:
70% of the population may develop athletes foot at the same time.
The infected skin may be scaly, flacy and dry.
Most symptoms/ infections of athletes foot can be treated at home, making the disease not too dangerous.
Aspergillosis is a common fungal disease, which usually infects people with weak immune systems or with lung diseases. According to the Center of Disease Control and Prevention, "most people breath in Aspergillosis spores everyday without being infected". Therefore, Aspergillosis is transmitted through the air by certain spores and can be found in both, moist indoor and moist outdoor environments. The most common symptoms of this disease are allergic reactions, lung infections, and infections in other organs.
Keyfacts about Aspergillosis are listed below:
Fungal diseases, including Aspergillosis, pose an increasing threat to public health.
Aspergillosis is a very rare fungal disease.
About 1 or 2 in every 100,000 people living in San Francisco are/ or have been infected by Aspergillosis in the past.
According to the Center for Disease Control and Prevention, Fungal Meningitis "is rare and usually the result of the spread of fungus through blood to the spinal cord". Just like Aspergillosis, Meningitis mostly infects people with weakened immune diseases (E.g. someone with a HIV infection). Meningitis is mostly transmitted by 'bird droppings', particularly in the Middle East of the USA. Therefore, this disease is mostly found in the soil of endemic areas. The main symptoms of Meningitis are fever, headache, vomiting and a stiff neck.
Keyfacts about Meningitis are listed below:
Meningitis can also spread to your brain.
Meningitis is spread by fungal spores in the air.
This disease is also called 'valley fever'.
Just like Aspergillosis, Meningitis is a very rare fungal disease.
Antibody - mediated defenses
Cell - mediated defenses
According to the U.S. National Library of medicine, an antigen is any substance that causes your immune system to produce antibodies against it. Examples of antigens (forgein substances) are chemicals, bacteria, viruses and/ or pollen. An antigen might aswell develop with in the human body (E.g. bacterial toxins or tissue cells). The human body has many different ways to defend itself against invading antigens, which might infect and damage the body's health: These types of defenses are listed, and explained, below. In the fight against antigens, the immune system stockpiles a huge arsenal of lymphocyte and phagocyte cells. Some of these blood cells are stored in the bone marrow.
Body's Defense Against Antigens
Non-specific defenses of our bodies are generally the different ways our body keeps away forgein substances that might cause harm to its health. Most non-specific defenses of the human's body are barriers that prevent infectious, forgein substances entering the body. There are two different lines of non-specific defenses of our bodies. The first line of non-specific defenses are the surface defenses. The second line of non-specific defenses are the natural responses of the body's immune sytsem, which take place as soon as an invaded threat has entered the body (E.g. white blood cells.) These non-specific defenses are described below. A non-specific defense targets any forgein agent.
Mechanical barriers are natural barriers designed by the body to keep forgein, threatening agents away. Our skin and mucous membranes for example, are mechanical barriers that are designed to prevent these infectious agents from invading the body. Mechanical barriers help protect against antigens, as they "work by preventing unwanted microorganisms from gaining entry into the body and destroying them before they do so" (National Library of Medicine). Therefore, mechanical barriers are surfaces developed by the body to keep out infectious agents that tend to threaten the health of the body.
Example: Human Skin
Forms a waterproof barrier between invading agents and the body.
Largest organ of the human body.
Unless the skin is broken, microorganisms can not get through.
In average, the skin is between 2-3 millimeters thick.
The whole body is covered with skin and it therefore Interfaces with the environment.
Chemical barriers are acids, proteins and other substances with natural attributes that help the body defend against any kind of disease or infection by a forgein agent. These substances, often with a low pH, help protect against antigens as they break down or destabilize forgein cells that might cause damage to the body's health. In addition, chemical barriers of the body fall under the category of anatomical barriers. Just like every anatomical barrier, the chemical barriers are present outside of the body's tissues, rather than at cellular level. Internal chemical barriers also protect against infection.
Lysozymes, which prevents pathogens (antigens) entering the human body.
Increasingly produced when one has a cold or a fever.
Classified into two types: Phlegm and nasal mucus.
Mucus helps absorbing the viruses and the pathogens, which have invaded and infected the body.
As soon as the immune system is alerted, more mucus is produced.
According to the U.S. National Institute of Allergy and Infectious Diseases, phagocytes are large (white blood) cells that can swallow and digest microbes and other forgein particles, which have entered the body. Therefore, phagocytes help protect the body from any invading antigens, as these cells ingest harmful forgein particles, bacteria, and dead or dying cells. In addition, during an infection by a forgein substance, chemical signals attract phagocytes to places where pathogens have invaded the body. Phagocytes are one of the most important non-specific defenses, as they heavily help the human body and the immune system to kill off invading agents and dead cells.
Example: White Blood Cells
Continously on the 'look out' for signs of diseases and infections.
Short life cycle (min. a few days/ max. weeks)
Drop of blood contains 7,000 - 25,000 white blood cells.
Can kill a germ by producing antibodies or by surrounding and devouring the bacteria.
If an infection fights back, white blood cells are produced more increasingly.
Also called leukocyte or white corpuscle.
In the human's immunology , a specific defense of the body is a specific mechanism against one certain antigen (disease). The most important characteristic of the cells of specific defenses, are that they have the ability to recognize and differentiate between the body's own cells and the infected cells of the forgein agent, who tries to infect and harm the body. In addition, any kind of antigen that has invaded the body causes the formation of an antibody, which is produced to inactivate the forgein agent (antigen). Therefore, specific defenses - other than non-specific defenses - concentrate on one antigen only, to make it inactive and harmless. Specific-defense cells are produced as a reaction to the threat of forgein matter that entered the body.
In the human immunology, antibodies play a big role in the defense against forgein agents, who have entered the body. According to the U.S. National Library of Medicine, an antibody "is a protein produced by the body's immune system when it detects harmful substances, called antigens". Each type of antibody is unique and defends the body against one type of antigen only. As shown and explained below, B and T cells are the main types of lymphocyte cells. Both of these cells play an important role in the defense against antigens, as both of them contribute to kill off forgein substances, viruses, bacteria and diseases.
B cells play a major role in the defense against antigens. In the human immonulogy, each B cell is programmed to make one specific antibody. For example, "one B cell will make an antibody that blocks a virus", while "another produces an antibody that attacks a bacterium that causes pneumonia". (N.I.A.I.D.). B cells work the following: when the B cell encounters its antigen, the B cell releases many plasma cells. Each of these plasma cells produce millions of antibodies and release them into the blood stream.
Whenever these produced antibodies interlock with the invaded antigens, they mark the antigens for destruction.
Just like B cells, T cells also play an important role in the cell mediated immunity. However, in comparison with the B cells, T cells contribute to the bodies defense against antigens in two ways: Some T cells regulate the immune responses and others attack and kill cells that are infected. They are called T cells, since they mature in the thymus. The regulatory T cells are extremely important for the maintainance of 'immunological tolerance'. They "maintain order in the immune system by enforcing a dominant negative regulation on other immune cells" (eBioscience). Unlike regulatory T cells, Killer T cells only attack their specific matching antigens (A.C.D.C.P.).
As soon as the killer T cell, which actually belongs to the cell mediated defense, encounters its antigen, it attaches itself to it and releases a chemical, which bursts the forgein antigen cell apart.
Cell mediated defense in the human immunology is an immune response that does not involve antibodies. According to the American Heritage, cell mediated defense is an "immune response produced when T cells, especially cytotoxic T cells, that are sensitized to foreign antigens, attack and lyse target cells". In addition, cell mediated defense heavily helps the body in the defense against forgein antigens, as this immune response activates phagocytes, specific T cells, and cytokines as soon as an antigen has started to invade the body.
According to the department of the Public Health of England, vaccines are "a way of priming the immune system to provide protection from disease caused by a pathogen without subjecting the person to the disease". In addition, active vaccines in the human immunology are vaccines, which are "induced by giving a preparation of antigens to stimulate a protective immune response to a particular infectious agent" (Public Health of England). After an infection by a disease, the vaccine imitates the same infection, which causes the immune system to develop the same response as it has before. This process initiated by the vaccines help the body fight the same disease again, as the body can recognize and successfully fight the vaccine-preventable disease in the future.
This process helps the body
form partial immunity against
diseases, which it has already
been infected by.
An Antiserum is a product which is used to activate the immune system of someone, who is encountered with a pathogen or a toxin. As an anitserum is a product derived from blood, it is extremely useful to the immune system as it helps the immune system eliminate the pathogen or toxin, which is trying to cause harm to the body's health. Once the antiserum is injected into the patient, the antibodies that are in the antiserum attach onto antigens they recognize so that the patients immune system can attack and kill them. As several pathogens attack the body while the immune system is very weak, the antiserum 'wakes it up' as soon as it is injected. Therefore, antisera are extremely important in the defense against antigens, as they help the immune system eliminate invading pathogens. The source of an antiserum depends on the pathogen or
toxin someone in encountered
Antibiotics play a very important role in the body's defense against forgein invaders. They protect the public health and are responsible for many million lives saved. According to U.S. National Library of Medicine, antibiotics are powerful man-made medicines that fight bacterial infections. Once the antibiotics enter the body, they either kill the infectious bacteria or stop them from reproducing. Just like the antiserum, each different type of antibiotic effects the bacteria in a different way. However, the main goal of antibiotics is to kill the chosen bacteria, so that one can prevent oneself from getting a disease which is caused by the bacteria. Therefore, antibiotics play a major role in the protection against antigens, as they can successfully kill of infectious bacteria before they develop into an even more dangerous disease.
Used to treat skin infections, chest infections and urinary tract infections.
About 1 in every 15 people might develop an allergic reaction to penicillin.
As penicillin is widely used, some strains of bacteria have created a certain kind of resistance to this antibiotic.
Amoxicillin and flucloxacillin are widely used types of penicillin.
Discovered in 1928.
First used in the United States in 1942.
Alexander Flemming discovered penicillin.
A penicillin bottle
HIV / AIDS
Lab Report: Microbes
6th of August in Scottland
11th of March 1955 in England
Nobel Prize, Knight Bachelor
Sir Alexander Flemming was a scottish biologist, who is well known for his discovery of penicillin. Penicillin is a well known anitbiotic, which is used to kill of bacteria that are trying to multiply in the body. It is one of the most commonly used antibiotics in the world. Penicillin has saved millions of human lives, as it helps the weakened immune systems to attack the antigens, which have invaded the body. Once injected, penicillin kills all recognized bacteria cells and stops them from reproducing and eventually causing an even more dangerous disease.
In his early life, Flemming was more and more interested in the study of natural bacterial action of the blood. In 1928, while he was working on the influenza virus, "he observed that mould had developed accidently on a staphylococcus culture plate and that the mould had created a bacteria-free circle around itself" (Nobelprize.org).
This discovery inspired him to further study and experiment what he saw. He found out that a mould culture was able to prevent growth of staphylococci, even when it was diluted eight hundred times. He named the active substance penicillin.
This coincidence has led Flemming to discover one of the most important and most commonly used antibiotics and he has therefore heavily contributed to the human's defense against pathogens.
17th of May 1749 in Gloucestershire
26th of January 1823 in England
Medicine/surgery, natural history
- Edward Jenner was born as the eight of nine children.
Received strong basic education, as his father was the vicar of Berkeley.
According to BBC, Edward Jenner was an English physician and scientist, who was the pioneer of the world's first vaccine, which was his most important contribution to the human's defense against pathogens (immunity). His work is said to have saved more lifes than the work of any other scientist. His nickname is the 'father of immunology'.
Edward Jenner discovered vaccination in 1798 by conducting an experiment on a farmer's son in his home town. One of his patients, had cow pox, which were widely spread and almost undiscovered in the late 18th century. He extracted some of the cowpox bacteria and mixed it with the boy's blood. He then inoculated him with the small pox virus. When Edward Jenner realized that the farmer's son had survived the attack of small pox, he found out what vaccination was able to do to man-kind. He knew that the injected cow pox sores were the reason as to why the farmer's son's immune system was able to cope with the small pox bacteria. This discovery/ invention heavily contributed to the defense against pathogens, as it was a milestone in human's immunity against certain diseases and bacteria (BBC History).
According to BBC, due to Edward Jenner's discovery, many people around the world are immune to many different diseases and these diseases can therefore cause no more harm to man-kind. Vaccines are the most often used immunity substances, as they have proofed their trustworthyness and effectiveness over a long period of time.
13th of September 1851 in Virginia
22th of November 1902 in Washington
U.S. military physician
Major Walter Reed was an U.S. army physican who confirmed and discovered that yellow fever can (or is) transmitted by a distinctive mosquito species. By his discovery, Walter Reed gave an insight and introduced epidemiology and biomedicine forms of diseases. His discovery was a milestone in the defense against pathogens, as he proofed that diseases can also be spread by other things rather than by direct contact.
- Walter Reed discovered that yellow fever is transmitted by mosquitos during his habitation in a U.S. military camp in Cuba.
According to the University Library of Virginia, whilst Reed was part of the U.S. occupation in Cuba, Reed and a team of young doctors were sent to Cuba to investigate the tropical diseases: especially the yellow fever disease.
Instead of searching for a specific agent, Reed rather searched for the means by which yellow fever was transmitted. Dr. Lazear, who worked with Reed observed that there was a delay of two or three weeks between the first and the second case of Yellow Fever in a community. Reed suspected that an insect was the transmitter, as this would explain the delay.
Walter Reed's theory was finally proofed. This was a milestone in the human's defense against pathogens, as it showed that diseases are not only spread by direct contact.
15th of March 1813 in York
16th of June 1858 in London
- John Snow is known for locating the source of a cholera outbreak. He was the first of nine children in his family.
In John Snow's early life, he was born into a labourer's family. After he moved to London in 1836, he started a formal medicine education. After he graduated from the University of London in 1844, he was "admitted to the Royal College of Physicians in 1850" (BBC History). During the time of 1850, it was believed that chlorea was transmitted through the air. Snow however did not believe this theory and said that in fact it entered the body through the mouth.
According to the UCLA School of Health, in 1854, a chlorea outbreak occured in Soho. During the epidemic outbreak, Snow plotted chlorea cases onto a map of the area to identify where the disease was infecting the people. According to BBC, "Snow was able to identify a water pump in Broad (now Broadwick) Street as the source of the disease". As soon as Snow had the handle of the pump removed, the chlorea cases started to decrease.
Therefore, John Snow's theory of disease was accpeted in 1960, which was another milestone in the human's defense against pathogens, as man-kind found out that diseases can be spread by water and can enter the body through the mouth.
John Snow's map
Works Cited & Works Consulted (URL's):
According to Aids.gov, HIV can only infect human beings. HIV "weakens your immune system by destroying important cells that fight disease and infection", and the virus can only reproduce itself by taking over control of a cell in the body of its host (Aids.gov).
HIV stands for the "Human Immunodeficiency Virus". HIV is an abnormal disease, which the immune system is not able to get rid of by itself. Scientists are still trying to figure out why. However, it has been reported that in several cases, the HIV virus has been successfully treated.
According to the Center of Disease Control and Prevention, HIV is transmitted through "different types of sex, injection drug use, and other activities that include body fluid exchange". Therefore, HIV is mainly a sexually transmitted disease (STD).
Once the body is infected with HIV, the disease can hide in the cells of your body for a certain amount of time. Afterwards, the Human Immunodeficiency Virus attacks the key parts of your immune system: the T cells. Even though, "your body has to have these cells to fight infections and disease, HIV invades them, and uses them to make more copies of itself, and then destroys them" (aids.gov). Once your body does not have enough of the important T cells anymore, the HIV infection will lead to AIDS.
Most treatments for HIV include approved-treatment drugs. Since 1987, over 30 different drugs were approved to treat people with HIV. The "The Cocktail",
the Antiretrovirals (ARVs), and the Highly Active Antiretroviral Therapy (HAART or ART) are three of them. There are currently five different "classes" of HIV drugs. "Each class of drug attacks the virus at different points in its life cycle—so if you are taking HIV meds, you will generally take 3 different antiretroviral drugs from 2 different classes" to treat an HIV infection (Aids.gov).
According to aids.gov, AIDS stands for Acquired Immunodeficiency Syndrome, which is the "final stage of HIV infection". At this stage, the immune systems of the people with AIDS are extremely weakened. These weakened immune systems put the body of an AIDS patient to a high risk of being infected by another disease. Since the immune systems of the AIDS patients are extremely weakened, common diseases (such as the flu) can easily affect/ infect the body. These disease can then easily infect and invade the body's cells without being attacked by any counterattack cells of the body (E.g. T cells).
According to aids.gov, "you will be diagnosed with AIDS if you have one or more specific OIs, certain cancers, or a very low number of T cells." A patient with AIDS will need medical intervention and distinctive treatment to prevent death.
Therefore, the difference of HIV and AIDS, is that HIV is the infection, which infects the body and kills it's T cells. AIDS however, is the disease, which happens through HIV. AIDS is the disease, which can cause various symptoms and death if not treated correctly.