In literature every illness symbolizes something different for different characters with different implications. Illnesses in literature are usually: mysterious, especially in earlier novels when disease origins were unknown; picturesque, so the reader can picture it; and metaphorical, depending on the character and the story.
In “The Lion, the Witch and the Wardrobe,” C.S. Lewis uses the winter to represent a time of hopelessness and despair under the rule of the White Witch in Narnia.
In “The Sisterhood of the Traveling Pants” series by Ann Brashares, each book takes place during the summer. Summer symbolizes freedom and growth for the characters as they search for self acceptance, love and their identities.
"...it seems God's plan called for Mother and Ruth May to fall sick nigh unto death. They grew flushed and spotted and thick-tongued and tired and slow-moving near unto the lower limit of what is generally thought to consitute a living human body." (Kingsolver 217)
Seasons are used to portray emotion, and age. The author chooses events to happen at certain times in the year, for a reason. Each one has meaning. For example:
Spring - fertility, life, childhood, happiness, growth, resurrection
Summer - Romance, Passion, adulthood
Fall - harvest, middle aged, reaping what we sow, both rewards and punishments
Winter - hibernation, lack of growth, death, punishment
Authors use seasons to create contrast, irony, and feeling in their work.
"Daisy Miller" by Henry James, in which Daisy dies of Roman fever, or malaria, symbolizing the "bad air" around her full of gossip and negative public opinion.
"Father says Anatole is 'our only ally in all this' good enough reason to invite him to dinner." (Kingsolver 127)
People are very particular with who they share meals with. When people do share a meal in a novel it often has meaning behind it. If the meal goes well, that symbolizes things are going good in the novel or the character's life. If the meal goes bad then it is the opposite.