Parasites

Parasites are organisms that are adapted to living in or in close proximity to another organism, or host. While parasites rarely kill the host they feed on, they do produce varying degrees of ill effects.

The following is a list of parasites that enter the body through the food we eat and by piercing the skin. There are many parasites that afflict humans by bites, such as mosquitoes, ticks, lice, mites, fleas and hookworms, but other parasites are sometimes found in the food we eat. Lesson two discussed how to minimize our risk to parasites in food; mainly by cleaning and cooking our food thoroughly. Protection from parasites that enter through the skin is mainly a matter of proper control of insect pests. Click on the Lesson Guide for pesticides to learn more about that topic.

Parasites	Habitat	Disease	Symptoms
Lice	Humans, clothing, bedding	Epidemics such as Typhus fever	Fever, headache, muscle ache, jaundice, etc.
Ticks	Found in woodlands, fields and shrubbery	Carries encephalitis, tick paralysis, typhus, and Lyme disease	Fever, headache, muscle pains, stiff neck, vomiting,
Mosquitoes	Near shallow pools of water	Malaria, Typhus, West Nile fever	Fever, headache, rashes, muscle aches, joint aches, anemia, coma
Fleas	Rats	Bubonic plague	High fever, chills, muscular pains, severe headache, painful swellings, swollen lymph glands
Horse Flies	Meadows and open grasslands; near marshy areas or slow streams	Transmits diseases from species to species	Depends on the disease
Toxoplasma gondii	Cat litter and raw meat	Meningitis/ pneumonia	Sensitivity to light, fever, headache, stiff neck, cough, fever, chest pain, fatigue
Cryptosporidium parvum	Contaminated food	Cryptosporidosis	Watery diarrhea, cramps, nausea and anorexia, lasting ten to fifteen days
Cyclospora	Food/water contaminated by infected fecal matter	Cayetanensis	Watery diarrhea, with frequent sometimes explosive bowel movements
Giardia lamblia	Passed in the feces of infected persons	Giardiasis	May cause severe chronic diarrhea
Trichinella spiralis	Undercooked meat	Trichinosis	Fever, muscle soreness, pain and swelling of the muscles and eyes: failure to treat could be fatal