The human hosting of parasites is relatively rare in the United States, particularly in urban areas. But these problems can be present in immigrants or travelers that have spent time out of the country, bringing back an unexpected souvenir from trips to Asia, Africa and Latin American countries where parasites are more common.
Typical parasites include tapeworms, dog tapeworms, whipworms, roundworms, and Toxoplasma gondii, but there are many others. Most are ingested through the mouth or skin, usually through food, but there are many ways that a parasite can enter the body.
Because food and drink are risk factors, travelers to foreign lands are often advised to avoid eating raw foods or drinking unfiltered or unboiled water. Instead, travelers should live by the practice of cooking, peeling or boiling anything presented in a foreign country before consuming it.
Some parasitic infections occur because of poor sanitation practices at institutions or care centers, while still others may be acquired by sexual practices, including fecal ingestion.
MOST AT RISK
Elderly adults and children are most likely to be infected by parasites, and those having a weakened immune system caused by HIV or AIDS are also particularly vulnerable. Once acquired, how long a patient remains ill and how seriously ill is a matter of individual health and the specific parasite that caused the illness.