Key Factors Leading to Parasite Development: Causes You Need to Know

Parasites are caused by exposure through contaminated food or water, insect bites, or poor hygiene.

How parasites spread

• Contaminated food or water (giardia).
• Undercooked meat (tapeworm, toxoplasma).
• Insect bites (malaria, Lyme isn’t a parasite).
• Poor hygiene.
• Contact with feces or soil.
• Sexual contact (trichomonas).

Common ones

Pinworms, giardia and lice.

Prevention

Wash hands, cook food and drink clean water.

See a doctor

For diarrhea that lasts more than 2 weeks.

How infections spread

Parasites are organisms that live on or in a host. They spread through contaminated food or water, insect bites, soil, undercooked meat or fish, contact with infected animals or people, and poor sanitation. Types include protozoa (Giardia, Plasmodium), helminths (worms such as tapeworms and roundworms) and ectoparasites (lice, scabies mites, ticks).

• Malaria, caused by Plasmodium and spread by Anopheles mosquitoes, caused an estimated 608,000 deaths in 2022, mostly in Africa, per the WHO.
• Toxoplasma infects an estimated 11 percent of US residents over age 6, from cat feces and undercooked meat.
• Roughly 1.5 billion people are infected with soil-transmitted helminths worldwide.

Prevention and care

Wash hands, drink safe water, cook meat and fish thoroughly, wash produce, use insect repellent and bed nets in endemic areas, and avoid walking barefoot on contaminated soil. See a doctor for persistent diarrhea, weight loss, abdominal pain, itching around the anus or fever after travel. Stool tests and blood tests diagnose, and antiparasitic drugs such as albendazole and metronidazole treat.

How infections spread

Parasites spread via contaminated water, undercooked food, insect bites, soil and contact. Examples include Giardia, tapeworms and malaria. The WHO notes malaria caused about 608,000 deaths in 2022.

Prevention and care

Wash hands, cook meat thoroughly, drink safe water and use mosquito protection. See a doctor for diagnosis and prescription treatment.

Groups of parasites

Parasites include protozoa (Giardia, Plasmodium), helminths (roundworms, hookworms, tapeworms) and ectoparasites (lice, scabies mites). The WHO estimates that over 1.5 billion people are infected with soil transmitted helminths. Malaria caused 249 million cases and 608,000 deaths in 2022.

Prevention and treatment

Handwashing, food safety, safe water, shoes in endemic areas, insect nets and deworming programs reduce infections. Treatments are specific: albendazole for helminths, metronidazole or tinidazole for Giardia, ivermectin for scabies and artemisinin combination therapy for malaria. Stool tests and blood smears diagnose. Travelers should see a clinic for prophylaxis.

Based on data from the World Health Organization and the CDC