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How do malaria parasites and tapeworms affect their human hosts?

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Diagram showing the West Nile virus transmission cycle: a mosquito bites an infected bird (the primary reservoir host), then transmits the virus to humans or horses (incidental hosts) through subsequent bites. — infectious disease Birds are the primary reservoirs of West Nile virus. The virus is transmitted to humans and horses by mosquitoes that have bitten infected birds.

Malaria parasites and tapeworms affect human hosts through distinct biological mechanisms.

Malaria Parasites

Malaria is caused by Plasmodium protozoans transmitted via mosquito bites. Once in the human body, the parasites travel to the liver to replicate before invading red blood cells. The parasites multiply within these cells, causing them to rupture and release new generations of parasites into the bloodstream. This cycle leads to characteristic symptoms such as intermittent fever, chills, anemia, and, in severe cases (particularly with P. falciparum), organ obstruction, coma, and death.12

Tapeworms

Tapeworms are flatworms that typically infect humans through the ingestion of contaminated, undercooked meat or fish.134
* Intestinal Cestodiasis: Adult worms attach to the intestinal wall, where they may cause abdominal pain, nausea, or diarrhea, though many infections are asymptomatic. Some species, such as the fish tapeworm, can cause severe anemia by consuming the host's vitamin B12.143
* Visceral and Somatic Cestodiasis: Juvenile tapeworms (larvae) pose a greater risk by burrowing through the intestinal wall to migrate into tissues like the brain, muscle, or lungs. This can lead to cysts, inflammation, and neurological complications such as seizures.14