Three types of parasites can cause disease in humans. They are protozoa, carried by mosquitos, helminths, such as roundworm, and ectoparasites, for instance lice and bed bugs. Parasites are organisms ...

The woman’s mysterious symptoms started in her stomach. Weeks of abdominal pain and diarrhea led to night sweats and a dry cough. Then, doctors found lesions on her lungs, liver and spleen. An ...