A genome-wide screen in live hosts reveals new secrets of parasite infection

Apicomplexan parasites are a common cause of disease, infecting hundreds of millions of people each year. They are responsible for spreading malaria; cryptosporidiosis—a severe childhood diarrheal disease; and toxoplasmosis—a disease that endangers immune compromised people and fetuses, and is the reason why pregnant women are told to avoid changing cat litter.