Malaria is a tropical illness caused by parasites called plasmodia. Plasmodia depend on female mosquitoes for part of their life cycle. Most cases of malaria follow the bite of an infected mosquito, although the disease can also be spread by exposure to infected blood through transfusions, organ transplants, contaminated needles and childbirth.

Malaria is characterised by recurring episodes of fevers then chills and often severe anaemia. It is a common disease in people with HIV, with many complex interactions between the two diseases.