Interactions between malaria parasite species: Do they matter?

Multiple species of malaria parasites cause disease in humans. The ranges of these species often overlap, and they may be found infecting the same populations at the same time. Due to this, mixed-species infections, in which hosts are simultaneously infected by multiple malaria parasite species, are common, and are yet relatively understudied. Malaria parasite species in mixed infections interact and compete for host resources such as space and nutrition. The consequences of these interactions for disease severity, pathology and parasite fitness are currently poorly understood. I will discuss laboratory experiments in which mixed malaria parasite species infections have been studied in mice, and relate these to recent field work involving analysis of mixed species infections in asymptomatic malaria parasite carriers in central Africa.