Suppression of Plasmodium cynomolgi in rhesus macaques by co-infection with Babesia microti.

Infect Immun. 2010 Jan 4;

Authors: van Duivenvoorde LM, Voorberg-van der Wel A, van der Werff NM, Braskamp G, Remarque EJ, Kondova I, Kocken CH, Thomas AW

Plasmodium and Babesia species are both intra-erythrocytic protozoa that infect a wide range of hosts, including humans, eliciting similar inflammatory responses and clinical manifestations showing markedly different degrees of severity. We recently reported that a rhesus macaque, chronically infected with Babesia microti, was better able to control infection with Plasmodium cynomolgi (a parasite of macaques with characteristics closely similar to P. vivax) than naïve monkeys. To confirm this and investigate the underlying immunopathology, six naïve rhesus monkeys were infected with B. microti. After 24 days, 4 of these monkeys and 4 naïve rhesus monkeys were challenged with P. cynomolgi blood stage parasites. B. microti persisted at low levels in all monkeys, and clinical parameters were comparable to non-infected controls. There was a significant decrease in P. cynomolgi parasitaemia in animals co-infected with B. microti compared to those infected with P. cynomolgi alone. This decrease in P. cynomolgi parasitaemia correlated with an increase in pro-inflammatory monocytes at the time of P. cynomolgi infection and more elevated CRP serum levels one week after malaria infection. Therefore, we conclude that ongoing infection with B. microti parasites leads to suppression of the malaria infection.

PMID: 20048045 [PubMed - as supplied by publisher]