Exacerbation of murine malaria by concurrent infection with lactic dehydrogenase-elevating virus.

The simultaneous infection of mice with lactic dehydrogenase-elevating virus (LDV) and Plasmodium yoelii resulted in an exacerbated attack of malaria. Peak parasitaemia was higher and the patent infection more prolonged in doubly infected mice. The results indicate that contamination with LDV must be considered when a change in parasite virulence is observed, particularly when the parasite is maintained by blood passage in mice.