Background: Long-tailed and pig-tailed macaque monkeys are natural hosts of Plasmodium knowlesi, which has been identified as a fifth malaria parasite infecting humans. In this study, we investigated possible infection by this Plasmodium parasite in macaque monkeys using a combination of polymerase chain reaction amplification and sequencing.
Methods: Forty-five blood samples were obtained in 2010 from macaques in northern Myanmar near Yunnan Province of China and investigated for possible infection with Plasmodium species using a nested polymerase chain reaction method for amplification of 18S SSU rRNA genes.
Results: Positive amplification was obtained from one monkey, and both sequence and phylogenetic analysis indicated that the parasite was of the Hepatocystis species lineage.
Conclusion: The results suggest that a combination of polymerase chain reaction amplification and sequence identification would be necessary for detection of Plasmodium knowlesi infection in both humans and its natural hosts.
Keywords: Plasmodium knowlesi; malaria; monkey; parasite.