Dengue Virus Serotype 4, Roraima State, Brazil

bred outdoors in malaria-endemic areas is not uncommon. However, with the exception of P. knowlesi, it is my understanding that malarial organisms found in cynomolgus monkeys do not pose a major zoonotic concern (although this can always change). Furthermore, it is my understanding that P. vivax does not infect macaques, including cynomolgus monkeys. Other malarial parasites of cynomolgus monkeys, apart from P. knowlesi, may include P. cynomologi, P. inui, P. fi eldi, and P. coatneyi. A recent publication reported that in wild-source cynomolgus monkeys in Malaysia, >90% of the animals tested were positive for >1 Plasmodium species. Furthermore, >80% of samples from these animals were positive by specifi c PCR for >1 of these organisms (2). Using PCR for Plasmodium spp. identifi cation, I have tested newly imported research cynomolgus monkeys from various breeding centers in China. I can confi rm that some animals have subclinical malarial infections. Except for the report by Li et al. (1), I am unaware of other reports of P. vivax in cynomolgus monkeys. It would be interesting to confi rm the presence of this organism by using PCR primers specifi c for Plasmodium spp. My questions to the authors relate to the test method used in their study. Was an ELISA for detecting P. vivax antibodies the only diagnostic method used to identify this parasite? It may be useful to re-address the specifi city of this test in differentiating various Plasmodium spp. Until these issues are clearly addressed, their reported results are not reliable.