To investigate the potential role of non-human primates (NHPs) in a dengue virus (DENV) epidemic, we conducted serological and genomic studies using plasma samples collected from 100 cynomolgus monkeys (Macaca fascicularis) in an animal breeding facility in the Philippines. An ELISA revealed 21 monkeys with a positive IgM reaction and 19 positive for IgG. Five of the monkeys were positive for both IgM and IgG. Of the 21 IgM-positive samples, a neutralization assay identified seven containing DENV-specific antibodies. We amplified the viral non-structural 1 (NS1) gene in two and the envelope (E) gene in one of these seven samples by RT-PCR. Phylogenetic analyses revealed that these DENV genes belonged to the epidemic DENV-2 family, not the sylvatic DENV family. These results suggest that NHPs may serve as a reservoir of epidemic DENV; therefore, the ecology of the urban DENV infection cycle should be investigated in these animals in detail.
InoueS., MoritaK., MatiasR. R., TuplanoJ. V., ResuelloR. R., CandelarioJ. R., CruzD. J., MapuaC. A., HasebeF.other authors2003; Distribution of three arbovirus antibodies among monkeys (Macaca fascicularis) in the Philippines. J Med Primatol 32:89–94 [View Article][PubMed]
ItoM., YamadaK., TakasakiT., PandeyB., NeromeR., TajimaS., MoritaK., KuraneI.2007; Phylogenetic analysis of dengue viruses isolated from imported dengue patients: possible aid for determining the countries where infections occurred. J Travel Med 14:233–244 [View Article][PubMed]
KinneyR. M., ButrapetS., ChangG. J., TsuchiyaK. R., RoehrigJ. T., BhamarapravatiN., GublerD. J.1997; Construction of infectious cDNA clones for dengue 2 virus: strain 16681 and its attenuated vaccine derivative, strain PDK-53. Virology 230:300–308 [View Article][PubMed]
TajimaS., NukuiY., ItoM., TakasakiT., KuraneI.2006; Nineteen nucleotides in the variable region of 3′ non-translated region are dispensable for the replication of dengue type 1 virus in vitro. Virus Res 116:38–44 [View Article][PubMed]
VasilakisN., ShellE. J., FokamE. B., MasonP. W., HanleyK. A., EstesD. M., WeaverS. C.2007b; Potential of ancestral sylvatic dengue-2 viruses to re-emerge. Virology 358:402–412 [View Article][PubMed]
VasilakisN., CardosaJ., HanleyK. A., HolmesE. C., WeaverS. C.2011; Fever from the forest: prospects for the continued emergence of sylvatic dengue virus and its impact on public health. Nat Rev Microbiol 9:532–541 [View Article][PubMed]
YenchitsomanusP. T., SricharoenP., JaruthasanaI., PattanakitsakulS. N., NitayaphanS., MongkolsapayaJ., MalasitP.1996; Rapid detection and identification of dengue viruses by polymerase chain reaction (PCR). Southeast Asian J Trop Med Public Health 27:228–236[PubMed]