Short report: Infection dynamics of sylvatic dengue virus in a natural primate host, the African green monkey

The four serotypes of mosquito-borne dengue virus (DENV-1, -2, -3, and -4) that circulate in humans each emerged from an enzootic, sylvatic cycle in non-human primates. Herein, we present the first study of sylvatic DENV infection dynamics in a primate. Three African green monkeys were inoculated with 10⁵plaque-forming units (pfu) DENV-2 strain PM33974 from the sylvatic cycle, and one African green monkey was inoculated with 10⁵pfu DENV-2 strain New Guinea C from the human cycle. All four monkeys seroconverted (more than fourfold rise in 80% plaque reduction neutralization titer [PRNT₈₀]) against the strain of DENV with which they were inoculated; only one (33%) of three monkeys infected with sylvatic DENV showed a neutralizing antibody response against human-endemic DENV. Virus was detected in two of three monkeys inoculated with sylvatic DENV at low titer (≤ 1.3 log₁₀pfu/mL) and brief duration (≤ 2 days). Clinical signs included rash and elevated aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels.