Zoonotic Potential of Simian Arteriviruses

Abstract

Wild nonhuman primates are immediate sources and long-term reservoirs of human pathogens. However, ethical and technical challenges have hampered the identification of novel blood-borne pathogens in these animals. We recently examined RNA viruses in plasma from wild African monkeys and discovered several novel, highly divergent viruses belonging to the family Arteriviridae. Close relatives of these viruses, including simian hemorrhagic fever virus, have caused sporadic outbreaks of viral hemorrhagic fever in captive macaque monkeys since the 1960s. However, arterivirus infection in wild nonhuman primates had not been described prior to 2011. The arteriviruses recently identified in wild monkeys have high sequence and host species diversity, maintain high viremia, and are prevalent in affected populations. Taken together, these features suggest that the simian arteriviruses may be "preemergent" zoonotic pathogens. If not, this would imply that biological characteristics of RNA viruses thought to facilitate zoonotic transmission may not, by themselves, be sufficient for such transmission to occur.

FIG 1

Features of simian arterivirus infections among African monkeys. (A) Map of Africa depicting the geographic locations where wild monkeys harboring simian arteriviruses have been sampled. Colors correspond to the respective host species and virus throughout the figure. (Map from Lokal_Profil [https://commons.wikimedia.org/wiki/File:BlankMap-Africa.svg].) (B) Plasma viral loads, as measured by quantitative reverse transcription-PCR, showing simian arterivirus viremia in infected monkeys. N.T., not tested. (C) Prevalence of simian arterivirus-positive monkeys in affected populations, as determined by quantitative reverse transcription-PCR, reverse transcription-PCR, and/or unbiased deep sequencing. (D and E) Phylogeny of known simian arteriviruses (D) with a simian immunodeficiency virus (SIV) phylogeny shown on the same scale for comparison (E). Maximum likelihood trees were generated using MEGA6.06 (1,000 bootstrap replicates, GTR+I+γ model) from codon-based alignments (via MAFFT) of 12 simian arterivirus ORF1b sequences or 27 simian immunodeficiency virus gag sequences. Bootstrap values of less than 70 are not shown. DeBMV-1, De Brazza's monkey virus 1; DMVV-1, Drakensberg Mountain vervet virus 1; KKCBV-1, Kafue kinda-chacma baboon virus 1; KRCV-1/2, Kibale red colobus virus 1/2; KRTGV-1/2, Kibale red-tailed guenon virus 1/2; MYBV-1, Mikumi yellow baboon virus 1; PBJV, Pebjah virus; SHEV, simian hemorrhagic encephalitis virus; SHFV, simian hemorrhagic fever virus; SWBV-1, Southwest baboon virus 1.