Natural infection of free-ranging mandrills (Mandrillus sphinx) by enteroviruses and astroviruses in southern Gabon.

Enteroviruses (Picornaviridae) and astroviruses (Astroviridae) cause various diseases in humans and animals, including in non-human primates (NHPs). Some enteroviruses and astroviruses detected in NHPs are genetically related to those infecting humans, indicating the occurrence of interspecies transmissions. In this study, we screened 200 fecal samples of 56 free-ranging mandrills (Mandrillus sphinx) by nested reverse transcription-PCR with primers targeting the VP1 and RdRp genes, to evaluate the diversity of enterovirus and astrovirus infection, respectively, and the associated zoonotic risk. Overall, ten samples from six mandrills were enterovirus-positive (5%), and three samples from three mandrills were astrovirus-positive (1.5%). This is the first evidence of astrovirus infection in mandrills. Phylogenetic analyses based on the VP1 sequences revealed that all ten enterovirus sequences were part of the species Enterovirus J, suggesting low zoonotic risk. Phylogenetic analysis of the three astrovirus sequences showed that they all belonged to the Mamastrovirus genus. Two astrovirus sequences were highly divergent from all human astrovirus sequences (63.4-73% nucleotide identity), while one sequence (AstV-5) suggested cross-species transmission from humans to mandrills. Additional studies are needed to better characterize the identified astroviruses and to confirm whether mandrills are host of astroviruses than can be transmitted to humans.

Detection of novel astroviruses among rodents of Gabon, Central Africa.

Astroviruses (AstVs) are mostly responsible for mild to severe gastroenteritis infections in humans and animals. AstVs infect a wide range of host species, have a large genetic diversity with different circulating variants and are thus a high zoonotic risk for human populations. Among these host species, rodents are known to harbor several AstVs variants. Therefore, it is important to identify in rodent species which AstVs are circulating and evaluate their potential zoonotic risk for humans. In this context, this study aimed to screen the presence of AstVs in 267 rodents trapped in 2012 in Franceville and Makokou, two cities in Gabon. RNA extracted from grinded intestines were used for the screening of AstVs by amplification of a conserved region of the RNA dependent RNA polymerase. Results report the identification of AstVs in 12 individuals (4.6% rate), belonging to three different species including Rattus rattus, Mus musculus and Hybomys univittatus. These findings report the first identification of AstVs in R. rattus and H. univittatus. The phylogenetic analyses indicate host specificity of rodents AstVs. The absence of rodent AstVs within the human AstV clade suggests a low rate of interspecies transmission of these viruses and consequently a low zoonotic risk.