Serological Evidence of Orthopoxvirus Infection in Neotropical Primates in Brazil

Abstract

The genus Orthopoxvirus (OPXV) of the family Poxviridae comprises several viruses that are capable of infecting a wide range of hosts. One of the most widespread OPXVs is the Vaccinia virus (VACV), which circulates in zoonotic cycles in South America, especially in Brazil, infecting domestic and wild animals and humans and causing economic losses as well as impacting public health. Despite this, little is known about the presence and/or exposure of neotropical primates to orthopoxviruses in the country. In this study, we report the results of a search for evidence of OPVX infections in neotropical free-living primates in the state of Minas Gerais, southeast Brazil. The sera or liver tissues of 63 neotropical primates were examined through plaque reduction neutralization tests (PRNT) and real-time PCR. OPXV-specific neutralizing antibodies were detected in two sera (4.5%) from Callithrix penicillata, showing 55% and 85% reduction in plaque counts, evidencing their previous exposure to the virus. Both individuals were collected in urban areas. All real-time PCR assays were negative. This is the first time that evidence of OPXV exposure has been detected in C. penicillata, a species that usually lives at the interface between cities and forests, increasing risks of zoonotic transmissions through spillover/spillback events. In this way, studies on the circulation of OPXV in neotropical free-living primates are necessary, especially now, with the monkeypox virus being detected in new regions of the planet.

Immunopathogenesis of Orthopoxviridae: insights into immunology from smallpox to monkeypox (mpox)

“…Between 1980 and 2000, MPXV remained detected in mostly African countries with cases reported in the Democratic Republic of Congo (DRC), Gabon, Ivory Coast, and the Central African Republic until 2003 in the United States of America (USA) [17]. Notably, research during the DRC outbreak quantified incidence risk between outbreaks of 1981-1986 and 2005-2007. During the 1980s, this is suggested at 0.72/10,000 individuals, with latter outbreaks at 14.42/10,000 individuals, respectively [42]. Prior articles indicate occurrences in individuals between the age of 21 and 40 that may be indicative of a lack of immunity to OPXVs, like VARV, unknown to date [22].…”

Immunopathogenesis of Orthopoxviridae: Insights into Immunology from Smallpox to Monkeypox (Mpox)

“…Analysis indicated either 93% or 98% met the criteria for MPXV infection; however low specificity to the available serological analysis of between 9%-26% respectively was indicated [6]. Serological diagnostic testing is validated before use as a diagnostic for the specificity of reagents (e.g., monoclonal antibodies) and was indicated as problematic with OPXVs before and after 2000 due to antibody cross-reactivity with other OPXVs [43][44][45][46]. However, more recently 119 antigen, DNA, and antibody tests are now available subject to specificity and licensing approval (see Supplementary Data S1).…”