Zoonotic infection of Brazilian primate workers with New World simian foamy virus
Cláudia P Muniz1,2, Liliane T F Cavalcante1, Hongwei Jia2
1Departamento de Genética, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Abstract:
Simian foamy viruses (SFVs) are retroviruses present in nearly all nonhuman primates (NHPs), including Old World primates (OWP) and New World primates (NWP). While all confirmed human infections with SFV are from zoonotic transmissions originating from OWP, little is known about the zoonotic transmission potential of NWP SFV. We conducted a longitudinal, prospective study of 56 workers occupationally exposed to NWP in Brazil. Plasma from these workers was tested using Western blot (WB) assays containing NWP SFV antigens. Genomic DNA from blood and buccal swabs was analyzed for the presence of proviral SFV sequences by three nested PCR tests and a new quantitative PCR assay. Exposure histories were obtained and analyzed for associations with possible SFV infection. Ten persons (18%) tested seropositive and two persons were seroindeterminate (3.6%) for NWP SFV. Six persons had seroreactivity over 2-3 years suggestive of persistent infection. All SFV NWP WB-positive workers reported at least one incident involving NWP, including six reporting NWP bites. NWP SFV viral DNA was not detected in the blood or buccal swabs from all 12 NWP SFV seroreactive workers. We also found evidence of SFV seroreversion in three workers suggestive of possible clearance of infection. Our findings suggest that NWP SFV can be transmitted to occupationally-exposed humans and can elicit specific humoral immune responses but infection remains well-controlled resulting in latent infection and may occasionally clear.
Insights
New World Primate foamy viruses (SFV) can transmit to humans through occupational exposure. While infection elicits immune responses, it appears well-controlled, potentially leading to latent or cleared infections.
Area of Science:
- Virology
- Zoonotic Diseases
- Primate Health
Background:
- Simian foamy viruses (SFVs) are retroviruses common in nonhuman primates (NHPs).
- Human SFV infections are typically zoonotic, originating from Old World Primates (OWP).
- The zoonotic potential of New World Primate (NWP) SFV is largely unknown.
Purpose of the Study:
- To investigate the zoonotic transmission potential of NWP SFV in occupationally exposed humans.
- To assess the serological and virological evidence of NWP SFV infection in exposed workers.
Main Methods:
- A longitudinal study of 56 workers with occupational exposure to NWP.
- Western blot (WB) assays for NWP SFV antibodies.
- PCR and quantitative PCR for proviral SFV DNA in blood and buccal swabs.
- Analysis of exposure histories.
Main Results:
- 18% of workers tested seropositive for NWP SFV.
- Seroreactivity persisted for 2-3 years in some individuals.
- No NWP SFV viral DNA was detected in seroreactive workers.
- Evidence of SFV seroreversion suggesting possible infection clearance was observed.
Conclusions:
- NWP SFV can transmit to occupationally exposed humans, eliciting humoral immune responses.
- SFV infection in humans appears to be well-controlled, resulting in latent infection.
- Spontaneous clearance of SFV infection may occur in some individuals.
