Simian T-lymphotropic virus diversity among nonhuman primates, Cameroon

Area of Science:

• Virology
• Primatology
• Epidemiology

Background:

• Cross-species transmission of retroviruses, including simian T-cell lymphotropic virus (STLV), is a recognized concern in Cameroon.
• Understanding the risk of STLV transmission from nonhuman primates to humans, particularly hunters, is crucial for public health.

Purpose of the Study:

• To investigate the prevalence and diversity of STLV in nonhuman primates hunted in Cameroon.
• To assess the potential for STLV transmission to humans, specifically hunters, by examining STLV sequences in hunted primates and screening hunters for infection.

Main Methods:

• Analysis of 170 hunter-collected dried blood spots (DBS) from 12 primate species using PCR with generic tax and group-specific long terminal repeat primers.
• Phylogenetic analysis to determine STLV diversity, including novel sequences.
• Screening of peripheral blood mononuclear cell DNA from 63 HTLV-seroreactive, PCR-negative hunters.

Main Results:

• STLV was detected in 12% (7%) of specimens from 4 nonhuman primate species.
• Phylogenetic analyses revealed significant STLV diversity, including novel STLV-1 and STLV-3 sequences.
• A highly divergent STLV-3 subtype was identified in Mona monkeys (Cercopithecus mona) and red-tailed guenons (C. nictitans).
• No human infections with this divergent STLV-3 were identified in the screened hunter population.

Conclusions:

• Hunter-collected DBS are effective for capturing STLV diversity at the point of pathogen spillover.
• This collection strategy offers a feasible approach for large-scale monitoring of retrovirus cross-species transmission in high-risk human populations.
• The findings highlight the importance of monitoring primate retroviruses for potential zoonotic risks.