Serological and molecular surveillance of West Nile virus in domesticated mammals of peninsular Malaysia.
Authors: Mohammed Mohammed Nma, Yasmin Abd Rahaman, Ramanoon Siti Zubaidah, Noraniza Mohd Adzahan, Ooi Peck Toung, Ain-Najwa Mohd Yuseri, Natasha Jafar Ali, Nur-Fazila Saulol Hamid, Arshad Siti Suri, Mohammed Hussni Omar
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: West Nile Virus in Malaysian Domestic Mammals West Nile virus presents an emerging threat to equine and livestock health globally, yet surveillance data from Southeast Asia remain sparse—prompting this first systematic investigation into WNV exposure among cattle, goats and horses in peninsular Malaysia. Researchers collected 203 serum samples and nasopharyngeal swabs from these species, testing for anti-WNV IgG antibodies via competitive ELISA and WNV RNA through RT-PCR respectively. Seroprevalence varied considerably by species, with horses showing the highest exposure at 53.84% (49/91), followed by goats at 48.27% (14/29) and cattle at 32.53% (27/83); notably, seven horses also tested positive for active WNV RNA (7.69% molecular prevalence), whilst no viraemia was detected in cattle or goats—suggesting horses may be more susceptible to infection or represent a spill-over host of particular concern. Cross-reactivity with Japanese encephalitis virus antibodies complicated interpretation in 36 animals, indicating the need for more specific serological assays in this region. For equine professionals, these findings underscore the circulation of WNV in Malaysia and warrant heightened awareness of neurological and systemic clinical signs; integrated vector control and further surveillance should be prioritised to understand transmission dynamics and assess risk to both horses and the broader community.
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Practical Takeaways
- •Horses in Malaysia have the highest WNV exposure risk among domesticated livestock, with over half showing serological evidence of infection; implement mosquito control and consider epidemiological surveillance
- •Active viral shedding detected in some horses suggests they may serve as reservoir hosts; monitor for neurological signs and implement biosecurity measures during outbreak periods
- •Cross-reactivity between WNV and JEV antibodies complicates diagnosis; serological testing alone is insufficient—RT-PCR confirmation is essential for definitive WNV identification in this region
Key Findings
- •WNV seroprevalence was 32.53% in cattle, 48.27% in goats, and 53.84% in horses in peninsular Malaysia
- •Seven horses (7.69% molecular prevalence) tested positive for WNV RNA via RT-PCR; no positive results in cattle or goats
- •Cross-reactive JEV antibodies detected in 2 cattle and 34 horses, indicating potential prior flavivirus exposure
- •This is the first reported detection of WNV in domesticated mammals in Malaysia, confirming active vector-to-host transmission