No Evidence of Oropouche Virus Circulation Found in Thai Arbovirus Hotspots, Study Reveals
BANGKOK, Thailand – A new study published in BMC Research Notes has found no evidence of Oropouche virus (OROV) circulation among acute febrile illness cases in Thailand, despite the country’s established presence of other arboviruses. Researchers conducted molecular screening of samples collected between 2018 adn 2024 from patients presenting with fever in regions known to harbor viruses like dengue, chikungunya, and Zika.
The investigation, which analyzed samples from multiple provinces, utilized RT-PCR to detect OROV RNA.While the study successfully screened a cohort of patients,the absence of OROV detection highlights a gap in understanding the virus’s potential presence and transmission dynamics within Thailand.
Researchers acknowledge several limitations to the study. Reliance on molecular detection alone,without serological testing,could have resulted in false negatives,especially if samples were collected outside the peak of viremia. Limited residual sample volumes and the lack of validated serological assays in Thailand prevented broader serological analysis. Furthermore, the retrospective design, limited temporal coverage, and relatively small sample size may not fully represent seasonal or nationwide OROV circulation patterns.
The study emphasizes the need for future research incorporating seroepidemiological approaches to assess past exposure and population immunity. Researchers also recommend prospective longitudinal surveillance with larger sample sets, including those from under-represented rural and border populations.
Given the prevalence of Culex quinquefasciatus – a potential OROV vector - in Thailand, the authors stress the importance of vector surveillance and competence testing. While Culicoides paraensis, another known OROV vector, hasn’t been reported in Thailand, other culicoides species have been documented in the country [references 14 & 15]. Determining the competence of local Thai vector species for OROV transmission is crucial, particularly considering Thailand’s high tourism rate and the potential for virus importation. currently, no entomological studies in Thailand have specifically investigated OROV vectors.
The researchers conclude that further investigation is critical for preparedness and to comprehensively assess the potential risk of OROV emergence in Thailand. Parallel OROV testing in arbovirus-positive cases is also recommended for future studies.
