Baseline molecular surveillance of monkeypox virus virus in wildlife and exotic animals during the pre- and early-2022 outbreak in Thailand
Issued Date
2026-01-01
Resource Type
ISSN
09728988
eISSN
22310916
Scopus ID
2-s2.0-105036657985
Journal Title
Veterinary World
Volume
19
Issue
4
Start Page
1504
End Page
1520
Rights Holder(s)
SCOPUS
Bibliographic Citation
Veterinary World Vol.19 No.4 (2026) , 1504-1520
Suggested Citation
Chamsai T., Ketchim N., Thongdee M., Chaiwattanarungruengpaisan S., Sariya L., Kaewchot S., Suwanpakdee S., Paungpin W., Chaisilp N. Baseline molecular surveillance of monkeypox virus virus in wildlife and exotic animals during the pre- and early-2022 outbreak in Thailand. Veterinary World Vol.19 No.4 (2026) , 1504-1520. 1520. doi:10.14202/vetworld.2026.1504-1520 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/116478
Title
Baseline molecular surveillance of monkeypox virus virus in wildlife and exotic animals during the pre- and early-2022 outbreak in Thailand
Author's Affiliation
Corresponding Author(s)
Other Contributor(s)
Abstract
Background and Aim: The global outbreak of monkeypox (mpox) in 2022 raised major concerns regarding the potential establishment of new animal reservoirs outside endemic regions. Although human-to-human transmission was the primary driver of the outbreak, reverse zoonotic transmission (spillback) from infected humans to animals could lead to long-term viral persistence in wildlife populations. Thailand, a non-endemic country affected during the 2022 outbreak, has extensive human-animal interfaces involving free-ranging wildlife, exotic pets, and urban scavenging mammals, which may facilitate cross-species transmission. The present study aimed to perform molecular surveillance for mpox virus (MPXV) DNA in selected high-risk animal populations in Thailand using archival samples collected during the pre-outbreak (2019) and early-outbreak (2022) periods to establish baseline evidence of viral presence or absence. Materials and Methods: A total of 1,248 animals, including 593 free-ranging cynomolgus macaques (Macaca fascicularis), 436 exotic pets, and 219 garbage-scavenging small mammals, were included in this cross-sectional surveillance study. Swab samples (oral, nasal, buccal, or rectal) collected during 2019 and 2022 were retrieved from archival storage. Viral DNA was extracted using a commercial genomic DNA kit, and detection of MPXV was performed by real-time polymerase chain reaction targeting the B7R gene, a conserved region specific to MPXV. Samples were pooled in groups of 4–5 to increase screening efficiency. Descriptive statistics were used to determine prevalence, and the rule-of-three method and binomial probability model were applied to estimate confidence limits and surveillance power in the absence of positive results. Results: All 1,248 samples tested negative for MPXV DNA. The studied population represented 29 animal species across multiple ecological settings, including urban, peri-urban, and rural environments in several provinces of Thailand. Based on the sample size, the upper 95% confidence limit for prevalence was estimated to be <0.24%. Power analysis indicated a 99.81% probability of detecting at least one positive case if the true prevalence had been ≥0.5%, confirming strong surveillance sensitivity. Conclusion: This study provides the first ecological baseline evidence of the absence of MPXV in wildlife, exotic pets, and garbage-scavenging mammals in Thailand before and during the early phase of the 2022 global outbreak. The findings support the importance of One Health-based surveillance integrating wildlife, domestic animals, and environmental interfaces to prevent spillback events and the establishment of new reservoirs in non-endemic regions. Continued longitudinal monitoring using both molecular and serological approaches is essential for early detection of emerging zoonotic threats.