Abstract / Summary
Brucellosis is an important zoonosis affecting public health and livestock production in Southeast Asia, but its regional epidemiology remains incompletely characterized. In this study, PubMed, Embase, Web of Science, and Scopus were searched for primary studies from the 11 Southeast Asian countries that reported serological findings, molecular detection, bacterial isolation, or Brucella species identification in human or animal populations. Publicly available PubMLST records were also analyzed using the 1764-locus Brucella core-genome multilocus sequence typing scheme. Across the eligible studies, reported crude seropositivity proportions ranged from 0.72% to 5.40% in humans and from 0.24% to 8.83% in animals. Molecular evidence included PCR positivity rates of 3.36% in goat vaginal swabs from Thailand and 39.2% in a selected mixed-livestock population from Indonesia, together with the identification of Brucella melitensis, B. abortus, and B. suis in several Southeast Asian countries. These findings provide epidemiological evidence of brucellosis in several countries. cgMLST analysis of the 24 available profiles from Malaysia and Thailand revealed close genetic relatedness among several isolates. Malaysian and Thai B. melitensis isolates differed by fewer than 11 alleles within the main cluster and by 41-81 alleles relative to isolates from India and the United Kingdom. Two Thai B. abortus isolates differed at only one locus and by 68-150 alleles from isolates from Bangladesh, India, and Bolivia, whereas five Malaysian B. suis isolates differed by 7-78 alleles, indicating limited genetic diversity within the Malaysian cluster. Additional genomic and epidemiological data are needed to determine whether genetically similar isolates are epidemiologically linked. Brucellosis appears endemic in parts of Southeast Asia, but important gaps in published data remain. Integrated One Health surveillance is needed to improve regional risk assessment and control.