The Seroprevalence Rates and Approach Management of Brucellosis in Thailand

Abstract

Background: Brucellosis is an important re-emerging zoonosis with worldwide distribution. In Thailand, endemic bovine and caprine brucellosis is a serious public health threat. Brucellosis in cattle and buffalo is primarily due to Brucella abortus while Brucella melitensis predominates in sheep and goats. The main factors maintaining the disease in humans and animals are unhygienic food habits, poor animal husbandry processes, lack of awareness and ineffective surveillance systems. Therefore, prevention of human brucellosis would depend on controlling the disease in livestock. The current study aimed to study the epidemiological situation to develop an effective control strategy. Methods: The estimated seropositivity rates at the herd and animal levels were compiled during 2009-2018. The sera were submitted to the National Institute of Animal Health (NIAH) and the Regional Veterinary Research and Development Centers (VRDCs), where serological tests were performed. The testing used screening based on the Rose Bengal test (RBT) followed by confirmatory tests, the complement fixation test (CFT) and the indirect enzyme-linked immunosorbent assay (I-ELISA). The data were collected, the proportion of the estimated seropositivity rate was analyzed. The seropositive animals were followed up and specimens were collected for isolation and PCR identification. Result: The results of the accumulated seropositivity rate of the brucellosis of dairy cattle, beef cattle, buffaloes, goats and sheep at the herd level from 2009 to 2018 was 7.12% (95% CI: 6.99-7.26) and the animal level was 0.92% (95% CI: 0.91-0.93). The species identification presented Brucella abortus five isolates, whereas Brucella melitensis presented 31 isolates from the total of 36 isolates. This information of the serological status and Brucella spp., including diagnostics patterns could be used as base data for better managing the prevention and control measures of brucellosis in Thailand and other countries.