Sero-epidemiology of Brucellosis in migratory nomads of Fars province of Iran

This study assessed the sero-prevalence of brucellosis and its risk factors among migratory nomads in the Fars province of Iran. Active brucellosis was defined as the combination of clinical symptoms, including fever, chills, night sweats, headache, low back pain, arthralgia, or myalgia, and positive laboratory testing, including either a serum agglutination test (SAT) ≥1:80 with a 2-mercaptoethanol (2ME) ≥1:40, or a SAT <1:80 combined with a positive Coombs Wright test (CWT) at a titre of at least 3-fold higher than SAT titre results. Among the 536 participants, the female (316; 59%) to male (220; 41%) ratio was 1.4 and the participants mean age was 32.4±18.9 years, with a range of 1 to 96 years. Among all participants, 325 (60.6%) showed clinical symptoms; among symptomatic participants, the Rose Bengal plate test was positive in 33 (6.1%) cases, the SAT was positive in 18 (3.3%) cases, and the 2ME was positive in 30 (5.5%) cases. Positive SAT and 2ME results were seen in 18 (3.3%) cases, but a negative SAT and a positive CWT were found in 36 (6.7%) cases. As a result, active brucellosis was detected in 54 cases, indicating a prevalence of 10% (95% confidence interval: 8-12%). In conclusion, we determined that brucellosis is a prevalent yet neglected disease among this nomadic population. Brucellosis control is not possible as long as these high-risk populations remain neglected.