Original Articles Seroprevalence and Risk Factors for Brucellosis in a High-Risk Group of Individuals in Bangladesh A.K.M. Anisur Rahman, 1–3 Berkvens Dirk, 2 David Fretin, 4 Claude Saegerman, 3 Muzahed Uddin Ahmed, 1 Noor Muhammad, 5 Akram Hossain, 5 and Emmanuel Abatih 2 Abstract Brucellosis is an occupational hazard of livestock farmers, dairy workers, veterinarians, slaughterhouse workers, and laboratory personnel, all of whom are considered to belong to the high-risk occupational group (HROG). A study was undertaken to determine the seroprevalence of brucellosis, identify risk factors associated with brucellosis seropositivity, and detect Brucella at genus level using real-time polymerase chain reaction (PCR) among people in the HROG in the Dhaka division of Bangladesh. A sample of 500 individuals from the HROG was collected from three districts of Dhaka division of Bangladesh. A multiple random effects logistic regression model was used to identify potential risk factors. Two types of real-time PCR methods were applied to detect Brucella genus–specific DNA using serum from seropositive patients. The prevalence of brucellosis based on the three tests was observed to be 4.4% based on a parallel interpretation. The results of the multiple random effects logistic regression analysis with random intercept for district revealed that the odds of brucellosis seropositivity among individuals who had been in contact with livestock for more than 26 years was about 14 times higher as compared to those who had less than 5 years of contact with livestock. In addition, when the contact was with goats, the odds of brucellosis seropositivity were about 60 times higher as compared to when contact was with cattle only. Noticeable variation in brucellosis seropositivity among humans within the three districts was noted. All of the 13 individuals who tested positive for the serological tests were also positive in two types of real-time PCR using the same serum samples. Livestock farmers of brucellosis positive herds had a significantly higher probability to be seropositive for brucellosis. The study emphasized that contact with livestock, especially goats, is a significant risk factor for the transmission of brucellosis among individuals in the HROG. Introduction B rucellosis is an occupational hazard of livestock farmers, dairy workers, veterinarians, slaughterhouse workers, and laboratory personnel, all of whom are consid- ered to belong to the high-risk occupational group (HROG). It is caused by bacteria of the genus Brucella, which mani- fests in different variants in different animal species. For ex- ample, Brucella abortus is mostly associated with cattle and B. melitensis with sheep, goats, and humans (Pappas et al., 2005). Infection can be acquired through ingestion of unpas- teurized dairy products such as soft cheeses, yogurts, and ice creams. However, direct contact with infected animals and contact with vaginal discharge, urine, feces, or blood of infected animals (especially among abattoir workers, herds- men, veterinarians, butchers, and personnel in microbio- logic laboratories) is an important transmission route. Also, Brucella can be transmitted through skin lesions and the mucous membrane of conjunctiva, and by inhalation of infected aerosolized particles (Wise, 1980; Young, 1983; Pappas, 2005). Human brucellosis remains the commonest zoonotic dis- ease worldwide, with more than 500,000 new cases reported annually (Pappas et al., 2006). It is associated with a chronic debilitating infection with substantial residual disabilities. The onset of the disease may be sudden, over a period of a few days, gradual, over a period of weeks to months, or associated with non-specific symptoms that include undulating fever, 1 Department of Medicine, Bangladesh Agricultural University, Mymensingh, Bangladesh. 2 Unit of Epidemiology, Department of Animal Health, Institute of Tropical Medicine, Antwerpen, Belgium. 3 Research Unit of Epidemiology and Risk Analysis applied to the Veterinary Sciences (UREAR), Department of Infectious and Parasitic Diseases, Faculty of Veterinary Medicine, University of Lie `ge, Lie `ge, Belgium. 4 Department of Bacteriology and Immunology, Veterinary and Agrochemical Research Centre, Brussels, Belgium. 5 Department of Microbiology, Mymensingh Medical College, Mymensingh, Bangladesh. FOODBORNE PATHOGENS AND DISEASE Volume 9, Number 3, 2012 ª Mary Ann Liebert, Inc. DOI: 10.1089/fpd.2011.1029 190