Seroprevalence and risk factors of brucellosis among slaughtered indigenous cattle, abattoir personnel and pregnant women in Ngaoundéré, Cameroon

Background: Brucellosis is a neglected debilitating zoonosis with a high prevalence in many developing countries. Bovine brucellosis is widespread in Cameroon but the epidemiological situation of human brucellosis is not known. A cross sectional study was carried to determine the seroprevalence and factors associated with bovine and human Brucellosis among abattoir personnel and pregnant women in Ngaoundéré, Cameroon. Methods: Serum sample from 590 abattoir cattle and 816 plausible occupational risk and vulnerable humans to brucellosis (107 abattoir personnel and 709 pregnant women) were collected and screened for anti-brucella antibodies using Rose Bengal Plate Test (RBPT) and ELISA tests. Structured questionnaires were used to collect data on socio-demographics and risk-factors. The differences in proportions between seropositive and seronegative reactors were tested using odds-ratio and χ2tests. Results: Bovine brucellosis seroprevalence was at 3.40% (n = 590; 3.4% for RBPT, 5.93% for i-ELISA). Human Brucella seroprevalence was at 5.6% among abattoir personnel (n = 107; 5.6% for RBPT, 12.15% for Brucella IgG ELISA) and 0.28% in pregnant women (n = 709; both tests). Breed (P < 0.00001) was associated with increased risk of brucellosis in cattle and the seroprevalence was highest among the Djafoun (OR = 16.67, 95%CI: 4.49-28.85) and Akou (OR = 16.96, 95% CI: 0.10-23.91) cattle compared to the other breeds. There was a moderate positive correlation (R2 = 0.5025) of Brucella IgG concentrations (> 200 U/ml) and clinical data for Brucella IgG ELISA seropositive humans. Several potential factors were associated (P > 0.05) with increased risk of human brucellosis seroprevalence among the abattoir personnel. The abattoir personnel were essentially males; the seropositive respondents were male and did not use protective equipment at work. Handling of foetus and uterine contents (OR = 13.00, 95%CI: 1.51-111.88) was associated with increased risk of human brucellosis. Conclusions: Antibrucella antibodies are prevalent in cattle (3.40%), among abattoir personnel (5.60%) and in pregnant women (0.28%) in Ngaoundéré, Cameroon. The study reports the first evidence of human brucellosis in Cameroon and therefore, an indication of a real public health problem. Public awareness campaigns and health education especially among livestock professional and in agropastoral communities should be highlighted to disseminate knowledge, associated risk factors and control measures of brucellosis.