Study on Seroprevalence and Associated Factors of Bovine Brucellosis in Selected Districts of Afar National Regional State, Afar, Ethiopia

Abstract

Bovine brucellosis is among the top five diseases primarily threatening both public health and livestock economy. Available data are limited to central and highland areas of the country leaving documented literature on the disease in cattle to be found hardly in pastoral and agropastoral regions of the country. As a result, the magnitude and extent of the disease remained to be investigated. A cross-sectional study design was conducted on local Afar cattle aged six months and above from February 2017 to January 2019 in selected districts of Afar region. Technically, study districts and kebeles were selected purposively whereas simple random sampling technique was applied to select cattle owners and individual animals for sample collection. An average of 8 ml whole blood was drawn of jugular vein into plain vacutainer tube using sterile needle. Using Thrusfield formula, a total of 420 blood samples were collected. The sera were tested by RBPT and CFT tests for detection of Brucella antibodies. Data were analyzed using Stata v14.0. Of the 420 sera tested by RBPT, 50 were positive for Brucella antibodies providing an overall animal level prevalence of 11.9% and those RBPT positive sera were further retested by specific and sensitive confirmatory CFT test and 24 of the retested samples had come positive for the disease providing an overall individual animal seroprevalence of 5.7% over the three districts. Of the 3 associated factors (sex, age, and district) considered, only sex had significantly associated ( P < 0.05 : 0.036 ) with the disease. To estimate the strength of sex impact, odds ratio was generated using bivariate and multivariate logistic regression analyses with 95% CI and P < 0.05 providing OR of 2.484 (1.061–5.815) and 2.514 (1.041–6.07), respectively. Hence, the computations revealed that male cattle were 2.484 and 2.514 times more likely at higher risk for the disease as compared to their female counterparts.

Cross-Sectional Study of Seroprevalence and Associated Risk Factors of Bovine Brucellosis in Selected Districts of Jimma Zone, South Western Oromia, Ethiopia

“…In comparison with this finding, the relatively lower seroprevalence of 1.7%, 0.2%, and 1.04% were reported by Tschopp et al [ 60 ] in Arsi zone, Bashitu et al [ 19 ] in Debrebirhan and Ambo Towns, and Tadesse et al [ 61 ] in Becho District, South West Shewa, respectively. However, higher seroprevalence reports were made by Megersa et al [ 62 ] (10.6%) in Borena zone and Negash and Dubie [ 63 ] (5.7%) in Afar region. Similarly, relatively higher results of seroprevalence were reported in other African countries; Matope et al [ 64 ] with 5.6% in Zimbabwe, Mensah et al [ 65 ] with 21.9% in Ghana, and Mai et al [ 66 ] with 24.0% in Nigeria.…”

Bovine Brucellosis and Its Public Health Significance in Ethiopia

“…Another cross-sectional study in the Jimma Zone, Oromia Region, has reported an animal and herd level cattle prevalence of 16.4% and 4.3%, respectively [64]. Very recent studies have also recorded a prevalence of 11.9% and 22.5% in Afar National Regional State and East Wollega, Oromia Region, respectively [14,17].…”

“…Bovine brucellosis in Ethiopia is endemic and widely distributed in urban, peri-urban, highlands= and lowland areas with extensive and intensive farming, as well as smallholder farms and ranches in the country. It has caused high economic losses and is becoming a serious public health threat [14,46,47].…”

“…For the past two decades, bovine brucellosis serological studies reported by various researchers have indicated that the disease is endemic and widespread (Table 1). However, the prevalence of bovine brucellosis varies among farms and areas (Fig 2 ), and this seropositive prevalence may be due to natural infection, because of the absence of a brucellosis prevention and control vaccination history in Ethiopia [14,25].…”

“…In the past decade, several bovine brucellosis serological surveys conducted in Ethiopia have shown the endemic and widespread characteristics of the disease. Between 2010 and 2021, seroprevalence studies conducted on bovine brucellosis in Ethiopia have reported prevalence rates ranging from 0.4% to 11.9% at the individual animal level [12][13][14], and 12% to 63.6% at the herd level [15][16][17]. Most previous studies have been performed in central Ethiopia on institutionally owned commercial, large and medium scale dairy farms, situated in Addis Ababa and its surrounding area [18].…”