Prevalence of and factors associated with <i>Brucella</i> sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Uganda

Abstract

Brucellosis is a key zoonosis of major public health, animal welfare and economic significance, and is endemic in livestock in Uganda. A cross-sectional epidemiological study was carried out to estimate the sero-prevalence of brucellosis and identify factors associated with sero-positivity in cattle in urban and peri-urban Gulu and Soroti towns of Northern and Eastern Uganda, respectively. A total of 1007 sera and data on biologically plausible risk factors from 166 herds and their spatial locations, were collected from cattle reared in urban and peri-urban Gulu and Soroti towns of Uganda. The sera were analyzed using indirect ELISA and sero-positive reactors confirmed by competitive ELISA. Multivariable models were used to investigate for risk factors. The overall animal-level and herd-level sero-prevalence was 7.5% (76/1007, 95% Confidence Interval (CI): 6.15–9.4%) and 27.1% (45/166, 95% CI: 20.9–34.3%), respectively. Herd-level sero-prevalence was significantly (P<0.001) higher in Soroti than Gulu. In Gulu town, sero-positivity increased with an increase in herd size (P=0.03) and age (P=0.002), and was higher in cattle brought in from western Uganda (P<0.0001). In Soroti town, introduction of new cattle into a herd was significantly (P=0.027) associated with herd sero-positivity. There was a geographically differential risk (clustering) of Brucella sero- positivity in herds in Soroti, while sero-positivity was homogeneously distributed in Gulu. The data highlight brucellosis occurrence and major risk factors for its transmission in cattle in urban and peri-urban areas.

Serological prevalence and public health significance of brucellosis on a dairy farm in Namibia from 2011 to 2014

“…Brucellosis is a zoonosis of major public health, animal welfare and economic significance [1]. It is endemic in most African countries [2].…”

“…It is endemic in most African countries [2]. A number of biovars of Brucella abortus , B. melitensis and B. suis are responsible for the disease in domestic animals [1] and zoonotic disease. Brucella abortus and B. melitensis are common causes of brucellosis in cattle, sheep and goats respectively [3].…”

“…The economic significance of brucellosis results from production losses associated with abortions, mastitis, milk fever, retained placenta, metritis, impaired fertility and arthritis [1]. Milk production losses in infected dairy cows can be up to 20% and the inter-calving period can be prolonged by several months [2].…”

A Review on Epidemiology and Public Health Importance of Brucellosis with Special Reference to Sudd Wetland Region South Sudan

“…Other risk factors include interactions with wildlife, communal grazing and introduction of asymptomatic infected animals into a herd (Diaz et al, 2013). In Gulu and Soroti towns of Uganda prevalences of individual animal-and herd-level were 7.5% (76/1007, 95% CI: 6.15 -9.4%) and 27.1% (45/166, 95% CI: 20.9% 34.3%), respectively (Mugizi et al, 2015).…”

“…It depends on the animals' natural resistance, age, sex, level of immunity and environmental stress (Ahmed, 2009). Adult animals are highly susceptible to and both sexes become infected with brucellosis (Ibrahim, 1990) and that large herd size and age of cattle had a significant association with brucellosis seropositivity (Mugizi et al, 2015). Apart from humans, cattle, sheep and goats, deers, elks, dogs and pigs (CDC, 2002), brucellosis also affects camels (Teshome et al, 2003;Hegazy et al, 2004).…”