Seroprevalence of Brucella infection in small ruminants from two institutional farms and a slaughter slab in Zaria, Nigeria

Brucellosis has continued to become a disease of major economic concern in developing countries. In a study to determine the seroprevalence of brucellosis in small ruminants in Zaria, Kaduna State, Nigeria, 1036 samples comprising 768 goats from institutional farms (n=384) and a slaughter slab (n=384), and 268 sheep all from institutional farms were used. The sera samples obtained from the animals were subjected to the Modified Rose Bengal Plate Test (m-RBPT) followed by Serum Agglutination Test with ethylene diamine tetraacetic acid (SAT-EDTA) for Brucella antibodies detection. Milk samples were collected from lactating sheep and goats and subjected to the Milk Ring Test (MRT) for detection of Brucella antibodies. Results of the study revealed an overall seroprevalence rate of 6.37%, 8.90% and 12.96% for m-RBPT, SAT-EDTA and MRT, respectively. The seroprevalence in sheep and goats showed significant species difference (P < 0.05) for m-RBPT (10.05% vs 5.08%), but insignificant (P > 0.05) species difference for SAT-EDTA (9.33% vs 8.72%) and MRT (15.00% vs 11.76%) respectively. The seroprevalence in males and females showed insignificant sex difference (P > 0.05) for m-RBPT (6.59% vs 6.21%) and SAT-EDTA (7.76% vs 9.66%). On the other hand, the seroprevalence was higher in young (< 1 year old) than adult (> 1 year old) animals for SAT-EDTA (15.32% vs 8.11%). The seroprevalence in Red Sokoto, Sahel and West African Dwarf goats showed significant breed difference (P < 0.05) for m-RBPT (4.59% vs 5.55% vs 8.33%) and SAT-EDTA (6.80% vs 16.67% vs 12.50%). It was concluded that the seroprevalence of brucellosis was higher in sheep, Sahel goats and younger animals. To understand the pattern and dynamics of transmission of brucellosis in different groups of animals, there is the need for further studies to identify the Brucella species circulating in small ruminants. Keywords: Antibodies, Brucellosis, m-RBPT, SAT-EDTA, Small ruminant

Geo-spatial distribution of Brucella melitensis infection in selected local government areas of Katsina and Sokoto States, Nigeria

Brucellosis due to Brucella melitensis infects mostly small ruminants and has been reported to be the most invasive and pathogenic species for humans. A cross-sectional sero-geospatial study was conducted in 4 and 3 Local Government Areas (LGAs) of Katsina and Sokoto States, Nigeria respectively. Sera were analysed using c-ELISA while A Global Positioning System (GPS) receiver was used to take geographic coordinates of all sampling points. Data were analysed with SPSS version 20. Chi-square test was used to measure associations among categorical variables. ArcGIS 10.3 was used to map the geospatial pattern of distribution of B. melitensis. Three-dimensional analysis was also performed using the Inverse Distance Weighted (IDW) interpolation to determine the distribution pattern of B. melitensis in unsampled LGAs. Six (10.52%), 11 (20.0%), 11(2.0%) and 23 (23.0%) sera were positive from Bakori (n=57), Baure (n=56), Daura (n=55) and Funtua (n=101) LGAs of Katsina State respectively while 4 (12.5%), 1 (5.6%), 13 (14.8%) were positive from Illela (n=22), Tambuwal (n=19) and Yabo (n=90) LGAs respectively in Sokoto State were positive for B. melitensis antibodies. All the variables tested were not statistically significant (p ≤ 0.05). The geospatial maps for both States were produced to show the prevalence of B. melitensis using c-ELISA throughout the LGAs sampled and extrapolation was done for other unsampled LGAs. Small ruminants in the study areas harboured antibodies to B. melitensis. The maps may serve as an excellent tool for active surveillance and control strategies for livestock diseases like brucellosis in the study area.Keywords: Brucella melitensis, Small Ruminants, Nigeria, c-ELISA, GI