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

Abstract

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, GIS