Detection of Brucella abortus in Chiredzi district in Zimbabwe

Abstract

Brucellosis is an endemic disease in Zimbabwe caused by the genus Brucella. Brucella seroprevalence was recently reported to be high in the wildlife-livestock interface in the Chiredzi district and the neighbouring Gonarezhou National Park (GNP) in Zimbabwe, and higher amongst communal cattle with an abortion history and access to grazing in GNP than amongst communal cattle with no abortion history or access to grazing in GNP. The aim of this study was to investigate Brucella species in brucellosis seropositive cattle in the Chiredzi district with access to GNP using isolation and identification. Isolation of Brucella species from whole blood (n = 18) and milk samples (n = 10) from seropositive animals with an abortion history was based on the rose Bengal test (RBT) and enzyme-linked immunoassays (enzyme-linked immunosorbent assay [ELISA]; indirect ELISA and complement ELISA), using microbiology and polymerase chain reaction (PCR) methods. Brucella abortus was cultured and identified from blood and milk collected from seropositive cows in both communal areas. The Brucella-specific 16-23S intergenic spacer (ITS) PCR and multiplex AMOS-PCR assays verified the identification of the cultures. Our results confirmed that B. abortus is present in cattle on communal farms in the Chiredzi district in Zimbabwe and might cause cattle abortions. The need for implementing control measures and raising public awareness on zoonotic transmission of brucellosis are recommended.