Survey of brucellosis at the wildlife–livestock interface on the Zimbabwean side of the Great Limpopo Transfrontier Conservation Area

Abstract

A cross-sectional study was conducted to determine the seroprevalence of bovine brucellosis in communal cattle and wildlife at a wildlife-livestock interface in the southeast lowveld of Zimbabwe, part of the Great Limpopo Transfrontier Conservation Area. RBT and c-Elisa were used in serial for detection of antibodies against Brucella spp. Between July 2007 and October 2009, a total of 1,158 cattle were tested and the overall seroprevalence of brucellosis was 9.9%. A total of 97 wild animals (African buffaloes (n=47), impala (n=33), kudu (n=16), and giraffe (n=1)) were tested and only one animal (giraffe) was seropositive for brucellosis (1.03%). Brucella seroprevalence showed an increasing trend with age, with adult cattle (>6 years) recording the highest seroprevalence (11.1%), but the differences were not statistically significant. Similarly, female cattle recorded a relatively higher seroprevalence (10.8%) compared to males (7.9%), but the difference was not significant. However, a significant (P<0.001) association between Brucella seropositivity and abortion history was recorded in female cattle. Similarly, Brucella seropositivity was significantly (P<0.01) associated with a history of grazing in the park for female cattle. Overall, from the interface area, cattle with a history of grazing in the park recorded a significantly (P<0.01) higher Brucella seroprevalence (13.5%) compared to those with no history of grazing in the park (4.9%). The significant association between abortion history and seropositivity observed in this study illustrates the potential economic significance of Brucella in cattle in this area. Hence, public awareness and further epidemiological studies of the disease in wildlife, livestock, and humans in the study area are of great importance.

Buffalo, Bush Meat, and the Zoonotic Threat of Brucellosis in Botswana

“…Others have found Brucella antibody positive giraffe despite a similarly limited number of giraffe evaluated [22]. The clinical significance of this finding is unknown as is the potential for diagnostic cross-reactions with other brucellosis strains, including the possibility that there is an unknown giraffe-specific strain.…”

Relationship between burden of infection in ungulate populations and wildlife/livestock interfaces

“…However, brucellosis was detected in all cattle populations except at the fenced interface [27,44]. The absence of brucellosis in buffalo is counter-intuitive and could be explained by: (1) some cattle-herding strategies such as cattle kraaling at night which could reduce the potential for buffalo getting infected from abortion products left in the environment by cattle; (2) a possible isolation of the buffalo population in GNP from other infected buffalo populations such as the KNP buffalo population, more than 40 km away on the other side of the Sengwe communal land; however, this hypothesis seems to contradict the hypothesis of a spread of bTB from KNP to GNP across the Limpopo River; (3) a small buffalo sample size that would fail to detect a low prevalence in buffalo.…”

Detection of Brucella abortus DNA in aborted goats and sheep in Egypt by real-time PCR

“…B. abortus infections have been reported in sheep in the USA [21], in Nigeria [22, 23] and in Iran [24]. The protective efficacy of vaccines against B. abortus infections has not been studied in small ruminants and may play a role for the persistence of brucellosis in cattle [1, 25, 26]. In Egypt, B. abortus bv one and three have been reported in cattle and buffaloes [12, 27].…”