Brucellosis in the Brazilian Pantanal wetland: threat to animal production and wildlife conservation

This review was performed to gather knowledge about brucellosis in livestock and wildlife in the Brazilian Pantanal, a biome with a huge biodiversity and extensive livestock production. Following the preferred reporting items for narrative review guidelines and using the terms "Brucella" and "Pantanal," we explored the PubMed, SciELO, Jstor, Science Direct, and Scholar Google databases. Information on host species, diagnostic test, number of positive animals, and positivity rates were acquired. Articles dating from 1998 to 2022 registered 14 studies including cattle, dogs, and the following wildlife species: Ozotoceros bezoarticus, Sus scrofa, Tayassu peccari, Nasua nasua, Cerdocyon thous, Panthera onca, Dasypus novemcintus, Cabassous unicinctus, Euphractus sexcinctus, Priodontes maximus, Myrmecophaga tridactyla and Hydrochoerus hydrochaeris. Brucella occurrence in cattle was demonstrated through the serological confirmatory test 2-mercaptoetanol. Molecular diagnosis detected Brucella abortus in dogs, smooth Brucella in O. beoarticus, and Brucella spp. in T. peccari. Cattle may have a pivotal importance in maintenance and spreading of Brucella spp. due to their high population density, environmental contamination from abortion of infected cows, and eventual excretion of B. abortus S19 strain from vaccinated heifers. The occurrence of Brucella spp. in O. bezoarticus and T. peccari represent a risk for wildlife conservation. These data indicate that Brucella spp. are enzootic in the Pantanal wetland, sustained by a reservoir system including domestic and wild mammals. Due to marked seasonality and large populations of wildlife species sharing same environments with livestock, brucellosis acquires great complexity in Pantanal and, therefore, must be analyzed considering both animal production and conservation.

Knowledge, attitudes and practices on African tick bite fever of rural livestock communities living in a livestock-wildlife interface area in the Eastern Cape Province of South Africa

BACKGROUND

African tick bite fever (ATBF) caused by Rickettsia africae and transmitted by Amblyomma spp. ticks is one of the zoonotic tick-borne fevers from the spotted fever group (SFG) of rickettsiae, which is an emerging global health concern. There is paucity of information regarding the occurrence and awareness of the disease in endemic rural livestock farming communities living in livestock-wildlife interface areas in South Africa.

METHODS

The purpose of the study was to assess the level of knowledge, attitudes and practices on ticks and ATBF infection from a community living in livestock-wildlife interface areas in South Africa. A focus group discussion (FGD) was carried out followed by verbal administration of a standardized semi-structured questionnaire a month later to 38 rural livestock farmers (23 from Caquba area and 15 from Lucingweni area where A. hebraeum was absent). An FGD was conducted in Caquba (situated at the livestock-wildlife interface where Amblyomma hebraeum was prevalent on cattle and infected with Rickettsia africae) in the O.R. Tambo district of the Eastern Cape province of South Africa.

RESULTS

Results from the FGD and questionnaire survey showed that participants from the two rural communities were not aware of ATBF and were not aware that ticks are vectors of the disease. Respondents from Caquba reported of having frequent exposure to tick bites (91.3%, 21/23) specifically from the anthropophilic A. hebrauem which they were able to identify as Qwelagqibe in IsiXhosa (their vernacular). Thirteen out of 15 (86.7%) of respondents from Lucingweni reported that they had never been bitten by ticks, which corresponded with the absence of A. hebraeum from their locality as evidenced from results of a concurrent study on prevalence of ticks on livestock in the area. Both communities confirmed to being "very concerned" of tick bites and we presume this was more related to the localized wounds from the bites than to the diseases transmitted by the ticks.

CONCLUSIONS

We recommend future studies encompassing seroprevalence of ATBF in Caquba and other communities at risk in South Africa including establishing surveillance systems to monitor the seasonal infection rates in ticks, cattle and humans.

Brucella seroprevalence in cattle near a wildlife reserve in Kenya

OBJECTIVES

Brucellosis is caused by bacteria from the genus Brucella which infect human and domestic animals as well as wildlife. The Maasai Mara National Reserve has vast populations of wild ruminants such as buffaloes and wildebeest which could contribute to the risk of brucellosis in livestock, and the surrounding pastoralist communities grazing cattle in and around the reserve may be exposed to a higher risk of zoonotic diseases like brucellosis due to the close contact with livestock. In this study, cattle from three villages at varying distance from the reserve, were screened for antibodies against Brucella abortus.

RESULTS

In total, 12.44% of 225 sampled animals were seropositive, with more females (15%) infected than males (5%). Seroprevalence was higher in livestock closer to Maasai Mara with the cattle in the village Mara Rianta having an odds ratio of 7.03 compared to Endoinyo Narasha further away (95% CI 1.4-11.1, p = 0.003), suggesting that a closer contact with wildlife may increase the circulation of infectious diseases between livestock and wildlife. Symptoms consistent with brucellosis were reported to occur in both humans and animals, and we thus conclude that brucellosis may be an important problem, both for the health and the economy.