Maintenance of foot and mouth disease viruses in buffalo (Syncerus caffer Sparrman, 1779) in southern Africa.

African buffalo were introduced into a wildlife conservancy in the southeast of Zimbabwe in an effortto increase the conservancy's economic viability, which is primarily based on eco-tourism. The buffalo were infected with SAT serotypes (SAT-1, SAT-2 and SAT-3) of foot and mouth disease (FMD) virus, and in order to isolate the conservancy and prevent the transmission of FMD to adjacent populations of domestic livestock, the conservancy was surrounded by a double-fence system, 1.8 m in height. The intention was to prevent the movement of both wildlife and domestic animals across the perimeter. However, two years after the buffalo were introduced, FMD occurred in cattle farmed just outside of the conservancy. Using serological and molecular diagnostic tests, epidemiological investigations showed that it was most likely that antelope (impala or kudu), infected through contact with the buffalo herd within the conservancy, had jumped over the fence and transmitted the virus to the cattle.

A serologic survey of blue wildebeest (Connochaetes taurinus Burchell) and African buffalo (Syncerus caffer Sparrman) in the Masai Mara area was conducted. Antibodies to Brucella spp. were found in 18% of the blue wildebeest and 30% of the African buffalo examined. There were titers in all age groups and in both sexes. Hygromata were seen in both species. The increase in numbers of blue wildebeest and African buffalo which share grazing and watering areas with cattle of the Masai people, makes the presence of infections by Brucella spp. in wildlife an important consideration in any program for control of brucellosis.

Six of the seven serotypes of foot and mouth disease (FMD) virus (i.e. all but Asia 1) are prevalent in Africa although there are marked regional differences in distribution. Three of these serotypes are unique to Africa, namely the three South African Territories (SAT) serotypes. Serotype C may also now be confined to Africa because it has not been reported elsewhere recently. In southern Africa at least, the SAT serotypes have an intimate and probably ancient association with African buffalo (Syncerus caffer) that is instrumental in their maintenance. Within each of the six prevalent serotypes, with the possible exception of C, there are a number of different lineages with more or less defined distributions (i.e. topotypes) that in some cases are sufficiently immunologically different from one another to require specific vaccines to ensure efficient control. This immunological diversity in prevalent serotypes and topotypes, in addition to uncontrolled animal movement in most parts of the continent, render FMD difficult to control in present circumstances. This fact, together with poorly developed intercontinental trade in animals and animal products has resulted in the control of FMD being afforded a low priority in most parts of the continent, although the northern and southern regions of the continent are an exception. As a consequence, eradication of FMD from Africa as a whole is not a prospect within the foreseeable future. In southern Africa, the use of fencing and other means to strictly control the movement of wildlife and livestock as well as judicious application of vaccine has resulted in countries of the region being able to access beef and other livestock markets in Europe and elsewhere in the developed world. Significant marketing of livestock and livestock products from Africa outside the continent is unlikely to be achieved unless similar approaches can be developed for other regions of Africa. This will result in continuing under-exploitation of a valuable resource in the arid and semi-arid regions of Africa, with increasing marginalisation of human populations living there.

Genetic characterisation of two pathogens, namely foot and mouth disease (FMD) virus and Mycobacterium bovis, isolated from African buffalo (Syncerus caffer) in southern Africa was used to determine the origin of buffalo in situations where the source of infection was obscure. By determining the phylogenetic relatedness of various FMD virus isolates using partial sequencing of the main antigenic determinant, VP1, the origin of buffalo moved illegally to the non-endemic region of South Africa was traced to the Kruger National Park (KNP) where FMD is endemic in the buffalo population. Comparative analysis of the 'genetic fingerprints' of bovine tuberculosis isolates from buffalo and cattle has aided in tracing the original source of infection of buffalo populations in the KNP. Furthermore, these analyses have assisted in tracing the origin of infected animals that have been moved to other parts of South Africa.

Here, we report the results of a cross-sectional study designed to monitor the circulation and genetic diversity of foot and mouth disease virus (FMDV) in Uganda between 2014 and 2017. In this study, 13,614 sera and 2,068 oral-pharyngeal fluid samples were collected from cattle and analysed to determine FMDV seroprevalence, circulating serotypes and their phylogenetic relationships. Circulation of FMDV was evidenced by the detection of antibodies against non-structural proteins of FMDV or viral isolations in all districts sampled in Uganda. Sequence analysis revealed the presence of FMDV serotypes A, O, SAT 1 and SAT 2. FMDVs belonging to serotype O, isolated from 21 districts, were the most prevalent and were classified into six lineages within two East African topotypes, namely EA-1 and EA-2. Serotype A viruses belonging to the Africa G-I topotype were isolated from two districts. SAT 1 viruses grouped within topotypes I and IV and SAT 2 viruses within topotypes VII, IV and X were isolated from six and four districts respectively. Phylogenetic analysis of SAT 1 and SAT 2 sequences from cattle clustered with historical sequences from African buffalo, indicating possible interspecies transmission at the wildlife-livestock interface. In some cases, Uganda viruses also shared similarities to viral strains recovered from other regions in East Africa. This 3-year study period provides knowledge about the geographical distribution of FMDV serotypes isolated in Uganda and insights into the genetic diversity of the multiple serotypes circulating in the country. Knowledge of circulating FMDV viruses will assist in antigenic matching studies to devise improved FMDV control strategies with vaccination and vaccine strain selection for Uganda.

The number of African buffaloes (Syncerus caffer Sparrman, 1779) inhabiting Ruaha National Park, Tanzania, is thought to be declining, but little data exist to determine whether the population is actually in decline. As an initial phase of collecting population data, we conducted demographic surveys, faecal egg counts and gastrointestinal parasite identification in Ruaha's buffalo herds in September 2011 and 2013. Most herds encountered in the two surveys appeared to be in good health, but with fewer calves in 2013 compared with 2011. The herd‐level body condition score was positively associated with the number of calves per 100 cows after adjusting for year, and the lower number of offspring in 2013 could possibly be associated with a below average rainfall in the 2012–2013 rainy season. Mean herd‐level egg counts ranged from 83 to 140 and from 28 to 113 eggs per g faeces in 2011 and 2013, respectively. Haemonchus, Nematodirus, Cooperia and Oesophagostomum spp., as well as coccidian oocysts, were detected in the population. Monitoring herd demographics and baseline health parameters over time will provide insight into population performance, increase the understanding of population stressors and contribute to buffalo conservation within Ruaha National Park and other protected areas of Africa.

Molecular characterization of circulating Foot and mouth disease virus (FMDV) serotype O topotype EA-3 and serotype A (African topotype) genotype IV in Egypt, 2016

Foot-and-mouth disease (FMD) inflicts severe economic losses within infected countries and is arguably the most important trade-restricting livestock disease in the world. In southern Africa, infected African buffaloes (Syncerus caffer) are the major reservoir of the South African Territories (SAT) types of the virus. With the progressive expansion of transfrontier conservation areas (TFCAs), the risk of FMD outbreaks is expected to increase due to a higher probability of buffalo/livestock contacts. To investigate the dynamics of FMD within and around the Great Limpopo TFCA (GLTFCA), 5 herds of buffaloes were sampled in June 2010 to characterize circulating viruses in South Africa and Zimbabwe. Three SAT-2 and three SAT-3 viral strains were isolated in both countries, including one that was genetically linked with a recent SAT-2 outbreak in Mozambique in 2011. In addition, two groups of unvaccinated cattle (n = 192) were serologically monitored for 1 year at the wildlife/livestock interface of Gonarezhou National Park (GNP) in Zimbabwe between April 2009 and January 2010, using the liquid-phase blocking ELISA (LPBE) and a test for antibodies directed against non-structural proteins (NSP). Neither clinical signs nor vaccination of cattle were reported during the study, yet a high proportion of the monitored cattle showed antibody responses against SAT-3 and SAT-1. Antibodies against NSP were also detected in 10% of the monitored cattle. The results of this study suggest that cattle grazing in areas adjacent to the GLTFCA can be infected by buffalo or other infected livestock and that cattle trade movements can act as efficient disseminators of FMD viruses to areas several hundred kilometres from the virus source. Current methods of surveillance of FMD at the GLTFCA interface seem insufficient to control for FMD emergence and dissemination and require urgent reassessment and regional coordination.

A preliminary study on the distribution of the African buffalo (Syncerus caffer) was conducted in 2014 in the Didessa River Valley of the upper Blue Nile in western Ethiopia, to confirm the presence of buffaloes and other co-existing wildlives in the area, which the government considers for settlement and investment because of unconfirmed wildlife distribution. Buffaloes were located by tracking their expected ranges in the upper Blue Nile Valley and each location was marked using GPS, and superimposed on the known range of buffaloes. The result showed that the present distribution of buffaloes is further extended from their known ranges. Moreover, the presence of several other wildlife species in the study area was also been confirmed, and the new distribution range map for buffaloes was generated. The current range of African buffaloes is the last green space left in the upper Blue Nile Valley for wildlife conservation, for which urgent conservation actions are necessary.

This study examines the population biology of African buffalo (Syncerus caffer Sparrman) at Hluhluwe-iMfolozi Park (HiP), South Africa. An analysis of buffalo census data covering the period from 1956 to 2006 shows that the population has a moderate intrinsic growth rate at around 12% per annum, which is similar to growth rates of buffalo populations measured elsewhere. The population is subject to density dependence when the number of buffalo in the park exceeds approximately 3500 animals. In most years over the past 25 years, the population has exceeded this threshold, and net annual population growth has averaged around 5%. Periods of buffalo population decline always coincided with heavy buffalo removals, suggesting limited resilience of the population to such disturbances. Demographic data from 826 buffalo in 12 herds, captured in 2001–2002, were used to parameterize an age-structured buffalo population model. The model yields an annual population growth rate of 4.05%, similar to recent growth estimates from buffalo censuses at HiP. The predicted stable age distribution is very similar to the age distribution observed in the captured population sample. Elasticity analysis of the model indicates that population growth in buffalo is most sensitive to adult and juvenile survival, and less sensitive to recruitment parameters and survival of old animals. Buffalo populations might therefore be expected to be more vulnerable to mortality factors affecting prime-aged adults than those affecting juveniles or senescent individuals.

Teneral Glossina morsitans centralis Machado were fed on the flanks of the African buffalo (Syncerus caffer Sparrman), N'Dama (Bos taurus L.) or Boran (Bos indicus L.) cattle infected with Trypanosoma congolense Broden. The infected tsetse were maintained on rabbits and on day 30 after the infected feed, the surviving tsetse were dissected to determine the infection rates. The mean infection rates (% +/- SE) in the midgut of tsetse fed on buffalo, N'Damas and Borans were 23.5 +/- 3.3, 31.6 +/- 2.7 and 33.7 +/- 4.6, respectively. The differences were not significant. However, the mean mature infection rate in tsetse fed on the buffalo (13.2 +/- 2.1%) was significantly lower compared to the rates in tsetse fed on the N'Dama (20.4 +/- 1.4) or the Boran cattle (21.4 +/- 1.1). When groups of teneral G.m.centralis, G.pallidipes Austen, G.p.gambiensis Vanderplank, G.f.fuscipes Newstead, G.brevipalpis Newstead and G.longipennis Corti were fed simultaneously on either an infected buffalo, an N'Dama or a Boran steer, the mature infection rates ranged from 0 to 16.1%. Irrespective of the host species used, the T.congolense infection rate was highest in G.m.centralis, lowest in the palpalis and fusca group tsetse, with G.pallidipes being intermediate. Nevertheless, the trypanoresistant African buffalo and N'Dama may serve as reservoirs of T.congolense as can trypanosusceptible Boran cattle.

An investigation of population structure and ecology of the African buffalo (Syncerus caffer Sparrman, 1779) was carried out in the Chebera Churchura National Park, Ethiopia during the wet and dry seasons of 2005–2006. Sample counts of African buffaloes were carried out in an area of 1,215 km2. The estimated population of buffalo was 2,617 individuals. Males comprised 35.0%, while females 52.8% of the population. The remaining 12% of the population was young of both sexes and of all ages of unknown sex. It was difficult to categorize the young into male and female in the field, as their primary sexual characteristics were not easily visible. Male to female sex ratio was 1.00 : 1.51. Age structure was dominated by adults, which constituted 72.06% of the total population. Subadults comprised 22.02%, and young accounted for 5.9% of the population. Larger herds of up to 27 individuals were observed during the wet season and smaller herds of eight individuals during the dry season. The mean herd size during wet and dry seasons was 24.81 and 7.77, respectively. The African buffaloes were distributed in four habitat types such as grasslands, woodlands, montane forests and riverine habitat in the study area. They were observed more in the riverine vegetation types during the dry season. Relative abundance of food resources, green vegetation cover and water availability in the area were the major factors governing their distribution in the present study area. They spent a greater proportion of the time in feeding and resting/ruminating activities. On the average, 49.7% of the daytime was spent in feeding, and 38.75% of the day on resting (lying down and standing). Morning and the late afternoon activity peaks were more pronounced during the dry season than the wet season.

Context The processes regulating ungulate populations have been the focus of numerous studies. For the African buffalo (Syncerus caffer Sparrman) population inhabiting the Mara–Serengeti ecosystem, rinderpest was the primary regulatory factor up to the mid-1960s. Following reduction of rinderpest and buffalo population increase, interspecific competition for food, notably with cattle and wildebeest (Connochaetes taurinus Burchell), was thought to be the primary regulatory factor in the ecosystem. Aims We analysed buffalo population trends and the relationship between buffalo population growth and rainfall and density dependence in the Mara–Serengeti ecosystem and discuss the findings in the context of the key ecosystem processes governing buffalo population dynamics in African savannas, namely, food limitation, competition, predation, disease and land use changes. Methods We analysed buffalo population dynamics in the Mara–Serengeti ecosystem in relation to rainfall and density dependence feedback between 1984 and 2010. Key results Buffalo population growth was both significantly density-dependent and positively correlated with the dry season rainfall after, but not before, a severe drought in 1993. Buffalo numbers crashed by 48.6% in 1984–85 and by 76.1% in 1993–94 during severe droughts when food availability was lowest and competition with the more numerous cattle and wildebeest was highest. Conclusions Recovery of buffalo numbers to pre-drought levels took 8–9 years after the 1984–85 drought but was much slower, with buffaloes numbering merely 36% of their 1993 population (12 895 animals) 18 years after the 1993–94 drought despite intermittent periods of high rainfall, probably due to demographic and/or reproductive factors, heightened competition with livestock, land use changes in the adjoining pastoral ranches, lion predation and recurrent severe droughts. Implications Our findings demonstrate how food limitation caused by droughts associated with the hemispheric El Niño–Southern Oscillation can cause severe declines in and threaten the persistence of large ungulate populations. The findings also portray how density-dependent food limitation, competition, predation, land use changes and other factors can accentuate the effect of droughts and greatly prolong population recovery.

Documenting within species group size variation is important to completely understand social organization within species and to interpret variation among species. Here, I investigated group size of African buffalo Syncerus caffer over 2 years in a heterogeneous landscape. African buffalo use closed continuous forest and vast open savannas, and anecdotal observations suggest that habitat type influences their social structure. While the Cape buffalo Syncerus caffer caffer is well studied, few data exist for the forest‐dwelling Syncerus caffer nanus. I observed forest buffalo at Lopé National Park, Gabon, and examined variation of group size. Eighteen forest buffalo herds used the study area with an estimated population of 342 individuals (∼5 buffalo km−2). The mean group size for the 18 herds was 12 ± 2 (range of means=3–24), considerably smaller than Cape buffalo herds. For eight radiocollared forest buffalo, the mean group size was stable, varying little with time of day, across seasons, or between savanna and marsh habitat. However, herd size varied widely across herds, from fewer than 10 individuals in the smallest herds to more than 20 buffalo in the largest. Large herd size is associated with home ranges that contain substantial areas of open habitat, and thus more food resources than forested habitats.

BackgroundBovine tuberculosis (BTB) is a zoonotic disease of global importance endemic in African buffalo (Syncerus caffer) in sub-Saharan Africa. Zoonotic tuberculosis is a disease of global importance, accounting for over 12,000 deaths annually. Cattle affected with BTB have been proposed as a model for the study of human tuberculosis, more closely resembling the localization and progression of lesions in controlled studies than murine models. If disease in African buffalo progresses similarly to experimentally infected cattle, they may serve as a model, both for human tuberculosis and cattle BTB, in a natural environment.Methodology/Principal findingsWe utilized a herd of African buffalo that were captured, fitted with radio collars, and tested for BTB twice annually during a 4-year-cohort study. At the end of the project, BTB positive buffalo were culled, and necropsies performed. Here we describe the pathologic progression of BTB over time in African buffalo, utilizing gross and histological methods. We found that BTB in buffalo follows a pattern of infection like that seen in experimental studies of cattle. BTB localizes to the lymph nodes of the respiratory tract first, beginning with the retropharyngeal and tracheobronchial lymph nodes, gradually increasing in lymph nodes affected over time. At 36 months, rate of spread to additional lymph nodes sharply increases. The lung lesions follow a similar pattern, progressing slowly, then accelerating their progression at 36 months post infection. Lastly, a genetic marker that correlated to risk of M. bovis infection in previous studies was marginally associated with BTB progression. Buffalo with at least one risk allele at this locus tended to progress faster, with more lung necrosis.Conclusions/SignificanceThe progression of disease in the African buffalo mirrors the progression found in experimental cattle models, offering insight into BTB and the interaction with its host in the context of naturally varying environments, host, and pathogen populations.