Cheryl Myra Ethelwyn McCrindle

Toxoplasma in Animals, Food, and Humans: An Old Parasite of New Concern

All hosts, including humans, can be infected by any one of the three forms of the parasite Toxoplasma gondii that correspond to three morphological stages: tachyzoite, bradyzoite, and sporozoite form. Felids are definitive hosts for T. gondii, which is an intracellular pathogen that infects a wide range of warm-blooded intermediate hosts. Toxoplasmosis is a disease where the interest of the diverse medical and veterinary specialties converge. Awareness needs to be increased that toxoplasmosis can induce clinical disease not only in immunocompromised patients or through congenital infections, but also in healthy patients. This is a review article that aims at illustrating why toxoplasmosis should be regarded a veterinary public health issue and how veterinary practitioners can contribute in controlling the infection.

Peracute vanadium toxicity in cattle grazing near a vanadium mine

Animals may act as bioindicators for potential human health problems associated with mining and refining. Eight cattle died after a vanadium mine dam collapsed close to the area in which they were grazing. Necropsies were conducted on five cattle. Affected animals had shown a watery bloody diarrhea, red urine and listlessness before collapsing. On necropsy (n = 5) there was a moderate bilateral multifocal granulomatous-like conjunctivitis. The most prominent lesions were eosinophillic granulomatous-like inflammation of the thymus, mediastinal and mesenteric lymph nodes, oesophagus, abomasum and colon. There was also marked hyperaemia of the abomasal mucosa with petechiation. Pulmonary and tracheal haemorrhage was also present. Histopathology showed severe inflammatory cell infiltration (mainly eosinophils with lesser numbers of neutrophils and macrophages) of lymphoid tissue associated with the thymus, lymph nodes, esophagus, abomasum, colon and conjunctiva. There were also areas of tissue necrosis, congested blood vessels and haemorrhage. Conjunctival lesions point to a systemic rather than a local effect as the cattle in this case died following ingestion rather than inhalation of vanadium. The causal relationship between intoxication and death is conventionally based on the level of that toxin present in tissues at necropsy. The variability in demonstrating vanadium in biological samples may have been due to the rapid excretion of vanadium by the living animal, or the solubility of the salts, which results in the substance leaching into the fluid portion of the samples. Cross-reactions with colorimetric tests for arsenic should also be noted.

Cattle Farming at the Wildlife/Livestock Interface: Assessment of Costs and Benefits Adjacent to Kruger National Park, South Africa

This study examined the extent and magnitude of cattle loss to wildlife depredation and diseases and also considered the benefits from the park for households adjacent to Kruger National Park. Data were from interviews with 540 randomly sampled households, inspection of records, and focus-group discussions. Households in villages close to the park reported higher incidence of livestock depredation (32%) than those further from the park (13%). Livestock diseases described by farmers included foot-and-mouth and heartwater. A partial budget was used to compare costs incurred and benefits derived by households. Mean annual costs of wildlife/livestock interactions, taking into account benefits associated with proximity to the park, averaged US

Animals in Books Used for Preschool Children

34 per household. Farmers viewed wildlife as an obstacle to cattle farming. Mechanisms to reduce effects of wildlife damages and increase livelihood benefits of coexistence with wildlife for households and the community are suggested.

Orf in South Africa: Endemic but neglected

AbstractChildrens literature has been considered a tool of socialization. It is likely that the way in which animal protagonists appear in books for young children could influence later attitudes. The aim of this study is to investigate books from preschools in high and low-income areas in South Africa, in order to analyze animal content and frequency of animal books chosen by the children. The method was to categorize the books (n=2259) according to format, genre and subject. The animal characters were divided into the categories realistic, humanized, anthropomorphic and fantasy.The results show that the most commonly encountered format was that of picture books (77.3%). The genre most frequently encountered was realistic fiction (43.2%) and non-fiction information (30.0%). In 44.5% of books animal characters were central to the plot. The most popular books were realistic fiction where anthropomorphistic or fantasy animals were the main protagonists. Preschool children from low-income areas where illite...

Changing Roles of Dogs in Urban African Society: A South African Perspective

A survey amongst sheep and goat producers and veterinarians was undertaken to collect epidemiological data on orf in South Africa. Previous epidemiological studies on the presence of the disease in the country have not been documented and this report is the first descriptive epidemiological study of orf in South Africa. A seven-month investigation, realised by direct and indirect interviews and field observation, enabled us to outline incidence and risk factors of this disease and to better understand how the local farmers in rural areas relate to it. The results may contribute to better management of the disease in rural areas. By means of molecular analyses the phylogenetic relationships between field isolates from different areas have been identified. The findings gave a first important contribution to the general assessment of the economic impact of orf virus infections and the extent of the risk to human health.

Optimal feeding systems for small-scale dairy herds in the North West Province, South Africa

ABSTRACTIn Southern Africa domesticated dogs date back to the Iron Age (circa 1430 BP). Mainly of the sight hound type, they were traditionally used for hunting. In some more pastoral societies they played a role in guarding stock. Dogs were expected to forage for food and there was no control over breeding. Today South Africa has a large urban population and the interactions between humans and dogs have changed. A survey of households (n= 871) in Soweto, a densely populated urban area in Gauteng, was conducted using a structured interview and non-participant observation. There was a dog/human ratio of 1:12.4 or 0.42 dogs per household. This is not remarkably different from dog populations in urban areas elsewhere in the world. Dogs were kept for personal security, as companions, for guarding property and to keep feral cats away. The problems respondents had with dogs included strays in the road and in their yards, fighting, killing chickens, noise, biting children, faecal contamination of public places, ...

Copper, manganese, cobalt and selenium concentrations in liver samples from African buffalo (Syncerus caffer) in the Kruger National Park.

Land redistribution was legislated in 1994; it was designed to resolve historical imbalances inland ownership in South Africa. Between 2002 and 2006, a longitudinal observational studywas conducted with 15 purposively selected small-scale dairy farmers in a land redistributionproject in Central North West Province. Four farmers left the project over the period. For thepurposes of this study, a small-scale dairy farm was defined as a farm that produces less than500 L of milk a day, irrespective of the number of cows or size of the farm. The study wasconducted in three phases. In the first phase, situational analysis using participatory ruralappraisal (PRA) and observation was used to outline the extent of the constraints and designappropriate interventions. Feeds that were used were tested and evaluated. In the secondphase, three different feeding systems were designed from the data obtained from PRA. Thesewere: (1) A semi-intensive farm-based ration using available crops, pastures and crop residueswith minimal rations purchased. (2) An intensive, zero-grazing dairy system using a totalmixed ration. (3) A traditional, extensive or dual-purpose system, where the calf drank fromthe cow until weaning and milking was done only once a day. In the third phase, adoptionwas monitored. By July 2006, all remaining farmers had changed to commercially formulatedrations or licks and the body condition score of the cows had improved. It was concluded thatveterinary extension based on PRA and a holistic systems approach was a good option forsuch complex problems. Mentoring by commercial dairy farmers, veterinary and extensionservices appeared to be viable. Further research should be done to optimise the traditionalmodel of dairy farming, as this was relatively profitable, had a lower risk and was less labourintensive.

Designing a risk communication strategy for health hazards posed by traditional slaughter of goats in Tshwane, South Africa.

Animals may act as bio-indicators for the pollution of soil, air and water. In order to monitor changes over time, a baseline status should be established for a particular species in a particular area. The concentration of minerals in soil is a poor indicator of mineral uptake by plants and thus their availability to animals. The chemical composition of body tissue, particularly the liver, is a better reflection of the dietary status of domestic and wild animals. Normal values for copper, manganese and cobalt in the liver have been established for cattle but not for African buffalo. As part of the bovine tuberculosis (BTB) monitoring programme in the Kruger National Park (KNP) in South Africa, 660 buffalo were culled. Livers (n = 311) were randomly sampled in buffered formalin for mineral analysis. The highest concentrations of copper were measured in the northern and central parts of the KNP, which is downwind of mining and refining activities. Manganese, cobalt and selenium levels in liver samples indicated neither excess nor deficiency; however, there were some significant area, age and gender differences. The results will be useful as a baseline reference when monitoring variations in the level and extent of mineral pollution on natural pastures close to mines and refineries.

Assessment of the Occupational Health and Food Safety Risks Associated with the Traditional Slaughter and Consumption of Goats in Gauteng, South Africa

In African societies, traditional slaughter is linked to celebrations like weddings or births, as well as funerals and ancestor veneration. Participants in traditional slaughter of goats are at risk of exposure to hazards during slaughter, food preparation and consumption of goat meat. For risk mitigation strategies to be implemented, identification of the population at risk is required. This study is based on the premise that the demographic profile of people involved in traditional slaughter of goats is important for risk communication. Both structured and informal interviews were recorded and analysed using a thematic analysis. A total of 105 people were interviewed at taxi ranks in Tshwane, Gauteng. Of these, 48 were women and 57 men. The median age of women and men was 40.6 years and 44.3 years, respectively. The majority of respondents (61.9%, n = 65) interviewed were from the Gauteng Province. Sixty percent (n = 63) of respondents had a secondary education, whilst less than 4.81% (n = 5) of respondents had no formal education. This study demonstrated that interviewing commuters at taxi ranks gave access to a cross section of gender, age, language and origin. It was found that both genders were involved in traditional slaughter of goats. Risk communication strategies should thus target women as well as men. Communication strategies to mitigate the risks of traditional slaughter of goats should take into consideration the dynamic nature of demographic and cultural norms. In light of the wide demographic profile of the respondents, it was concluded that it should be possible to use taxi ranks for successful dissemination of food safety and occupational health risk mitigation messages.