The aim of this study was to investigate the economics of damage to crops and infrastructure, injuries and loss of life at the human-elephant interface within Tsavo Conservation Area between 2010 and 2013. Data was generated from the Kenya Wildlife Service occurrence data base. A total of 488 cases with complete data were extracted. Both descriptive and inferential statistics was used in data analysis. The study established that zones with a higher incidence of conflict were proximate to the park and near main water points. Crop damage was the most (83%) prominent reason for human-elephant conflict. Others were property destruction (8%), human injuries (5%) and human deaths (4%). Crop damage occurred more often during wet seasons than dry seasons. Correlation analyses showed that the size of land was significantly associated with the value of the crop destroyed, with mean land size being 0.7 (+/- 0.99) acres. This was equivalent to 984,254 kg of crop yields over four years with an average of 246 063.71 (+/- 21 288) kg/annum. The main crop destroyed was maize, planted as a single crop. The majority (76%) of those affected were small holders with less than 0.7acres and they practiced subsistence farming. Men were the only gender killed by elephants (n=21), although both sexes were injured (n=24). In total, 40 incidents recorded damage to buildings and infrastructure. The value of crop damage, human injuries and deaths was Kenyan shillings 32,618,500 over the four year study period. It is recommended that the government should reduce human/elephant interaction in Tsavo Conservation Area by erecting an electric fence around the park, involving the community and compensating them for the entire cost of the loss incurred due to elephants from the Park. / Dissertation (MSc)--University of Pretoria, 2015. / tm2016 / Veterinary Tropical Diseases / MSc / Unrestricted

This study is a questionnaire-based, descriptive assessment of informal livestock slaughter practices by small scale farmers in Gauteng. This study aims to assess if the practice of informal slaughter poses a potential risk to public health specifically to brucellosis exposure, a disease of high seroprevalence in Gauteng and South Africa. Informal livestock slaughter from antemortem selection to carcass dressing, butchering and product preparation were descriptively assessed for potential disease exposure and resultant public health risk. This study assessed the frequency of brucellosis testing and the occurrence of livestock abortions as a possible disease indicator. Farmers were asked on the particulars of informal slaughter to ascertain if disease exposure could occur through this practice. The study made use of a questionnaire where 109 study participants were interviewed individually. Questionnaire results were compiled in Microsoft® Excel where data was analysed through descriptive statistics to identify trends and frequency data from the results. The study found that the majority of small-scale farmers participating in the study were older individuals, the majority of whom were not earning an income. It was found that study participants would slaughter livestock informally themselves or with a family member. This would occur only once or twice a year, usually for cultural or religious purposes or for a special occasion. Livestock most commonly owned and slaughtered by small-scale farmers were cattle, carriers of Brucella abortus. Participants rarely made use of adequate protective personal protective equipment (PPE) when slaughtering informally. The use of PPE and the adequacy thereof was however found to increase in frequency with participant age group. Older individuals, elders in their communities were often given the responsibility of livestock slaughter, thus providing some risk mitigation to disease exposure during the process. High risk structures such as lymph nodes and reproductive organs were handled during slaughter, the former frequently consumed with the tripe due to lack of recognition. While some organs previously found to harbour Brucella organisms were consumed raw or only exposed to short cooking times, the majority of slaughter products were exposed to prolonged cooking times, sufficient to reduce bacterial loads, reducing risk through consumption. While many participants recognised brucellosis as a zoonotic disease, the routes of transmission were poorly recognised. Exposure to Brucella spp. through informal slaughter is likely in the current environment of high brucellosis seroprevalence, poor disease control and the unreliable disease history of animals sourced for slaughter, posing a risk to public health. Should a brucella infected animal be slaughtered informally, exposure of those performing the slaughter, dressing the carcass and those involved in food preparation is likely and may lead to brucellosis. / Dissertation (MSc)--University of Pretoria, 2018. / Veterinary Tropical Diseases / MSc / Unrestricted

Rickettsia africae is a gram-negative bacterium which causes African tick bite fever (ATBF) in humans. ATBF is a febrile disease mainly affecting travellers to Southern Africa. This bacterium is known to be transmitted by Amblyomma hebraeum and Amblyomma variegatum ticks. In Southern Africa, the principal vector is A. hebraeum. This project was performed in a rural community in Mpumalanga province and aimed at addressing knowledge gaps of R. africae infection in A. hebraeum ticks. Infection rates in adult ticks and larvae as well as transovarial transmission efficiency of R. africae from the tick to its offspring were determined. To accomplish this, 106 adult A. hebraeum ticks were collected from cattle from Utah A and 106 from Welverdiend A. Larvae (n=1060) were collected by dragging at each of the two targeted dip tanks. Engorged female A. hebraeum ticks (n=53) were also collected from cattle from each of the two dip tanks and they were incubated in a humidity tank to oviposit and egg masses were collected from each tick. DNA was extracted from the engorged ticks and the egg masses as well as from the adult ticks and the larvae. After DNA quantification, a real-time quantitative PCR targeting Rickettsia gltA gene was performed to screen all samples for Rickettsia DNA. The gltA gene is common in all Rickettsia species. Samples positive for the gltA gene were subjected to conventional PCR targeting the ompA gene, which is specific for the Spotted Fever Group to which R. africae belongs. The samples positive for amplicons of ompA gene were sequenced and all the sequenced samples were found to be 99.98% identical to R. africae sequences from GenBank. From the sampled adult ticks, 13.43% tested positive for R. africae and 13.20% of the larvae also tested positive. The infection rate for larvae and adult ticks collected from Utah A was 15.09% and those from Welverdiend A was 11.79%. From these results, there were no notable differences in the infection rates of ticks at different stages of development. R. africae infection rates for the two study sites were found to be similar which can be an indication of even distribution of R. africae in this area. Transovarial transmission was found to be 100% in engorged female ticks collected from Utah and 71.43% in ticks from Welverdiend, which indicates a high transmission rate of the pathogen to the offspring of the vector. The presence of R. africae in A. hebraeum ticks from this area is a cause of concern since there are chances of people getting ATBF after bites by these ticks. / Dissertation (MSc)--University of Pretoria, 2019. / Veterinary Tropical Diseases / MSc / Unrestricted

In Mnisi, a rural community in South Africa, Rhipicephalus sanguineus is one of the most prevalent ticks found on dogs. The community lies at the wildlife/livestock/human interface where humans are at risk of tick-borne diseases. The aim of this study was to investigate the diversity of the bacterial microbiome in R. sanguineus that may impact human health. Over a 12-month period, R. sanguineus (n=1,788), Rhipicephalus simus (n=61), Rhipicephalus turanicus (n=73), Amblyomma hebraeum (n=68), Haemaphysalis leachi (n=219) and Hyalomma truncatum (n=1) ticks were collected from 64 dogs. Genomic DNA was extracted from salivary gland and midgut tissues of 62 R. sanguineus tick pools (1 pool = 10 ticks); identifications were confirmed using Cytochrome c oxidase I barcoding. The 16S rRNA gene was amplified using barcoded primers and sent for Pacific Bioscience’s circular consensus sequencing. Characterisation of the bacterial microbiome of midgut and salivary gland pools revealed a total of 260,312 sequences with Proteobacteria (85.44%) being the most prevalent phylum found; with Anaplasma (21.69%), Coxiella (12.12%) and Ehrlichia (19.94%) species dominating the microbiome. Further classification of Ehrlichia revealed 95.46% Ehrlichia canis and 4.54% Ehrlichia species Anaplasma consisted of 15.36% Anaplasma centrale, 75.82% Anaplasma platys and 8.82% Anaplasma species Phylogenetic analysis indicated that the A. centrale and A. platys clustered with various other published A. centrale and A. platys sequences, respectively. It also confirmed that all Ehrlichia species sequences detected in this study are E. canis sequences (94.46%). Furthermore, we determined that the Coxiella sequences detected in the study belong to the R. sanguineus Coxiella-like endosymbionts group. Assessment of risk factors for R. sanguineus infestation indicates that higher average monthly temperatures have a significant association with an increased risk of R. sanguineus tick infestations on dogs. Additionally, rearing chickens at the household was significantly associated with a decreased risk of R. sanguineus tick infestations on dogs. Our study indicated that R. sanguineus could be a potential reservoir for important bacterial pathogens of zoonotic importance. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2019. / Veterinary Tropical Diseases / MSc (Veterinary Science) / Unrestricted

Background and motivation Informal food vending has many benefits that range from food security for the urban poor, to contribution to local economies. Yet, the street food sector is not recognized and is treated as a major public health risk. This is based partly on perceptions of local authorities that street food vendors are undesirable, or are a temporary phenomenon that will disappear in due course as a result of development. Moreover, a number of studies have documented contamination of street foods with pathogenic microorganisms like Staphylococci aureus and enteric organisms. The former can grow and express virulence in foods such as meat and meat products post cooking. To date no participatory risk analysis methods have been applied to informal markets in Tshwane, to study the food value chain of ready-to-eat (RTE) chicken and quantify the risk of exposure to selected foodborne diseases, or to determine predictors for contamination of RTE chicken sold by informal vendors. Methodology A cross-sectional analytical study design was adopted to achieve the objectives of the present study. The study area was city of Tshwane, Gauteng Province, South Africa. The study population was informal vendors selling RTE chicken to commuters at taxi and bus stations and the sampling design involved cluster sampling. Markets were the sampling units and the informal vendors the units of concern. All clusters (n=13) that were identified were included in the study and all informal vendors located within the markets were invited to be part of the study. A total of 237 vendors agreed to be interviewed, have checklists filled in for their vending stalls, and provided a sample of RTE chicken (n= 237) for laboratory analysis. Participatory Risk Analysis, a novel approach to understanding food safety in data scarce environments, was used to collect data for analysis. Participatory research methods employed in this study included: check-lists and structured interviews with informal vendors, proportional piling and focus group discussions. Enumeration of bacterial colonies from RTE chicken samples was performed using 3MTM PetrifilmTM plates (3M, St. Paul. Mn, USA). Data for the demographic profile of vendors (n=237) was analysed using descriptive statistics to establish means and proportions. Thematic analysis combined with descriptive statistical analysis was used to establish and quantify the food value chain of informally traded RTE chicken. Stochastic risk analysis using @Risk 4.5 (Palisade Corp., Ithaca, N.Y.), was used to estimate the risk of staphylococcal food poisoning from consumption of street-vended RTE chicken. Univariable and multivariable regression models were developed using Stata 9.0 (StataCorp, College Station, Texas, USA) to determine predictors for contamination of RTE chicken with E. coli and coliform bacteria respectively. Results The majority of vendors in the markets studied were females (92%), and were between 25-50 years of age. Very few young people (< 25 years) were involved. More than half of the vendors (69.47%) ran the informal food outlet as a personal business. The minority were long term employees (15.04%) or were hired to help out for a short period of time (0.88%). A high level of literacy was observed among informal vendors. Assessment of hygiene practices showed a low level of compliance with regard to possession of a certificate of acceptance, washing of hands and utensils in the same container and controlling flies at the vending site. The environment in which informal vendors operated was not conducive to production of safe food. This means that Key 1 of the WHO five keys to safer food that requires that food production takes place in a clean environment was violated. Contamination of RTE chicken was associated with the use of water collected and supplied in containers of questionable microbiological status. This was because vendors also violated Key 5 of the WHO five keys to safer food, which requires that raw materials, including water used to prepare food should be of a high microbiological quality. However, high compliance was observed with regard to the following aspects: not wearing jewellery while preparing food, using cutlery to pick up RTE chicken, washable floors (concrete slabs and cemented floors), use of potable municipal water, preparing food in a closed structure (temporary or permanent) and locating vending stalls within 30m from the toilets. Four food value chains for RTE chicken, sold by informal vendors, were identified showing extensive cross-over from the formal to informal sector. This extensive cross-over, was corroborated by the fact that over 79.3% of the RTE chicken sold on informal markets in Tshwane metropolis, was sourced from formal markets such as supermarkets or wholesalers. The food value chain for RTE chicken was short, meaning that it involved very few stages from farm to fork. Furthermore the tendency was for the RTE chicken to be purchased, cooked and consumed the same day. Although the prevalence of contamination of RTE chicken with S. aureus was high (44%), the risk of staphylococcal food poisoning was estimated to be only 1.3% (90% CI: 0% - 2.7%) for each meal of RTE chicken consumed. The mean S. aureus counts in the RTE chicken was 103.6 (90% CI: 103.3 – 103.9). This level was lower than the 105 CFU/g needed to induce staphylococcal food poisoning. While contamination of RTE chicken with E. coli (6.32 %) was low, contamination with coliforms (23.21 %) was moderate. This suggests a moderate level of food hygiene. The fly population at the stalls where the RTE was on display, intermittent washing of hands, the location of the stall >30 m from the toilets and holding RTE chicken at <70 C were identified as important predictors of contamination with E. coli. Whereas, the use of potable toilets without hand washing facilities and poor hand washing practices were a positive predictor for contamination with coliforms. Conclusions The informal trade in food in Tshwane is dominated by women and for the majority of these vendors the informal trade in food, is the main source of employment. A risk communication strategy needs to take this into consideration. There is need for intervention to improve the hygiene in the informal markets and ensure that informal vendors observe the WHO five keys to safe food. The high level of literacy observed among informal vendors is good news, as it presents a situation of educated vendors; a fertile ground for initiatives aimed at improving their lives and the service they offer to their customers. There is neither a food policy aimed at ensuring food security for the urban poor nor evidence it is being implemented. This is supported by the high number of vendors operating in temporary structures. There is a need for the municipal authorities to intervene, to provide appropriate structures. Planning of new taxi ranks should include a proper food market, with facilities that meet the legal requirements for production of safe food. Informal vendors have demonstrated an awareness of the need to practice good food hygiene as proved by the compliance with certain hygienic food handling practices. The link between the formal and informal markets suggests that the informal market of RTE chicken is well-established with a reliable source of raw chicken. Furthermore, the strong inter-linkage between the formal and informal value chain for RTE chicken, further confirms the informal sector as a potential market for locally produced product. It also emphasizes its potential to impact on the economy of the city. In addition, this strong inter-linkage, suggests that the risks associated with the formal sector might be mirrored in the informal. Therefore, as the supermarket proliferation takes root in the rest of Africa, this food value chain and its associated risks might become the norm on the continent. The present study shows that participatory risk analysis is a good way to obtain data on informal markets. Such data can then be subjected to quantitative microbial risk analysis using sophisticated biostatistical techniques, to determine and quantify the microbial risks. The low risk of staphylococcal food poisoning proved that despite the poor working conditions under which the informal food vendors prepare food, they are able to produce food that is unlikely to result in food poisoning. However, due to the high prevalence of contamination of RTE chicken with S. aureus, there is a need for the informal vendors in these markets to be trained to improve hygienic food handling practices. On the positive side, the present study demonstrated that high prevalence of contamination does not always translate into high risk. The relatively low to moderate level of contamination with E. coli and coliforms respectively, suggests a low risk of enteric foodborne diseases from ingestion of RTE chicken. Given that some and not all hygiene practices were significantly associated with contamination of RTE chicken, monitoring authorities should emphasise identified predicators to reduce the risk of contamination and the subsequent risk of contracting foodborne diseases. The difference in hygiene scoring highlights that the one-size-fits all approach to monitoring of informal markets may not be effective. These need to be tailored to suit the individual informal markets. / Thesis (PhD)--University of Pretoria, 2015. / tm2015 / Paraclinical Sciences / PhD / Unrestricted