A risk assessment was conducted for Salmonella enteritidis (SE) in the broiler production chain of the Western Cape of South Africa, using a literature review, historical data analysis, microbiological sampling from abattoirs and questionnaire responses. A questionnaire to characterise the risk pathway in the broiler chain was developed based on a review of the literature. Spatio-temporal analysis was conducted using historical data of reported SE outbreaks. The data showed spatio-temporal clustering, however, the analysis was not correct for groups of farms that form part of the same organisation. Neck skin samples were collected from five abattoirs and tested for salmonella. In total, 499 samples were collected, representing 46 broiler farms of which nine (20%) were positive. Salmonella positive cultures (2.81%) were serotyped. No SE was identified during the study. The questionnaire was completed for all stages of the broiler production chain. Significant risk factors were found using univariate analysis (Odds Ratio,OR). The significant risk factors identified by OR were further analysed using principal component analysis (PCA). The factors moving with or opposing, farm positivity were analysed using logistic regression and one layer farm was found to be a significant factor. The farms receiving eggs or chicks from that layer farm had a number of factors that were found to be significant using OR and therefore the presence of this layer farm could be a representation of these factors at the broiler farm level. SE was not identified in the samples collected from abattoirs, a number of other non-typhoidal Salmonella subspecies enterica were isolated. Given the high rates of immunosuppressive diseases within the South African population, it is important for broiler producers to be aware of the zoonotic potential of non-typhoidal Salmonella and continually improve their control measures. / Dissertation (MSc)--University of Pretoria, 2018. / Veterinary Tropical Diseases / MSc / Unrestricted

In the Bushbuckridge Local Municipality (BLM), Mpumalanga, the size and economic importance of the local, mostly informal, cattle trade has been considered negligible to date by local policy makers. Opportunities for the local cattle farmers to access formal live or product markets remain severely limited, mainly as a result of movement restrictions associated with foot-and-mouth disease (FMD) control. Data, in the form of movement permits and monthly cattle registers were used to analyse movement and trade activity in the area over a four-year period (May 2015 - April 2019). The population fluctuated around 77 166 head of cattle, distributed between 9739 emerging rural livestock farmers. The proportion of animals/products moved ranged between 3.1 and 7.2 percent (0.04 ± 0.02). Movements were found to be highly seasonal (p < 0.001) with the ‘cool dry’ season (April-July) being the most active. Most movements consisted of live cattle which were herded to their destinations. The vast majority of trade did not leave Bushbuckridge and was informal in nature. Farmers moved animals and products much further to access formal markets (p < 0.001) than informal markets, and generally required use of motorised transport to do so. The FMD outbreak of 2017 did not prove detrimental to the local cattle industry in the medium term. However, distinct changes to the overall Bushbuckridge herd dynamics were noted, with small scale farmers most severely affected. As a direct result of the heightened movement restrictions in this period, an estimated 96% of formal trade; 85% of informal trade, and 54% of local trade were lost. In 2018, an improvement in cattle prices stimulated farmers to access the formal marketplace, and an increase in the proportion of the cattle population moved was observed. It was concluded that farmers pursue formal marketing options only when financially incentivised or pressurised by adverse conditions such as environmental factors or disease outbreaks. Growing established local markets is likely the best way to assist the local population with market access, development and poverty reduction. The key constraints to marketability of animals/products originating in the BLM were identified as the absence of a competitive market system and associated infrastructure such as FMD designated abattoirs, disease control regulations, poor carcass quality, and seasonality of offtakes. These limitations will need to be considered when policy decisions are made. Context-specific solutions should be generated to address local needs and effectively support development of a sustainable cattle trade going forward. / Mini Dissertation (MSc (Tropical Animal Health))--University of Pretoria, 2019. / Veterinary Tropical Diseases / MSc (Tropical Animal Health) / Unrestricted

African swine fever (ASF) has been reported and confirmed in South Africa since the early 20th century, which lead to the inception of the Swine Fever control zone in 1935. In the South African context, the sylvatic cycle is the main maintenance and transmission cycle that leads to sporadic outbreaks in the domestic pig population, particularly reported in the designated ASF control area. ASF is endemic in sub-Saharan Africa and maintains itself through three different epidemiological cycles in different regions of the continent. The current outbreaks in the Caucasus and Russia have shown the ability of African swine fever virus (ASFV) to establish itself where low biosecurity conditions exist. In South Africa, the spread of ASF has been successfully controlled in the domestic pig populations with control based on the Animal Disease Act 35 of 1984. The act prohibits the movement of all suid species and their products from the ASF control area in the north, except where special permission has been granted by the Provincial Veterinary Services. One of the key uncertainties related to climate change is potential variations in the weather patterns and fluctuations in climatic conditions that could lead to alterations in production systems and land use patterns. These in turn raise the possibility of redistribution of both the arthropod vectors and wild suids to environmentally suitable areas. It is therefore critical for the zoning of ASF that patterns of distribution of the reservoir hosts are monitored in line with the possible variations in the weather patterns around and along the ASF control line. Nonetheless, there are no known records of the reassessment of the swine fever control line, which was instituted based on the distribution of previous outbreaks and the presence of warthogs and tampans, since its inception in 1935. The objective of this study was to evaluate the distribution of the ASF disease determinants; warthogs and warthog burrows, Ornithodoros moubata and ASFV; along the ASF control line with the view of determining whether there was a need to re-align the trajectory of the line or not. A total of 304 farms were randomly selected 20 km north and 20 km south of the ASF control line from the North West, Gauteng, Limpopo and Mpumalanga Provinces through proportional weighting. A total of 73 farms from the initial sample, distributed along the ASF control line, were sampled for the presence of warthogs, warthog burrows and soft ticks of the Ornithodoros spp. (tampans). One hundred and fifty seven warthog burrows were found, of which 92% were recently used by warthogs. Tampans were recovered from 22.2% of the 63 farms where warthog burrows were found and 12.74% of the total (157) warthog burrows. Of the infested warthog burrows, only 5% (one of the twenty burrows) constituting 7.14% (one out of 14 farms) found south but in close proximity to the ASF control line, was positive for ASFV DNA. There were no warthog burrows found with PCR positive tampans north of the ASF control line. The spread of tampans beyond the ASF control line poses a question on whether the control line needs to be moved further south in the affected parts of the country. The study confirmed that the reservoirs are found beyond the current ASF control line. Although the causes for this apparent re-distribution are unclear, changes in land use and the increase in wildlife farming may contribute to this finding. Examination of weather data along the control line between 1993 and 2012 found the maximum temperatures was increasing and humidity is decreasing. In the absence of previous data on warthog and tampan distribution along the control line, the present study cannot evaluate if these changes have had an impact on the distribution of warthogs and tampans in the vicinity of the control line. This study provides baseline data for future monitoring of the control line and concluded that there was currently no need to realign the trajectory of the ASF disease control line but to conduct scheduled monitoring of the O. moubata status in the future. / Dissertation (MSc)--University of Pretoria, 2015. / tm2015 / Production Animal Studies / MSc / Unrestricted

In rural areas of developing countries like South Africa, people typically depend on goat farming for both meat and milk production due to the shortage of grazing and the higher maintenance cost of cattle. An understanding of the functionality of the mammary gland and subsequent drug transport into milk are important factors in determining milk withdrawal periods and drug residues in milk intended for human consumption. Tight cellular monolayers, cultured to resemble the in vivo blood-milk-barrier, are used to evaluate the transepithelial transport of drugs into milk in vitro. The aim of this study was to culture and maintain tight monolayers of primary Boer goat mammary epithelial cells that would be a barrier to paracellular drug movement. Cells were cultured and maintained similarly to the method described by Pantschenko and colleagues (2000), with some adaptations and with MCF10a as growth medium. The formation of tight barriers was evaluated by measuring transepithelial electrical resistance (TEER) and the paracellular movement of dextran-FITC. An aggregated monolayer was established which had the characteristic cobblestone appearance, typical of epithelial cells, with no fibroblasts seen microscopically. On day 11 the monolayers appeared to be confluent under microscopic examination, they presented a significant barrier to the movement of FD70 dextran (Papp = 0.001), and the transepithelial electrical resistance (TEER) was greater than 200 ?.cm2. At day 18 of culture, macroscopically the cells started to stack and cell debris formed, presumably due to overgrowing and cell differentiation, and the monolayers were no longer appropriate for use. Furthermore, cryopreservation techniques were performed on the cells and these cells were frozen, stored, and regrown as viable epithelial cells. Primary Boer goat mammary epithelial cells, cultured and maintained using the methods described in this dissertation, form tight monolayers that are a significant barrier to the paracellular movement of relatively large molecules like dextran70, with TEER values appropriate for xenobiotic transcellular flux studies between day 11 and 18 of culture. This timeframe corresponds with the time in which drug transfer studies are typically done in cell cultures from other species. Viable cryopreservation of Boer goat mammary epithelial cells is a useful tool that can be used to enhance these studies. / Dissertation (MSc)--University of Pretoria, 2015. / tm2016 / Paraclinical Sciences / MSc

Emerging small-scale pig farmers in Limpopo province perceive pig production and management as an important means of improving their livelihood and alternative investment option for the future. Their performance has not been optimal due to the lack of practical understanding of the basics of animal production, biosecurity and efficient production system. Thus, an attempt was made to evaluate the challenges and constrains of pig farm production systems identified and reported by emerging small scale pig farmers (ESSPF) in the province. In addition, the risk factors associated with pig movement by ESSPF by means of spatio-temporal analysis was evaluated. The study revealed that the average number of sows/farm was 7.4, while the number of boars/farm was 1.7. On average, the number of days that the sows take to return to oestrus from weaning was 42.9 days while the number of piglet s weaned/sow/year was 4.85 pigs. Also the study showed that 98.77% of ESSPF don t vaccinate their breeding stock against major pig diseases and only 2.47% ESSPF farmers had previously benefited from the infrastructure programme of the department referred to as Comprehensive Agricultural Support Programme (CASP). The majority of the respondents (82.61%) will prefer to sell their pigs at local points and within communities and only 9.32% and 14.09% will sell at the auctions or formal abattoir/supermarkets respectively. It is therefore recommended CASP be evaluated to reach and impact more pig farmers positively. Good animal husbandry and transfer of knowledge by the veterinary officials is central to the growth of farmers and their productivity. The provision of regional slaughter facilities will reduce the travelling costs to Bronkhorstspruit and Belfast, but also reduce the likelihood of the disease spread within or outside the province. The involvement of different stakeholders should be encouraged to ensure ESSPF are trained, mentored, coached, with the aim of improving their livelihood, food security and safety. / Limpopo provinsie is n belangrike vark produseerende gebied met n groot populasie van huishoudelike en wilde diere. Om die rede dien dit as n interfase tussen huishoudelike diere, mense en wilde diere.Alhoewel opkomende varkboere in die provinsie die produksie en bestuur as n belangrike verbetering in hul lewensbestaan asook alternatiewe finansiële beleggingsopsies vir die toekoms beskou, is hul prestasie nie optimaal nie as gevolg van die gebrek aan praktiese begrip van die basiese beginsels van diereproduksie, biosekuriteit en doeltreffende produksie stelsels. Dus, is 'n poging aangewend om die uitdagings en beperkings van varkplaas produksiestelsels te ïdentifiseer en die opkomende kleinskaalse varkboere (ESSPF) in die provinsie te evalueer. Bykomend is die risikofaktore wat verband hou met vark beweging deur ESSPF deur middel van tydruimtelike analise ontleed. Die studie het getoon dat die gemiddelde aantal sôe per plaas was 7,4 terwyl die aantal bere per plaas 1,7 was. Die sôe neem gemiddeld 42,9 dae om terug te keer na estrus vanaf speen, terwyl die aantal varkies gespeen / sog / jaar is 4,85 varkies. Die studie het ook getoon dat 98,77% van ESSPF nie hul teeldiere ent teen die hoof vark siektes en slegs 2,47% ESSPF boere het voorheen voordeel getrek uit die program infrastruktuur van die departement verwys na as omvattende landbou?ondersteuningsprogram (CASP). Die meerderheid van die respondente (82,61%) verkies om hul varke by plaaslike punte binne gemeenskappe te verkoop en slegs 9,32% en 14,09% onderskeidelik verkoop by veilings of formele slagpale/ supermarkte. Dit word dus aanbeveel dat CASP herevalueer om n positiewe impak te bereik by meer varkboere. Goeie veeteelt en die oordrag van kennis deur die veeartseny?amptenare is sentraal tot die groei van die boere en hul produktiwiteit. Die voorsiening van plaaslike slaggeriewe sal die reiskoste na Bronkhorstspruit en Belfast (beide buite die provinsie en tans gekiesde slagpale van die ESSPF) verminder, maar ook die waarskynlikheid van die verspreiding van siektes binne of buite die provinsie verminder. Die betrokkenheid van die verskillende belanghebbendes moet aangemoedig word om te verseker ESSPF opgelei word, gementor, afgerig, met die doel om van die verbetering van hul lewensbestaan, voedselsekuriteit en veiligheid. / Dissertation (MMedVet)--University of Pretoria, 2015. / tm2016 / Production Animal Studies / MMedVet

Despite the occurrence of S. Typhimurium infections, little is known on the genetic diversity, virulence characteristics and antimicrobial resistance profiles of poultry S. Typhimurium in South Africa. Therefore, S. Typhimurium (n=141) isolated from organs (n=115) and environments (n=26) of diseased poultry between 1995 and 2002 were screened by PCR for bacteriophages, plasmids and Salmonella pathogenicity islands (SPIs) - encoded virulence genes (virulotyping) which are essential for invasion (invA, sopB, gtgB, sspH1, sopE, spvC, and pefA), survival (sifA, gipA, sodC1, gtgE, mig5, and sspH2) and serum killing (rck, and srgA) of the pathogen in the host. Isolates were also characterized by: pulsed field gel electrophoresis (PFGE) for genetic relatedness, and plasmid profiling (n=43). Furthermore, isolates (n=141) were tested for susceptibility to 16 antimicrobials by disk diffusion and further screened by PCR for the carriage of 27 resistance genes, and integrons. Multi-resistant S. Typhimurium definitive phage type (DT) 104 were determined by disk diffusion and confirmed by PCR. All isolates carried SPIs-encoded genes: invA, sopB, and sifA. Bacteriophages-encoded genes (sspH2, sspH1, sodC1, gtgB, and gtgE) occurred in more than 74.5% of the isolates expect for gipA (57.6%), and sopE (19%). The occurrence of plasmid-encoded genes (pefA, mig5, rck, spvC, and srgA) ranged from 48.2% to 74.5%. Two sample t - test showed that virulence genes: gtgB, spvC, gipA, gtgE, mig5, rck and srgA were more frequent (p ? 0.05) in S. Typhimurium isolates from environments. Virulotyping clustered 141 isolates into 59 virulotypes with 97 isolates clustering in 5 predominant virulotypes while 44 were single isolate virulotypes. PFGE grouped 140 isolates into 55 pulsotypes with 66 isolates clustering in 5 major pulsotypes, 51 isolates clustering in small pulsotypes (containing less than 5 isolates) while 33 were single isolate pulsotypes. Ten plasmid profiles ranging from 2kb to 90kb were observed. The most common plasmid profile contained the 90kb plasmid and was observed in 12/43 isolates. Major virulotypes and plasmid profiles corresponded approximately to pulsotypes and clustered isolates recovered from the same farms or during the same period. Virulotyping and PFGE showed identical discriminatory index (D=0.93). Multidrug resistance (resistance to ? 2 antimicrobials) was observed in 97.2% of isolates. High levels of resistance phenotypes and their respective resistance genes were observed for: streptomycin (94.3%) conferred by ant3'Ia (60.3%) and str (50.4%), sulphonamides (87.2%) conferred by sul1 (66%) and sul3 (31.9%), ciprofloxacin (79.4%) conferred by qnrA (79.4%), tetracycline (61%) conferred by tetB (35.5%) and tetG (28.4%), and cefotaxime (55.3%) conferred by blaSHV (57.4%). Two sample t - test revealed that isolates from poultry organs were more resistant (p?0.05) to ampicillin, amoxicillin clavulanic acid, chloramphenicol, tetracycline and sulfamethoxazole - trimethoprim while isolates collected from poultry environments were more resistant to cephalothin, cefotaxime, ceftazidime, colistin sulphate and nalidixic acid. Using the Kappa statistics, there were agreements ranging from good to perfect between phenotype and genotype. In addition, for every phenotypic resistance recorded, at least one corresponding resistance gene was detected. DT104 strains and class1 integrons were observed in 34.7% and 83% of the isolates respectively. Multi-resistant S. Typhimurium (97.2%) also carried SPIs - encoded virulence genes involved in invasion and survival in the host. In addition, more than 50% of resistant isolates to each of the antimicrobials also carried at least 12 virulence genes: invA, sopB, sifA, sspH2, sspH1, sodC1, gtgB, gtgE, pefA, mig5, spvC, and srgA. A significant number (44.9%) of the DT104 strains that were clustered in the same pulsotype X25 also belonged to virulotype V3a which contained 13 virulence genes: invA, sopB, sifA, sspH2, sspH1, sodC1, gtgB, gtgE, pefA, rck, mig5, spvC, and srgA. Most of isolates that belonged to the same antimicrobial resistance profile (phenotype and genotype) carried at least 8 common virulence genes. In conclusion, these data indicate that S. Typhimurium isolated from diseased poultry carry virulence genes that are usually incriminated in Salmonella human outbreaks. Virulotyping and PFGE showed the same discriminatory index (D=0.93) indicating that virulotyping can be an alternative subtyping method in laboratories where PFGE is not available. Salmonella Typhimurium are also genetically diverse since they were recovered from multiple farms and during a period spanning 8 years. Furthermore, isolates were resistant to multiple antimicrobials used in poultry operations (streptomycin, sulphonamides, and tetracycline) and those used to treat human salmonellosis: ciprofloxacin, and cefotaxime. Multidrug resistant isolates carried most of virulence genes. This relationship between virulence and antimicrobial resistance suggests that the adaptation of isolates against antimicrobial effects may induce expression of virulence factors. The increasing incidence of DT104 threatens the public health since DT104 strains are associated with hospitalizations and deaths in humans. Salmonella Typhimurium carried mobile genetic elements (bacteriophages, integrons and plasmids) which pose a public hazard as they propagate virulence and resistance genes with emerging new pathogenic bacteria as a result. Therefore, monitoring and surveillance of salmonellosis and prudent antimicrobials use need more efforts to ensure animal health and food safety for consumers in South Africa. / Dissertation (MSc)--University of Pretoria, 2016. / Paraclinical Sciences / MSc / Unrestricted

Introduction: Campylobacter spp. is the most frequent cause of bacterial gastroenteritis in humans globally. Campylobacter spp. infections are characterized by acute watery or bloody diarrhoea, fever, weight loss and abdominal cramps. Campylobacteriosis complications include extra-intestinal diseases such as Guillain-Barre Syndrome (GBS) or its variant the Miller Fisher Syndrome (MFS). Consumption of contaminated foods of animal origin including undercooked meat, contaminated dairy products has been associated with foodborne campylobacteriosis in humans. Cattle are considered an important reservoir of Campylobacter spp. and a source of foodborne Campylobacteriosis. Antimicrobial treatment failure in most bacterial infections including campylobacteriosis has emerged and led to the increase of animal and human health care costs. The use of antimicrobials in cattle for therapy in both cattle and humans and for growth promotion in exerts selective pressure on bacterial pathogens, which may result in the emergence of antimicrobial resistant Campylobacter spp. strains which can be transferred from animals to humans along the food chain or through contact between animals and humans. In South Africa, studies on the occurrence and antimicrobial resistance profiles of Campylobacter spp. of public health importance are lacking. The main objectives of this study were to: 1) investigate the occurrence of Campylobacter spp. in beef cattle on cow-calf operations in Gauteng and North West Provinces and 2) determine the antimicrobial resistance profiles of Campylobacter spp. isolates. The overall aim of the study was to contribute to monitoring and surveillance of Campylobacter spp. of public health importance in South Africa. Methodology: A total of 537 fresh faecal samples from beef cattle consisting of 453 from adult cows and 102 from calves were collected on 5 cow-calf operations in Gauteng and North West provinces. The samples were screened for Campylobacter spp., including C. jejuni subsp. jejuni, C. coli and C. upsaliensis by culture and the polymerase chain reaction (PCR). Furthermore, 86 Campylobacter spp. isolates consisting of 46 C. jejuni subs. jejuni, 24 C. coli and 16 C. upsaliensis were tested for antimicrobial resistance against a panel of nine antimicrobial agents including azithromycin, ciprofloxacin, erythromycin, gentamicin, tetracycline, florfenicol, nalidixic acid, telithromycin and clindamycin by the broth microdilution method. Results: Out the 537 cattle faecal samples tested in this study, PCR revealed that 29.4% (158/537) [16.23%-42.57%] 95%CI of cattle carried Campylobacter spp. Among the 158 Campylobacter spp. positive cattle, 62.6% (99/158) carried C. jejuni subsp. jejuni, 25.3% (40/158) C. coli, 10.1% (16/158) C. upsaliensis and 3.1% (5/158) cows that had mixed infections. Three cows harbored both C. jejuni and C. coli, one cow carried C. jejuni and C. upsaliensis and one cow carried both C. coli and C. upsaliensis. Further antimicrobial resistance profiling of 86 Campylobacter spp. isolates (46 C. jejuni isolates, 24 C. coli and 16 C. upsaliensis) by the broth microdilution method revealed that the highest resistance rates for clindamycin (36%), nalidixic acid (19.7%), tetracycline (18.6%) and erythromycin (17.4%). However, lower resistance rates against florfenicol (3.4%), gentamicin (4.6%), telithromycin and ciprofloxacin (5.8%) were observed. The isolates were multidrug resistant against tetracycline/clindamycin, erythromycin/tetracycline/clindamycin, and nalidixic acid/clindamycin. Conclusion: Little is known about the occurrence rates of Campylobacter spp. in beef cattle in South Africa. The prevalence of Campylobacter recorded in this study was consistent with various studies that have reported Campylobacter spp. prevalence rates within the same range in cattle in a number of countries with C. jejuni subsp. jejuni as the most predominant species. Campylobacter spp. isolates were mainly resistant to clindamycin, nalidixic acid and tetracycline. Findings from this study highlight the importance of beef cattle as a reservoir and a potential source of clinically relevant and antimicrobial resistant Campylobacter spp. isolates in South Africa. / Dissertation (MSc)--University of Pretoria, 2018. / Paraclinical Sciences / MSc / Unrestricted

Access to international and regional markets for beef has been an on-going problem for southern African countries for many decades because the South African Territories (SAT) serotypes of foot and mouth disease (FMD) viruses are endemic to wildlife populations in the southern African region. This makes establishment of FMD-free zones, essential for accessing high-value beef markets difficult, expensive and impractical for many locations in southern Africa. For that reason commercialization of livestock production in the region has been inhibited. The creation of FMD-free zones which requires use of artificial or natural boundaries and in southern Africa it has been the construction of veterinary cordon fences (VCFs) to separate animal populations of different FMD status which has proven successful in some countries (such as Botswana, Namibia & South Africa) but not in others for a variety of reasons, i.e. the current model has only been possible for a small proportion of cattle producers in southern Africa. This means that apart from the damaging effects that some VCFs have had or have on the environment generally and wildlife conservation in particular, only roughly 15% of the cattle population in the mainland countries of the Southern African Development Community (SADC) are raised in FMD-free zones. For balanced rural development of the SADC Region, where cattle are culturally and economically vital to the indigenous inhabitants and wildlife conservation and associated economic activities are important contributors to regional gross domestic product, it is essential to improve access to regional and international markets for beef and other animal products produced in locations outside FMD-free zones. The World Organisation for Animal Health (OIE) has introduced a partially non-geographic FMD standard for trade in deboned beef (viz. Terrestrial Animal Health Code Article 8.8.22) that potentially overcomes this problem; however, Article 8.8.22 contains at least one killer requirement that makes its implementation impossible. The issues associated with this problem have been identified in this study and possible solutions proposed. An attempt was made to gauge acceptance by SADC Member States but the responses to the questionnaire used were inadequate to reach a reliable conclusion in this respect. It was concluded that taking technical, logistical and financial constraints into account, non-geographic approaches represent the best opportunity that SADC countries have of expanding access to regional and international markets. Moreover, it is suggested that non-geographic approaches could be integrated into the Standard Methods and Procedures in Animal Health (SMP-AH) Programme once adopted by SADC, thereby strengthening the capacity of the Region s competent authorities. SMP-AH Programme is at a proposal stage and has not been officially launched in SADC. The SMP AH Programme proposes to harmonize activities of animal health authorities of SADC Member States in respect of selected diseases that impact trade and/or human health. / Dissertation (MSc)--University of Pretoria, 2015. / tm2016 / Veterinary Tropical Diseases / MSc

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