Meat Safety in Tanzania's Value Chain: Experiences, Explanations and Expectations in Butcheries and Eateries

A scoping review of zoonotic parasites and pathogens associated with abattoirs in Eastern Africa and recommendations for abattoirs as disease surveillance sites

Abattoirs are facilities where livestock are slaughtered and are an important aspect in the food production chain. There are several types of abattoirs, which differ in infrastructure and facilities, sanitation and PPE practices, and adherence to regulations. In each abattoir facility, worker exposure to animals and animal products increases their risk of infection from zoonotic pathogens. Backyard abattoirs and slaughter slabs have the highest risk of pathogen transmission because of substandard hygiene practices and minimal infrastructure. These abattoir conditions can often contribute to environmental contamination and may play a significant role in disease outbreaks within communities. To assess further the risk of disease, we conducted a scoping review of parasites and pathogens among livestock and human workers in abattoirs across 13 Eastern African countries, which are hotspots for zoonoses. Our search results (n = 104 articles) showed the presence of bacteria, viruses, fungi, and macroparasites (nematodes, cestodes, etc.) in cattle, goats, sheep, pigs, camels, and poultry. Most articles reported results from cattle, and the most frequent pathogen detected was Mycobacterium bovis, which causes bovine tuberculosis. Some articles included worker survey and questionnaires that suggested how the use of PPE along with proper worker training and safe animal handling practices could reduce disease risk. Based on these findings, we discuss ways to improve abattoir biosafety and increase biosurveillance for disease control and mitigation. Abattoirs are a 'catch all' for pathogens, and by surveying animals at abattoirs, health officials can determine which diseases are prevalent in different regions and which pathogens are most likely transmitted from wildlife to livestock. We suggest a regional approach to biosurveillance, which will improve testing and data gathering for enhanced disease risk mapping and forecasting. Next generation sequencing will be key in identifying a wide range of pathogens, rather than a targeted approach.

How Perspectives on Food Safety of Vendors and Consumers Translate into Food-Choice Behaviors in 6 African and Asian Countries

Background

Consumption of unsafe foods increases morbidity and mortality and is currently an issue, particularly in low- and middle-income countries. Policy actions to ensure food safety are dominated by mitigation of biological and chemical hazards through supply-side risk management, lessening the degree to which consumer perspectives of food safety are considered.

Objectives

This study aimed to provide an in-depth understanding, from vendor and consumer perspectives, of how food-safety concerns of consumers translate into their subsequent food-choice behaviors in 6 diverse low- and middle-income countries.

Methods

Six Drivers of Food Choice projects (2016-2022) provided transcripts from 17 focus group discussions and 343 interviews conducted in Ghana, Guinea, India, Kenya, Tanzania, and Vietnam. Qualitative thematic analysis was used to identify emerging themes important to food safety.

Results

The analysis suggests that consumers constructed meaning about food safety through personal lived experience and social influences. Community and family members contributed knowledge about food safety. Concerns about food safety were influenced by reputations of and relationships with food vendors. Consumers' mistrust of food vendors was amplified by purposeful adulteration or unsafe selling practices and new methods used to produce food. Moreover, consumers were reassured of food safety by positive relationships with vendors; meals cooked at home; implementation of policies and following regulations; vendor adherence to environmental sanitation and food-hygiene practices; cleanliness of vendors' appearance; and vendors' or producers' agency to use risk mitigation strategies in production, processing, and distribution of food.

Conclusions

Consumers integrated their meanings, knowledge, and concerns about food safety to achieve assurance about the safety of their foods when making food-choice decisions. The success of food-safety policies hinges on consideration of consumers' food-safety concerns in their design and implementation, alongside actions to reduce risk in food supply.

Evaluating the Spatial Risk of Bacterial Foodborne Diseases Using Vulnerability Assessment and Geographically Weighted Logistic Regression

Foodborne diseases are an increasing concern to public health; climate and socioeconomic factors influence bacterial foodborne disease outbreaks. We developed an “exposure–sensitivity–adaptability” vulnerability assessment framework to explore the spatial characteristics of multiple climatic and socioeconomic environments, and analyzed the risk of foodborne disease outbreaks in different vulnerable environments of Zhejiang Province, China. Global logistic regression (GLR) and geographically weighted logistic regression (GWLR) models were combined to quantify the influence of selected variables on regional bacterial foodborne diseases and evaluate the potential risk. GLR results suggested that temperature, total precipitation, road density, construction area proportions, and gross domestic product (GDP) were positively correlated with foodborne diseases. GWLR results indicated that the strength and significance of these relationships varied locally, and the predicted risk map revealed that the risk of foodborne diseases caused by Vibrio parahaemolyticus was higher in urban areas (60.6%) than rural areas (20.1%). Finally, distance from the coastline was negatively correlated with predicted regional risks. This study provides a spatial perspective for the relevant departments to prevent and control foodborne diseases.

Vendor Knowledge, Attitudes, and Practices Related to Food Safety in Low- and Middle-Income Countries: A Scoping Review

ABSTRACT

Foodborne diseases are a significant cause of illness in low- and middle-income countries (LMICs). Poor infrastructure, lack of regulatory oversight, and environmental conditions can increase food safety risks, particularly in traditional markets. Food vendors in traditional markets shoulder a heavy responsibility to keep food safe under often challenging conditions. The ability of these vendors to ensure food is safe is shaped by their knowledge, attitudes, and practices (KAP). Hence, understanding vendor KAP is important when designing interventions to improve food safety. To date most research on food vendors in LMICs has focused on vendors of ready-to-eat street foods and not on vendors of fresh food commodities. To fill this gap, a scoping review was undertaken to compile existing research on food safety KAP of vendors of food commodities in LMICs. PubMed, Google Scholar, Ovid Medline, and institutional Web sites of major research organizations were searched for original research articles and reports. Of 17,483 titles screened, 84 relevant studies were identified. Of the studies included, most were conducted after 2014 and focused on urban and periurban Africa. Most studies had a cross-sectional design with mixed methods (e.g., quantitative and qualitative analyses of vendor KAP through interviews and observations) and had small sample sizes (<50 participants). Common food value chains studied were dairy, meat, and fruits and vegetables. Very few studies included more than one type of commodity or value chain. Food vendor knowledge typically ranged from little to none, which was evident from observations of vendors operating under unsafe and unhygienic conditions, such as poor food handling and storage practices. Poor compliance with existing food safety policies, laws, and regulations was evident in some cases primarily due to either limited awareness of their existence or limited knowledge of how to implement them. However, vendors generally had positive attitudes toward food safety. No significant gaps were found between food safety knowledge and actual practices, although this correlation was not always examined rigorously in the reviewed studies. KAP and gaps between food safety behavior did not differ with vendor age or gender, type of product sold, or geography. Local government staff were identified as key enabling actors, interacting with food market vendors to foster improved food safety practices.

HIGHLIGHTS

Spread of Nontyphoidal Salmonella in the Beef Supply Chain in Northern Tanzania: Sensitivity in a Probabilistic Model Integrating Microbiological Data and Data from Stakeholder Interviews

East Africa is a hotspot for foodborne diseases, including infection by nontyphoidal Salmonella (NTS), a zoonotic pathogen that may originate from livestock. Urbanization and increased demand for animal protein drive intensification of livestock production and food processing, creating risks and opportunities for food safety. We built a probabilistic mathematical model, informed by prior beliefs and dedicated stakeholder interviews and microbiological research, to describe sources and prevalence of NTS along the beef supply chain in Moshi, Tanzania. The supply chain was conceptualized using a bow tie model, with terminal livestock markets as pinch point, and a forked pathway postmarket to compare traditional and emerging supply chains. NTS was detected in 36 (7.7%) of 467 samples throughout the supply chain. After combining prior belief and observational data, marginal estimates of true NTS prevalence were 4% in feces of cattle entering the beef supply and 20% in raw meat at butcheries. Based on our model and sensitivity analyses, true NTS prevalence was not significantly different between supply chains. Environmental contamination, associated with butchers and vendors, was estimated to be the most likely source of NTS in meat for human consumption. The model provides a framework for assessing the origin and propagation of NTS along meat supply chains. It can be used to inform decision making when economic factors cause changes in beef production and consumption, such as where to target interventions to reduce risks to consumers. Through sensitivity and value of information analyses, the model also helps to prioritize investment in additional research.

What Is Safe and How Much Does It Matter? Food Vendors' and Consumers' Views on Food Safety in Urban Nigeria

This study examines the food safety beliefs of vendors and consumers in a mid-sized Nigerian city using data from in-depth interviews and cognitive mapping techniques drawn from ethnography. We examine vendors' and consumers' perspectives on which foods are safe, which are not, and why; the place of foodborne illness among other health concerns and motivators of food choice; and how salient food safety is as a concern for vendors. The main perceived causes of unsafe food were found to be chemicals and insects; while bacterial illnesses were widely mentioned as a cause of gastrointestinal symptoms, these were not necessarily linked to food in consumers' minds. Respondents agreed strongly that certain foods (e.g., cowpea, beef, green leafy vegetables, and local rice) were less safe than others. The importance of food safety as a choice motivator among consumers varies depending on framing: when asked directly, it was prominent and closely related to visible cleanliness, but concerns about food safety competed in consumers' minds against other salient motivators of food and vendor choice, such as price. Most vendors did not see food safety, cleanliness, or hygiene as a key trait of a successful vendor, and just over half of vendors had any concern about the safety of their food. In conclusion, we note the implications for intervention designs, particularly the need to build upon consumers' and vendors' current beliefs and practices related to food safety in order to make foodborne disease prevention a more salient concern in food choice.

Laboratory analysis as support to slaughterhouse inspection in Songea cattle abattoir (Tanzania): A public health perspective

Livestock breeding is one of the main agricultural activities in Tanzania, recognized as one of the African countries with the greatest livestock resources. Cattle is the most widely bred animal species, especially with traditional farming methods such as pastoralism and agro-pastoralism. Slaughtering takes place mainly in rural slaughter slabs and municipal slaughterhouses, and according to local legislation it must be supervised by Official Veterinarians, who report any organs to be discarded and, after stamping the carcass, authorize its free consumption. Since the Ruvuma region lacks data on cattle diseases, the aim of this study was to collect information at Songea slaughterhouse, with particular attention to conditions of parasitic aetiology and potential zoonotic interest, deepening inspective diagnoses by means of parasitological and histological investigations on tissue samples. Overall, the slaughter data of 614 animals are reported. In most cases slaughtered cattle belonged to local breeds and came from the Mbeya region. Fasciolosis (diagnosed in 44.6% of animals) was the most frequent condition, followed by respiratory diseases (24.4%), aortic onchocerciasis (6.5%), hydatidosis (5.5%) and bovine cysticercosis (3.4%). Laboratory analysis identified Fasciola gigantica as the species involved in hepatic distomatosis in this area. Cases macroscopically ascribed to cysticercosis turned out to be a muscular form of onchocerciasis (by Onchocerca dukei), a neglected and unrecognised parasitic disease in Tanzania, questioning the real frequence of a zoonosis that causes primarily major economic losses. Pulmonary cysts, referred as hydatidosis at visual inspection, were histologically identified as haemal nodes, lymphoid organs common in ruminants, but described in cattle lungs for the first time in the present paper. Slaughterhouse is an important epidemiological observatory, especially for neglected parasitoses. The possibility of having basic laboratory diagnostics as an aid to visual inspection can ensure greater efficiency of veterinary services in the control of important livestock diseases and zoonoses, in the frame of a One Health perspective.

Quantitative versus qualitative risk assessment of meat and its products: what is feasible for Sub-Saharan African countries?

Prevalent risks in meat value-chains of sub-Saharan African (SSA) countries are increasingly attributed to microbial rather than chemical hazards. Resource constraints and lack of capacity has limited the utilization of risk assessment tools in the instituting of food controls to mitigate the risks. The review sought to bring to light the focus of risk assessment studies in SSA while generating evidence of feasible options to further the contribution of this component in risk mitigation. The informal street vending sector emerges as a priority in the meat value chain with a vendor population that are unwilling to abandon it. Campylobacter and Staphylococcus aureus are prevalent risks that have bedeviled this sector. However, limited risk assessment studies with capacity to inform proper food controls for the sector have been done. Evidence in place indicate that the incorporation of qualitative aspects in quantitative approaches serve as less-costly and effective ways of generating risk estimates. Limitations of capacity and gaps in epidemiological data are also circumvented. Considering that the street-vending sector is robust and its dynamics of operation are not fully in the picture of policy actors; incorporation of a participatory approach that combines qualitative and quantitative aspects of risk assessment is highly recommended.