The spatial ecology of free-ranging domestic pigs (Sus scrofa) in western Kenya

Background In many parts of the developing world, pigs are kept under low-input systems where they roam freely to scavenge food. These systems allow poor farmers the opportunity to enter into livestock keeping without large capital investments. This, combined with a growing demand for pork, especially in urban areas, has led to an increase in the number of small-holder farmers keeping free range pigs as a commercial enterprise. Despite the benefits which pig production can bring to a household, keeping pigs under a free range system increases the risk of the pig acquiring diseases, either production-limiting or zoonotic in nature. This study used Global Positioning System (GPS) technology to track free range domestic pigs in rural western Kenya, in order to understand their movement patterns and interactions with elements of the peri-domestic environment. Results We found that these pigs travel an average of 4,340 m in a 12 hr period and had a mean home range of 10,343 m2 (range 2,937–32,759 m2) within which the core utilisation distribution was found to be 964 m2 (range 246–3,289 m2) with pigs spending on average 47% of their time outside their homestead of origin. Conclusion These are the first data available on the home range of domestic pigs kept under a free range system: the data show that pigs in these systems spend much of their time scavenging outside their homesteads, suggesting that these pigs may be exposed to infectious agents over a wide area. Control policies for diseases such as Taenia solium, Trypanosomiasis, Trichinellosis, Toxoplasmosis or African Swine Fever therefore require a community-wide focus and pig farmers require education on the inherent risks of keeping pigs under a free range system. The work presented here will enable future research to incorporate movement data into studies of disease transmission, for example for the understanding of transmission of African Swine Fever between individuals, or in relation to the life-cycle of parasites including Taenia solium

Using economic and social data to improve veterinary vaccine development: Learning lessons from human vaccinology

The drivers of vaccine development are many and varied. They include, for example, recognition of the burden of a vaccine-targeted disease, prioritisation of the multiple problems associated with a disease, consideration of the differing socio-economic situations under which vaccines are used, the influence of advocacy groups, and assessment of the feasibility of large-scale vaccine manufacture and distribution. In the field of human health, data-driven development of vaccines is becoming increasingly common through the availability of reliable information on the Global Burden of Disease (GBD) and stringent evaluations of vaccination programmes utilising empirical data on costing and effectiveness, and standardised cost-effectiveness thresholds. The data generated from such analyses allow policymakers, implementing partners, industries and researchers to make decisions based on the best, and most contextually relevant, available evidence. In this paper, we wish to explore the current use of economic and social data for the development of veterinary vaccines. Through comparison with the development of human vaccines, we will look for opportunities in animal health sciences to better integrate socio-economic data and analyses into the process of veterinary vaccine selection, development, and field implementation. We believe that more robust animal health impact assessments could add value to veterinary vaccine development by improving resource allocation and animal disease management

Structure of the pork value chain in Northern Uganda: implications for Taenia solium control interventions

IntroductionThis study characterizes the pork value chain in Agago, Kitgum, Lamwo, and Pader districts of Northern Uganda and analyzes its implications on the transmission and control of Taenia solium infections.Methodology:Data were collected through focus group discussions (FGDs) with farmers and pig and pork traders, key informant interviews (KIIs) with local government officials and consumers, and district-level multi-stakeholder mini workshops organized in the study area. The value chain actors identified include input and services providers, pig farmers, live pig traders, pork traders, and consumers.ResultsMost of the pig production, marketing and consumption was found to occur through informal channels. Pig production in this area is dominated by smallholder extensive systems, with most producers keeping less than 10 pigs. The production segment of the pig value chain is characterized by low use of inputs and services such as veterinary extension, drugs and improved feeds. Pigs scavenge for food under free-range systems and are at risk of parasitic infections such as the zoonotic helminth Taenia solium. This risk is exacerbated by the inherent contextual aspects of the study sites including low latrine coverage, open defecation, and high poverty. In addition, some respondents viewed pigs as “sanitation policemen” where they leave them to roam around and eat dirt including feaces thereby cleaning the environment. T. solium was recognized as an important pig health constraint in this value chain alongside African swine fever (ASF). Unlike ASF that was associated with the pig mortalities, the cysts were associated with rejection of pigs by traders at purchase, condemnation of pig carcasses by meat inspectors and rejection of raw pork by consumers at points of sale.DiscussionPoor organization of the value chain and lack veterinary extension and meat inspection services results in some pigs infected with T. solium entering the food chain, exposing consumers to infection with the parasite. To reduce the pig production losses and public health impact from T. solium infections, there is need for control and prevention interventions targeting specific nodes of the value chain where the risk of transmission is highest

Identifying Pig- and Pork-Associated Zoonotic and Foodborne Hazards in Eastern and Southern Africa: A Systematised Review

Zoonotic and foodborne diseases are a major cause of morbidity and mortality, especially in low- and middle-income countries. Pork is a potential source of zoonotic and foodborne diseases, and pork consumption is rapidly increasing in Eastern and Southern Africa (ESA). Here, studies conducted in ESA describing pig- and pork-associated zoonotic and foodborne hazards were identified to clarify the distribution and prevalence of these hazards and identify research gaps in this region. A systematised literature review was conducted using MEDLINE and Web of Science to identify relevant articles according to pre-determined inclusion/exclusion criteria. In total, 140 articles from 14 countries were identified for review. A total of 42 hazards were identified, categorised as bacterial, viral, parasitic, arthropodal, or other, including drug residues. Among all identified hazards, Taenia spp. (n=40) was the most often studied, followed by Salmonella spp. (21), Escherichia coli (17), and Staphylococcus spp. (9). Further research is required to determine baseline data on the epidemiology and health and economic burden associated with pig- and pork-borne hazards and appropriate strategies are needed to mitigate the risk these hazards pose to communities.</jats:p

Consumer preferences, and willingness to pay for safe pork products in rural Kenya

Designing interventions to support the safe development of rapidly growing livestock value chains in sub-Saharan Africa requires a clear understanding of consumer demands. This study aimed to determine purchase patterns, consumers' preferences, and willingness to pay for safe pork attributes; specifically, the presence of a veterinary inspection stamp and the cleanliness of the butchery.A discrete choice experiment-based survey was used to investigate the purchasing behavior of 401 pork consumers: 253 buying raw pork for household consumption, and 148 buying cooked pork for out-of-home consumption. The study findings indicate that the average quantity of pork purchased by consumers was approximately 0.4 Kg per transaction, with the majority of consumers making several purchases per week.The average price per Kg of pork was KES 310 (Approx. 2.60 USD) at the time of the study. Data from the choice experiment showed that consumers were willing to pay a price premium of KES 245 (Approx. 2.1 USD) and KES 164 (Approx. 1.4 USD) per Kg for evidence of better veterinary meat inspection and higher butchery hygiene respectively; further, these were the two most important attributes they considered while making a pork purchase decision.These findings highlight the potential to leverage consumers' willingness to pay to improve the food safety within pork value chains in this context. Investing to increase consumer awareness on food safety issues should be considered to generate an effective market demand, especially in rural areas with relatively lower literacy levels

An integrated study of human and animal infectious disease in the Lake Victoria crescent small-holder crop-livestock production system, Kenya

Background: The neglected zoonotic diseases (NZD) are an understudied group that are a major cause of illness throughout the developing world. In general, little is known about the prevalence and burden of NZDs in affected communities, particularly in relation to other infectious diseases with which they are often co-endemic. We describe the design and descriptive epidemiological outputs from an integrated study of human and animal zoonotic and non-zoonotic disease in a rural farming community in western Kenya. Methods: This cross-sectional survey involved 2113 people, their cattle (n = 983) and pigs (n = 91). People and animals were tested for infection or exposure to a wide range of zoonotic and non-zoonotic pathogens. Prevalence estimates, with adjustment for the complex study design, were derived. Evidence for spatial clustering in exposure or infection was identified using the spatial scan statistic. Results: There was a high prevalence of human parasitism in the community, particularly with hookworm (Ancylostoma duodenale or Necator americanus) (36.3% (95% CI 32.8–39.9)), Entamoeba histolytica/dispar (30.1% (95% CI 27.5–32.8)), and Plasmodium falciparum (29.4% (95% CI 26.8–32.0)). Human infection with Taenia spp. was also prevalent (19.7% (95% CI 16. 7–22.7)), while exposure to other zoonotic pathogens was comparatively rarer (Brucella spp., 0.6% (95% CI 0.2–0.9); Coxiella burnetii, 2.2% (95% CI 1.5–2.9); Rift Valley fever, 0.5% (95% CI 0.2–0.8)). A low prevalence of exposure to Brucella spp. was observed in cattle (0.26% (95% CI 0–0.56). This was higher for Rift Valley fever virus (1.4% (95% CI 0.5–2.22)) and C. burnetii (10.0% (95% CI 7.7–12.2)). The prevalence of Taenia spp. cysticercosis was 53.5% (95% CI 48.7–58.3) in cattle and 17.2% (95% CI 9.1–25.3) in pigs. Mycobacterium bovis infection was found in 2.2% of cattle (95% CI 1.3–3.2), while the prevalence of infection with Mycobacterium spp. was 8.2% (95% CI 6.8–9.6) in people. Conclusion: Zoonotic infections in people and animals occur in the context of a wide range of co-endemic pathogens in a rural community in western Kenya. The wide diversity of pathogens under study provides a unique opportunity to explore the distribution and determinants of infection in a multi-pathogen, multi-host system

Countering the double-whammy of zoonotic diseases

Estimates put the number of people dying from endemic zoonoses at more than two million each year. Those affected above all belong to the low- and middle-income strata of society who have already been overlooked by both policy-makers and healthcare providers. Our authors give an overview of the key drivers of zoonoses and show how the One Health approach can help to control and prevent zoonotic diseases