Cow in Kenya

Cow in Kenya. A new Rift Valley fever risk map for Kenya will help develop prevention and control measures to combat the disease in the country (photo credit: ILRI/Stevie Mann).

A new Rift Valley fever risk map for Kenya, based on data from a period spanning over 50 years, will be an important tool for use in developing measures to prevent and control the disease in the country.

Rift Valley fever is a viral disease that affects animals such as cattle, sheep, camels and goats. It is also a zoonotic disease, meaning it can be transmitted from animals to people.

Rift Valley fever epidemics occur every 3 to 10 years in specific regions of the Greater Horn of Africa, southern and western Africa and in the Arabian Peninsula, resulting in high rates of infection and death among people and livestock.

In Kenya, the most recent outbreaks of the disease occurred in 1997-98 and 2006-07. Experts agree that the severity of Rift Valley fever epidemics can be reduced through the use of effective early warning systems followed by rapid implementation of prevention and control measures.

In 2008, international experts and decision-makers from eastern Africa developed a risk-based decision support framework designed to guide responses during various stages of the Rift Valley fever disease cycle.

Now, a team of researchers from Kenya, the Netherlands and the United States of America has added to the arsenal of tools to prevent and control Rift Valley fever by using surveillance data from 1951 to 2007 to develop a Rift Valley fever risk map for Kenya.

The map shows the risk of an outbreak of the disease for each of the 391 administrative divisions in the country (based on the 1999 administrative map), classifying the divisions as high, medium or low risk.

The authors of the study say that the Rift Valley fever risk map will provide the Government of Kenya with an evidence-base from which it can respond to a Rift Valley fever epidemic warning as well as develop long-term prevention and control programs in high-risk areas.

The map is published in an article in the journal PLOS ONE (25 Jan 2016): Predictive factors and risk mapping for Rift Valley fever epidemics in Kenya

Munyua, P.M., Murithi, R.M., Ithondeka, P., Hightower, A., Thumbi, S.M., Anyangu, S.A., Kiplimo, J., Bett, B., Vrieling, A., Breiman, R.F. and Njenga, M.K. 2016. Predictive factors and risk mapping for Rift Valley fever epidemics in Kenya. PLOS ONE 11(1): e0144570.

Local breed sow and piglets on a farm in Masaka district, Uganda

Local breed sow and piglets on a farm in Masaka district, Uganda (photo credit: ILRI/Eliza Smith).

Zoonotic diseases are most dangerous when they take animal and human health workers by surprise, giving the public and disease control officials no advance warning or time to put prevention measures in place. The recent Ebola outbreak in West Africa illustrates the adverse consequences of trying to tackle a disease outbreak too late and with little information.

Ebola is a serious but mysterious disease; in Uganda, there is little solid information on the reservoir and transmission of Ebola. However, research findings in the last few decades have given rise to speculation that there could be associations between pigs and Ebola.

Currently, there is no evidence that pigs have had any role in past outbreaks of Ebola virus disease. But given the huge importance of pigs to the Ugandan economy, diet and livelihoods, it is important to investigate any potential links sooner rather than later.

A recent study by the International Livestock Research Institute (ILRI) argues there are several factors that support the potential role of pigs in the transmission of Ebola to humans in Uganda. It is critical that this hypothesis be investigated in order to understand the risks to the country’s burgeoning pig production industry.

A spatial representation of potential risk factors for zoonotic transmission involving pigs in Uganda could be used to initiate further investigations into Ebola and other zoonotic diseases known to affect pigs in Uganda.

The researchers call for a One Health approach to the continued research. The benefit of this multidisciplinary approach is that limited resources can be utilized efficiently to improve the health and livelihoods of Ugandans through enhanced food safety and security, and the preservation of important ecosystem services, such as those provided by bats and other wildlife.

Clear and consistent risk communication from all research partners will be of utmost importance in preventing hysteria and delivering good outcomes for wildlife conservation and livelihoods.

Download the policy brief, One Health approach recommended in investigating and communicating the potential role of pigs in transmitting Ebola in Uganda written by Eliza Smith of KYEEMA Foundation and Christine Atherstone and Delia Grace of ILRI.

The following is an excerpted version of a blog post originally published on the CGIAR Research Program on Agriculture for Nutrition and Health (A4NH) website.

Some of the foods that would most enhance nutrition in diets in the developing world are also the riskiest in terms of food safety. Numerous health risks exist along the value chain for livestock and fish products, from production to consumption. In this post, Sophie Theis (Research Analyst, Poverty, Health, Nutrition Division, International Food Policy Research Institute) and Delia Grace (Program Manager, International Livestock Research Institute) relate findings from a recent A4NH/International Livestock Research Institute analysis of 20 livestock and fish value chains in Africa and Asia that reveal how gender differences in value chain participation influence risk exposure.

The results from the participatory risk assessment of these value chains are published in Grace et al. (2010) and a paper analyzing the gendered dimensions of risk is underway by Delia Grace, Sophie Theis, Kristina Roesel, Erastus Kang’ethe and Bassirou Bonfoh.

Selling milk

Selling milk in Ethiopia (photo credit: ILRI).

In rural Mali, a Fulani herder finishes milking a cow and hoists the calabash to his head, the milk sloshing gently in the vessel as he carefully carries the milk to Mariam, the woman he works for. By custom, Mariam has never milked a cow, but once the milk is in her domain, she is in charge of its business and use. Today she decides to keep this calabash for the family, since she has been able to sell milk at a favorable price often in the past week. She sets most aside to naturally sour, which will preserve it in the absence of refrigeration; the fermentation gives a sharp taste that consumers find thirst quenching in the hot season.

In the outskirts of Nairobi, Faith works the udders of her dairy cow. A male relative she has hired to help with the milking approaches with another pail of milk. She accepts it absentmindedly; she is already estimating the prices she will get selling the milk to neighbors and the local milk bar and considering whether she should invest the revenues in hiring another person.

In rural Mali, periurban Kenya, and many other parts of Africa, women play important and varied roles in livestock and fish value chains. The milk that Mariam and Faith helped to produce goes both to their families and to the market; it is also valued as gifts and in Mali as a sacrifice that brings blessing and protection against evil.

The decisions that Mariam and Faith make have bearings on many people’s nutrition: the quantity of milk that they keep for their household, how they apportion milk amongst household members, the use of the income from milk that they sell, and – less often acknowledged, but critical – the extent to which they effectively manage food safety risk, preventing contamination of the milk.

Many of the most nutritious foods, including animal source foods, are amongst the riskiest in terms of pathogen transmission. Meat, milk, fish and eggs provide plenty of nutrients for pathogenic organisms and can also carry infections from animals that harbor them to people. Food-borne disease persists as a major public health problem in Africa and Asia, where the majority of these foods are produced by smallholders, marketed through the informal sector, and sold in wet markets.

Food safety in these products is a major concern, as informal markets are important sources of food for the poor and tend to provide food that is more accessible, affordable, and compatible with local preferences for certain varieties of food and quantities than supermarkets.

Women like Mariam and Faith manage risk as they interact with informal markets by selling and buying food for their households. Informal value chains are complex, shaped by a number of actors. While risk management training interventions tend to focus on the owners of livestock or on actors only in one node of the value chain (e.g. butchers), risk management relies on all the actors along the value chain, from production, aggregation, processing, retail, and consumption. Many of these actors are women, and attention to local norms in the division of labor is critical for targeting food safety assessments and interventions.

Read the complete blog post on the A4NH website

Butchers of Hmong black pig meat in Northwest Vietnam

Hmong butchers selling pig meat from the indigenous Hmong black pig, recognizable from its thick layer of fat below the skin, Bac Ha, Lao Cai Province, Vietnam (photo credit: ILRI/Jo Cadilhon).

The July 2014 issue of Partners Magazine, the flagship publication of the Australian Centre for International Agricultural Research (ACIAR), features an article on an ACIAR-funded project led by the International Livestock Research Institute (ILRI) that uses a risk assessment approach towards improving the safety of pig and pork value chains in Vietnam.

Hung Nguyen-Viet, an ILRI scientist and deputy director of the Center for Public Health and Ecosystem Research (CENPHER) at the Hanoi School of Public Health, is playing a lead role in the project which is working to strengthen local capacity on risk assessment for effective management of food safety along the entire value chain.

Read the article, Food safety from farm to fork

Read more about CENPHER in their new report, CENPHER five year report 2009–2014: From a research project to a research center

Local breed sow and piglets on a farm in Masaka district, Uganda

Local breed sow and piglets on a farm in Masaka district, Uganda. A new research report assesses the risk of Ebola in the pig value chain in Uganda. (photo credit: ILRI/Eliza Smith).

Scientists from the International Livestock Research Institute (ILRI) have published a report of a risk assessment to determine the threat of the deadly Ebola virus in the pig value chain in Uganda.

Uganda is currently witnessing a rise in demand for pork and this has led to increased pig production in the country, mostly under smallholder production systems.

These higher pig populations raised under free-range or tethering systems may create overlap of fruit bat habitats where the pigs scavenge for food, thereby presenting a possible risk of Ebola transmission as some bat species have been identified as reservoir hosts of the Ebola virus.

Uganda has experienced outbreaks of Ebola virus disease in the past. However, there are still many unanswered questions on the ecology and mode of transmission of the Ebola virus.

The risk assessment study, based on a systematic review of literature, identified possible routes of transmission of the Ebola virus if pigs are involved, for example, spread between wild and domestic pigs, direct contact between infected pigs and humans, and contact between pigs and fruit bats.

The study recommends more research on the possible role of pigs in Ebolavirus transmission, an area that is not well understood at the moment.

“The present data suggest that pigs may act as amplifying hosts, but likely not reservoir hosts. This suggests the conditions under which pigs become infected with Ebolavirus and the role they play in transmission may have many variables that will have to be elucidated,” the report states.

Further research is underway to investigate the possible role of domestic pigs in the ecology of Ebola virus in Uganda and understand the public health significance of the virus to the pig value chain in this country.

The work includes laboratory diagnostics from a large sample of blood from domestic pigs collected as part of the initial wider value chain disease assessment.

This will be accompanied by a risk mapping study using spatial epidemiology and key informant surveys as well as some participatory techniques with key stakeholders to better understand risk factors and to serve as a ‘ground-truthing’ exercise for the risk map.

It is hoped that this research will lead to further collaborations with other public health organizations and serve as a potential predictive tool in the event of future outbreaks of Ebola in Uganda.

Access the research report here

Atherstone C, Roesel K and Grace D. 2014. Ebola risk assessment in the pig value chain in Uganda. ILRI Research Report 34. Nairobi, Kenya: ILRI.

Feeding pigs in Nagaland

A woman feeds her pigs in Nagaland, India (photo credit: ILRI/Stevie Mann).

The first risk-based study of food safety in the pork value chain in Nagaland, Northeast India has identified several important microbiological hazards and assessed their impacts on human health.

Nagaland has the highest density of pigs in India and the highest pork consumption levels. Therefore, information on pathogens in pigs and pork in the region, and their health impacts, is useful for decision-making on interventions aimed at improving food safety and safeguarding the health of consumers.

The study investigated samples from pigs and pork sourced at slaughter in urban and rural environments, and at retail, to assess a selection of food-borne hazards. In addition, consumer exposure was characterized using information about hygiene and practices related to handling and preparing pork.

The food-borne pathogens identified include Listeria spp. and Brucella suis. A risk assessment framework assessed the health impacts of three representative hazards or hazards proxies, namely, Enterobacteriaceae, Taenia solium cysticercosis and antibiotic residues.

The study found that by using participatory methods and rapid diagnostics alongside conventional methods, risk assessment can be used in a resource-scarce setting.

The findings are published in a special issue on food safety and public health in the International Journal of Environmental Research and Public Health.

View the article

Fahrion AS, Jamir L, Richa K, Begum S, Rutsa V, Ao S, Padmakumar VP, Deka RP and Grace D. 2014. Food-safety hazards in the pork chain in Nagaland, North East India: Implications for human health. International Journal of Environmental Research and Public Health 11(1): 403-417.

Maize contaminated with aflatoxin

Maize contaminated with aflatoxin (photo credit: IITA).

On 22 August 2013, the Biosciences eastern and central Africa hub at the International Livestock Research Institute (ILRI) and ILRI’s Food Safety and Zoonoses program hosted a half-day seminar on the current status on aflatoxin research and management at ILRI.

The open forum was an opportunity for different working groups to engage in discussions on the ongoing and planned research projects. The seminar brought together some 30 participants and a total of 13 presentations were given on aflatoxin assessment, diagnostics, analysis and mitigation.

Aflatoxins are highly toxic metabolites produced by the mould Aspergillus flavus and known to cause suppression of the immune system, liver disease and death in both humans and animals.

Aspergillus can grow in a wide range of foods and feed and thrive under favourable growth conditions of high temperature and moisture content. Aflatoxins from contaminated animal feed can end up in milk.

Three research studies that are part of the project Measuring and mitigating the risk of mycotoxins in maize and dairy products for poor consumers in Kenya (MyDairy project) were featured during the seminar.

The goal of the MyDairy project – the fifth of seven work packages of the FoodAfrica program – is to reduce the risk of mycotoxin contamination of staple crops in Kenya.

ILRI graduate fellow Anima Sirma presented an overview of her planned PhD research on risk assessment of aflatoxins in the Kenyan dairy value chain. The objectives of the study are to characterize the key risks of aflatoxins, identify the best control options and provide risk managers with information for decision-making.

Daniel Senerwa, another ILRI graduate fellow working towards a PhD, presented his proposed research that seeks to quantify the economic costs of aflatoxins in the Kenyan dairy value chain and examine the cost effectiveness of mitigation strategies.

Sirma and Senerwa are veterinary scientists and are undertaking their PhD studies at the University of Nairobi’s Faculty of Veterinary Sciences.

Sara Ahlberg, a dairy technologist from Finland and ILRI associate research officer, presented an overview of her work on a novel biological method to mitigate aflatoxin-induced risks in food and feed with dairy-derived proteins and peptides and lactic acid bacteria that have the ability to bind aflatoxins or inhibit the growth of mycotoxin-producing moulds.

Download the seminar report

Sale of raw milk at Port-Bouët market in Abidjan, Côte d’Ivoire

Sale of raw milk at Port-Bouët market in Abidjan, Côte d’Ivoire (photo credit: ILRI/Sylvie Mireille Kouamé-Sina).

Every day, some 652 consumers of raw milk in Abidjan, Côte d’Ivoire are exposed to the risk of gastro-intestinal infection caused by harmful milk-borne bacteria, a study has shown. The study was done under the collaborative Safe Food, Fair Food project which is led by International Livestock Research Institute (ILRI).

As is the case in most countries in sub-Saharan Africa, milk in the informal or traditional market in Côte d’Ivoire is often sold raw. Many consumers routinely boil milk before drinking it, thus eliminating the health risk presented by milk-borne pathogens. However, some choose to consume the milk raw without any form of heat treatment. Unhygienic handling and storage of milk can also compromise the quality of raw milk sold to consumers.

Sylvie Mireille Kouamé-Sina, an Ivorian researcher at the Centre Suisse de Recherches Scientifiques en Côte d’Ivoire (CSRS), led the study on bacterial risk assessment of informally marketed milk in Abidjan.

Just over half (51.6%) of sampled milk consumers in Abidjan reportedly drank their milk raw. The main disease-causing bacteria isolated from the marketed raw milk were E. coli, Enterococcus sp. and Staphylococcus aureus. These species were found in about 58% of samples of informally marketed milk.

A risk model revealed that consumers of raw milk in Abidjan have a 30% chance of drinking milk that is not microbiologically safe. For this reason, boiling of informally marketed milk is recommended as a risk-mitigation strategy against milk-borne pathogenic bacteria.

Kouamé-Sina presented these findings during a poster session at the 5th Congress of European Microbiologists (FEMS 2013) which was held on 21-25 July 2013 in Leipzig, Germany. The international conference brought together 2270 participants from 70 countries across all continents. Africa was represented by 27 participants from Côte d’Ivoire (1), Egypt (2), Nigeria (11), South Africa (12) and Tunisia (1).

Various topics on the latest advances in microbiology and biotechnology were discussed, including microbial food safety, trends in pathogen monitoring, viral ecology and evolution, new perspectives in bioenergy, and microbial interactions and climate change.

“The conference was a very interesting forum for thousands of international microbiologists from Europe and around the world to assess the current status of techniques used in microbiology,” said Kouamé-Sina.

“It was especially useful for young scientists as it allowed for interaction with leading researchers and exchange of knowledge and information on the latest advances in microbiology,” she added.

View the poster, Bacterial risk assessment of milk produced locally in Abidjan, Côte d’Ivoire


Read more about ILRI’s research on food safety in informal markets.

Cover of special issue of Vietnam Journal of Preventive Medicine on risk assessment

The Vietnamese Journal of Preventive Medicine has published a special edition on risk assessment for health research in Vietnam. The June 2013 special edition is a compilation of over 10 original research papers on the application of risk analysis to the management of animal, human and environmental health in Vietnam. The subject of training and capacity development in health risk assessment in Vietnam is also featured.

Risk analysis is a scientific, risk-based approach to assessing the health effects and economic impacts of various hazards (for example, disease-causing microorganisms in food or chemical pollutants in water) in order to develop appropriate interventions to mitigate the health risks posed by the hazards, thus ensuring that people, animals and the environment are safe.

Risk analysis comprises three components: risk assessment, risk management and risk communication. In the developed world, risk assessment is widely applied and used as a tool for risk management, thanks to the availability and accessibility of large databases of diseases.

However, many developing countries – including Vietnam – do not have the research data and risk analysis expertise needed to be able to adequately inform policymaking on risk-based approaches to health management.

The research papers featured in the special issue provide insights into the current status of research on risk analysis in Vietnam, specifically, risk assessment of the health impacts of Salmonella, E. coli and Listeria monocytogenes in the pork value chain in Hanoi, arsenic contamination in drinking water in Hanam Province, dioxin contamination in food in Da Nang and pesticide residues in farms in Thai Binh.

The work is a result of the collaborative efforts of the Vietnamese Journal of Preventive Medicine and the Center for Public Health and Ecosystem Research (CENPHER) at the Hanoi School of Public Health (HSPH).

Among the co-authors of the research papers are Delia Grace and Lucy Lapar, scientists at the International Livestock Research Institute (ILRI), and Hung Nguyen-Viet who leads research at CENPHER-HSPH and is a joint appointee of the Swiss Tropical and Public Health Institute and ILRI.

The papers are in Vietnamese with abstracts available in English. Listed below are the titles of the papers.

  • Risk assessment and health research in Vietnam (editorial)
  • Risk assessment of Salmonella in pork in Hanoi, Vietnam
  • Food-borne hazards in a transforming pork value chain in Hanoi: Basis for future risk assessments
  • Health risk due to exposure to chlorpyrifos for farmers in Thai Binh: Probabilistic risk assessment
  • Risk assessment of arsenic contamination in tube-well drinking water in Hanam Province
  • Environmental health risk assessment of dioxin in foods in Da Nang dioxin hot spot
  • Prevalence of Salmonella contamination in pig and pork at farms and slaughterhouses in the northern provinces of Vietnam
  • Air pollution as a health issue in Hanoi, Vietnam: An opportunity for intensified research to inform public policy
  • Environmental health risk communication: Concept, principles and challenges
  • Training and research programs in health risk assessment in Vietnam
  • Task force of risk assessment for food safety in Vietnam: Linking science to policy to increase food safety and livelihood generation of the poor farmer
  • Research projects on health risk assessment implemented by the Hanoi School of Public Health

The special edition also includes news on risk assessment training in Vietnam and reviews of two books on risk assessment.

For more information on this special edition, please contact Hung Nguyen-Viet (hung.nguyen @