OneHealth


Taking sheep for disease testing in Bako, Ethiopia
Taking sheep for disease testing in Bako, Ethiopia (photo credit: ILRI/Barbara Wieland).

World Zoonoses Day is marked annually on 6 July to commemorate the day in 1885 when Louis Pasteur successfully administered the first vaccine against a zoonotic disease when he treated a young boy who had been mauled by a rabid dog. The day is also an opportunity to raise awareness of the risk of zoonoses, infectious diseases that are spread between animals and people. 

Scientists estimate that 60% of known infectious diseases in people and 75% of new or emerging infectious diseases in people are transmitted from animals. Neglected zoonoses associated with livestock, such as brucellosis and cysticercosis, impose a huge health burden on poor people and reduce the value of their livestock assets.

Through its Animal and Human Health program, the International Livestock Research Institute (ILRI) carries out research with national and international partners towards improving the control of zoonotic diseases through a range of tools and approaches such as risk mapping and risk targeting, modelling of zoonotic pandemics, decision-support tools and advice on vaccination strategies. The program also generates evidence for policymakers on the cost and impact of zoonoses and the benefits of their prevention.

Some of our collaborative research on zoonoses includes work on developing optimal vaccination strategies for Rift Valley fever in East Africa, studying the epidemiology, ecology and socio-economics of disease emergence in Nairobi and developing an effective surveillance program for zoonoses in livestock in Kenya.

For an in-depth look, listed below are some of our research publications on zoonoses:

For more information on ILRI’s research on zoonoses, contact Bernard Bett, senior scientist at ILRI (b.bett@cgiar.org) or Eric Fèvre, professor of veterinary infectious diseases, Institute of Infection and Global Health, University of Liverpool on joint appointment at ILRI (eric.fevre@liverpool.ac.uk).

Researchers entering sampling data (photo credit: Zoonoses and Emerging Diseases).

In the cities of developing nations, where unregulated antibiotic use is common and livestock jostle with people amid often unsanitary conditions, scientists have found a potentially troubling vector for the dissemination of antimicrobial resistant bacteria: wildlife.

The epidemiological study published in the June 2019 issue of the journal Lancet Planetary Health shows that urban wildlife in Nairobi carry a high burden of clinically relevant antimicrobial resistant bacteria. The research team included scientists from the International Livestock Research Institute (ILRI), the University of Liverpool and the Kenya Medical Research Institute, among other research institutions.

Antimicrobial resistance is an increasingly serious threat to public health. Through misuse and overuse of antibacterial medication, more and more of the bacterial diseases that were once easily treated with antibiotics have become drug-resistant; these new strains of old germs require expensive and prolonged treatment at best and at worst can be lethal.

The study deployed teams of veterinary, medical, environmental and wildlife personnel to sample 99 households randomly chosen from Nairobi’s socio-economically diverse neighbourhoods.

The study found higher diversity of antimicrobial resistance in livestock and the environment than humans and wildlife. Rodents and birds were significantly more likely to carry resistance to multiple drugs when exposed to human and livestock waste through poor management practices, a common feature of lower-income neighbourhoods.

“This paper shows that contamination of urban environments with antimicrobial resistance is a serious issue. This is not just specific to Nairobi but findings can be extrapolated to other cities in Africa,” said Eric Fèvre, a joint appointed scientist at ILRI and professor of veterinary infectious diseases at the University of Liverpool.

“We tend to think of antimicrobial resistance in primarily medical terms, of developing new drugs and better using old ones. But we need to take an ecological approach to addressing this threat. Urban cities can address this by better urban planning, better waste disposal, better livestock husbandry practices. This can go far toward disrupting antimicrobial resistance exchange between wildlife, livestock and humans,” said Fèvre.

The lead author of the study, James Hassell, said, “Although we found no evidence to suggest that antimicrobial resistance carried by urban wildlife poses a direct threat to human health, that these animals harbour high levels of resistance to drugs used in human and animal medicine is particularly worrisome. Since wildlife are not treated with antibiotics, this is indicative of how pervasive antimicrobial resistance is in urban environments. Species that move freely across cities and further afield could disseminate resistance acquired in urban areas more widely.”

“We cannot address the rise of antimicrobial resistance without focusing on the environmental, ecological and social settings in which humans exist,” said Hassell.

Citation

Hassell, J.M., Ward, M.J., Muloi, D., Bettridge, J.M., Robinson, T.P., Kariuki, S., Ogendo, A., Kiiru, J., Imboma, T., Kang’ethe, E.K., Öghren, E.M., Williams, N.J., Begon, M., Woolhouse, M.E.J. and Fèvre, E.M. 2019. Clinically relevant antimicrobial resistance at the wildlife–livestock–human interface in Nairobi: An epidemiological study. Lancet Planetary Health 3(6): e259–e269.


Farmer herds his three bulls in Nikhekhu Village, Dimapur, Nagaland, India (photo credit: ILRI/Stevie Mann).

Rapid urbanization in India has led to expansion of peri-urban fringes, where intensive, industry-style livestock rearing has led to emerging vulnerabilities at the human-animal-environment interface.

To better understand the health system and farm-level factors that influence the risk of transmission of bovine tuberculosis in animals and humans, a qualitative study was undertaken among smallholder dairy farms in peri-urban zones in three cities in India: Guwahati, Ludhiana and Bangalore. Data were collected through literature reviews, expert consultations and in-depth interviews.

The study, published in BMC Public Health (March 2019), found that farmers consulted veterinarians as a last resort after home remedies and quacks had failed. Damage control measures, especially with respect to selling or abandoning sick animals, added to the risk of disease transmission.

Although civic authorities believed in the adequacy of a functioning laboratory network, end users were aggrieved at the lack of services. Despite the presence of extension services, knowledge and awareness were limited, promoting risky behaviour.

In addition, the absence of policies on the management of bovine tuberculosis may have influenced stakeholders not to consider it to be a major animal and public health concern.

“Evidence is needed not only about the burden and risks, but also on possible options for control applied in the local Indian setting,” the authors say.

The study also recommends that the identified gaps in knowledge be addressed through collaborative research and One Health interventions involving both animal and human health sectors.

Access the article Community, system and policy level drivers of bovine tuberculosis in smallholder periurban dairy farms in India: A qualitative enquiry by A.S. Chauhan and others.

Sheep market in Doyogena, Ethiopia (photo credit: ILRI/Zerihun Sewunet).

To tackle a growing problem of rising antimicrobial resistance in low- and middle-income countries, CGIAR, a global research partnership for a food-secure future, is forming an international hub to help integrate and channel research and development efforts.

The hub, launched on 21–22 February 2019, in Nairobi, Kenya, will be led and hosted by the International Livestock Research Institute (ILRI).

Antibiotics and other antimicrobial drugs are among the most important tools available to medical and veterinary professionals for curing human and animal diseases and improving their welfare, yet these drugs are increasingly failing. Development of resistance to these drugs in disease-causing bacteria and other microbes poses a major threat to global development; the World Bank estimates that annual global gross domestic product could fall by more than 1 trillion United States dollars (USD) by 2030 because of it.

While the World Bank also estimates that investments of USD 6 to 8 billion annually could mitigate this loss, at present, it seems the antimicrobial resistance problem will get rapidly worse before it gets better. Large quantities of antimicrobial drugs are used to cure human illness and provide healthy livestock and fish for food.

Though specifics are unknown, use of antimicrobials for livestock and in aquaculture, is rising, particularly in low- and middle-income countries. These antimicrobials are often used in suboptimal ways, such as applying dosages too little to be effective or over too long a time period to be environmentally healthy, or the wrong drugs are used, or antibiotics are used for diseases not caused by bacteria. Humans, livestock and fish excrete these drugs, which leads to environmental contamination, including that of water systems.

Globally, the main driver of the growing incidence of antimicrobial resistance in humans is overuse and misuse of antibiotics in human medicine, which applies selective pressure for resistant pathogens. But antimicrobial use in agriculture to control animal and plant diseases also contributes to this growing drug resistance problem, although experts don’t know the contribution of agriculture to the problem in humans.

The greatest challenges and burdens of antimicrobial resistance will be felt by the poorest in poorer countries. While these countries with their rapidly growing populations face the greatest and rising demand for increased food production, their populations also tend to have poorer access to relevant knowledge, veterinary and health services. The countries face challenges in enforcing regulations and understanding and implementing effective antimicrobial resistance surveillance.

With its mandate to improve the livelihoods of poor people, improve food and nutrition security and improve natural resource management through agriculture and food research, CGIAR is ideally positioned to tackle agriculture-related antimicrobial risks in developing countries and to develop, test and promote solutions to mitigate these risks together with its partners.

Like climate change and malnutrition, two other global challenges CGIAR works to address, antimicrobial resistance challenges us to use evidence and find ways to change the knowledge, attitudes and behaviors of people. Any solutions will require combining technical, institutional and policy innovations and leveraging the contributions of different sectors and disciplines, and both public and private actors.

The new CGIAR Antimicrobial Resistance Hub will work to foster learning from past experiences, support research excellence in the global south and ensure a critical mass of coordinated research to find suitable and sustainable solutions. ILRI will be joined in this effort by three CGIAR research programs—Agriculture for Nutrition and Health, FISH and LIVESTOCK—along with three CGIAR centers—the International Food Policy Research Institute, the International Water Management Institute and WorldFish. Together, these seven research programs and institutions with their national partners and partner research organizations outside CGIAR, will support global research efforts among experts the world over—from low- to middle- to high-income countries.

For more information about the CGIAR Antimicrobial Resistance Hub, contact Barbara Wieland at b.wieland@cgiar.org or Delia Grace Randolph at d.randolph@cgiar.org.

Johanna Lindahl, senior scientist at the International Livestock Research Institute

Johanna Lindahl, senior scientist at the International Livestock Research Institute (photo credit: ILRI/Dinesh).

We congratulate Johanna Lindahl, a senior veterinary epidemiologist at the International Livestock Research Institute (ILRI), on receiving the 2018 Swedish Institute for Global Health Transformation (SIGHT) Award and SEK 100,000 in recognition of her excellent scientific contribution to global health. The award was presented at a ceremony held in Stockholm on 25 November 2018.

The citation for her award reads: “Johanna Lindahl has, from a holistic perspective and in cooperation with researchers from low- and middle-income countries, developed our knowledge within areas of crucial relevance for the well-being and survival of mankind globally, namely human and animal interaction (One Health) as well as antibiotic resistance.”

The decision on the recipient of the SIGHT Award 2018 was taken by the board of the Royal Swedish Academy of Sciences.

Lindahl is also an associate professor at the Swedish University of Agricultural Sciences and Uppsala University.

Pipetting in ILRI's biosciences laboratories

Pipetting in ILRI’s biosciences laboratories (photo credit: ILRI/David White).

The scourge of infectious diseases in Africa was the subject of a recent symposium co-hosted by the Academy of Science of South Africa, the Uganda National Academy of Sciences and the German National Academy of Sciences (Leopoldina) in Durban, South Africa on 12–13 April 2018.

The symposium titled Surveillance and response to infectious diseases and co-morbidities: An African and German perspective was attended by about 100 participants from Africa and Germany including senior researchers, policymakers and representatives from the private sector. Presentations and discussions revolved around antimicrobial resistance, One Health, co-morbidities of infectious diseases and the ‘Big Four’ infectious diseases in humans (HIV/AIDS, malaria, tuberculosis and hepatitis C).

Scientists from the human medical field dominated the symposium but in a panel discussion, the few animal health scientists present, including Kristina Roesel from the Animal and Human Health program of the International Livestock Research Institute, drew the audience’s attention to the importance of a One Health perspective on human disease as two thirds of human pathogens are of animal origin. Thomas Mettenleiter, member of the Leopoldina and president of the Friedrich-Loeffler-Institut (German Federal Research Institute for Animal Health), moderated the panel discussion.

The symposium was preceded by a one-day workshop on science advice jointly organized with the International Network for Government Science Advice–Africa and the International Council for Science Regional Office for Africa. Invited junior scientists got practical exposure to science advice including drafting communication strategies and role plays on infectious disease outbreak scenarios.

Article by Kristina Roesel

Cross-bred Pigs in Kiboga District, Uganda

Cross-bred Pigs in Kiboga District, Uganda (photo credit: ILRI/Kristina Roesel).

Today is International One Health Day, an occasion celebrated around the world every year on 3 November to bring global attention to the need for One Health interactions and for the world to ‘see them in action’.

To mark this day, we highlight a new discussion paper published by the International Livestock Research Institute (ILRI) that contributes towards a greater understanding of One Health from a largely overlooked social science perspective.

The report provides a summary of research conducted in 2016 in the peri-urban to urban pig value chain between Mukono District and Kampala in Uganda’s central region. Its focus is the zoonotic parasite Taenia solium, also referred to as the pork tapeworm, and cysticercosis, an infection with the larvae of T. solium. It highlights perceptions of T. solium and other pathogens associated with pigs as articulated by farmers, butchers, slaughterhouse workers, pork consumers and medical professionals.

Download the report, Pigs, people, pathogens: A qualitative analysis of the pig value chain in the central region of Uganda by Rebekah Thompson.

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