Animal-to-human diseases: From panic to planning–new recommendations for policymakers

Greatest Burden of Zoonoses Falls on One Billion Poor Livestock Keepers

Map by ILRI, published in an ILRI report to the UK Department for International Development (DFID): Mapping of Poverty and Likely Zoonoses Hotspots, 2012.

The UK’s Institute for Development Studies (IDS) has published a 4-page Rapid Response Briefing titled ’Zoonoses: From panic to planning’.

Veterinary epidemiologist Delia Grace, who is based at the International Livestock Research Institute (ILRI), along with other members of a Dynamic Drivers of Disease in Africa Consortium, based at the STEPS Centre at IDS, c0-authored the document.

The briefing recommends that policymakers take a ‘One-Health’ approach to managing zoonotic diseases.

‘Over two thirds of all human infectious diseases have their origins in animals. The rate at which these zoonotic diseases have appeared in people has increased over the past 40 years, with at least 43 newly identified outbreaks since 2004. In 2012, outbreaks included Ebola in Uganda . . . , yellow fever in the Democratic Republic of Congo and Rift Valley fever (RVF) in Mauritania.

‘Zoonotic diseases have a huge impact – and a disproportionate one on the poorest people in the poorest countries. In low-income countries, 20% of human sickness and death is due to zoonoses. Poor people suffer further when development implications are not factored into disease planning and response strategies.

‘A new, integrated “One Health” approach to zoonoses that moves away from top-down disease-focused intervention is urgently needed. With this, we can put people first by factoring development implications into disease preparation and response strategies – and so move from panic to planning.

Read the Rapid Response Briefing: Zoonoses: From panic to planning, published Jan 2013 by the Dynamic Drivers of Disease in Africa Consortium and funded by the UK Department for International Development (DFID).

About the Dynamic Drivers of Disease in Africa
The Dynamic Drivers of Disease in Africa is a consortium of 30 researchers from 19 institutions in Africa, Europe and America. It conducts a major program to advance understanding of the connections between disease and environment in Africa. Its focus is animal-to-human disease transmission and its objective is to help move people out of poverty and promote social justice.

Over the past few decades, more than 60 per cent of emerging infectious diseases affecting humans have had their origin in wildlife or livestock. As well as presenting a threat of global disease outbreak, these zoonotic diseases are quietly devastating lives and livelihoods. At present, zoonoses are poorly understood and under-measured — and therefore under-prioritized in national and international health systems. There is great need for evidence and knowledge to inform effective, integrated One Health approaches to disease control. This Consortium is working to provide this evidence and knowledge.

Natural and social scientists in the Consortium are working to provide this evidence and knowledge for four zoonotic diseases, each affected in different ways by ecosystem changes and having different impacts on people’s health, wellbeing and livelihoods:

  • Henipavirus infection in Ghana
  • Rift Valley fever in Kenya
  • Lassa fever in Sierra Leone
  • Trypanosomiasis in Zambia and Zimbabwe

Of the 30 scientists working in the consortium, 4 are from ILRI: In addition to Delia Grace, these include Bernard Bett, a Kenyan veterinary epidemiologist with research interests in the transmission patterns of infectious diseases as well as the technical effectiveness of disease control measures; Steve Kemp, a British molecular geneticist particularly interested in the mechanisms of innate resistance to disease in livestock and mouse models, and Tom Randolph, an American agricultural economist whose research interests have included animal and human health issues and assessments of the impacts of disease control programs.

Delia Grace leads a program on Prevention and Control of Agriculture-associated Diseases, which is one of four components of a CGIAR Research Program on Agriculture for Nutrition and Health. Tom Randolph directs the CGIAR Research Program on Livestock and Fish. Steve Kemp is acting director of ILRI’s Biotechnology Theme.

 

 

Taking Stock: Jul 2012 round-up of news from ILRI

Remembering Jeff Haskins

JEFF HASKINS
Last month, we at the International Livestock Research Institute (ILRI) and within CGIAR and the wider agricultural development communities grieved over the sudden loss of American media guru Jeff Haskins, who had spent six years in Africa covering African agriculture news stories for the American PR firm Burness Communications. Haskins, who had just turned 32, died at the Kenya coast on 14 Jul 2012. See online tributes to him from the ILRI News Blog (with links to 25 major news releases and 20 major opinion pieces that ILRI produced with the help of Jeff and his Burness team over the last five years), Pictures of Jeff Haskins (ILRI Pinterest Board), Pictures by Jeff Haskins (ILRI Pinterest Board)Burness Communications Blog, Global Crop Diversity Trust, CGIARInternational Center for Tropical AgricultureLa Vie Verte and Jeff Haskins Facebook page.

Emerging Zoonotic Diseases Events 1940-2012

MAPPING ZOONOSES
Before his untimely death, Jeff Haskins in early Jul orchestrated major and widespread media coverage of a groundbreaking report by ILRI revealing a heavy burden of zoonoses, or human diseases transmitted from animals, facing one billion of the world’s poor. Some 60 per cent of all human diseases originate in animal populations. The ILRI study found five countries—Bangladesh, China, Ethiopia, India and Nigeria—to be hotspots of poverty and zoonoses. The study also found that northeastern United States, Western Europe (especially the United Kingdom), Brazil and parts of Southeast Asia may be hotspots of ‘emerging zoonoses’—those that are newly infecting humans, are newly virulent, or have newly become drug resistant. The study, Mapping of Poverty and Likely Zoonoses Hotspots, examined the likely impacts of livestock intensification and climate change on the 13 zoonotic diseases currently causing the greatest harm to the world’s poor. It was developed with support from the United Kingdom’s Department for International Development (DFID).

An opinion piece by the main author of the study, ILRI veterinary epidemiologist Delia Grace, wearing her hat as a member of the Dynamic Drivers of Disease in Africa Consortium, appeared this Jul in The Guardian‘s Poverty Matters Blog.

Azage Tegegne of IPMS awarded an honorary Doctorate of Science degree

ILRI AWARD
Azage Tegegne, of ILRI and the Improving Productivity and Market Success of Ethiopian Farmers (IPMS) project, was awarded an honorary doctorate of science degree by Ethiopia’s prestigious Bahir Dar University.

Bruce Scott with ILRI Addis colleagues

ILRI STAFF
ILRI bid goodbye to Bruce Scott, who served ILRI as a director for 13 years, the last decade as director of ILRI’s partnerships and communications department. Bruce is moving only down the road in Nairobi, from Kabete to Westlands, where he is taking up the position of deputy director of a new initiative of Columbia University (USA): Columbia Global Centers  ⁄ Africa.

ILRI & FODDER AT RIO+20
We  compiled links to ILRI inputs to the Rio+20 conference, including how to ‘turn straw into gold’ with dual-purpose crop residues and, with the International Center for Tropical Agriculture (CIAT), how livestock feed innovations can reduce poverty and livestock’s environmental ‘hoofprint’.

POLICY BRIEF
ILRI produced a policy brief on ‘Preventing and controlling classical swine fever in northeast India‘.

VIDEO INTERVIEWS
We film interviewed ILRI director general Jimmy Smith on ILRI’s evolving new livestock strategy and on ILRI’s role in providing evidence about the ‘bads’ as well as ‘goods’ of livestock production, marketing and consumption. And we interviewed ILRI scientist Joerg Jores on his research results, which, as reported in Scientific American, show that the pathogen that causes cattle pneumonia (CBPP) arose with domestication of ruminants ten thousand years ago, but only ‘heated up’ and began causing disease relatively recently.

Commissioners in Africa

VIP VISITORS
An Australian contingent visited ILRI this month and launched a new initiative, the Australian International Food Security Centre, to improve food security in Africa. The centre, which falls under the Australian Centre for International Agricultural Research (ACIAR), will spend USD33.8 million over four years to support food production in Africa as well as in Asia and the Pacific region.

Visit by Korea's Rural Development Authority (RDA) to ILRI in Nairobi

PROJECT NEWS
We reported on the signing of a memorandum of understanding by ILRI and Korea‘s Rural Development Authority (RDA) for laboratory work in Kenya, innovative platforms in an imGoats project in India and Mozambique, and training sessions on controlling zoonoses conducted by the Vietnamese members of an ILRI-led project known by its acronym EcoZD (‘Ecosystem Approaches to the Better Management of Zoonotic Emerging Infectious Diseases in Southeast Asia’).

Curious pig in Uganda raised for sale

SELECTED RECENT PRESENTATIONS
Azage Tegegne Livestock and irrigation value chains for Ethiopian smallholders (LIVES) project, Addis Ababa, Jun (256 views).
Danilo Pezo Smallholder pig value chain development in Uganda, Wakiso, Jun (1186 views).
Derek Baker Livestock farming in developing countries: An essential resource, World Meat Congress, Paris, Jun (874 views).
Derek Baker Interpreting trader networks as value chains: Experience with Business Development Services in smallholder dairy in Tanzania and Uganda, ILRI Nairobi, Jun (1879 views).
Peter Ballantyne Open knowledge sharing to support learning in agricultural and livestock research for development projects, Addis Ababa, Jun (1589 views).
John Lynam Applying a systems framework to research on African farming systems, CGIAR drylands workshop, Nairobi, Jun (1884 views).
Bernard Bett Spatial-temporal analysis of the risk of Rift Valley fever in Kenya, European Geosciences Union Conference, Vienna, Apr (1164 views).
Nancy Johnson The production and consumption of livestock products in developing countries: Issues facing the world’s poor, Farm Animal Integrated Research Conference, Washington DC, Mar (542 views).

Researchers strengthen their partnerships in the fight against Rift Valley fever

Typical mixed crop-livestock farming of western Kenya

A mixed crop-livestock farm in Western Kenya. Livestock researchers are working towards joint efforts of preventing and controlling Rift Valley fever in eastern Africa (photo credit: ILRI/Charlie Pye-Smith).

A new effort to align the work of partners in eastern Africa and implement more synergetic research on Rift Valley fever was the focus of a recent multi-stakeholder workshop that reviewed research strategies and approaches used by veterinarians, epidemiologists, economists and public health experts in projects across Kenya.

The meeting, which was held at the International Livestock Research Institute (ILRI) on 2 February 2012, discussed ILRI’s Rift Valley fever research program, potential collaborations with partners and options of controlling the mosquito-borne viral disease that affects cattle herds in eastern and southern Africa. Epidemics of the disease, which can also infect humans, emerge after above-average and widespread rainfall and lead to death and abortion in livestock.

Participating organizations, which are conducting research on Rift Valley fever, included Kenya’s ministries in charge of livestock development and public health, the universities of Nairobi and Egerton, Kenya Agricultural Research Institute and Kenya Medical Research Institute. Also attending the workshop were staff of the African Union Interafrican Bureau for Animal Resources (AU-IBAR), Swiss Tropical and Public Health Institute, the Nairobi office of the US Centres for Disease Control and Food and Agriculture Organization of the United Nations (FAO).

‘Our research in Rift Valley fever is benefitting from increasing collaboration,’ said Bernard Bett, an epidemiologist with ILRI. ‘These “joined up” efforts, are supporting joint assessments of the prevalence of zoonotic diseases in both animals and humans and are helping to increase the relevance of the research leading to more effective interventions.’

This strategy should lead to lower costs of doing research and implementing human and animal health interventions and a reduced burden of Rift Valley fever on the region’s livestock, people, wildlife and markets.

Esther Schelling, a epidemiologist with the Swiss Tropical and Public Health Institute, and formerly a researcher with ILRI, said: ‘Collaborative efforts in addressing the challenge of Rift Valley fever can support “one health” initiatives that seek to raise the research profile of neglected zoonotic diseases in Africa and improve the effectiveness of interventions through joint surveillance, preparedness and contingency planning to reduce the amount of time it takes to control outbreaks of these diseases.’

During the meeting, ILRI shared findings from a collaborative project known as ‘Enhancing prevention and control of Rift Valley fever in East Africa by inter-sectorial assessment of control options.’ For example, an analysis, by the project, of the public health burden of Rift Valley fever outbreaks measured in disability adjusted live years (DALYs) – the first of its kind in Kenya – shows that the 2006 and 2007 outbreak resulted in 3.4 DALYs per 1000 people and household costs of about Ksh 10,000 (USD120) for every human case reported. In 2008, ILRI estimated the disease cost the Kenyan economy USD30 million. Findings from the project also included a dynamic herd model developed for pastoral systems for simulating herd dynamics during normal and drought periods and in Rift Valley fever outbreaks. This model will be used to simulate the impacts of prevention and control options for the disease.

The Nairobi meeting discussed gaps in current research practice including the absence of climate models, sampling tools and methods to support decision support tools. Participants highlighted the need for a vector profile of the disease to enable mapping of most affected and high-risk areas and the need to understand how Rift Valley fever interacts between livestock and wildlife.

The prevention and control options discussed at the meeting will be further simulated using the herd dynamic model, which will be followed by an economic analysis using a process that was agreed on in an earlier (September 2011) workshop that discussed Rift Valley fever surveillance. A cost-benefit analysis of vaccination, vector control, surveillance, and sanitary measures is now scheduled. Results from the analysis will give much-needed evidence to support creation of policies and strategies for appropriate surveillance, prevention and control of Rift Valley fever in eastern Africa.

According to Tabitha Kimani, an agricultural economist with ILRI, ‘preliminary cost benefit analysis is already showing that it is beneficial to control Rift Valley fever through vaccination.’

 

Read more on Rift Valley fever research at ILRI and the region:

ILRI news archive

http://www.ilri.org/ilrinews/index.php?s=%22Rift+Valley+fever%22&submit=Search

ILRI clippings archive

http://ilriclippings.wordpress.com/2012/02/12/could-rift-valley-fever-be-a-weapon-of-mass-destruction-an-insidious-insect-animal-people-infection-loop-explored/

 

 

 

Amid soaring meat costs, officials from East Africa and Middle East seek plan to keep animal diseases from disrupting livestock trade

Orma Boran cattle crossing a river in Kenya

New approach to Rift Valley fever outbreaks aims to ensure food safety as region boosts livestock imports from Africa (photo credit: ILRI/Dolan)

With increased trade in livestock products offering a possible antidote to high food prices, livestock experts from the Middle East and 12 African countries are meeting this week (13-16 June, 2011) in Dubai to develop a strategy that eliminates the need to impose devastating bans on livestock imports from the Horn of Africa, as prevention against the spread of Rift Valley fever. The strategy should expedite the flow of livestock products while increasing safety of the overall livestock trade in the region.

Convened by the African Union’s Interafrican Bureau for Animal Resources (AU-IBAR), the International Livestock Research Institute (ILRI) and the United States Agency for International Development (USAID), the workshop will encourage officials and livestock traders to use a simple ‘Decision Support Planning Tool’ to guide and moderate their responses to Rift Valley fever outbreaks.

The ‘decision support tool’ for Rift Valley fever was developed by 30 experts and decisions-makers from across the Horn of Africa with technical assistance from researchers at ILRI, the United Nations’ Food and Agriculture Organization (FAO), and other partners. The tool will be used by chief veterinary officers and other national decision-makers. Its framework identifies the sequence of events likely to occur as the risk of a disease outbreak increases.

Rift Valley fever is a mosquito-borne virus found in eastern, western and southern Africa, Yemen and Saudi Arabia. Epidemics emerge periodically with prolonged rains. Climate and land-use changes could make outbreaks more frequent. A study done by ILRI economists Karl Rich and Francis Wanyoike indicated that the Rift Valley fever outbreak in 2007 cost Kenya at least USD32 million.

‘We must avoid unnecessary disruptions in agricultural trade between East Africa and the Middle East,’ said Ahmed El Sawalhy, director of AU-IBAR. ‘Livestock products must be safe and action concerning disease outbreaks must be in line with the actual threat.’ To this end, an animal health certification model suitable for pastoral livestock production systems and that promotes OIE standards has been developed by AU-IBAR in partnership with FAO and the Royal Veterinary College, London. The model is based on risk assessment and involves integration of both upstream animal health inspection and certification at entry points, markets and at the quarantines.

Time is also of critical importance in prevention and control of transboundary animal diseases. ‘In the last Kenyan Rift Valley fever outbreak, control measures were implemented late—not until there were definitive signs of an outbreak,’ said Jeffrey Mariner, an epidemiologist at ILRI. ‘This tool links early warning signs to control measures that can be implemented before animals or people begin falling ill. The new tool could reduce the impact of Rift Valley fever, and maybe even prevent some local outbreaks and has the potential to prevent the spread of Rift Valley fever through trade.’

‘The good news,’ says Bernard Bett, an epidemiologist at ILRI, ‘is that the impact of Rift Valley fever can be mitigated with early action during an outbreak, but veterinary officers and  decision-makers need to know what interventions to implement—and when—as the  stages of an epidemic  unfold.’

Rift Valley fever is best prevented through animal vaccination. But vaccines are expensive and few governments are willing to pay for expensive vaccines unless evidence indicates an epidemic is imminent. Regional cooperation is required to build consensus on managing the disease and to prevent trade disruptions.

Larry Meserve, USAID/EA’s regional mission director commented, ‘President Obama’s Feed the Future initiative aims to increase food security throughout Africa. To succeed, we must all help to improve the capacity of leadership in the Horn of Africa to anticipate potentially disastrous events like disease epidemics so that appropriate preventive or mitigating measures are taken before it is too late. Livestock is a vital staple crop in this part of the world, and both the private and public sectors have to do everything possible to prevent unnecessary disruptions in the trade of livestock and other commodities.’

Visit the official workshop blog site: http://rvfworkshop2011.wordpress.com

Kenya study finds prototype tsetse-repellent technology does not sufficiently protect cattle under normal field conditions

Testing a tsetse-repellent technology

Cattle fitted with tsetse-repellent dispensers suspended from neck collars were used to test the effectiveness of a prototype tsetse repellent in preventing tsetse fly bites (Photo credit: ILRI/Bett).

Recently published findings from a study done among Maasai livestock in Kenya to test whether repellents can successfully reduce tsetse fly bites in cattle show that tsetse-repellent technologies may have some success in typical field conditions but do not yet offer a viable alternative for controlling trypanosomosis in field-based livestock.

The study, ‘Field trial of a synthetic tsetse-repellent technology developed for the control of bovine trypanosomosis in Kenya,’ was the first to evaluate the use of a mobile tsetse repellent in the field. It was conducted between April 2005 and August 2006 in Nkuruman, in Kajiado District, and Nkineji, in Narok District.

Trypanosomosis is the most pervasive and serious cattle disease in sub-Saharan Africa. It kills between three and seven million cattle each year and costs farmers millions of dollars in lost production and treatment costs. The disease is transmitted mainly by blood-feeding tsetse flies that infect susceptible animals with the causative trypanosome parasite during their feeding. Other trypanosome parasites can infect humans, causing sleeping sickness, a disease that attacks the central nervous system.

Animal trypanosomosis is difficult to control because its spread is influenced by many factors, including the age, sex and colour of the cattle at risk as well as the herd size, its geographical area and climate. Adult and male cattle, for example, are more likely to contract the disease than calves and females. And tsetse flies prefer to take their feeds from animals with dark coats.

International Livestock Research Institute (ILRI) researchers Bernard Bett, Tom Randolph and John McDermott participated in the evaluation, which was designed with the help of veteran African tsetse researchers Glyn Vale and John Hargrove, and Steve Torr of Greenwich University (UK). The evaluation involved 2000 cattle: 1000 formed the control group, while the other 1000 animals were fitted with tsetse-repellent dispensers suspended from neck collars. The effectiveness of the repellent was then monitored for 16 months.

The study stipulated at the outset that the repellent would be considered effective if it reduced the incidence of trypanosomosis by 50 percent or more in the repellent-treated animals versus the control animals. Failure to achieve this level of reduction would mean that the repellent technology was clearly not ‘a viable alternative to existing control techniques’.

Results from the trial showed that the technology reduces trypanosomosis infection rates only modestly. ‘The synthetic repellent reduced the incidence of the disease only by 18 percent,’ said Bett, the ILRI scientist who implemented the trial.

Bett went on to explain that the technology had been proposed for evaluation based on initial experiments using stationary cattle that suggested that the repellents could reduce infection rates by more than 80 percent. ‘Under typical field conditions, however,’ said Bett, ‘the repellent did not provide adequate levels of protection, so we are recommending that it not be considered for further commercial development at this point.’

That the effectiveness of the repellent in the field was lower than expected could be attributed to both the fragile nature of the repellent dispensers, which, sensitive to abrasions, often leaked, as well as the repellent itself. Tsetse flies, especially hungry ones, will alight even on animals that smell bad to them. This is why people, for example, whose odour should put off tsetse flies, still get bitten by them.

‘The earlier experiments might have also overestimated the benefit of the technology,’ said Bett. ‘Those initial experiments evaluated the reduction in numbers of flies feeding on tethered cattle; other flies, however, could bite quickly without feeding and still transmit the disease before the repellent drives them away. In addition, while flies mainly use odour to find a stationary cow, they use vision more than odour to guide them to moving animals, such as those in the pastoralist herds used in the field trial.’

The study found that many variables determine the effectiveness of the repellent technology. Among these are changes in grazing (during the dry season, herders tend to move their stock to pastures with higher densities of tsetse) and herd sizes (the larger the herd, the lesser are the chances that an individual animal within the herd will be bitten). Trypanosomosis incidence also differed in the two test districts. While cattle were the preferred hosts for the flies in Narok, the cattle in Kajiado came fifth in fly preference—after warthog, elephant, zebra and buffalo—which reduced the effectiveness of the repellent worn by the cattle.

Bett says that ‘the results of this study show that the tsetse-repellent technologies currently proposed are unlikely to be useful replacements of existing methods of controlling trypanosomosis.’ These include keeping indigenous ‘trypanotolerant’ cattle breeds, which can tolerate trypanosome infections without getting sick; treating sick animals with trypanocidal drugs to cure them of the disease; introducing sterile tsetse flies into an area to reduce its tsetse population; and controlling tsetse populations using pyrethrum-based insecticides.’

The findings of this study should help scientists improve their research on methods for controlling tsetse fly populations and the trypanosomosis they spread. ‘In the short term, however,’ says Bett, ‘we need to continue sensitizing livestock keepers on how to best use the existing control methods.’

‘We also urgently need to develop integrated strategies for controlling the fly and disease,’ concludes Bett, ‘so that we stop over-relying on popular interventions, such as regularly treating cattle with trypanocides, which will inevitably lead to drug resistance in the trypanosome parasites.’

Read the complete findings of the evaluation on this link http://dx.doi.org/10.1016/j.prevetmed.2010.09.001

This blog entry by Tezira Lore, a communication specialist with ILRI’s Market Opportunities Theme, compares findings of this field trial with findings of other ILRI studies in typanosomosis.