Rodents and bats as reservoirs of zoonoses: ecological and social determinants of human disease risk in Kenya

Lead Research Organisation: University of Glasgow
Department Name: School of Life Sciences

Abstract

Recent decades have seen a growing number of dangerous diseases spreading to humans from animal populations. Nearly two-thirds of new human diseases recognized in the past three decades originally came from animals, and two types of animals ? rodents and bats ? are responsible for a disproportionately large percentage of these. Scientists are still trying to understand how these diseases behave in their natural hosts, and what causes them to spill over into human populations, with often fatal consequences. Addressing these complex questions calls for new approaches to research, and particularly for the creation of new partnerships between scientists in different fields. Under the new paradigm, doctors must work closely with veterinarians; these allied health professionals must in turn engage with wildlife ecologists, environmental scientists, and those studying human behaviour, to create novel, effective partnerships that will enable us to predict and, importantly, prevent future disease outbreaks.

For the first time in human history, more of us now live in cities than in the countryside, and this number is still growing rapidly. More and more, cities will become the new battleground where the war against emerging diseases will be fought. Nowhere is this more true than in the slums of the third world, where nearly a third of the world?s population already live in overcrowded conditions, with inadequate access to safe water, sanitation and health services. Certain species of rodents and bats are adapted to this human environment, living in houses, stores, sewers and gardens, and exchanging pathogens through excreta, parasites (fleas, mites and ticks), or direct contact, including bites. In our increasingly connected world, a new human disease which emerges from such an environment has the capacity to spread rapidly across the globe, an event we have already witnessed with the emergence of SARS from bats in south-east Asia.

This project, led by the University of Glasgow with partners in Kenya, UK and USA, aims to bring together scientists from different backgrounds, ranging from human and animal health to history and social science. Their aim will be to help understand when and why human diseases emerge from animal hosts, and what can be done to prevent future outbreaks. The strength of the project lies in the creation of new, effective partnerships to address emerging disease threats, under the new paradigm of ?One World, One Health?.

Technical Summary

Emerging zoonotic diseases pose a growing threat to human health, but little is still known about the factors affecting pathogen dynamics in wild animal host populations or the specific drivers of emergence in humans. Of particular concern are rodent and bat species, which are disproportionately represented as hosts of human emerging zoonoses. Many rodent and bat species have adapted to and thrive in human environments, including informal urban settlements in developing countries, and pose a threat to public health by acting as reservoirs of pathogens that are capable of infecting humans. Transmission of these pathogens to humans is frequently fatal, as in the case of haemorrhagic fever viruses or plague. The current proposal aims to establish a novel, interdisciplinary research consortium to improve our understanding of the role of rodents and bats in the maintenance and spread of emerging and re-emerging infectious diseases in different human environments in a developing country, and to explore the ecological, social and cultural factors which may contribute to pathogen spill-over into human populations. Most research on the ecology of rodent and bat pathogens has been conducted in Europe, Asia and the Americas, with little known about these zoonotic pathogens in African contexts, particularly urban environments. There is also very little understanding of the social and cultural determinants of human disease risk in these settings. Specific questions which will be explored by the consortium include the effect of the natural and social environment on host community structure (species diversity and abundance); the influence of host community structure on the dynamics and infection risk for humans of a range of zoonotic pathogens; the social and cultural factors which determine if this background disease risk leads to human exposure and disease; and an examination of the historical occurrence of and response to rodent-borne zoonotic disease outbreaks in the selected study sites. These questions will be addressed through the creation of new, interdisciplinary, cross-sector partnerships encompassing teams involved in high-quality, innovative research across the spectrum of health, environmental, social and biological sciences, and involving stakeholders and end-users. Previous and ongoing research by existing medical-veterinary collaborations applying the concept of One Health in Kenya will form the nucleus of the new consortium.

Publications

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Halliday J (2012) Bringing together emerging and endemic zoonoses surveillance: shared challenges and a common solution. in Philosophical transactions of the Royal Society of London. Series B, Biological sciences

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Bouley AJ (2012) Brucellosis among hospitalized febrile patients in northern Tanzania. in The American journal of tropical medicine and hygiene

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Maina AN (2012) Rickettsia felis infection in febrile patients, western Kenya, 2007-2010. in Emerging infectious diseases

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Knobel DL (2013) Coxiella burnetii in humans, domestic ruminants, and ticks in rural western Kenya. in The American journal of tropical medicine and hygiene

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Vanderburg S (2014) Epidemiology of Coxiella burnetii infection in Africa: a OneHealth systematic review. in PLoS neglected tropical diseases

 
Description Zoonotic Disease Unit, Kenya
Geographic Reach Africa 
Policy Influence Type Participation in a national consultation
Impact Project was important catalyst for establishment of the zoonotic disease unit in Kenya, a cross-Ministry unit involved with policy development for zoonoses, including establishment of a national rabies control program (launched in September 2014) and a joint brucellosis surveillance program in Kenya involving the Ministry of Health and Ministry of Livestock, inclusion of zoonoses (for the first time) within the ISDR guidelines, inclusion of veterinarians within public health emergency response teams at both national and local levels.
URL http://zdukenya.org
 
Description Integrated Veterinary Training Fellowship
Amount £454,700 (GBP)
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2011 
End 09/2017
 
Description NSF NIH BBSRC Ecology of Infectious Diseases
Amount £1,088,000 (GBP)
Organisation National Institutes of Health (NIH) 
Sector Public
Country United States
Start 11/2011 
End 04/2015
 
Description Zoonoses and Emerging Livestock Systems - SEEDZ
Amount £2,738,706 (GBP)
Funding ID BB/L018926/1 
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start 10/2014 
End 09/2018
 
Description Collaboration with University of Aberdeen - rodent borne zoonoses (plague, leptospirosis) 
Organisation University of Aberdeen
Department School of Biological Sciences Aberdeen
Country United Kingdom 
Sector Academic/University 
PI Contribution Sharing of data across sites in Madagascar and Tanzania, inputs/advice on human febrile illness studies
Collaborator Contribution Support for training in rodent studies, shared expertise in laboratory diagnostics, contacts with other collaborators, sharing of data/experiences across sites in Madagascar and Tanzania
Impact Sharing of expertise, expanding contact networks for research on rodent-borne zoonoses
Start Year 2010
 
Description Duke University - febrile illness 
Organisation Duke University
Department School of Medicine Duke
Country United States 
Sector Academic/University 
PI Contribution Design of field epidemiological research for animal health studies, veterinary expertise, development of laboratory diagnostic tests for animal samples.
Collaborator Contribution Development of an integrated human-animal health research project in Tanzania, establishment of human febrile surveillance platform for research on bacterial zoonoses, shared use of laboratory diagnostic facilities, institutional support, training and capacity-building.
Impact Major new integrated human-animal health research project in northern Tanzania investigating bacterial zoonoses as causes of non-malaria febrile illness. Zhang HL, Kunda W, Mnzava KW, Mitchell ST, Melubo ML, Kibona TJ, Sharp JP, Kazwala RR, Cleaveland S, Crump JA, Halliday JEB. Mixed methods survey of zoonotic disease awareness and practice among animal and human healthcare providers in Moshi, Tanzania. Abstract 1105. 64th American Society of Tropical Medicine and Hygiene annual meeting, Philadelphia, PA, 25-29 October 2015.
Start Year 2011
 
Description Inter-disciplinary collaboration with social scientists 
Organisation University of Glasgow
Department School of Geographical and Earth Sciences Glasgow
Country United Kingdom 
Sector Academic/University 
PI Contribution Developing the multi-disciplinary teams, providing field infrastructure for research
Collaborator Contribution Providing expertise and training in social science methodology, building links with new African partners.
Impact One publication under review, new collaborative grant funding (BBSRC - £1,088,00), multi-disciplinary collaboration involving animal and human health and social sciences.
Start Year 2010
 
Description Moredun Research Institute 
Organisation Moredun Research Institute
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Provision of samples from East African and epidemiological data.
Collaborator Contribution Generation of data on toxoplama prevalence and strain typing in East Africa, training in laboratory diagnostic methods
Impact Papers in preparation.
Start Year 2010
 
Description Royal Tropical Institute, Netherlands 
Organisation Institute of Tropical Medicine Antwerp
Department Leptospirosis Reference Laboratory
Country Belgium 
Sector Academic/University 
PI Contribution Establishing links between field sites and reference laboratory, provision of field samples, generating grant income
Collaborator Contribution Support for leptospirosis research, particularly establishment of leptospirosis diagnostic capacity in Tanzania.
Impact New research collaboration for Leptospirosis in Tanzania recently started, training and capacity-building for UK and Tanzanian research personnel in Netherlands (training for two Glasgow staff completed in August/September 2012)
Start Year 2011
 
Description University of Antwerp 
Organisation University of Antwerp
Department Department of Zoology
Country Belgium 
Sector Academic/University 
PI Contribution Building collaborative links across projects in Tanzania, plans for sharing of rodent samples for Arena and Hantavirus analyses.
Impact Extended collaborative links in Tanzania, shared expertise, plans for sharing of rodent samples
Start Year 2011
 
Description Washington State University 
Organisation Washington State University
Department School of Global Animal Health
Country United States 
Sector Academic/University 
PI Contribution Establishing links between CDC/KEMRI and WSU to extend diagnostic capacity for zoonoses in Kenya; providing the operational platform for developing zoonoses surveillance projects in western Kenya. Establishing links between CDC/KEMRI and KCMC for developing diagnostic capacity in Tanzania and molecular epidemiology research in Q-fever and antimicrobial resistance.
Collaborator Contribution Training provided to Kenyan and Tanzanian staff in laboratory diagnostic methods at Washington State University, support for quality assurance, provision of reagents.
Impact Serological and PCR diagnosis for Q-fever established in Kenya and Tanzania.
Start Year 2011
 
Description Community outreach in Kenya 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact 350 community members involved in discussions about rodent-borne health risks in Kenya

Impacts not measured
Year(s) Of Engagement Activity 2011
 
Description Presentation at World Veterinary Congress 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Health professionals
Results and Impact Presentation sparked discussions regarding One Health engagement, in particular issues relating to shared use of laboratory facilities for human and animal diagnostic testing, and rationalisation of ethical review procedures for One Health research.

Impacts not measured
Year(s) Of Engagement Activity 2011