Effects of grazing practices on transmission of pathogens between humans, domesticated animals, and wildlife in Laikipia, Kenya Explorers Club Project Brief Report Aimee Massey M.S. Candidate, University of Michigan, School of Natural Resources and Environment Summer 2011 Photo by Aimee Massey Background: As part of an Integrated Assessment project through the Graham Environmental Sustainability Institute and the University of Michigan s School of Natural Resources and Environment, I traveled to Laikipia, Kenya to investigate the role of zoonotic disease in conflicts between wildlife and a number of ranching communities in Laikipia. While there are an array of zoonotic diseases that impact the relationship between communities and wildlife in central Kenya, our project focused on the impacts of Q Fever. Q Fever is a bacterial disease known to affect the fertility of livestock and wildlife as well as cause malaria-like symptoms in humans that also has chronic implications for human health if not treated correctly. Much of central Kenya is focused in ecotourism and preserving wildlife as a means of economy; however, this is
contrasted with the inherent conflicts between wildlife and ranching and pastoralist communities. While literature has shown that there is facilitation and benefits for livestock grazing with the presence of other herding species in the savanna ecosystem (Rubenstein, 2010), there are still enduring ideologies, such as the transfer of disease from wildlife to the livestock communities that make coexistence of livestock and wildlife a contentious issue in ranching and pastoral communities. Project Description: The Integrated Assessment pilot project breached disciplines of research and involved a variety of stakeholders. As part of a team of student researchers from the University of Michigan, my goals included to identify and reach out to potential stakeholders who would want to be involved in subsequent disease ecology research in Kenya, to assist in interviews conducted with the varying stakeholders, and to collect serological data from livestock at different ranching communities. Thus, the project was divided into two major avenues of investigation: the socio-economic implications of disease in these rangeland communities and the ecological interactions between disease/livestock/wildlife. I. Socio-economic dynamics: Our team decided to tackle our questions related to the socioeconomic dynamics through a twofold process of developing a large network of stakeholders in Kenya and aboard and conducting interviews with the stakeholders deemed to be most intimately impacted by zoonotic disease, which included pastoralists, herders, and ranch personnel. The impact of pathogens is felt both through the health of the communities as well as through the impact to their economies. With little access to regular health care, many pastoralists and herders disregard the potential health impacts of disease. There is also the issue of misdiagnosis; many diseases in central Kenya present similar symptoms and often patients are treated for malaria without further testing. Perhaps seen as more important impact, pathogens also disrupt the functioning of the economies of these communities. Infertility and miscarriages in livestock can cause huge disruptions in the livelihoods of the pastoralists. While this is also an issue in the larger ranching communities, the structure of the pastoralist societies makes the impact of pathogens especially costly. Our interviews were designed to first assess the impact of disease among members of these communities and then to establish if Q Fever was a known disease and if the impacts of this disease were felt in the communities. II. Ecological dynamics: My primary role in the project was tied to the ecological implications of the role of disease in human/wildlife conflict. As previously stated, Photo by David O'Connor
Photo of Coxiella burnetti courtesy of Rocky Mountain Laboratory contraction of Q Fever is a serious health concern for humans, while conducting our interviews it became apparent that the more pressing issue was the potential implications it had for the health and fertility of livestock in the communities. Pastoralists and ranchers were most interested in discovering if Q Fever was in the livestock populations, and if it was to what degree it had infected the animals. What also became apparent were the differing attitudes towards wildlife between the ecotourism ranches and the more traditional pastoralist communities. The pastoralist communities had a more negative attitude towards wildlife; grazing species were blamed for competing with livestock for food while predator species were regularly seen as a threat to livestock when livestock were corralled in the bomas overnight. While the ranches also shared similar thoughts concerning wildlife, wildlife were also seen as an important economy to the ranches as a way of attracting tourists and promoting conservation so wildlife were actively protected. the zoonotic disease that our team focused on was Q Fever. Q Fever (Coxiella burnetti) is a bacterial pathogen that has an infectious dose of one bacterium, making it the most contagious pathogen known to man (Madariaga MG, 2003). While the health implications are not as severe as other diseases, it is still known to cause fatalities in both animals and humans. Q Fever is usually transmitted to humans through contact with infected livestock, including goats, sheep, and cattle (Arricau-Bouvery, 2005). Methods of infection are thought to be through the inhalation of endospores in livestock pens or through direct contact with blood, urine, feces, or milk of infected animals. While the Photo by David O'Connor As a result, I collected serological samples from livestock at six different ranching communities. Three communities consisted of the larger, ecotourism operations where wildlife densities were expected to be larger; the other three communities consisted of the traditional pastoralist communities where wildlife were more scarce across time due to lack of adequate grazing areas or from active discouragement from pastoralists. This allowed for our sampling to be split into two conditions that could be compared for Q Fever incidence. If a more abundant presence of wildlife was a factor in disease transmission between wildlife and livestock, then we could expect to see differences in the
incidence of Q Fever between the livestock at ecotourism ranches and at pastoralist communities. To test our assumption that wildlife was more abundant and dense at the ecotourism ranches than at the pastoralist communities, we obtained wildlife transect data for each site that is part of long-term, ongoing wildlife population research undertaken by Dr. Tim O Brien and Dr. Margaret Kinnaird at Mpala Research Centre in Laikipia. The methodology for blood collection and laboratory procedures for collecting serum samples was consistent across all sites. I collected over 200 samples, of which 192 were tested at the International Livestock Research Institute in Nairobi, Kenya for the presence of antibodies of the bacteria using a standard ELISA test. These samples were representative of cattle, sheep, goat, and camel populations from the six sites. Photo by Aimee Massey Preliminary Results: Our serological results were combined with the information we obtained through our interviews to assess if Q Fever is a disease of concern in Laikipia, Kenya. Due to previous testing of sheep at the Mpala Research Centre, we knew that there was a baseline presence of Coxiella burnetti at the Mpala ranch. Our more extensive sampling allowed us to see how widespread Q Fever is across Laikipia and if there were varying degrees of incidence between different ranch operations. While analysis has not yet been completed on the results from the blood samples, there are some preliminary results to report. We found that the highest incidence of Q Fever occurred in the camels tested at the Mpala ranch. However, this was the only camel population tested so we cannot make a comparison to the incidence of Q Fever in camels at other ranches. Otherwise, the incidence of Q Fever was low in cattle, sheep, and goats across all ranches and there does not seem to be any significant differences between the incidence of Coxiella between the larger, wildlife-friendly ranches and the pastoralist
communities. In fact, at one of the largest and most wildlife-dense sites, we found no positive results in the tested cattle population. Future Research: The pilot data are currently being compiled for a larger research grant to continue this Q Fever work in Laikipia. Using our network of stakeholders, future research will emphasize the relationship between actors and pathogens with more in-depth serological work including both livestock testing and human testing. Future research will also continue to stress the importance of the inclusion of actors at international, regional, and local levels. Special thanks to Dr. Johannes Foufopoulos, Dr. Rebecca Hardin, Dr. Margaret Kinnaird, Dr. Tim O Brien for guidance on this project; The Explorer s Club, Graham Environmental Sustainability Institute, School of Natural Resources and Environment, and Rackham Graduate School for financial support; Mpala Research Centre personnel for assistance and logistical support that made this project possible and helped maintain my sanity Photo by David O'Connor
References: Arricau-Bouvery, N. a. (2005). Is Q Fever an emerging or re-emerging zoonosis? Veterinary Research, 327-349. Madariaga MG, R. K. (2003). Q Fever: a biological weapon in your backyard. Lancet Infectious Disease, 709-721. Rubenstein, D. (2010). Ecology, Social Behavior, and Conservation of Zebras. Advances in the Study of Behavior, 231-258.