General research interests
My research interests are focused on understanding sources of variance in disease risk in wild populations of non-human primates. Research in disease ecology aims to understand principles that influence disease transmission over time and space. Studies of disease ecology are thus central to our understanding of disease prevalence and of zoonoses (diseases that can be transmitted between animals and humans). Within human and animal populations, individuals vary in their risk of disease; traits of the host, traits of the pathogens, and features of the environment all contribute to this variation. Despite a growing number of studies aimed at understanding how these factors influence disease risk, numerous sources of variation in disease risk are yet to be fully identified.
One health at human-non-human primate interfaces. Zoonotic pathogens are among the most important causes of ill health all over the world. Nonhuman primates are our close genetic relatives and share many zoonotic diseases with us. Consequently, studies of non-human primates provide data that are essential for understanding disease etiology, progression and transmission. Non-human primates(NHPs) have been implicated in the transmission of zoonoses and emerging diseases, which are increasingly important challenges facing medical and public health practitioners. In Kenya, the encroachment of NHP habitats has led to increased interaction between humans and NHPs with increasing risk of transmission of zoonoses. This study focused on two human-NHP interface sites adjacent to Tsavo National Parks and Tana River Primate Reserve. The objectives of our study were 1) to disseminate results from zoonotic epidemiological surveys carried out in the two study areas and 2) to brainstorm on the possible ways of reducing human-NHP interaction to limit zoonoses transmission.
Behavior and health in natural primate populations.
Host behavior contributes to variation in disease incidence by facilitating exposure to pathogens and subsequent transmission in natural environments, and also by influencing the host’s stress response and immune function.
Grooming and health. As a result, I decided to pursue my master’s degree in Medical Physiology at the University of Nairobi. My thesis focused on the relationship between grooming behavior, tick presence and tickborne infection in free ranging yellow baboons. The research project was carried out in collaboration with the Amboseli Baboon Research Project under the supervision of Dr. Susan Alberts, a faculty member in the department of biology, Duke University. Resulting from fieldwork at Amboseli and lab work at IPR and Duke University, I found that the more grooming the animal received the less likelihood of tick presence and tick borne infections. I was also able to demonstrate the prevalence of a zoonotic tickborne infection in this population of baboons.
Dynamics of Co-infection in wild primates. Parasites are ubiquitous in natural populations of animals. Furthermore, virtually all animals in natural populations have multiple parasite infections at any given time, i.e., they harbor parasite co-infections. When multiple parasites co-infect a host, they may influence each other by facilitating or inhibiting each other’s proliferation and transmission, often via immune-mediated processes. The aims of this project are to examine potential immune mechanisms regulating parasite co-infections in natural populations of nonhuman primates, and to measure the health consequences of these co-infections. Nonhuman primates are our close genetic relatives, and studies of nonhuman primates can therefore provide essential information regarding disease etiology, progression, and transmission, not only in nonhuman primate populations themselves, but in the human populations with which they share habitat.
Surveillance of zoonoses in understudied non-human primates. Disease surveillance in wildlife is challenging because of logistical and financial challenges associated with longitudinal sample collection especially in developing countries. There is thus scarce knowledge on pathogens that circulate in wildlife. In addition, mechanisms by which pathogens cross species barriers to infect multiple hosts including humans are still poorly understood. In this study, we aim to identify and characterize circulating coronaviruses and their associated host receptors in wild NHP populations in Kenya. Pathogen screening, typing and database creation is key in monitoring reservoirs of epidemic pathogens and in providing a starting point for vaccine development in the event of an outbreak. In addition, results from this study can give insights into the origins of human pathogens.