WSU Global Health - Kenya Faculty 

M. Kariuki Njenga

M. Kariuki Njenga

Professor of Epidemiology and Virology


  • WSU Paul G. Allen School for Global Health

Affiliated Organizations

  • Member, US National Academy of Medicine
  • American Society for Virology
  • Kenya Veterinary Association
Phone: +254-700354441 (Kenya)



Dr. Kariuki Njenga is Professor at the Washington State University Paul G. Allen School for Global Animal Health, and the Country Director of the WSU Global Health Program - Kenya. He holds a Bachelor of Veterinary Medicine and Master of Science degrees from the University of Nairobi, Kenya, and a PhD from the Pennsylvania State University, US. Dr. Njenga obtained 5 years of post-doctoral training at the Mayo Clinic in Rochester, Minnesota, US. His research training is in virology and immunology but he has gained extensive experience in conducting basic and field studies in infectious diseases over the past 16 years, resulting in publication of more than 170 peer-reviewed papers on the subject. Between 2004-2011 (8 years), Dr. Njenga served as Laboratory Director of the CDC in Kenya, first to establish and equip the laboratories and later to lead diagnostic testing for outbreaks in the horn of Africa and East Africa (Kenya, Somalia, Sudan, Ethiopia, Tanzania, Uganda, and Rwanda) for disease such as Rift Valley fever, Avian influenza, Hepatitis E, Leptospirosis, and anthrax. At CDC, Dr Njenga also worked with CDC epidemiologists to establish a human population-based syndromic surveillance for acute febrile illness, jaundice, respiratory illness and diarrheal in among urban and rural populations.

Between 2011 and 2014, Dr. Njenga served as head of the One Health Program at CDC-Kenya and the Kenya Medical Research Institute (KEMRI), focusing on establishing a multisectoral OH approach (setting up policies, institutions, and research) that enhanced Kenya’s efforts in preventing and controlling zoonotic diseases. For One Health research, he focused on conducting systematic burden of disease studies on priority episodic and endemic zoonotic diseases in the East Africa region, and studies at the animal-human-environment interface in order to elucidate the mechanisms of animal-to-human transmission. In addition, he was instrumental in developing a linked human-animal population based syndromic surveillance platform that investigated the nutritional, economic, and zoonotic interactions between rural sub-Saharan people and their livestock. 

Personal Statement

My desire to become a microbiologist and research scientist became obvious in my 2nd year of Veterinary School, and since then I have stayed the course. The pursuit of this path was inspired by two things; my early knowledge of the simplicity of a virus life cycle and its ability to harness the replication cycle of eukaryotic cells to propagate itself and cause disease, and a desire to do research, publish, and be cited by others. Apart from research, I love playing golf and lawn tennis, and traveling.

Education and Training

  • 1980-1985.  Bachelor of Veterinary Medicine (BVM), University of Nairobi, Nairobi, Kenya
  • 1986-1989.  Master of Science, University of Nairobi, Nairobi, Kenya
  • 1990-1994.  Doctor of Philosophy, Pennsylvania State University, State College, Pennsylvania, US
  • 1994-1999.  Postdoctoral Fellowship, Mayo Clinic and Foundation, Rochester, Minnesota, US

Curriculum Vitae

General Research / Expertise

Presently, Dr. Njenga manages a number of research grants funded by US Government agencies, including two from Centers for Disease Control and Prevention (CDC) and one from the DOD’s Defense Threat Reduction Agency (DTRA), totaling >$7million/year. The research focuses on investigating antimicrobial resistance (AMR) and the burden of emerging and endemic infectious diseases particularly zoonotic disease that cross from animals to humans, among the various populations of the people of Kenya. He also investigate the transmission mechanisms and pathways of AMR and zoonotic diseases from animals to humans, and ecological factors associated with the maintenance and persistence of these public health problems in different ecosystems.  

Research Contributions

Dr. Njenga’s most important research contributions are in two areas. First, to determine the burden of disease priority endemic and emerging zoonotic diseases in animals and humans the East Africa region in order to enhance their prevention and control. Second, to promote the understanding of how these diseases are maintained in the environment, and how they are transmitted from animals to humans.

Research Details

We highlight 3 areas in which Dr. Njenga’s research has been impactful.

1. Epidemiology and evolution of Rift Valley fever virus in East Africa.
Following another major epidemic of Rift Valley fever (RVF) in East Africa in 2006-2007, our team has over the past 10 years worked to characterize the genetic diversity of RVF virus strains involved in the sequential outbreaks in the East African countries, and subsequently developed a risk map for Kenya identifying the hotspot for RVF disease in livestock. We have also defined the mechanism of virus maintenance during the inter-epidemic periods through a cryptic cycle in livestock, human, and possibly wildlife. Most recently, we conducted field trials for a 2nd generation of RVF virus vaccine for livestock (cattle, sheep, goats) in order to support its registration in Eastern Africa and modeled the vaccination strategies in livestock. The outcome of these studies, published in >20 manuscripts, has been development of better RVF prevention and control policies in Kenya and the region, and enhanced preparedness for the periodic RVF epidemics in the region.

2. Population-based human syndromic surveillance in urban and rural Kenya to define burden and etiology of disease syndromes.
Working with CDC epidemiologists, we established two population-based syndromic surveillance sites in 2004-2005 – one in unban informal settlement (slum) with high poverty and poor sanitation, and the other in rural poor mixed (livestock and crop) farming community of Western Kenya.   We have published over 35 papers in this research area.

3. Studies at the human-animal interface to define the burden of endemic and emerging zoonotic diseases and investigate the beneficial and harmful interactions between humans and their livestock.
In addition to building an institutionalized One Health approach in Kenya, we have in the past 6 years conducted a series of cross-sectional studies to start defining the burden of zoonotic pathogens among rural and urban human populations and their animals in Kenya. These studies include investigating presence of emerging diseases as illustrated by the published study on Middle east respiratory syndrome coronavirus (MERS-CoV). In addition, we have established linked human-animal population based syndromic surveillance platform in an effort to investigate the nutritional, economic, and zoonotic interactions between rural sub-Saharan people and their livestock. We have published >10 manuscripts in this research area.

Select Publications
  • Munyua PM, Murithi RM, Ithondeka P, Hightower A, Thumbi SM, Anyangu SA, Kiplimo J, Bett B, Vrieling A, Breiman RF, Njenga MK. (2016) Predictive Factors and Risk Mapping for Rift Valley Fever Epidemics in Kenya. PLoS One. 11(1):e0144570. doi: 10.1371/journal.pone.0144570. PMID: 26808021 PMCID: PMC4726791
  • Luce-Fedrow A, Maina AN, Otiang E, Ade F, Omulo S, Ogola E, Ochieng L, Njenga MK, Richards AL. (2015) Isolation of Candidatus Rickettsia asemboensis from Ctenocephalides Fleas. Vector Borne Zoonotic Dis. PMID: 25897814 PMCID:
  • Nderitu L, Lee JS, Omolo J, Omulo S, O'Guinn ML, Hightower A, Mosha F, Mohamed M, Munyua P, Nganga Z, Hiett K, Seal B, Feikin DR, Breiman RF, Njenga MK. (2011) Sequential Rift Valley fever outbreaks in eastern Africa caused by multiple lineages of the virus. J Infect Dis. 203(5):655-65. doi: 10.1093/infdis/jiq004. PMID: 21282193 PMCID: PMC3071275
  • Richards AL, Jiang J, Omulo S, Dare R, Abdirahman K, Ali A, Sharif SK, Feikin DR, Breiman RF, Njenga MK. (2010) Human Infection with Rickettsia felis, Kenya. Emerg Infect Dis. PMID: 20587178 PMCID: PMC3321909
  • Njenga MK, Paweska J, Wanjala R, Rao CY, Weiner M, Omballa V, Luman ET, Mutonga D, Sharif S, Panning M, Drosten C, Feikin DR, Breiman RF. (2009) Using a field quantitative real-time PCR test to rapidly identify highly viremic rift valley fever cases. J Clin Microbiol. 47(4):1166-71. doi: 10.1128/JCM.01905-08. PMID: 19171680 PMCID: PMC2668310

Curriculum Vitae

List of Publications

Dr. Njenga’s research training is in virology and immunology but he have gained extensive experience in conducting basic and field studies in infectious diseases over the past 16 years. In 2017, he was elected into the United States’ National Academy of Medicine (