Doctor of Philosophy (PhD)


Veterinary Medical Sciences - Pathobiological Sciences

Document Type



Arthropod-borne viruses (arboviruses) are among the most common agents of human febrile illnesses worldwide. As crucially important emerging pathogens, they have caused multiple, notable epidemics of human disease and unnoticed epizootics over recent decades. Despite the public health relevance, very little is known about the geographic distribution of the agents and vectors, relative impact, and risk factors associated to the arboviral infection in many regions of the world and in the tropics in particular. Presented in this dissertation is an experimental study that explores the serology screening of serum samples from 151 patients whom were diagnosed with undifferentiated febrile illness in Sierra Leone, after ruling out endemic malaria and Lassa fever. Related to the laboratory results of the testing, three exploratory experiments on Koutango virus were developed. The experiment directed special interest into the vector mosquito Aedes aegypti and its ability to uptake, disseminate, and transmit the virus. The study of the early events occurring during the interaction between the virus and cells performed in the laboratory was another area of interest with the objective to predict the disease outcome. In order to explore the vertebrate viremia profile, we attempted to develop a suitable animal model for the Koutango virus study in the laboratory. The overall hypothesis of this research is that arboviruses circulating in West Africa are the cause of undiagnosed febrile illnesses. To investigate the hypothesis, this research explores the poorly understood epidemiological features and geographic range of certain endemic arboviruses, particularly the Koutango virus, and whether or not they circulate in the region with the Aedes aegypti mosquito being the competent vector that transmits the virus. The research in this dissertation contributes to the understanding of the epidemiological features and the actual expanding geographical range of many arboviruses. It describes the gold standard laboratory technique for the serology diagnostic of diverse arboviral diseases. In addition, it explores novel laboratory research techniques that may serve as an important tool for the implementation of effective surveillance programs necessary to explore and control the circulation of diverse arboviruses, particularly those associated with human illnesses in West Africa.



Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Mores, Christopher N