Abstract: Xenorhabdus spp. (Enterobacteriaceae) are endosymbionts of entomopathogenic nematodes from the Steinernema genus. They cause insect mortality by producing potent insecticidal toxin complexes composed of XptA1, XptA2 (class A), XptB1 (class C) and XptC1 (Class B) proteins. However, the use of only the bacterium as a biopesticide is limited as they depend on their nematode hosts for survival in the environment. The XptAs exhibit different spectra of activity, requiring XptB1 and XptC...
Abstract: Tsetse and trypanosomosis have been extensively studied and an array of vector and disease control measures have been developed and applied with varying degrees of success. Current trypanosomosis control strategies rely on use of trypanocidal drugs, breeding of trypanotolerant cattle and tsetse control or eradication. Since none of these control options has proved to be a fully viable solution to the control of trypanosomosis, search for more tsetse fly and trypanosomosis control m...
Abstract: Malaria is one of the public health problems facing people in many parts of Kenya including semi-arid areas. It is caused by an infectious bite of female Anopheles mosquitoes. To effectively implement malaria control program, the knowledge of colonization, resting behavior of the vectors and effect of distance between houses and breeding habitats on mosquito abundance is required. This research set out to determine seasonal dynamics, outdoor resting habits and colonization of larva...
Abstract: Susceptibility of Ae. aegypti mosquito to dengue virus (DENV) varies geographically and can be influenced by climatic factors such as temperature, which affect the incidence, seasonality and distribution of vector-borne diseases. The first outbreak of dengue fever (DF) in Kenya occured in 1982 in the coastal towns of Malindi and Kilifi. Unlike Nairobi where no active dengue transmission has been reported, DF is currently re-emerging at the Coast causing major outbreaks. This study ...
Abstract: Farmers’ knowledge on pesticides use, the practices and the associated health effects is of great importance. The effect of pesticides on human health and the environment is a major global public health issue. The main objective of this study was to determine the knowledge and practices on pesticide use against the bean fly and the associated health effects among bean smallholder farmers in Kabaru location, Nyeri County. A cross-sectional study design was used in which a semi-str...
Abstract: Arboviruses cause emerging and re-emerging infections affecting humans and animals. They are spread primarily by blood-sucking insects such as mosquitoes, ticks, midges and sand flies. Changes in climate, ecology, demographics, land-use patterns and increasing global travel have been linked to an upsurge in arboviral disease. Outbreaks occur periodically followed by persistent low level circulation. This study aimed at determining the seroepidemiology of selected arboviruses among ...
Description: A Thesis Submitted in Partial Fulfillment of Requirements for the Degree of Master of Science in Applied Veterinary Parasitology, Faculty of Veterinary Medicine University of Nairobi
Abstract: Aphids are the major pests of vegetables leading to a significant yield loss in African indigenous vegetables including amaranth and nightshades. Information on the types of aphids that infest these vegetables and their genetic diversity in Kenya and Tanzania is scanty. This is an important diagnostic component in developing management strategies such as integrated pest management and early detection and control of invasive species. This study used a fragment of the mitochondrial c...
Abstract: Tsetse fly-borne trypanosomiasis remains a significant problem in Africa despite years of interventions and research. The need for new strategies to control and possibly eliminate trypanosomiasis cannot be over-emphasized. Entomopathogenic fungi infect specific arthropod hosts through the cuticle and penetrate deep into the internal tissues causing death in about 3-14 days depending on the initial infectious dose. In addition, they can reduce blood feeding abilities in haematophago...
Abstract: Malaria remains a major health problem in africa, with anopheles gambiae giles as the principle vector. Plant nectar feeding forms an integral part of the vectorial capacity of this mosquito species, yet paucity of information on the nature of this behaviour persists. While it is recognized that olfactory cues play an important role in mediating orientation and attraction of mosquitoes to host plants as sources of sugar, little effort has been made to identify the kairomones involv...
Abstract: Sialo-oligosaccharides are found on the distal ends of glycans present on mammalian cell surfaces. They play major roles in cell growth, function, and are determinants of many disease states. Due to the important physiological role of glycoconjugates, there has been increased focus towards the development of drugs and vaccines that are carbohydrate based. Sialo-oligosaccharides can be synthesized through chemical means or by use of enzymes. Enzymes are preferred in the synthesis pr...
Abstract: Mosquito host seeking behaviour is mediated by chemical, physical and visual cues. Identification of chemical and physical cues utilized by mosquitoes in host location can lead to the development of novel vector management strategies. This research set out to identify synthetic odour blends that simulate human body emanations that can be used to develop mass trapping devices for vector management. The relative attractiveness of human body emanations and synthetic odour blends as at...
Abstract: During the course of malaria infection, a range of pro- and anti-inflammatory cytokines are produced by the host immune system. Successful recovery from malaria involves striking a balance between these counteracting cytokines. The cytokine imbalance contributes to pathological features but their exact levels have not been elucidated. The present study aimed at investigating the role played by circulating cytokines in pathophysiology of cerebral malaria. Using an experimental cereb...
Abstract: Arboviral pathogens are a growing public health problem especially in Africa. Bridge vectors facilitate virus transmission to humans from forest or sylvatic environments although the species involved are not fully understood. In this study, we investigated the role of Aedes chaussieri in sylvatic arboviral transmission cycle. Archived samples collected from the Oloolua Forest in the outskirts of Nairobi, Kenya, were analyzed in pools for viruses by cell culture in Vero Cells follow...
Abstract: Zoophilic mosquitoes play an important role in the transmission of arboviruses of medical importance at human-wildlife interfaces, yet arbovirus surveillance efforts have been focused mostly on anthropophilic mosquitoes. Besides pathogen identification, knowing mosquito blood-meal sources aids in identifying disease transmission trends and reservoir hosts during inter-epidemic periods, which can inform appropriate vector control strategies. We morphologically identified mosquito sp...