A5060021315- Mosquito-borne diseases and control
- Viral Infections and Vectors
- Insect symbiosis and bacterial influences
- Vector-Borne Animal Diseases
- Malaria Research and Control
- Dengue and Mosquito Control Research
- Viral Infections and Outbreaks Research
- Vector-borne infectious diseases
- Insect Pest Control Strategies
- COVID-19 epidemiological studies
- Fire effects on ecosystems
- Zoonotic diseases and public health
- Yersinia bacterium, plague, ectoparasites research
- Poxvirus research and outbreaks
- Herpesvirus Infections and Treatments
- Primate Behavior and Ecology
- Insect Utilization and Effects
- Bacillus and Francisella bacterial research
- Insect Resistance and Genetics
- Neurobiology and Insect Physiology Research
- Parasite Biology and Host Interactions
- Olfactory and Sensory Function Studies
Kenya Medical Research Institute
2016-2025
United States Army Medical Research Directorate - Africa
2013-2020
United States Department of the Army
2013
Understanding the processes by which species colonize and adapt to human habitats is particularly important in case of disease-vectoring arthropods. The mosquito Aedes aegypti , a major vector dengue yellow fever viruses, probably originated as wild, zoophilic sub-Saharan Africa, where some populations still breed tree holes forested habitats. Many species, however, have evolved thrive bite humans. This includes within Africa well almost all those outside Africa. It not clear whether...
Mosquitoes, especially Aedes aegypti, are becoming important models for studying invasion biology. We characterized genetic variation at 12 microsatellite loci in 79 populations of Ae. aegypti from 30 countries six continents, and used them to infer historical modern patterns invasion. Our results support the two subspecies formosus as genetically distinct units. outside Africa derived ancestral African monophyletic. The co-occur both East (Kenya) West (Senegal). In rural/forest settings...
The majority of mosquito-borne illness is spread by a few mosquito species that have evolved to specialize in biting humans, yet the precise causes this behavioral shift are poorly understood. We address gap arboviral vector Aedes aegypti. first collect and characterize behavior mosquitoes from 27 sites scattered across species' ancestral range sub-Saharan Africa, revealing previously unrecognized variation preference for human versus animal odor. then use modeling show over 80% can be...
In December 2006, Rift Valley fever (RVF) was diagnosed in humans Garissa Hospital, Kenya and an outbreak reported affecting 11 districts. Entomologic surveillance performed four districts to determine the epidemic/epizootic vectors of RVF virus (RVFV). Approximately 297,000 mosquitoes were collected, 164,626 identified species, 72,058 sorted into 3,003 pools tested for RVFV by reverse transcription-polymerase chain reaction. Seventy-seven representing 10 species positive RVFV, including...
The drivers and patterns of zoonotic virus emergence in the human population are poorly understood. mosquito Aedes aegypti is a major arbovirus vector native to Africa that invaded most world's tropical belt over past four centuries, after evolution "domestic" form specialized biting humans breeding water storage containers. Here, we show specialization subsequent spread A. out were accompanied by an increase its intrinsic ability acquire transmit emerging pathogen Zika virus. Thus, recent...
Increased frequency of arbovirus outbreaks in East Africa necessitated the determination distribution risk by entomologic surveillance. A systematic vector surveillance programme spanning 5 years and covering 11 sites representing seven eight provinces Kenya located diverse ecological zones was carried out. Mosquitoes were sampled bi-annually during wet seasons screened for arboviruses. identified to species, pooled collection date site arboviruses isolation cell culture and/or RT-PCR...
Dengue outbreaks were first reported in East Africa the late 1970s to early 1980s including 1982 outbreak on Kenyan coast. In 2011, dengue occurred Mandera northern Kenya and subsequently Mombasa city along coast 2013-2014. Following laboratory confirmation of fever cases, an entomologic investigation was conducted establish mosquito species, densities, causing outbreak. Affected parts identified with help public health officials. Adult Ae. aegypti mosquitoes collected using various tools,...
Tick-borne viruses infect humans through the bite of infected ticks during opportunistic feeding or crushing by hand and, in some instances, contact with viremic animals. The Ijara District, an arid to semiarid region northern Kenya, is home a pastoralist community for whom livestock keeping way life. Part District lies within boundaries Kenya Wildlife Service–protected conservation area. Arbovirus activity among mosquitoes, animals, and reported region, mainly because prevailing conditions...
The diversity of mosquito arbovirus vectors was investigated to define regional risk transmission in Kenya. Mosquitoes were sampled between April, 2007 and December, 2010 at thirteen sites across seven administrative provinces ecological zones. CDC light traps used collect mosquitoes while human-landing collection conducted five the target day-feeding Aedes (Stegomyia) species. Over 524,000 collected identified into 101 species, 30 them known arboviruses endemic Ae. (Neomelaniconion)...
A broad diversity of arthropod-borne viruses (arboviruses) global health concern are endemic to East Africa, yet most surveillance efforts limited just a few key viral pathogens. Additionally, estimates arbovirus in the tropics likely be underestimated as their discovery has lagged significantly over past decades due limitations fast and sensitive identification methods. Here, we developed nearly pan-arbovirus detection assay that uses high-resolution melting (HRM) analysis RT-PCR products...
Chromosomal inversions play a fundamental role in evolution and have been shown to regulate epidemiologically important traits malaria mosquitoes. However, they never characterized Aedes aegypti, the major vector of arboviruses, because poor structure its polytene chromosomes. In this study, we applied Hi-C proximity ligation approach identify chromosomal 25 strains Ae. acquired from worldwide distribution, as well one strain mascarensis. The study identified 21 multi-megabase with uneven...
African populations of the mosquito Aedes aegypti are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear what extent true dengue (DENV), most prevalent flavivirus humans. Addressing question complicated substantial genetic diversity among DENV strains, notably in form four types (DENV1 DENV4), that can lead genetically specific...
Aedes aegypti ( Ae. ) is the primary vector of several arboviruses, including dengue virus (DENV), chikungunya (CHIKV), yellow fever (YFV), and Zika (ZIKV). This widespread globally in tropical subtropical areas but also found temperate areas. Kenya experienced its first outbreak Lamu County 2004, followed by subsequent outbreaks Mandera 2016 Mombasa 2017. Despite presence Kisumu Busia counties, no have been reported these two western counties. To investigate this phenomenon, we collected...
ABSTRACT We report the genome of a case mpox detected in Kenya involving truck driver with travel history to Uganda. Whole sequencing and phylogenetic analysis virus (MPXV) showed that clustered clade Ib, which was recently identified Democratic Republic Congo.
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 distribution vector-borne diseases. The first outbreak fever (DF) in Kenya occured 1982 coastal towns Malindi Kilifi. Unlike Nairobi where no active transmission has been reported, DF is currently re-emerging at Coast causing major outbreaks. This study investigated vector competence populations from two...
Background: Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Blood-fed mosquitoes collected during the 2006–2007 RVF outbreak Kenya were analyzed to determine virus infection status and animal source blood meals. Materials Methods: Blood meals from individual mosquito abdomens screened for viruses using Vero cells RT-PCR. DNA was also extracted cytochrome c oxidase 1 (CO1) b (cytb) genes amplified by PCR. Purified amplicons sequenced queried GenBank Barcode Life...
Aedes aegypti is a competent arthropod vector of chikungunya virus (CHIKV). The rate at which the disseminate in limited by temperature their environment can be an important determinant geographical and seasonal limits to transmission arthropods tropics. This study investigated competence Ae. for CHIKV ambient 32 26 °C (Coastal Western Kenya respectively) reared Extrinsic Incubation Temperature (EIT) that resembles those two regions. eggs were collected from coastal Kenya, hatched insectary...
Chikungunya is a reemerging vector borne pathogen associated with severe morbidity in affected populations. Lamu, along the Kenyan coast was by major chikungunya outbreak 2004. Twelve years later, we report on entomologic investigations and laboratory confirmed cases northeastern Kenya. Patient blood samples were received at Kenya Medical Research Institute (KEMRI) viral hemorrhagic fever immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) used to test for presence of IgM...
Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that found in most regions of sub-Saharan Africa, and it affects humans, livestock, some wild ungulates. Outbreaks are precipitated by an abundance mosquito vectors associated with heavy persistent rainfall flooding. We determined the impact flood-irrigation farming effect environmental parameters on ecology densities primary secondary RVF virus (RVFV) RVF-epidemic hotspot Tana River Basin, Kenya. Mosquito sampling was conducted...
Yellow fever, Dengue, West Nile and Zika viruses are re-emerging mosquito-borne Flaviviruses of public health concern. However, the extent human exposure to these associated disease burden in Kenya Africa at large remains unknown. We assessed seroprevalence fever other populations Pokot Turkana Counties Kenya. These areas border Uganda, South Sudan Ethiopia where recent outbreaks Dengue have been reported, with possibility spillover Human serum samples collected through a cross-sectional...
Abstract Adaptations to anthropogenic domestic habitats contribute the success of mosquito Aedes aegypti as a major global vector several arboviral diseases. The species inhabited African forests before expanding into and spreading other continents. Despite well‐studied evolutionary history, how this initially moved human settlements in Africa remains unclear. During initial habitat transition, Ae. switched their larval sites from natural water containers like tree holes artificial clay...
Mosquitoes collected during an outbreak of Rift Valley fever in Kenya from December 2006 to February 2007 were tested isolate other mosquito-borne arboviruses circulating the region. Twenty-seven virus isolations made comprising seven viruses three arbovirus families.
West Nile virus (WNV) is currently active in Kenya as evidenced by the detection of antibodies birds bled part an avian influenza surveillance program 2009. Although WNV has been isolated from several mosquito species Kenya, no studies have ever conducted to determine which these are competent vectors this virus. Therefore, we allowed Kenyan mosquitoes feed on 2- or 3-d-old chickens that had infected with a Lineage one strain 24–48 h earlier. These were tested ≈2 wk later infection,...
Rift Valley fever (RVF) outbreaks in Kenya have increased frequency and range to include northeastern where viruses are increasingly being isolated from known (Aedes mcintoshi) newly-associated (Ae. ochraceus) vectors. The factors contributing these changing outbreak patterns unclear the population genetic structure of key vectors and/or specific virus-vector associations, particular, under-studied. By conducting mitochondrial nuclear DNA analyses on >220 Kenyan specimens Ae. mcintoshi...