Edward Walker

Edward Walker
Michigan State University | MSU · Department of Microbiology and Molecular Genetics

PhD

About

456
Publications
59,150
Reads
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11,736
Citations
Citations since 2017
90 Research Items
4856 Citations
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20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
20172018201920202021202220230200400600800
Introduction
My position is full professor at Michigan State University, with appointments in the Department of Microbiology and Molecular Genetics and the Department of Entomology. Research areas: (1) insect/microbe interactions with emphasis on mosquitoes; (2) ecology of vector-borne zoonotic diseases; (3) ecology of urban-rural malaria; (4) interventional effects on malaria transmission and Anopheles population structure, including insecticide resistance; (5) interactions of irrigation and malaria.
Additional affiliations
January 1986 - present
Michigan State University
Position
  • Professor

Publications

Publications (456)
Article
Full-text available
West Nile virus (WNV) is prevalent in the United States but shows considerable variation in transmission intensity. The purpose of this study was to compare patterns of WNV seroprevalence in avian communities sampled in Atlanta, Georgia and Chicago, Illinois during a 12-year period (Atlanta 2010–2016; Chicago 2005–2012) to reveal regional patterns...
Article
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Background Despite the scale-up of insecticide-treated nets and indoor residual spraying, the bulk of malaria transmission in western Kenya still occurs indoors, late at night. House improvement is a potential long-term solution to further reduce malaria transmission in the region. Methods The impact of eave screening on mosquito densities was eva...
Article
Full-text available
Malaria remains a threat to public health in Malawi. It is well acknowledged that malaria research and robust evidence can have an impact on malaria policy and practice, resulting in positive population health gains. We report policy-relevant research contributions that the Malawi International Center of Excellence for Malaria Research (ICEMR) in p...
Article
Full-text available
Despite the scale-up of interventions against malaria over the past decade, this disease remains a leading threat to health in Malawi. To evaluate the epidemiology of both Plasmodium falciparum infection and malaria disease, the Malawi International Center of Excellence for Malaria Research (ICEMR) has developed and implemented diverse and robust s...
Article
Full-text available
Background Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control intervent...
Article
Full-text available
Dengue virus (DENV) is a highly prevalent vector-borne virus that causes life-threatening illnesses to humans worldwide. The development of a tool to control vector populations has the potential to reduce the burden of DENV. Toxic sugar bait (TSB) provides a form of vector control that takes advantage of the sugar-feeding behavior of adult mosquito...
Article
Two Culex pipiens form Pipiens colony strains and a field population of Cx. restuans from Michigan were susceptible and a Cx. pipiens form Molestus colony strain was comparatively less susceptible to a dose of 43 μg/ml of permethrin in Centers for Disease Control and Prevention (CDC) bottle bioassays. Using this diagnostic dose and these population...
Preprint
Background : Despite the scale-up of insecticide treated nets and indoor residual spraying, the bulk of malaria transmission in western Kenya still occurs indoors, late at night. House improvement is a potential long-term solution to further reduce malaria transmission in the region. Methods: We evaluated the impact of eave screening on mosquito de...
Article
Full-text available
Background Access to human hosts by Anopheles mosquitoes is a key determinant of vectorial capacity for malaria, but it can be limited by use of long-lasting insecticidal nets (LLINs). In Malawi, pyrethroid-treated LLINs with and without the synergist piperonyl butoxide (PBO) were distributed to control malaria. This study investigated the blood-fe...
Article
Full-text available
Background A malaria control programme based on distribution of long-lasting insecticidal bed nets (LLINs) and artemisinin combination therapy began in Papua New Guinea in 2009. After implementation of the programme, substantial reductions in vector abundance and malaria transmission intensity occurred. The research reported here investigated wheth...
Article
Sugar is an essential source of nutrition for adult mosquitoes to acquire energy. Toxic sugar bait (TSB) provides a promising method for mosquito control by incorporating toxins into artificial sources of sugar (i.e., toxic baits) presented to wild populations. Spinosyns comprise a family of bacterial secondary metabolites with a unique mode of act...
Article
Full-text available
Eastern equine encephalomyelitis (EEE) is a mosquito-borne viral disease that is an emerging public health concern in the state of Michigan. Although Michigan has one of the highest incidence rates of EEE in the United States, much of the information known about cases in humans, equines, and other animals residing in Michigan is unpublished. This a...
Article
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The emergence of nanotechnology has created unprecedented hopes for addressing several unmet industrial and clinical issues, including the growing threat so‐termed “antibiotic resistance” in medicine. Over the last decade, nanotechnologies have demonstrated promising applications in the identification, discrimination, and removal of a wide range of...
Article
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As countries of sub-Saharan Africa expand irrigation to improve food security and foster economic growth, it is important to quantify the malaria risk associated with this process. Irrigated ecosystems can be associated with increased malaria risk, but this relationship is not fully understood. We studied this relationship at the Bwanje Valley Irri...
Article
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Nonrandom selection and multiple blood feeding of human hosts by Anopheles mosquitoes may exacerbate malaria transmission. Both patterns of blood feeding and their relationship to malaria epidemiology were investigated in Anopheles vectors in Papua New Guinea (PNG). Blood samples from humans and mosquito blood meals were collected in villages and h...
Preprint
Full-text available
Background Selection of blood meal hosts by mosquitoes is a key variable in the vectorial capacity of Anopheles mosquitoes for human malaria. Blood feeding on humans is likely to be modulated by use of different types of long-lasting insecticidal nets (LLINs) and the effectiveness of LLINs is impacted by the relative intensity of insecticide resist...
Poster
Larval Aedes triseriatus mosquitoes live in the water-filled containers where they utilize plant detritus as carbon sources. During the microbial decomposition of leaf litter in container aquatic habitats, the chemical alterations and microbial processing of leaf litter releases compounds such as tannins into the water column, which affects the mos...
Article
Full-text available
Asaia bacteria commonly comprise part of the microbiome of many mosquito species in the genera Anopheles and Aedes, including important vectors of infectious agents. Their close association with multiple organs and tissues of their mosquito hosts enhances the potential for paratransgenesis for the delivery of antimalaria or antivirus effectors. The...
Article
During the 2019 Eastern equine encephalitis virus (EEEV) outbreak in Michigan, two 2-month old Mexican wolf pups experienced neurologic signs, lymphohistiocytic neutrophilic meningoencephalitis with neuronal necrosis and neuronophagia, and acute death. We identified EEEV by reverse transcription real-time PCR and in situ hybridization. Vector mosqu...
Preprint
Full-text available
Asaia bacteria commonly comprise part of the microbiome of many mosquito species in the genera Anopheles and Aedes, including important vectors of infectious agents. Their close association with multiple organs and tissues of their mosquito hosts enhances the potential for paratransgenesis for delivery of anti-malaria or anti-virus effectors. The m...
Article
Full-text available
Background Larval source management is recommended as a supplementary vector control measure for the prevention of malaria. Among the concerns related to larviciding is the feasibility of implementation in tropical areas with large numbers of habitats and the need for frequent application. Formulated products of spinosad that are designed to be eff...
Presentation
The use of long-lasting insecticidal nets has reduced the global malaria burden by impacting vector populations. Prior work suggests that piperonyl butoxide (PBO) impregnated nets (PBO nets) work better than pyrethroid only nets (Standard nets), especially in regions with pyrethroid insecticide resistance. We evaluated, in two sites in southern Mal...
Article
Full-text available
Abstract The citrus fruit fly Bactrocera (Tetradacus) minax is a major and devastating agricultural pest in Asian subtropical countries. Previous studies have shown that B. minax interacts with plant hosts via the efficient chemosensory system. However, the molecular components of the B. minax chemosensory system have not been well characterized. H...
Article
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In an era of big data, the availability of satellite-derived global climate, terrain, and land cover imagery presents an opportunity for modeling the suitability of malaria disease vectors at fine spatial resolutions, across temporal scales, and over vast geographic extents. Leveraging cloud-based geospatial analytical tools, we present an environm...
Article
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In this study, we investigated the global gene expression responses of Elizabethkingia anophelis to iron fluxes in the midgut of female Anopheles stephensi mosquitoes fed sucrose or blood, and in iron-poor or iron-rich culture conditions. Of 3,686 transcripts revealed by RNAseq technology, 218 were upregulated while 112 were down-regulated under ir...
Article
Full-text available
The bacterium Serratia fonticola strain S14, isolated from the midgut of a female Aedes triseriatus mosquito, has a genome size of 6,176,978 bp. The genome includes genes responsible for acyl-homoserine lactone-mediated quorum sensing, enterobactin, and aerobactin.
Article
Full-text available
Background: Determination of blood-meal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed ho...
Preprint
Full-text available
Background: Determination of blood-meal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed hos...
Article
Full-text available
The bacterium “Flavobacteriaceae strain W22,” was isolated from the water column of the tree hole larval habitat of the mosquito Aedes triseriatus. The draft genome contained 3,796,379 bp, G+C content of 35.7%, several genes encoding enzymes functioning in polysaccharide degradation, and gliding motility and type IX protein secretion system (T9SS).
Preprint
Full-text available
Background: Determination of bloodmeal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host...
Article
Full-text available
Background: The association between irrigation and the proliferation of adult mosquitoes including malaria vectors is well known; however, irrigation schemes are treated as homogenous spatio-temporal units, with little consideration for how larval breeding varies across space and time. The objective of this study was to estimate the spatio-tempora...
Preprint
Full-text available
Background: Determination of bloodmeal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host...
Article
Full-text available
Elizabethkingia anophelis 12012‐2 PRCM was isolated from a patient with multiple organ dysfunction syndrome and lower respiratory tract infection in China. Minimum inhibitory concentration (MIC) analysis demonstrated that it was resistant to 20 antibiotics including trimethoprim/sulfamethoxazole and ciprofloxacin, which were effective for the elimi...
Article
Full-text available
Three human clinical isolates of bacteria (designated strains Em1, Em2 and Em3) had high average nucleotide identity (ANI) to Elizabethkingia meningoseptica. Their genome sizes (3.89, 4.04 and 4.04 Mb) were comparable to those of other Elizabethkingia species and strains, and exhibited open pan-genome characteristics, with two strains being nearly...
Article
Three human clinical isolates of bacteria (designated strains Em1, Em2 and Em3) had high average nucleotide identity (ANI) to Elizabethkingia meningoseptica. Their genome sizes (3.89, 4.04 and 4.04 Mb) were comparable to those of other Elizabethkingia species and strains, and exhibited open pan-genome characteristics, with two strains being nearly...
Preprint
Full-text available
Elizabethkingia anophelis bacteria encounter fluxes of iron in the midgut of mosquitoes, where they live as symbionts. They also establish bacteremia with severe clinical manifestations in humans, and live in water service lines in hospitals. In this study, we investigated the global gene expression responses of E. anophelis to iron fluxes in the m...
Preprint
Full-text available
Three human clinical isolates of bacteria (designated strains Em1, Em2 and Em3) had high average nucleotide identity (ANI) to Elizabethkingia meningoseptica. Their genome sizes (3.89, 4.04 and 4.04 Mb) were comparable to those of other Elizabethkingia species and strains, and exhibited open pan-genome characteristics, with two strains being nearly...
Article
Full-text available
Background Community composition of Anopheles mosquitoes, and their host-seeking and peridomestic behaviour, are important factors affecting malaria transmission. In this study, barrier screen sampling was used to investigate species composition, abundance, and nocturnal activity of Anopheles populations in villages of Papua New Guinea. Methods Mo...
Article
Full-text available
Anopheles mosquitoes vary in habitat preference, feeding pattern, and susceptibility to various measures of vector control. Consequently, it is important that we identify reservoirs of disease, identify vectors, and characterize feeding patterns to effectively implement targeted control measures. Using 467 anopheline mosquito abdomen squashes captu...
Article
Full-text available
Genetic profiling has been used to link mosquito bloodmeals to the individual humans, but this analysis has not been done for other mammalian bloodmeals. In this study, we describe a microsatellite-based method for identifying individual pigs in mosquito bloodmeals based on their unique multilocus genotypes. Eleven tetranucleotide microsatellites a...
Preprint
Full-text available
Anopheles mosquitoes vary in habitat preference, feeding pattern, and susceptibility to various measures of vector control. Consequently, it is important that we identify reservoirs of disease, identify vectors, and characterize feeding patterns to effectively implement targeted control measures. Using 467 Anopheline mosquito abdomen squashes captu...
Article
Full-text available
Arthropod-borne viruses are among the most genetically constrained RNA viruses, yet they have a remarkable propensity to adapt and emerge. We studied wild birds and mosquitoes naturally infected with West Nile virus (WNV) in a 'hot spot' of virus transmission in Chicago, IL, USA. We generated full coding WNV genome sequences from spatiotemporally m...
Article
Full-text available
Background: Malaria is increasing in some recently urbanized areas that historically were considered lower risk. Understanding what drives urban transmission is hampered by inconsistencies in how "urban" contexts are defined. A dichotomized "urban-rural" approach, based on political boundaries may misclassify environments or fail to capture local...