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Articles 61 - 90 of 128
Full-Text Articles in Diseases
Predicting Rift Valley Fever Inter-Epidemic Activities And Outbreak Patterns: Insights From A Stochastic Host-Vector Model, Sansao A. Pedro, Shirley Abelman, Henri E.Z. Tonnang
Predicting Rift Valley Fever Inter-Epidemic Activities And Outbreak Patterns: Insights From A Stochastic Host-Vector Model, Sansao A. Pedro, Shirley Abelman, Henri E.Z. Tonnang
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Rift Valley fever (RVF) outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in East Africa. Between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female Aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. Here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. By applying branching process theory we establish novel relationships between the basic reproduction number, R0, vertical transmission and the invasion and extinction probabilities. Optimum climatic conditions and presence …
Molecular Identification Of Different Trypanosome Species And Subspecies In Tsetse Flies Of Northern Nigeria, Clement Isaac, Marc Ciosi, Alana Hamilton, Kathleen Maria Scullion, Peter Dede, Igho Benjamin Igbinosa, Oyebiguwa Patrick Goddey Nmorsi, Dan Masiga, C. Michael R. Turner
Molecular Identification Of Different Trypanosome Species And Subspecies In Tsetse Flies Of Northern Nigeria, Clement Isaac, Marc Ciosi, Alana Hamilton, Kathleen Maria Scullion, Peter Dede, Igho Benjamin Igbinosa, Oyebiguwa Patrick Goddey Nmorsi, Dan Masiga, C. Michael R. Turner
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Background: Animal African Trypanosomiasis (AAT) is caused by several species of trypanosomes including Trypanosoma congolense, T. vivax, T. godfreyi, T. simiae and T. brucei. Two of the subspecies of T. brucei also cause Human African Trypanosomiasis. Although some of them can be mechanically transmitted by biting flies; these trypanosomes are all transmitted by tsetse flies which are the cyclical vectors of Trypanosoma congolense, T. godfreyi, T. simiae and T. brucei. We present here the first report assessing the prevalence of trypanosomes in tsetse flies in Nigeria using molecular tools. Methods: 488 tsetse flies of three species, Glossina palpalis palpalis, G. …
Association Of Ecological Factors With Rift Valley Fever Occurrence And Mapping Of Risk Zones In Kenya, Gladys Mosomtai, Magnus Evander, Per Sandström, Clas Ahlm, Rosemary Sang, Osama Ahmed Hassan, Hippolyte Affognon, Tobias Landmann
Association Of Ecological Factors With Rift Valley Fever Occurrence And Mapping Of Risk Zones In Kenya, Gladys Mosomtai, Magnus Evander, Per Sandström, Clas Ahlm, Rosemary Sang, Osama Ahmed Hassan, Hippolyte Affognon, Tobias Landmann
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Objective: Rift Valley fever (RVF) is a mosquito-borne infection with great impact on animal and human health. The objectives of this study were to identify ecological factors that explain the risk of RVF outbreaks in eastern and central Kenya and to produce a spatially explicit risk map. Methods: The sensitivity of seven selected ecological variables to RVF occurrence was assessed by generalized linear modelling (GLM). Vegetation seasonality variables (from normalized difference vegetation index (NDVI) data) and 'evapotranspiration' (ET) (metrics) were obtained from 0.25-1 km MODIS satellite data observations; 'livestock density' (N/km2), 'elevation' (m), and 'soil ratio' (fraction of all significant …
Uncertainty And Sensitivity Analysis Of A Rift Valley Fever Model, S. A. Pedro, H. E.Z. Tonnang, S. Abelman
Uncertainty And Sensitivity Analysis Of A Rift Valley Fever Model, S. A. Pedro, H. E.Z. Tonnang, S. Abelman
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Rift Valley fever (RVF) is a vector-borne viral disease with pronounced health and economic impacts on domestic animals and humans in much of sub-Saharan Africa. Using techniques of uncertainty and sensitivity analysis (both local derivatives and sampling-based methods) of a mathematical model for RVF transmission in livestock by two population of mosquitoes (Aedes and Culex). We systematically investigate the relative importance of each model parameter for both disease epidemic and endemic activities. The relationship between vertical transmission and basic reproduction number reveals that during epidemic activities vertical transmission accelerates the course of the outbreak as it increases the size of …
Species-Specific Adaptations Of Trypanosome Morphology And Motility To The Mammalian Host, Joel L. Bargul, Jamin Jung, Francis A. Mcodimba, Collins O. Omogo, Vincent O. Adung’A, Timothy Krüger, Daniel K. Masiga, Markus Engstler
Species-Specific Adaptations Of Trypanosome Morphology And Motility To The Mammalian Host, Joel L. Bargul, Jamin Jung, Francis A. Mcodimba, Collins O. Omogo, Vincent O. Adung’A, Timothy Krüger, Daniel K. Masiga, Markus Engstler
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African trypanosomes thrive in the bloodstream and tissue spaces of a wide range of mammalian hosts. Infections of cattle cause an enormous socio-economic burden in sub-Saharan Africa. A hallmark of the trypanosome lifestyle is the flagellate’s incessant motion. This work details the cell motility behavior of the four livestock-parasites Trypanosoma vivax, T. brucei, T. evansi and T. congolense. The trypanosomes feature distinct swimming patterns, speeds and flagellar wave frequencies, although the basic mechanism of flagellar propulsion is conserved, as is shown by extended single flagellar beat analyses. Three-dimensional analyses of the trypanosomes expose a high degree of dynamic pleomorphism, typified …
Phylogenetic Analysis Of Bunyamwera And Ngari Viruses (Family Bunyaviridae, Genus Orthobunyavirus) Isolated In Kenya, C. Odhiambo, M. Venter, O. Lwande, R. Swanepoel, R. Sang
Phylogenetic Analysis Of Bunyamwera And Ngari Viruses (Family Bunyaviridae, Genus Orthobunyavirus) Isolated In Kenya, C. Odhiambo, M. Venter, O. Lwande, R. Swanepoel, R. Sang
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Orthobunyaviruses, tri-segmented, negative-sense RNA viruses, have long been associated with mild to severe human disease in Africa, but not haemorrhagic fever. However, during a Rift Valley fever outbreak in East Africa in 1997-1998, Ngari virus was isolated from two patients and antibody detected in several others with haemorrhagic fever. The isolates were used to identify Ngari virus as a natural Orthobunyavirus reassortant. Despite their potential to reassort and cause severe human disease, characterization of orthobunyaviruses is hampered by paucity of genetic sequences. Our objective was to obtain complete gene sequences of two Bunyamwera virus and three Ngari virus isolates from …
Plant Resting Site Preferences And Parity Rates Among The Vectors Of Rift Valley Fever In Northeastern Kenya, Samwel O. Arum, Christopher W. Weldon, Benedict Orindi, Caroline Tigoi, Francis Musili, Tobias Landmann, David P. Tchouassi, Hippolyte D. Affognon, Rosemary Sang
Plant Resting Site Preferences And Parity Rates Among The Vectors Of Rift Valley Fever In Northeastern Kenya, Samwel O. Arum, Christopher W. Weldon, Benedict Orindi, Caroline Tigoi, Francis Musili, Tobias Landmann, David P. Tchouassi, Hippolyte D. Affognon, Rosemary Sang
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Background: Mosquito lifespan can influence the circulation of disease causing pathogens because it affects the time available for infection and transmission. The life-cycle of mosquitoes is determined by intrinsic and environmental factors, which can include the availability of hosts and suitable resting environments that shelter mosquitoes from extreme temperature and desiccating conditions. This study determined the parity rates (an indirect measure of survival) and plant resting preference of vectors of Rift Valley fever (RVF) in northeastern Kenya. Methods: Resting mosquitoes were trapped during the rainy and the dry season using a Prokopack aspirator from vegetation, whereas general adult populations were …
Mosquito Host Choices On Livestock Amplifiers Of Rift Valley Fever Virus In Kenya, David P. Tchouassi, Robinson O.K. Okiro, Rosemary Sang, Lee W. Cohnstaedt, David Scott Mcvey, Baldwyn Torto
Mosquito Host Choices On Livestock Amplifiers Of Rift Valley Fever Virus In Kenya, David P. Tchouassi, Robinson O.K. Okiro, Rosemary Sang, Lee W. Cohnstaedt, David Scott Mcvey, Baldwyn Torto
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Background: Animal hosts may vary in their attraction and acceptability as components of the host location process for assessing preference, and biting rates of vectors and risk of exposure to pathogens. However, these parameters remain poorly understood for mosquito vectors of the Rift Valley fever (RVF), an arboviral disease, and for a community of mosquitoes. Methods: Using three known livestock amplifiers of RVF virus including sheep, goat and cattle as bait in enclosure traps, we investigated the host-feeding patterns for a community of mosquitoes in Naivasha, an endemic area of Rift Valley fever (RVF), in a longitudinal study for six …
Complete Genome Sequence Of Staphylococcus Aureus, Strain Ilri_Eymole1/1, Isolated From A Kenyan Dromedary Camel, Saima Zubair, Anne Fischer, Anne Liljander, Jochen Meens, Jan Hegerman, Hadrien Gourlé, Richard P. Bishop, Ina Roebbelen, Mario Younan, Mudassir Imran Mustafa, Mamoona Mushtaq, Erik Bongcam-Rudloff, Joerg Jores
Complete Genome Sequence Of Staphylococcus Aureus, Strain Ilri_Eymole1/1, Isolated From A Kenyan Dromedary Camel, Saima Zubair, Anne Fischer, Anne Liljander, Jochen Meens, Jan Hegerman, Hadrien Gourlé, Richard P. Bishop, Ina Roebbelen, Mario Younan, Mudassir Imran Mustafa, Mamoona Mushtaq, Erik Bongcam-Rudloff, Joerg Jores
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We report the genome of a Staphylococcus aureus strain (ILRI_Eymole1/1) isolated from a nasal swab of a dromedary camel (Camelus dromedarius) in North Kenya. The complete genome sequence of this strain consists of a circular chromosome of 2,874,302 bp with a GC-content of 32.88 %. In silico annotation predicted 2755 protein-encoding genes and 76 non-coding genes. This isolate belongs to MLST sequence type 30 (ST30). Phylogenetic analysis based on a subset of 283 core genes revealed that it falls within the human clonal complex 30 (CC30) S. aureus isolate cluster but is genetically distinct. About 79 % of the protein …
Knowledge, Attitudes And Practices (Kap) On Rift Valley Fever Among Pastoralist Communities Of Ijara District, North Eastern Kenya, Ismail H. Abdi, Hippolyte D. Affognon, Anthony K. Wanjoya, Washington Onyango-Ouma, Rosemary Sang
Knowledge, Attitudes And Practices (Kap) On Rift Valley Fever Among Pastoralist Communities Of Ijara District, North Eastern Kenya, Ismail H. Abdi, Hippolyte D. Affognon, Anthony K. Wanjoya, Washington Onyango-Ouma, Rosemary Sang
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Outbreaks of Rift Valley fever (RVF), a mosquito-borne viral zoonosis, have previously been associated with unusually heavy rainfall and extensive flooding. The disease is a serious public health problem in Africa and the Middle East, and is a potential global health threat. In Kenya, outbreaks of the disease have disproportionately affected impoverished pastoralist communities. This study sought to assess the knowledge, attitudes and practices (KAP) regarding RVF among the pastoralists of North Eastern Kenya, and to establish the determinants of KAP on RVF. A cross-sectional study involving 392 pastoralists living in Ijara district (Masalani and Ijara wards) was carried out …
Linalool Oxide: Generalist Plant Based Lure For Mosquito Disease Vectors, Vincent O. Nyasembe, David P. Tchouassi, Charles M. Mbogo, Catherine L. Sole, Christian Pirk, Baldwyn Torto
Linalool Oxide: Generalist Plant Based Lure For Mosquito Disease Vectors, Vincent O. Nyasembe, David P. Tchouassi, Charles M. Mbogo, Catherine L. Sole, Christian Pirk, Baldwyn Torto
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Background: Lack of effective vaccines and therapeutics for important arboviral diseases such as Rift Valley fever (RVF) and dengue, necessitates continuous monitoring of vector populations for infections in them. Plant-based lures as surveillance tools has the potential of targeting mosquitoes of both sexes and females of varied physiological states; yet such lures are lacking for vectors of these diseases. Here, we present evidence of the effectiveness of linalool oxide (LO), a single plant-based lure previously developed for malaria vectors in trapping RVF vectors, Aedes mcintoshi and Aedes ochraceus, and dengue vector, Aedes aegypti. Methods: For RVF vectors, we used CDC …
Distribution And Diversity Of The Vectors Of Rift Valley Fever Along The Livestock Movement Routes In The Northeastern And Coastal Regions Of Kenya, Samwel O. Arum, Christopher W. Weldon, Benedict Orindi, Tobias Landmann, David P. Tchouassi, Hippolyte D. Affognon, Rosemary Sang
Distribution And Diversity Of The Vectors Of Rift Valley Fever Along The Livestock Movement Routes In The Northeastern And Coastal Regions Of Kenya, Samwel O. Arum, Christopher W. Weldon, Benedict Orindi, Tobias Landmann, David P. Tchouassi, Hippolyte D. Affognon, Rosemary Sang
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Background: Knowledge of vector ecology is important in understanding the transmission dynamics of vector borne disease. In this study, we determined the distribution and diversity of mosquitoes along the major nomadic livestock movement routes (LMR) in the traditional pastoral ecozone of northeastern Kenya. We focused on the vectors of Rift Valley fever virus (RVFv) with the aim of understanding their ecology and how they can potentially influence the circulation of RVFv. Methods: Mosquito surveys were conducted during the short and long rainy seasons from November 2012 to August 2014 using CO2-baited CDC light traps at seven sites selected for their …
Review Article: Sociocultural And Economic Dimensions Of Rift Valley Fever, Geoffrey Otieno Muga, Washington Onyango-Ouma, Rosemary Sang, Hippolyte Affognon
Review Article: Sociocultural And Economic Dimensions Of Rift Valley Fever, Geoffrey Otieno Muga, Washington Onyango-Ouma, Rosemary Sang, Hippolyte Affognon
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Health researchers have advocated for a cross-disciplinary approach to the study and prevention of infectious zoonotic diseases, such as Rift Valley Fever. It is believed that this approach can help bring out the social determinants and effects of the zoonotic diseases for the design of appropriate interventions and public health policy. A comprehensive literature review using a systematic search strategy was undertaken to explore the sociocultural and economic factors that influence the transmission and spread of Rift Valley Fever. Although the findings reveal a paucity of social research on Rift Valley Fever, they suggest that livestock sacrificial rituals, food preparation …
Population Genetics Of Two Key Mosquito Vectors Of Rift Valley Fever Virus Reveals New Insights Into The Changing Disease Outbreak Patterns In Kenya, David P. Tchouassi, Armanda D.S. Bastos, Catherine L. Sole, Mawlouth Diallo, Joel Lutomiah, James Mutisya, Francis Mulwa, Christian Borgemeister, Rosemary Sang, Baldwyn Torto
Population Genetics Of Two Key Mosquito Vectors Of Rift Valley Fever Virus Reveals New Insights Into The Changing Disease Outbreak Patterns In Kenya, David P. Tchouassi, Armanda D.S. Bastos, Catherine L. Sole, Mawlouth Diallo, Joel Lutomiah, James Mutisya, Francis Mulwa, Christian Borgemeister, Rosemary Sang, Baldwyn Torto
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Rift Valley fever (RVF) outbreaks in Kenya have increased in frequency and range to include northeastern Kenya where viruses are increasingly being isolated from known (Aedes mcintoshi) and newly-associated (Ae. ochraceus) vectors. The factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. By conducting mitochondrial and nuclear DNA analyses on >220 Kenyan specimens of Ae. mcintoshi and Ae. ochraceus, we uncovered high levels of vector complexity which may partly explain the disease outbreak pattern. Results indicate that Ae. mcintoshi consists of a species complex …
Occurrence Of Rift Valley Fever In Cattle In Ijara District, Kenya, Nelson O. Owange, William O. Ogara, Hippolyte Affognon, Gathura B. Peter, Jacqueline Kasiiti, Sam Okuthe, W. Onyango-Ouma, Tobias Landmann, Rosemary Sang, Murithi Mbabu
Occurrence Of Rift Valley Fever In Cattle In Ijara District, Kenya, Nelson O. Owange, William O. Ogara, Hippolyte Affognon, Gathura B. Peter, Jacqueline Kasiiti, Sam Okuthe, W. Onyango-Ouma, Tobias Landmann, Rosemary Sang, Murithi Mbabu
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Ijara district in Kenya was one of the hotspots of rift valley fever (RVF) during the 2006/2007 outbreak which led to human and animal deaths causing huge economic and public health losses. The main constraint in the control and prevention of RVF is inadequate knowledge on its occurrence during the interepidemic period. This study was aimed at understanding the occurrence of RVF in cattle in Ijara to enable the development of improved community-based disease surveillance, prediction, control and prevention.Six herds each 700-1000 cattle were identified with participatory involvement of locals and project technical team of the project. One animal per …
Stability, Bifurcation And Chaos Analysis Of Vector-Borne Disease Model With Application To Rift Valley Fever, Sansao A. Pedro, Shirley Abelman, Frank T. Ndjomatchoua, Rosemary Sang, Henri E.Z. Tonnang
Stability, Bifurcation And Chaos Analysis Of Vector-Borne Disease Model With Application To Rift Valley Fever, Sansao A. Pedro, Shirley Abelman, Frank T. Ndjomatchoua, Rosemary Sang, Henri E.Z. Tonnang
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This paper investigates a RVF epidemic model by qualitative analysis and numerical simulations. Qualitative analysis have been used to explore the stability dynamics of the equilibrium points while visualization techniques such as bifurcation diagrams, Poincaré maps, maxima return maps and largest Lyapunov exponents are numerically computed to confirm further complexity of these dynamics induced by the seasonal forcing on the mosquitoes oviposition rates. The obtained results show that ordinary differential equation models with external forcing can have rich dynamic behaviour, ranging from bifurcation to strange attractors which may explain the observed fluctuations found in RVF empiric outbreak data, as well …
Human African Trypanosomiasis Research Gets A Boost: Unraveling The Tsetse Genome, Serap Aksoy, Geoffrey Attardo, Matt Berriman, Alan Christoffels, Mike Lehane, Dan Masiga, Yeya Toure
Human African Trypanosomiasis Research Gets A Boost: Unraveling The Tsetse Genome, Serap Aksoy, Geoffrey Attardo, Matt Berriman, Alan Christoffels, Mike Lehane, Dan Masiga, Yeya Toure
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Human African trypanosomiasis (HAT), also known as sleeping sickness, is a neglected disease that impacts 70 million people distributed over 1.55 million km2 in sub-Saharan Africa [1]. Trypanosoma brucei gambiense accounts for almost 90% of the infections in central and western Africa, the remaining infections being from T. b. rhodesiense in eastern Africa [1]. Furthermore, the animal diseases caused by related parasites inflict major economic losses to countries already strained [2]. The parasites are transmitted to the mammalian hosts through the bite of an infected tsetse fly.
Comparative Diagnostic And Analytical Performance Of Pcr And Lamp-Based Trypanosome Detection Methods Estimated Using Pooled Whole Tsetse Flies And Midguts, Imna I. Malele, Johnson O. Ouma, John C.K. Enyaru, Enock Matovu, Vincent Alibu, Joanna E. Auma, Samuel G. Onyoyo, Rosemary Bateta, Robert E. Changasi, Phoebe W. Mukiria, Kariuki Ndung'u, Purity K. Gitonga, Lilian M. Mwaniki, Hamisi S. Nyingilili, Eugene A. Lyaruu, Lupakisyo A. Kapange, Peter Kuria Kamau, Daniel K. Masiga
Comparative Diagnostic And Analytical Performance Of Pcr And Lamp-Based Trypanosome Detection Methods Estimated Using Pooled Whole Tsetse Flies And Midguts, Imna I. Malele, Johnson O. Ouma, John C.K. Enyaru, Enock Matovu, Vincent Alibu, Joanna E. Auma, Samuel G. Onyoyo, Rosemary Bateta, Robert E. Changasi, Phoebe W. Mukiria, Kariuki Ndung'u, Purity K. Gitonga, Lilian M. Mwaniki, Hamisi S. Nyingilili, Eugene A. Lyaruu, Lupakisyo A. Kapange, Peter Kuria Kamau, Daniel K. Masiga
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Detection of trypanosomes that cause disease in human beings and livestock within their tsetse fly hosts is an essential component of vector and disease control programmes. Several molecular-based diagnostic tests have been developed for this purpose. Many of these tests, while sensitive, require analysis of trypanosome DNA extracted from single flies, or from pooled tsetse fly heads and amplified trypanosome DNA. In this study, we evaluated the relative analytical and diagnostic sensitivities of two PCR-based tests (ITS and TBR) and a Trypanozoon specific LAMP assay using pooled whole tsetse flies and midguts spiked with serially diluted procyclics of a laboratory …
Camel Streptococcus Agalactiae Populations Are Associated With Specific Disease Complexes And Acquired The Tetracycline Resistance Gene Tetm Via A Tn916-Like Element, Anne Fischer, Anne Liljander, Heike Kaspar, Cecilia Muriuki, Hans Henrik Fuxelius, Erik Bongcam-Rudloff, Etienne P. De Villiers, Charlotte A. Huber, Joachim Frey, Claudia Daubenberger, Richard Bishop, Mario Younan, Joerg Jores
Camel Streptococcus Agalactiae Populations Are Associated With Specific Disease Complexes And Acquired The Tetracycline Resistance Gene Tetm Via A Tn916-Like Element, Anne Fischer, Anne Liljander, Heike Kaspar, Cecilia Muriuki, Hans Henrik Fuxelius, Erik Bongcam-Rudloff, Etienne P. De Villiers, Charlotte A. Huber, Joachim Frey, Claudia Daubenberger, Richard Bishop, Mario Younan, Joerg Jores
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Camels are the most valuable livestock species in the Horn of Africa and play a pivotal role in the nutritional sustainability for millions of people. Their health status is therefore of utmost importance for the people living in this region. Streptococcus agalactiae, a Group B Streptococcus (GBS), is an important camel pathogen. Here we present the first epidemiological study based on genetic and phenotypic data from African camel derived GBS. Ninety-two GBS were characterized using multilocus sequence typing (MLST), capsular polysaccharide typing and in vitro antimicrobial susceptibility testing. We analysed the GBS using Bayesian linkage, phylogenetic and minimum spanning tree …
Parasitological Prevalence Of Bovine Trypanosomosis In Kubo Division Of Kwale County Of Coastal: Baseline Survey, N. Mbahin, H. Affognon, J. Andoke, M. Tiberius, D. Mbuvi, J. Otieno, P. Muasa, R. K. Saini
Parasitological Prevalence Of Bovine Trypanosomosis In Kubo Division Of Kwale County Of Coastal: Baseline Survey, N. Mbahin, H. Affognon, J. Andoke, M. Tiberius, D. Mbuvi, J. Otieno, P. Muasa, R. K. Saini
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Prior to field trials of large scale tsetse repellent technology validation in July 2011, a cross-sectional survey of bovine trypanosomosis and its vectors was carried out to know the disease level in Kwale County of Coastal Kenya. A total of 584 adult cattle were examined at ten different Locations. The trypanosome prevalence in cattle with regard to age, sex, location and apparent tsetse density was investigated. The overall trypanosome prevalence in cattle in Kubo Division of Kwale County was 33.9%. Two types of infections were recorded in various parts of the Division in the following proportions: T. congolense 61.1%, T. …
Common Host-Derived Chemicals Increase Catches Of Disease-Transmitting Mosquitoes And Can Improve Early Warning Systems For Rift Valley Fever Virus, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Peter E.A. Teal, Christian Borgemeister, Baldwyn Torto
Common Host-Derived Chemicals Increase Catches Of Disease-Transmitting Mosquitoes And Can Improve Early Warning Systems For Rift Valley Fever Virus, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Peter E.A. Teal, Christian Borgemeister, Baldwyn Torto
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Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health and veterinary problem in sub-Saharan Africa. Surveillance to monitor mosquito populations during the inter-epidemic period (IEP) and viral activity in these vectors is critical to informing public health decisions for early warning and control of the disease. Using a combination of field bioassays, electrophysiological and chemical analyses we demonstrated that skin-derived aldehydes (heptanal, octanal, nonanal, decanal) common to RVF virus (RVFV) hosts including sheep, cow, donkey, goat and human serve as potent attractants for RVFV mosquito vectors. Furthermore, a blend formulated from the four aldehydes and combined with …
Sheep Skin Odor Improves Trap Captures Of Mosquito Vectors Of Rift Valley Fever, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Klaus Mithoefer, Baldwyn Torto
Sheep Skin Odor Improves Trap Captures Of Mosquito Vectors Of Rift Valley Fever, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Klaus Mithoefer, Baldwyn Torto
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In recent years, the East African region has seen an increase in arboviral diseases transmitted by blood-feeding arthropods. Effective surveillance to monitor and reduce incidence of these infections requires the use of appropriate vector sampling tools. Here, trapped skin volatiles on fur from sheep, a known preferred host of mosquito vectors of Rift Valley fever virus (RVFV), were used with a standard CDC light trap to improve catches of mosquito vectors. We tested the standard CDC light trap alone (L), and baited with (a) CO2 (LC), (b) animal volatiles (LF), and (c) CO2 plus animal volatiles (LCF) in two highly …
Viral Metagenomics Demonstrates That Domestic Pigs Are A Potential Reservoir For Ndumu Virus, Charles Masembe, George Michuki, Maria Onyango, Cecilia Rumberia, Martin Norling, Richard P. Bishop, Appolinaire Djikeng, Stephen J. Kemp, Alan Orth, Robert A. Skilton, Karl Ståhl, Anne Fischer
Viral Metagenomics Demonstrates That Domestic Pigs Are A Potential Reservoir For Ndumu Virus, Charles Masembe, George Michuki, Maria Onyango, Cecilia Rumberia, Martin Norling, Richard P. Bishop, Appolinaire Djikeng, Stephen J. Kemp, Alan Orth, Robert A. Skilton, Karl Ståhl, Anne Fischer
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Background: The rising demand for pork has resulted in a massive expansion of pig production in Uganda. This has resulted in increased contact between humans and pigs. Pigs can act as reservoirs for emerging infectious diseases. Therefore identification of potential zoonotic pathogens is important for public health surveillance. In this study, during a routine general surveillance for African swine fever, domestic pigs from Uganda were screened for the presence of RNA and DNA viruses using a high-throughput pyrosequencing method. Findings. Serum samples from 16 domestic pigs were collected from five regions in Uganda and pooled accordingly. Genomic DNA and RNA …
Trapping Of Rift Valley Fever (Rvf) Vectors Using Light Emitting Diode (Led) Cdc Traps In Two Arboviral Disease Hot Spots In Kenya, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Lee W. Cohnstaedt, Baldwyn Torto
Trapping Of Rift Valley Fever (Rvf) Vectors Using Light Emitting Diode (Led) Cdc Traps In Two Arboviral Disease Hot Spots In Kenya, David P. Tchouassi, Rosemary Sang, Catherine L. Sole, Armanda D.S. Bastos, Lee W. Cohnstaedt, Baldwyn Torto
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Background: Mosquitoes response to artificial lights including color has been exploited in trap designs for improved sampling of mosquito vectors. Earlier studies suggest that mosquitoes are attracted to specific wavelengths of light and thus the need to refine techniques to increase mosquito captures following the development of super-bright light-emitting diodes (LEDs) which emit narrow wavelengths of light or very specific colors. Therefore, we investigated if LEDs can be effective substitutes for incandescent lamps used in CDC light traps for mosquito surveillance, and if so, determine the best color for attraction of important Rift Valley Fever (RFV) vectors. Methods. The efficiency …
The Origin Of The 'Mycoplasma Mycoides Cluster' Coincides With Domestication Of Ruminants, Anne Fischer, Beth Shapiro, Cecilia Muriuki, Martin Heller, Christiane Schnee, Erik Bongcam-Rudloff, Edy M. Vilei, Joachim Frey, Joerg Jores
The Origin Of The 'Mycoplasma Mycoides Cluster' Coincides With Domestication Of Ruminants, Anne Fischer, Beth Shapiro, Cecilia Muriuki, Martin Heller, Christiane Schnee, Erik Bongcam-Rudloff, Edy M. Vilei, Joachim Frey, Joerg Jores
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The 'Mycoplasma mycoides cluster' comprises the ruminant pathogens Mycoplasma mycoides subsp. mycoides the causative agent of contagious bovine pleuropneumonia (CBPP), Mycoplasma capricolum subsp. capripneumoniae the agent of contagious caprine pleuropneumonia (CCPP), Mycoplasma capricolum subsp. capricolum, Mycoplasma leachii and Mycoplasma mycoides subsp. capri. CBPP and CCPP are major livestock diseases and impact the agricultural sector especially in developing countries through reduced food-supply and international trade restrictions. In addition, these diseases are a threat to disease-free countries. We used a multilocus sequence typing (MLST) approach to gain insights into the demographic history of and phylogenetic relationships among the members of the 'M. …
Compatibility Between Calpurnia Aurea Leaf Extract, Attraction Aggregation, And Attachment Pheromone And Entomopathogenic Fungus Metarhizium Anisopliae On Viability, Growth, And Virulence Of The Pathogen, Paulin Nana, Nguya K. Maniania, Rosebella O. Maranga, Hamadi I. Boga, Helen L. Kutima, Jacobus N. Eloff
Compatibility Between Calpurnia Aurea Leaf Extract, Attraction Aggregation, And Attachment Pheromone And Entomopathogenic Fungus Metarhizium Anisopliae On Viability, Growth, And Virulence Of The Pathogen, Paulin Nana, Nguya K. Maniania, Rosebella O. Maranga, Hamadi I. Boga, Helen L. Kutima, Jacobus N. Eloff
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Metarhizium anisopliae sensu stricto (ss) (Metsch.) Sorok. isolate ICIPE 07 is being developed as biopesticide for the control of ticks. In addition, leaf extracts of Calpurnia aurea Benth, and the attraction aggregation and attachment pheromone (AAAP) are being used as ticks' attractant. The three agents are being considered for use in combination in an autodissemination approach, whereby ticks that are attracted to semiochemicals are infected with the inoculum. Experiments were therefore conducted to evaluate in vitro the compatibility between C. aurea, AAAP, and the M. anisopliae on vegetative growth, conidial production, and spore viability. Calpurnia aurea leaf extract was compatible …
The 2007 Rift Valley Fever Outbreak In Sudan, Osama Ahmed Hassan, Clas Ahlm, Rosemary Sang, Magnus Evander
The 2007 Rift Valley Fever Outbreak In Sudan, Osama Ahmed Hassan, Clas Ahlm, Rosemary Sang, Magnus Evander
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Rift Valley fever (RVF) is a neglected, emerging, mosquito-borne disease with severe negative impact on human and animal health and economy. RVF is caused by RVF virus (RVFV) affecting humans and a wide range of animals. The virus is transmitted through bites from mosquitoes and exposure to viremic blood, body fluids, or tissues of infected animals. During 2007 a large RVF outbreak occurred in Sudan with a total of 747 confirmed human cases including 230 deaths (case fatality 30.8%); although it has been estimated 75,000 were infected. It was most severe in White Nile, El Gezira, and Sennar states near …
Landmarks In The Evolution Of Technologies For Identifying Trypanosomes In Tsetse Flies, John C. Enyaru, Johnson O. Ouma, Imna I. Malele, Enock Matovu, Daniel K. Masiga
Landmarks In The Evolution Of Technologies For Identifying Trypanosomes In Tsetse Flies, John C. Enyaru, Johnson O. Ouma, Imna I. Malele, Enock Matovu, Daniel K. Masiga
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Understanding what the trypanosome pathogens are, their vectors and mode of transmission underpin efforts to control the disease they cause in both humans and livestock. The risk of transmission is estimated by determining what proportion of the vector population is carrying the infectious pathogens. This risk also depends on the infectivity of the trypanosomes to humans and livestock. Most livestock pathogens are not infective to humans, whereas the two sub-species that infect humans also infect livestock. As with other infectious diseases, we can therefore trace the foundation of many continuing disease control programs for trypanosomiasis to the discovery of the …
Performance Of A Metarhizium Anisopliae-Treated Semiochemical-Baited Trap In Reducing Amblyomma Variegatum Populations In The Field, F. Nchu, N. K. Maniania, A. Hassanali, J. N. Eloff
Performance Of A Metarhizium Anisopliae-Treated Semiochemical-Baited Trap In Reducing Amblyomma Variegatum Populations In The Field, F. Nchu, N. K. Maniania, A. Hassanali, J. N. Eloff
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Experiments were carried out to evaluate the efficacy of Metarhizium anisopliae (Metsch.) Sorok. (Ascomycota: Hypocreales)-treated semiochemical-baited traps for control of Amblyomma variegatum Fabriscius (Acari: Ixodidae) under field conditions. Unfed A. variegatum adults (118) were seeded in each 100-m plot and allowed to acclimatise for 3 days. On the fourth day (Day 4), an emulsifiable formulation of M. anisopliae (consisting of 49.5% sterile distilled water, fungal conidia, 49.5% corn oil and 1% Tween 80) titrated at 109conidiaml-1 was applied in semiochemical-baited traps (900cm2) which were placed at five spots within the plot. The control and fungal treatments were repeated after 14 …
Prospects For Developing Odour Baits To Control Glossina Fuscipes Spp., The Major Vector Of Human African Trypanosomiasis, Maurice O. Omolo, Ahmed Hassanali, Serge Mpiana, Johan Esterhuizen, Jenny Lindh, Mike J. Lehane, Philippe Solano, Jean Baptiste Rayaisse, Glyn A. Vale, Steve J. Torr, Inaki Tirados
Prospects For Developing Odour Baits To Control Glossina Fuscipes Spp., The Major Vector Of Human African Trypanosomiasis, Maurice O. Omolo, Ahmed Hassanali, Serge Mpiana, Johan Esterhuizen, Jenny Lindh, Mike J. Lehane, Philippe Solano, Jean Baptiste Rayaisse, Glyn A. Vale, Steve J. Torr, Inaki Tirados
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We are attempting to develop cost-effective control methods for the important vector of sleeping sickness, Glossina fuscipes spp. Responses of the tsetse flies Glossina fuscipes fuscipes (in Kenya) and G. f. quanzensis (in Democratic Republic of Congo) to natural host odours are reported. Arrangements of electric nets were used to assess the effect of cattle-, human- and pig-odour on (1) the numbers of tsetse attracted to the odour source and (2) the proportion of flies that landed on a black target (1 × 1 m). In addition responses to monitor lizard (Varanus niloticus) were assessed in Kenya. The effects of …