The Experts below are selected from a list of 8604 Experts worldwide ranked by ideXlab platform
Scott C. Weaver - One of the best experts on this subject based on the ideXlab platform.
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Ecological niche modeling of Aedes mosquito vectors of chikungunya virus in southeastern Senegal.
Parasites & Vectors, 2018Co-Authors: Rebecca Richman, Scott C. Weaver, Kathryn A. Hanley, Mawlouth Diallo, Amadou A. Sall, Diawo Diallo, Oumar Faye, Tidiane Diagne, Ibrahima Dia, Michaela BuenemannAbstract:Background Chikungunya virus (CHIKV) originated in a Sylvatic cycle of transmission between non-human animal hosts and vector mosquitoes in the forests of Africa. Subsequently the virus jumped out of this ancestral cycle into a human-endemic transmission cycle vectored by anthropophilic mosquitoes. Sylvatic CHIKV cycles persist in Africa and continue to spill over into humans, creating the potential for new CHIKV strains to enter human-endemic transmission. To mitigate such spillover, it is first necessary to delineate the distributions of the Sylvatic mosquito vectors of CHIKV, to identify the environmental factors that shape these distributions, and to determine the association of mosquito presence with key drivers of virus spillover, including mosquito and CHIKV abundance. We therefore modeled the distribution of seven CHIKV mosquito vectors over two sequential rainy seasons in Kedougou, Senegal using Maxent.
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Potential for Zika Virus to Establish a Sylvatic Transmission Cycle in the Americas.
PLOS Neglected Tropical Diseases, 2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host and vector population sizes, host birthrates, and ZIKV force of infection. Research on the host competence of New World monkeys or other small mammals to ZIKV, on vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of potential New World hosts and vectors is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire picture for the epidemiology of ZIKV and our ability to end the ongoing outbreak of congenital Zika syndrome.
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Potential for Zika virus to establish a Sylvatic transmission cycle in the Americas
2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host population sizes and birthrates and ZIKV force of infection, but a network of as few as 6,000 primates with 10,000 mosquitoes is capable of supporting establishment of a ZIKV Sylvatic cycle. Research on the susceptibility of New World monkeys or other small mammals to ZIKV, on the vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of these species is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire situation for the epidemiology of ZIKV and ending the ongoing outbreak of congenital Zika syndrome.
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Infection dynamics of Sylvatic dengue virus in a natural primate host, the African Green Monkey.
The American Journal of Tropical Medicine and Hygiene, 2014Co-Authors: Kathryn A. Hanley, Nikos Vasilakis, Scott C. Weaver, Mathilde Guerbois, Tiffany F. Kautz, Meredith Brown, Stephen S. Whitehead, Preston A. MarxAbstract:The four serotypes of mosquito-borne dengue virus (DENV-1, -2, -3, and -4) that circulate in humans each emerged from an enzootic, Sylvatic cycle in non-human primates. Herein, we present the first study of Sylvatic DENV infection dynamics in a primate. Three African green monkeys were inoculated with 10 5 plaque-forming units (pfu) DENV-2 strain PM33974 from the Sylvatic cycle, and one African green monkey was inoculated with 10 5 pfu DENV-2 strain New Guinea C from the human cycle. All four monkeys seroconverted (more than fourfold rise in 80% plaque reduction neutralization titer (PRNT80)) against the strain of DENV with which they were inoculated; only one (33%) of three monkeys infected with Sylvatic DENV showed a neutralizing antibody response against human-endemic DENV. Virus was detected in two of three monkeys inoculated with Sylvatic DENV at low titer (£ 1.3 log10pfu/mL) and brief duration (£ 2 days). Clinical signs included rash and elevated aspartate aminotransferase (AST) and alanine amino- transferase (ALT) levels.
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fever versus fever the role of host and vector susceptibility and interspecific competition in shaping the current and future distributions of the Sylvatic cycles of dengue virus and yellow fever virus
Infection Genetics and Evolution, 2013Co-Authors: Kathryn A. Hanley, Scott C. Weaver, Thomas P Monath, Shannan L Rossi, Rebecca Richman, Nikos VasilakisAbstract:Two different species of flaviviruses, dengue virus (DENV) and yellow fever virus (YFV), that originated in Sylvatic cycles maintained in non-human primates and forest-dwelling mosquitoes have emerged repeatedly into sustained human-to-human transmission by Aedes aegypti mosquitoes. Sylvatic cycles of both viruses remain active, and where the two viruses overlap in West Africa they utilize similar suites of monkeys and Aedes mosquitoes. These extensive similarities render the differences in the biogeography and epidemiology of the two viruses all the more striking. First, the Sylvatic cycle of YFV originated in Africa and was introduced into the New World, probably as a result of the slave trade, but is absent in Asia; in contrast, Sylvatic DENV likely originated in Asia and has spread to Africa but not to the New World. Second, while Sylvatic YFV can emerge into extensive urban outbreaks in humans, these invariably die out, whereas four different types of DENV have established human transmission cycles that are ecologically and evolutionarily distinct from their Sylvatic ancestors. Finally, transmission of YFV among humans has been documented only in Africa and the Americas, whereas DENV is transmitted among humans across most of the range of competent Aedes vectors, which in the last decade has included every continent save Antarctica. This review summarizes current understanding of Sylvatic transmission cycles of YFV and DENV, considers possible explanations for their disjunct distributions, and speculates on the potential consequences of future establishment of a Sylvatic cycle of DENV in the Americas.
Nikos Vasilakis - One of the best experts on this subject based on the ideXlab platform.
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Abundance and distribution of Sylvatic dengue virus vectors in three different land cover types in Sarawak, Malaysian Borneo
Parasites & vectors, 2017Co-Authors: Katherine I. Young, Nikos Vasilakis, Robert B. Tesh, Jane Cardosa, David Perera, Stephanie Mundis, Steven G. Widen, Thomas G. Wood, Kathryn A. HanleyAbstract:Abstract Background Mosquito-borne dengue virus (DENV) is maintained in a Sylvatic, enzootic cycle of transmission between canopy-dwelling non-human primates and Aedes mosquitoes in Borneo. Sylvatic DENV can spill over into humans living in proximity to forest foci of transmission, in some cases resulting in severe dengue disease. The most likely vectors of such spillover (bridge vectors) in Borneo are Ae. albopictus and Ae. niveus . Borneo is currently experiencing extensive forest clearance. To gauge the effect of this change in forest cover on the likelihood of Sylvatic DENV spillover, it is first necessary to characterize the distribution of bridge vectors in different land cover types. In the current study, we hypothesized that Ae. niveus and Ae. albopictus would show significantly different distributions in different land cover types; specifically, we predicted that Ae. niveus would be most abundant in forests whereas Ae. albopictus would have a more even distribution in the landscape. Results Mosquitoes were collected from a total of 15 sites using gravid traps and a backpack aspirator around Kampong Puruh Karu, Sarawak, Malaysian Borneo, where Sylvatic DENV spillover has been documented. A total of 2447 mosquitoes comprising 10 genera and 4 species of Aedes , were collected over the three years, 2013, 2014 and 2016, in the three major land cover types in the area, homestead, agriculture and forest. Mosquitoes were identified morphologically, pooled by species and gender, homogenized, and subject to DNA barcoding of each Aedes species and to arbovirus screening. As predicted, Ae. niveus was found almost exclusively in forests whereas Ae. albopictus was collected in all land cover types. Aedes albopictus was significantly ( P = 0.04) more abundant in agricultural fields than forests. Sylvatic DENV was not detected in any Aedes mosquito pools, however genomes of 14 viruses were detected using next generation sequencing. Conclusions Land cover type affects the abundance and distribution of the most likely bridge vectors of Sylvatic DENV in Malaysia Borneo. Conversion of forests to agriculture will likely decrease the range and abundance of Ae. niveus but enhance the abundance of Ae. albopictus .
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Potential for Zika Virus to Establish a Sylvatic Transmission Cycle in the Americas.
PLOS Neglected Tropical Diseases, 2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host and vector population sizes, host birthrates, and ZIKV force of infection. Research on the host competence of New World monkeys or other small mammals to ZIKV, on vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of potential New World hosts and vectors is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire picture for the epidemiology of ZIKV and our ability to end the ongoing outbreak of congenital Zika syndrome.
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Potential for Zika virus to establish a Sylvatic transmission cycle in the Americas
2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host population sizes and birthrates and ZIKV force of infection, but a network of as few as 6,000 primates with 10,000 mosquitoes is capable of supporting establishment of a ZIKV Sylvatic cycle. Research on the susceptibility of New World monkeys or other small mammals to ZIKV, on the vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of these species is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire situation for the epidemiology of ZIKV and ending the ongoing outbreak of congenital Zika syndrome.
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Infection dynamics of Sylvatic dengue virus in a natural primate host, the African Green Monkey.
The American Journal of Tropical Medicine and Hygiene, 2014Co-Authors: Kathryn A. Hanley, Nikos Vasilakis, Scott C. Weaver, Mathilde Guerbois, Tiffany F. Kautz, Meredith Brown, Stephen S. Whitehead, Preston A. MarxAbstract:The four serotypes of mosquito-borne dengue virus (DENV-1, -2, -3, and -4) that circulate in humans each emerged from an enzootic, Sylvatic cycle in non-human primates. Herein, we present the first study of Sylvatic DENV infection dynamics in a primate. Three African green monkeys were inoculated with 10 5 plaque-forming units (pfu) DENV-2 strain PM33974 from the Sylvatic cycle, and one African green monkey was inoculated with 10 5 pfu DENV-2 strain New Guinea C from the human cycle. All four monkeys seroconverted (more than fourfold rise in 80% plaque reduction neutralization titer (PRNT80)) against the strain of DENV with which they were inoculated; only one (33%) of three monkeys infected with Sylvatic DENV showed a neutralizing antibody response against human-endemic DENV. Virus was detected in two of three monkeys inoculated with Sylvatic DENV at low titer (£ 1.3 log10pfu/mL) and brief duration (£ 2 days). Clinical signs included rash and elevated aspartate aminotransferase (AST) and alanine amino- transferase (ALT) levels.
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fever versus fever the role of host and vector susceptibility and interspecific competition in shaping the current and future distributions of the Sylvatic cycles of dengue virus and yellow fever virus
Infection Genetics and Evolution, 2013Co-Authors: Kathryn A. Hanley, Scott C. Weaver, Thomas P Monath, Shannan L Rossi, Rebecca Richman, Nikos VasilakisAbstract:Two different species of flaviviruses, dengue virus (DENV) and yellow fever virus (YFV), that originated in Sylvatic cycles maintained in non-human primates and forest-dwelling mosquitoes have emerged repeatedly into sustained human-to-human transmission by Aedes aegypti mosquitoes. Sylvatic cycles of both viruses remain active, and where the two viruses overlap in West Africa they utilize similar suites of monkeys and Aedes mosquitoes. These extensive similarities render the differences in the biogeography and epidemiology of the two viruses all the more striking. First, the Sylvatic cycle of YFV originated in Africa and was introduced into the New World, probably as a result of the slave trade, but is absent in Asia; in contrast, Sylvatic DENV likely originated in Asia and has spread to Africa but not to the New World. Second, while Sylvatic YFV can emerge into extensive urban outbreaks in humans, these invariably die out, whereas four different types of DENV have established human transmission cycles that are ecologically and evolutionarily distinct from their Sylvatic ancestors. Finally, transmission of YFV among humans has been documented only in Africa and the Americas, whereas DENV is transmitted among humans across most of the range of competent Aedes vectors, which in the last decade has included every continent save Antarctica. This review summarizes current understanding of Sylvatic transmission cycles of YFV and DENV, considers possible explanations for their disjunct distributions, and speculates on the potential consequences of future establishment of a Sylvatic cycle of DENV in the Americas.
Kathryn A. Hanley - One of the best experts on this subject based on the ideXlab platform.
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Ecological niche modeling of Aedes mosquito vectors of chikungunya virus in southeastern Senegal.
Parasites & Vectors, 2018Co-Authors: Rebecca Richman, Scott C. Weaver, Kathryn A. Hanley, Mawlouth Diallo, Amadou A. Sall, Diawo Diallo, Oumar Faye, Tidiane Diagne, Ibrahima Dia, Michaela BuenemannAbstract:Background Chikungunya virus (CHIKV) originated in a Sylvatic cycle of transmission between non-human animal hosts and vector mosquitoes in the forests of Africa. Subsequently the virus jumped out of this ancestral cycle into a human-endemic transmission cycle vectored by anthropophilic mosquitoes. Sylvatic CHIKV cycles persist in Africa and continue to spill over into humans, creating the potential for new CHIKV strains to enter human-endemic transmission. To mitigate such spillover, it is first necessary to delineate the distributions of the Sylvatic mosquito vectors of CHIKV, to identify the environmental factors that shape these distributions, and to determine the association of mosquito presence with key drivers of virus spillover, including mosquito and CHIKV abundance. We therefore modeled the distribution of seven CHIKV mosquito vectors over two sequential rainy seasons in Kedougou, Senegal using Maxent.
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Abundance and distribution of Sylvatic dengue virus vectors in three different land cover types in Sarawak, Malaysian Borneo
Parasites & vectors, 2017Co-Authors: Katherine I. Young, Nikos Vasilakis, Robert B. Tesh, Jane Cardosa, David Perera, Stephanie Mundis, Steven G. Widen, Thomas G. Wood, Kathryn A. HanleyAbstract:Abstract Background Mosquito-borne dengue virus (DENV) is maintained in a Sylvatic, enzootic cycle of transmission between canopy-dwelling non-human primates and Aedes mosquitoes in Borneo. Sylvatic DENV can spill over into humans living in proximity to forest foci of transmission, in some cases resulting in severe dengue disease. The most likely vectors of such spillover (bridge vectors) in Borneo are Ae. albopictus and Ae. niveus . Borneo is currently experiencing extensive forest clearance. To gauge the effect of this change in forest cover on the likelihood of Sylvatic DENV spillover, it is first necessary to characterize the distribution of bridge vectors in different land cover types. In the current study, we hypothesized that Ae. niveus and Ae. albopictus would show significantly different distributions in different land cover types; specifically, we predicted that Ae. niveus would be most abundant in forests whereas Ae. albopictus would have a more even distribution in the landscape. Results Mosquitoes were collected from a total of 15 sites using gravid traps and a backpack aspirator around Kampong Puruh Karu, Sarawak, Malaysian Borneo, where Sylvatic DENV spillover has been documented. A total of 2447 mosquitoes comprising 10 genera and 4 species of Aedes , were collected over the three years, 2013, 2014 and 2016, in the three major land cover types in the area, homestead, agriculture and forest. Mosquitoes were identified morphologically, pooled by species and gender, homogenized, and subject to DNA barcoding of each Aedes species and to arbovirus screening. As predicted, Ae. niveus was found almost exclusively in forests whereas Ae. albopictus was collected in all land cover types. Aedes albopictus was significantly ( P = 0.04) more abundant in agricultural fields than forests. Sylvatic DENV was not detected in any Aedes mosquito pools, however genomes of 14 viruses were detected using next generation sequencing. Conclusions Land cover type affects the abundance and distribution of the most likely bridge vectors of Sylvatic DENV in Malaysia Borneo. Conversion of forests to agriculture will likely decrease the range and abundance of Ae. niveus but enhance the abundance of Ae. albopictus .
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Potential for Zika Virus to Establish a Sylvatic Transmission Cycle in the Americas.
PLOS Neglected Tropical Diseases, 2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host and vector population sizes, host birthrates, and ZIKV force of infection. Research on the host competence of New World monkeys or other small mammals to ZIKV, on vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of potential New World hosts and vectors is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire picture for the epidemiology of ZIKV and our ability to end the ongoing outbreak of congenital Zika syndrome.
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Potential for Zika virus to establish a Sylvatic transmission cycle in the Americas
2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host population sizes and birthrates and ZIKV force of infection, but a network of as few as 6,000 primates with 10,000 mosquitoes is capable of supporting establishment of a ZIKV Sylvatic cycle. Research on the susceptibility of New World monkeys or other small mammals to ZIKV, on the vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of these species is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire situation for the epidemiology of ZIKV and ending the ongoing outbreak of congenital Zika syndrome.
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Infection dynamics of Sylvatic dengue virus in a natural primate host, the African Green Monkey.
The American Journal of Tropical Medicine and Hygiene, 2014Co-Authors: Kathryn A. Hanley, Nikos Vasilakis, Scott C. Weaver, Mathilde Guerbois, Tiffany F. Kautz, Meredith Brown, Stephen S. Whitehead, Preston A. MarxAbstract:The four serotypes of mosquito-borne dengue virus (DENV-1, -2, -3, and -4) that circulate in humans each emerged from an enzootic, Sylvatic cycle in non-human primates. Herein, we present the first study of Sylvatic DENV infection dynamics in a primate. Three African green monkeys were inoculated with 10 5 plaque-forming units (pfu) DENV-2 strain PM33974 from the Sylvatic cycle, and one African green monkey was inoculated with 10 5 pfu DENV-2 strain New Guinea C from the human cycle. All four monkeys seroconverted (more than fourfold rise in 80% plaque reduction neutralization titer (PRNT80)) against the strain of DENV with which they were inoculated; only one (33%) of three monkeys infected with Sylvatic DENV showed a neutralizing antibody response against human-endemic DENV. Virus was detected in two of three monkeys inoculated with Sylvatic DENV at low titer (£ 1.3 log10pfu/mL) and brief duration (£ 2 days). Clinical signs included rash and elevated aspartate aminotransferase (AST) and alanine amino- transferase (ALT) levels.
Mawlouth Diallo - One of the best experts on this subject based on the ideXlab platform.
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Ecological niche modeling of Aedes mosquito vectors of chikungunya virus in southeastern Senegal.
Parasites & Vectors, 2018Co-Authors: Rebecca Richman, Scott C. Weaver, Kathryn A. Hanley, Mawlouth Diallo, Amadou A. Sall, Diawo Diallo, Oumar Faye, Tidiane Diagne, Ibrahima Dia, Michaela BuenemannAbstract:Background Chikungunya virus (CHIKV) originated in a Sylvatic cycle of transmission between non-human animal hosts and vector mosquitoes in the forests of Africa. Subsequently the virus jumped out of this ancestral cycle into a human-endemic transmission cycle vectored by anthropophilic mosquitoes. Sylvatic CHIKV cycles persist in Africa and continue to spill over into humans, creating the potential for new CHIKV strains to enter human-endemic transmission. To mitigate such spillover, it is first necessary to delineate the distributions of the Sylvatic mosquito vectors of CHIKV, to identify the environmental factors that shape these distributions, and to determine the association of mosquito presence with key drivers of virus spillover, including mosquito and CHIKV abundance. We therefore modeled the distribution of seven CHIKV mosquito vectors over two sequential rainy seasons in Kedougou, Senegal using Maxent.
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Potential for Zika Virus to Establish a Sylvatic Transmission Cycle in the Americas.
PLOS Neglected Tropical Diseases, 2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host and vector population sizes, host birthrates, and ZIKV force of infection. Research on the host competence of New World monkeys or other small mammals to ZIKV, on vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of potential New World hosts and vectors is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire picture for the epidemiology of ZIKV and our ability to end the ongoing outbreak of congenital Zika syndrome.
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Potential for Zika virus to establish a Sylvatic transmission cycle in the Americas
2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host population sizes and birthrates and ZIKV force of infection, but a network of as few as 6,000 primates with 10,000 mosquitoes is capable of supporting establishment of a ZIKV Sylvatic cycle. Research on the susceptibility of New World monkeys or other small mammals to ZIKV, on the vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of these species is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire situation for the epidemiology of ZIKV and ending the ongoing outbreak of congenital Zika syndrome.
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Letter to the Editor : Sylvatic Dengue Viruses Share the Pathogenic Potential of Urban/Endemic Dengue Viruses
2010Co-Authors: Nikos Vasilakis, Kathryn A. Hanley, Edward C. Holmes, Mawlouth Diallo, Amadou A. Sall, Mary Jane Cardosa, Scott C. WeaverAbstract:Dengue virus (DENV) exists in both Sylvatic and urban/endemic ecotypes (15), and the potential for emergence of Sylvatic strains has become a focus of research. Recently Mota and Rico-Hesse (10) attempted to evaluate the pathogenic potential of viruses belonging to different genetic subgroups of DENV serotype 2 (DENV-2). Based on the viremia levels and erythema index profiles of one Sylvatic genotype and three (Asian, American, and Indian) urban/endemic genotypes evaluated using the NOD-scid IL2rγnull humanized mouse model, the authors concluded that Sylvatic DENV-2 viruses possess a reduced pathogenic potential compared to strains belonging to urban/endemic DENV-2 genotypes. However, these conclusions ignore both patterns in their own data and a wealth of published ex vivo, in vivo, and epidemiological evidence collected over the past 40 years.
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Sylvatic dengue viruses share the pathogenic potential of urban endemic dengue viruses
Journal of Virology, 2010Co-Authors: Nikos Vasilakis, Kathryn A. Hanley, Edward C. Holmes, Mawlouth Diallo, Amadou A. Sall, Jane Cardosa, Scott C. WeaverAbstract:Dengue virus (DENV) exists in both Sylvatic and urban/endemic ecotypes (15), and the potential for emergence of Sylvatic strains has become a focus of research. Recently Mota and Rico-Hesse (10) attempted to evaluate the pathogenic potential of viruses belonging to different genetic subgroups of DENV serotype 2 (DENV-2). Based on the viremia levels and erythema index profiles of one Sylvatic genotype and three (Asian, American, and Indian) urban/endemic genotypes evaluated using the NOD-scid IL2rγnull humanized mouse model, the authors concluded that Sylvatic DENV-2 viruses possess a reduced pathogenic potential compared to strains belonging to urban/endemic DENV-2 genotypes. However, these conclusions ignore both patterns in their own data and a wealth of published ex vivo, in vivo, and epidemiological evidence collected over the past 40 years.
Amadou A. Sall - One of the best experts on this subject based on the ideXlab platform.
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Ecological niche modeling of Aedes mosquito vectors of chikungunya virus in southeastern Senegal.
Parasites & Vectors, 2018Co-Authors: Rebecca Richman, Scott C. Weaver, Kathryn A. Hanley, Mawlouth Diallo, Amadou A. Sall, Diawo Diallo, Oumar Faye, Tidiane Diagne, Ibrahima Dia, Michaela BuenemannAbstract:Background Chikungunya virus (CHIKV) originated in a Sylvatic cycle of transmission between non-human animal hosts and vector mosquitoes in the forests of Africa. Subsequently the virus jumped out of this ancestral cycle into a human-endemic transmission cycle vectored by anthropophilic mosquitoes. Sylvatic CHIKV cycles persist in Africa and continue to spill over into humans, creating the potential for new CHIKV strains to enter human-endemic transmission. To mitigate such spillover, it is first necessary to delineate the distributions of the Sylvatic mosquito vectors of CHIKV, to identify the environmental factors that shape these distributions, and to determine the association of mosquito presence with key drivers of virus spillover, including mosquito and CHIKV abundance. We therefore modeled the distribution of seven CHIKV mosquito vectors over two sequential rainy seasons in Kedougou, Senegal using Maxent.
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Potential for Zika Virus to Establish a Sylvatic Transmission Cycle in the Americas.
PLOS Neglected Tropical Diseases, 2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host and vector population sizes, host birthrates, and ZIKV force of infection. Research on the host competence of New World monkeys or other small mammals to ZIKV, on vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of potential New World hosts and vectors is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire picture for the epidemiology of ZIKV and our ability to end the ongoing outbreak of congenital Zika syndrome.
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Potential for Zika virus to establish a Sylvatic transmission cycle in the Americas
2016Co-Authors: Benjamin M. Althouse, Nikos Vasilakis, Scott C. Weaver, Mawlouth Diallo, Amadou A. Sall, Kathryn A. HanleyAbstract:Zika virus (ZIKV) originated and continues to circulate in a Sylvatic transmission cycle between non-human primate hosts and arboreal mosquitoes in tropical Africa. Recently ZIKV invaded the Americas, where it poses a threat to human health, especially to pregnant women and their infants. Here we examine the risk that ZIKV will establish a Sylvatic cycle in the Americas, focusing on Brazil. We review the natural history of Sylvatic ZIKV and present a mathematical dynamic transmission model to assess the probability of establishment of a Sylvatic ZIKV transmission cycle in non-human primates and/or other mammals and arboreal mosquito vectors in Brazil. Brazil is home to multiple species of primates and mosquitoes potentially capable of ZIKV transmission, though direct assessment of host competence (ability to mount viremia sufficient to infect a feeding mosquito) and vector competence (ability to become infected with ZIKV and disseminate and transmit upon subsequent feedings) of New World species is lacking. Modeling reveals a high probability of establishment of Sylvatic ZIKV across a large range of biologically plausible parameters. Probability of establishment is dependent on host population sizes and birthrates and ZIKV force of infection, but a network of as few as 6,000 primates with 10,000 mosquitoes is capable of supporting establishment of a ZIKV Sylvatic cycle. Research on the susceptibility of New World monkeys or other small mammals to ZIKV, on the vector competence of New World Aedes, Sabethes, and Haemagogus mosquitoes for ZIKV, and on the geographic range of these species is urgently needed. A Sylvatic cycle of ZIKV would make future elimination efforts in the Americas practically impossible, and paints a dire situation for the epidemiology of ZIKV and ending the ongoing outbreak of congenital Zika syndrome.
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Landscape Ecology of Sylvatic Chikungunya Virus and Mosquito Vectors in Southeastern Senegal
PLoS neglected tropical diseases, 2012Co-Authors: Diawo Diallo, Ousmane Faye, Amadou A. Sall, Oumar Faye, Tidiane Diagne, Ibrahima Dia, Michaela Buenemann, Rubing Chen, Douglas M. WattsAbstract:The risk of human infection with Sylvatic chikungunya (CHIKV) virus was assessed in a focus of Sylvatic arbovirus circulation in Senegal by investigating distribution and abundance of anthropophilic Aedes mosquitoes, as well as the abundance and distribution of CHIKV in these mosquitoes. A 1650 km2 area was classified into five land cover classes: forest, barren, savanna, agriculture and village. A total of 39,799 mosquitoes was sampled from all classes using human landing collections between June 2009 and January 2010. Mosquito diversity was extremely high, and overall vector abundance peaked at the start of the rainy season. CHIKV was detected in 42 mosquito pools. Our data suggest that Aedes furcifer, which occurred abundantly in all land cover classes and landed frequently on humans in villages outside of houses, is probably the major bridge vector responsible for the spillover of Sylvatic CHIKV to humans.
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Letter to the Editor : Sylvatic Dengue Viruses Share the Pathogenic Potential of Urban/Endemic Dengue Viruses
2010Co-Authors: Nikos Vasilakis, Kathryn A. Hanley, Edward C. Holmes, Mawlouth Diallo, Amadou A. Sall, Mary Jane Cardosa, Scott C. WeaverAbstract:Dengue virus (DENV) exists in both Sylvatic and urban/endemic ecotypes (15), and the potential for emergence of Sylvatic strains has become a focus of research. Recently Mota and Rico-Hesse (10) attempted to evaluate the pathogenic potential of viruses belonging to different genetic subgroups of DENV serotype 2 (DENV-2). Based on the viremia levels and erythema index profiles of one Sylvatic genotype and three (Asian, American, and Indian) urban/endemic genotypes evaluated using the NOD-scid IL2rγnull humanized mouse model, the authors concluded that Sylvatic DENV-2 viruses possess a reduced pathogenic potential compared to strains belonging to urban/endemic DENV-2 genotypes. However, these conclusions ignore both patterns in their own data and a wealth of published ex vivo, in vivo, and epidemiological evidence collected over the past 40 years.
