Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models

Vector-borne diseases (VBDs) of humans and domestic animals are a significant component of the global burden of disease and a key driver of poverty. The transmission cycles of VBDs are often strongly mediated by the ecological requirements of the vectors, resulting in complex transmission dynamics,...

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Main Authors: Lo Iacono, G., Cunningham, A.A., Bett, Bernard K., Grace, Delia, Redding, D.W., Wood, J.L.N.
Format: Journal Article
Language:Inglés
Published: National Academy of Sciences 2018
Subjects:
Online Access:https://hdl.handle.net/10568/96206
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author Lo Iacono, G.
Cunningham, A.A.
Bett, Bernard K.
Grace, Delia
Redding, D.W.
Wood, J.L.N.
author_browse Bett, Bernard K.
Cunningham, A.A.
Grace, Delia
Lo Iacono, G.
Redding, D.W.
Wood, J.L.N.
author_facet Lo Iacono, G.
Cunningham, A.A.
Bett, Bernard K.
Grace, Delia
Redding, D.W.
Wood, J.L.N.
author_sort Lo Iacono, G.
collection Repository of Agricultural Research Outputs (CGSpace)
description Vector-borne diseases (VBDs) of humans and domestic animals are a significant component of the global burden of disease and a key driver of poverty. The transmission cycles of VBDs are often strongly mediated by the ecological requirements of the vectors, resulting in complex transmission dynamics, including intermittent epidemics and an unclear link between environmental conditions and disease persistence. An important broader concern is the extent to which theoretical models are reliable at forecasting VBDs; infection dynamics can be complex, and the resulting systems are highly unstable. Here, we examine these problems in detail using a case study of Rift Valley fever (RVF), a high-burden disease endemic to Africa. We develop an ecoepidemiological, compartmental, mathematical model coupled to the dynamics of ambient temperature and water availability and apply it to a realistic setting using empirical environmental data from Kenya. Importantly, we identify the range of seasonally varying ambient temperatures and water-body availability that leads to either the extinction of mosquito populations and/or RVF (nonpersistent regimens) or the establishment of long-term mosquito populations and consequently, the endemicity of the RVF infection (persistent regimens). Instabilities arise when the range of the environmental variables overlaps with the threshold of persistence. The model captures the intermittent nature of RVF occurrence, which is explained as low-level circulation under the threshold of detection, with intermittent emergence sometimes after long periods. Using the approach developed here opens up the ability to improve predictions of the emergence and behaviors of epidemics of many other important VBDs.
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spelling CGSpace962062024-01-08T18:54:14Z Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models Lo Iacono, G. Cunningham, A.A. Bett, Bernard K. Grace, Delia Redding, D.W. Wood, J.L.N. environment research rift valley fever virus zoonoses Vector-borne diseases (VBDs) of humans and domestic animals are a significant component of the global burden of disease and a key driver of poverty. The transmission cycles of VBDs are often strongly mediated by the ecological requirements of the vectors, resulting in complex transmission dynamics, including intermittent epidemics and an unclear link between environmental conditions and disease persistence. An important broader concern is the extent to which theoretical models are reliable at forecasting VBDs; infection dynamics can be complex, and the resulting systems are highly unstable. Here, we examine these problems in detail using a case study of Rift Valley fever (RVF), a high-burden disease endemic to Africa. We develop an ecoepidemiological, compartmental, mathematical model coupled to the dynamics of ambient temperature and water availability and apply it to a realistic setting using empirical environmental data from Kenya. Importantly, we identify the range of seasonally varying ambient temperatures and water-body availability that leads to either the extinction of mosquito populations and/or RVF (nonpersistent regimens) or the establishment of long-term mosquito populations and consequently, the endemicity of the RVF infection (persistent regimens). Instabilities arise when the range of the environmental variables overlaps with the threshold of persistence. The model captures the intermittent nature of RVF occurrence, which is explained as low-level circulation under the threshold of detection, with intermittent emergence sometimes after long periods. Using the approach developed here opens up the ability to improve predictions of the emergence and behaviors of epidemics of many other important VBDs. 2018-07-31 2018-07-20T08:47:10Z 2018-07-20T08:47:10Z Journal Article https://hdl.handle.net/10568/96206 en Open Access National Academy of Sciences Lo Iacono, G., Cunningham, A.A., Bett, B., Grace, D., Redding, D.W. and Wood, J.L.N. 2018. Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models. Proceedings of the National Academy of Sciences of the United States of America 115(31): E7448–E7456.
spellingShingle environment
research
rift valley fever virus
zoonoses
Lo Iacono, G.
Cunningham, A.A.
Bett, Bernard K.
Grace, Delia
Redding, D.W.
Wood, J.L.N.
Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title_full Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title_fullStr Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title_full_unstemmed Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title_short Environmental limits of Rift Valley fever revealed using ecoepidemiological mechanistic models
title_sort environmental limits of rift valley fever revealed using ecoepidemiological mechanistic models
topic environment
research
rift valley fever virus
zoonoses
url https://hdl.handle.net/10568/96206
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