Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.

Malaria has been eliminated from over 40 countries with an additional 39 currently planning for, or committed to, elimination. Information on the likely impact of available interventions, and the required time, is urgently needed to help plan resource allocation. Mathematical modelling has been used...

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Main Authors: Michelle L Gatton, Qin Cheng
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2010-12-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC2996295?pdf=render
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spelling doaj-92d354c1dbef4dd392a9a48aca7b11f92020-11-25T01:45:07ZengPublic Library of Science (PLoS)PLoS ONE1932-62032010-12-01512e1514910.1371/journal.pone.0015149Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.Michelle L GattonQin ChengMalaria has been eliminated from over 40 countries with an additional 39 currently planning for, or committed to, elimination. Information on the likely impact of available interventions, and the required time, is urgently needed to help plan resource allocation. Mathematical modelling has been used to investigate the impact of various interventions; the strength of the conclusions is boosted when several models with differing formulation produce similar data. Here we predict by using an individual-based stochastic simulation model of seasonal Plasmodium falciparum transmission that transmission can be interrupted and parasite reintroductions controlled in villages of 1,000 individuals where the entomological inoculation rate is <7 infectious bites per person per year using chemotherapy and bed net strategies. Above this transmission intensity bed nets and symptomatic treatment alone were not sufficient to interrupt transmission and control the importation of malaria for at least 150 days. Our model results suggest that 1) stochastic events impact the likelihood of successfully interrupting transmission with large variability in the times required, 2) the relative reduction in morbidity caused by the interventions were age-group specific, changing over time, and 3) the post-intervention changes in morbidity were larger than the corresponding impact on transmission. These results generally agree with the conclusions from previously published models. However the model also predicted changes in parasite population structure as a result of improved treatment of symptomatic individuals; the survival probability of introduced parasites reduced leading to an increase in the prevalence of sub-patent infections in semi-immune individuals. This novel finding requires further investigation in the field because, if confirmed, such a change would have a negative impact on attempts to eliminate the disease from areas of moderate transmission.http://europepmc.org/articles/PMC2996295?pdf=render
collection DOAJ
language English
format Article
sources DOAJ
author Michelle L Gatton
Qin Cheng
spellingShingle Michelle L Gatton
Qin Cheng
Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
PLoS ONE
author_facet Michelle L Gatton
Qin Cheng
author_sort Michelle L Gatton
title Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
title_short Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
title_full Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
title_fullStr Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
title_full_unstemmed Interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
title_sort interrupting malaria transmission: quantifying the impact of interventions in regions of low to moderate transmission.
publisher Public Library of Science (PLoS)
series PLoS ONE
issn 1932-6203
publishDate 2010-12-01
description Malaria has been eliminated from over 40 countries with an additional 39 currently planning for, or committed to, elimination. Information on the likely impact of available interventions, and the required time, is urgently needed to help plan resource allocation. Mathematical modelling has been used to investigate the impact of various interventions; the strength of the conclusions is boosted when several models with differing formulation produce similar data. Here we predict by using an individual-based stochastic simulation model of seasonal Plasmodium falciparum transmission that transmission can be interrupted and parasite reintroductions controlled in villages of 1,000 individuals where the entomological inoculation rate is <7 infectious bites per person per year using chemotherapy and bed net strategies. Above this transmission intensity bed nets and symptomatic treatment alone were not sufficient to interrupt transmission and control the importation of malaria for at least 150 days. Our model results suggest that 1) stochastic events impact the likelihood of successfully interrupting transmission with large variability in the times required, 2) the relative reduction in morbidity caused by the interventions were age-group specific, changing over time, and 3) the post-intervention changes in morbidity were larger than the corresponding impact on transmission. These results generally agree with the conclusions from previously published models. However the model also predicted changes in parasite population structure as a result of improved treatment of symptomatic individuals; the survival probability of introduced parasites reduced leading to an increase in the prevalence of sub-patent infections in semi-immune individuals. This novel finding requires further investigation in the field because, if confirmed, such a change would have a negative impact on attempts to eliminate the disease from areas of moderate transmission.
url http://europepmc.org/articles/PMC2996295?pdf=render
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AT qincheng interruptingmalariatransmissionquantifyingtheimpactofinterventionsinregionsoflowtomoderatetransmission
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