Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes.
BACKGROUND: High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as "very zoophagic," meaning they...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2012-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3365128?pdf=render |
| _version_ | 1818323183301820416 |
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| author | Samson S Kiware Nakul Chitnis Sarah J Moore Gregor J Devine Silas Majambere Stephen Merrill Gerry F Killeen |
| author_facet | Samson S Kiware Nakul Chitnis Sarah J Moore Gregor J Devine Silas Majambere Stephen Merrill Gerry F Killeen |
| author_sort | Samson S Kiware |
| collection | DOAJ |
| description | BACKGROUND: High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as "very zoophagic," meaning they feed occasionally (<10% of blood meals) upon humans, so personal protection interventions have negligible impact upon their survival. METHODS AND FINDINGS: We extended a published malaria transmission model to examine the relationship between transmission, control, and the baseline proportion of bloodmeals obtained from humans (human blood index). The lower limit of the human blood index enables derivation of simplified models for zoophagic vectors that (1) Rely on only three field-measurable parameters. (2) Predict immediate and delayed (with and without assuming reduced human infectivity, respectively) impacts of personal protection measures upon transmission. (3) Illustrate how appreciable indirect communal-level protection for non-users can be accrued through direct personal protection of users. (4) Suggest the coverage and efficacy thresholds required to attain epidemiological impact. The findings suggest that immediate, indirect, community-wide protection of users and non-users alike may linearly relate to the efficacy of a user's direct personal protection, regardless of whether that is achieved by killing or repelling mosquitoes. High protective coverage and efficacy (≥80%) are important to achieve epidemiologically meaningful impact. Non-users are indirectly protected because the two most common species of human malaria are strict anthroponoses. Therefore, the small proportion of mosquitoes that are killed or diverted while attacking humans can represent a large proportion of those actually transmitting malaria. CONCLUSIONS: Simplified models of malaria transmission by very zoophagic vectors may be used by control practitioners to predict intervention impact interventions using three field-measurable parameters; the proportion of human exposure to mosquitoes occurring when an intervention can be practically used, its protective efficacy when used, and the proportion of people using it. |
| first_indexed | 2024-12-13T11:08:38Z |
| format | Article |
| id | doaj.art-40dcb74bfd0241cb920e15d0cef67deb |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-13T11:08:38Z |
| publishDate | 2012-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-40dcb74bfd0241cb920e15d0cef67deb2022-12-21T23:48:52ZengPublic Library of Science (PLoS)PLoS ONE1932-62032012-01-0175e3766110.1371/journal.pone.0037661Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes.Samson S KiwareNakul ChitnisSarah J MooreGregor J DevineSilas MajambereStephen MerrillGerry F KilleenBACKGROUND: High coverage of personal protection measures that kill mosquitoes dramatically reduce malaria transmission where vector populations depend upon human blood. However, most primary malaria vectors outside of sub-Saharan Africa can be classified as "very zoophagic," meaning they feed occasionally (<10% of blood meals) upon humans, so personal protection interventions have negligible impact upon their survival. METHODS AND FINDINGS: We extended a published malaria transmission model to examine the relationship between transmission, control, and the baseline proportion of bloodmeals obtained from humans (human blood index). The lower limit of the human blood index enables derivation of simplified models for zoophagic vectors that (1) Rely on only three field-measurable parameters. (2) Predict immediate and delayed (with and without assuming reduced human infectivity, respectively) impacts of personal protection measures upon transmission. (3) Illustrate how appreciable indirect communal-level protection for non-users can be accrued through direct personal protection of users. (4) Suggest the coverage and efficacy thresholds required to attain epidemiological impact. The findings suggest that immediate, indirect, community-wide protection of users and non-users alike may linearly relate to the efficacy of a user's direct personal protection, regardless of whether that is achieved by killing or repelling mosquitoes. High protective coverage and efficacy (≥80%) are important to achieve epidemiologically meaningful impact. Non-users are indirectly protected because the two most common species of human malaria are strict anthroponoses. Therefore, the small proportion of mosquitoes that are killed or diverted while attacking humans can represent a large proportion of those actually transmitting malaria. CONCLUSIONS: Simplified models of malaria transmission by very zoophagic vectors may be used by control practitioners to predict intervention impact interventions using three field-measurable parameters; the proportion of human exposure to mosquitoes occurring when an intervention can be practically used, its protective efficacy when used, and the proportion of people using it.http://europepmc.org/articles/PMC3365128?pdf=render |
| spellingShingle | Samson S Kiware Nakul Chitnis Sarah J Moore Gregor J Devine Silas Majambere Stephen Merrill Gerry F Killeen Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. PLoS ONE |
| title | Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. |
| title_full | Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. |
| title_fullStr | Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. |
| title_full_unstemmed | Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. |
| title_short | Simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes. |
| title_sort | simplified models of vector control impact upon malaria transmission by zoophagic mosquitoes |
| url | http://europepmc.org/articles/PMC3365128?pdf=render |
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