Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control
Abstract Background Recent resurgence of malaria in the highlands of Western Kenya has called for a more comprehensive understanding of the previously neglected complex highland vector ecology. Besides other drivers of malaria epidemiology, topography is likely to have a major effect on spatial vect...
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ftdoajarticles:oai:doaj.org/article:14173689fdc74b219c4fe9122eed8f26 2023-05-15T15:14:51+02:00 Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control Ndenga Bryson A Atieli Francis K Odada Peter K Ayisi John M Githeko Andrew K Githure John I Yan Guiyun 2006-11-01T00:00:00Z https://doi.org/10.1186/1475-2875-5-107 https://doaj.org/article/14173689fdc74b219c4fe9122eed8f26 EN eng BMC http://www.malariajournal.com/content/5/1/107 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-5-107 1475-2875 https://doaj.org/article/14173689fdc74b219c4fe9122eed8f26 Malaria Journal, Vol 5, Iss 1, p 107 (2006) Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2006 ftdoajarticles https://doi.org/10.1186/1475-2875-5-107 2022-12-31T07:12:59Z Abstract Background Recent resurgence of malaria in the highlands of Western Kenya has called for a more comprehensive understanding of the previously neglected complex highland vector ecology. Besides other drivers of malaria epidemiology, topography is likely to have a major effect on spatial vector and parasite distribution. The aim of this study was to determine the effects of topography on malaria spatial vector distribution and parasite prevalence. Methodology Indoor resting adult malaria vectors and blood parasites were collected in three villages along a 4 km transect originating from the valley bottom and ending at the hilltop for 13 months. Members of the Anopheles gambiae complex were identified by PCR. Blood parasites were collected from children 6–13 years old and densities categorized by site of home location and age of the children. Results Ninety eight percent (98%) of An. gambiae s.s . and (99%) Anopheles funestus were collected in houses located at the edge of the valley bottom, whereas 1% of An. gambiae s.s . were collected at mid hill and at the hilltop respectively. No An. funestus were collected at the hilltop. Malaria prevalence was 68% at the valley bottom, 40.2% at mid hill and 26.7% at the hilltop. Children aged six years and living at the edge of the valley bottom had an annual geometric mean number of 66.1 trophozoites for every 200 white blood cells, while those living at mid-hill had a mean of 84.8, and those living at hilltop had 199.5 trophozoites. Conclusion Malaria transmission in this area is mainly confined to the valley bottom. Effective vector control could be targeted at the foci. However, the few vectors observed at mid-hill maintained a relatively high prevalence rate. The higher variability in blood parasite densities and their low correlation with age in children living at the hilltop suggests a lower stability of transmission than at the mid-hill and valley bottom. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 5 1 |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
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Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Ndenga Bryson A Atieli Francis K Odada Peter K Ayisi John M Githeko Andrew K Githure John I Yan Guiyun Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
topic_facet |
Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Recent resurgence of malaria in the highlands of Western Kenya has called for a more comprehensive understanding of the previously neglected complex highland vector ecology. Besides other drivers of malaria epidemiology, topography is likely to have a major effect on spatial vector and parasite distribution. The aim of this study was to determine the effects of topography on malaria spatial vector distribution and parasite prevalence. Methodology Indoor resting adult malaria vectors and blood parasites were collected in three villages along a 4 km transect originating from the valley bottom and ending at the hilltop for 13 months. Members of the Anopheles gambiae complex were identified by PCR. Blood parasites were collected from children 6–13 years old and densities categorized by site of home location and age of the children. Results Ninety eight percent (98%) of An. gambiae s.s . and (99%) Anopheles funestus were collected in houses located at the edge of the valley bottom, whereas 1% of An. gambiae s.s . were collected at mid hill and at the hilltop respectively. No An. funestus were collected at the hilltop. Malaria prevalence was 68% at the valley bottom, 40.2% at mid hill and 26.7% at the hilltop. Children aged six years and living at the edge of the valley bottom had an annual geometric mean number of 66.1 trophozoites for every 200 white blood cells, while those living at mid-hill had a mean of 84.8, and those living at hilltop had 199.5 trophozoites. Conclusion Malaria transmission in this area is mainly confined to the valley bottom. Effective vector control could be targeted at the foci. However, the few vectors observed at mid-hill maintained a relatively high prevalence rate. The higher variability in blood parasite densities and their low correlation with age in children living at the hilltop suggests a lower stability of transmission than at the mid-hill and valley bottom. |
format |
Article in Journal/Newspaper |
author |
Ndenga Bryson A Atieli Francis K Odada Peter K Ayisi John M Githeko Andrew K Githure John I Yan Guiyun |
author_facet |
Ndenga Bryson A Atieli Francis K Odada Peter K Ayisi John M Githeko Andrew K Githure John I Yan Guiyun |
author_sort |
Ndenga Bryson A |
title |
Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
title_short |
Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
title_full |
Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
title_fullStr |
Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
title_full_unstemmed |
Topography and malaria transmission heterogeneity in western Kenya highlands: prospects for focal vector control |
title_sort |
topography and malaria transmission heterogeneity in western kenya highlands: prospects for focal vector control |
publisher |
BMC |
publishDate |
2006 |
url |
https://doi.org/10.1186/1475-2875-5-107 https://doaj.org/article/14173689fdc74b219c4fe9122eed8f26 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 5, Iss 1, p 107 (2006) |
op_relation |
http://www.malariajournal.com/content/5/1/107 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-5-107 1475-2875 https://doaj.org/article/14173689fdc74b219c4fe9122eed8f26 |
op_doi |
https://doi.org/10.1186/1475-2875-5-107 |
container_title |
Malaria Journal |
container_volume |
5 |
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1 |
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1766345259827068928 |