Low larval vector survival explains unstable malaria in the western Kenya highlands.
Trop Med Int Health
; 11(8): 1195-205, 2006 Aug.
Article
em En
| MEDLINE
| ID: mdl-16903883
ABSTRACT
Several highland areas in eastern Africa have recently suffered from serious malaria epidemics. Some models predict that, in the short term, these areas will experience more epidemics as a result of global warming. However, the various processes underlying these changes are poorly understood. We therefore investigated malaria prevalence, malaria vector densities and malaria vector survival in a highland area in western Kenya, ranging from approximately 1,550-1,650 m altitude. Although only five adult malaria vectors were collected during 180 light traps and 180 resting collections over a 23-month study period, malaria was prevalent among school children (average parasite prevalence 10%). During an extensive survey of potential larval habitats, we identified only seven habitats containing Anopheles gambiae Giles s.l. larvae. Their limited number and low larval densities suggested that their contribution to the adult vector population was small. Experiments on adult and larval survival showed that at this altitude, adult mosquitoes survived inside local houses, but that larval development was severely retarded only 2 of 500 A. gambiae s.l. larvae developed to the pupal stage, whereas all other larvae died prior to pupation. At present, high vector densities are unlikely because of unfavourable abiotic conditions in the area. However, temporary favourable conditions, such as during El Niño years, may increase larval vector survival and may lead to malaria epidemics.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Malária Falciparum
/
Altitude
/
Insetos Vetores
Tipo de estudo:
Etiology_studies
/
Prevalence_studies
/
Prognostic_studies
Limite:
Animals
/
Child
/
Child, preschool
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Humans
País/Região como assunto:
Africa
Idioma:
En
Revista:
Trop Med Int Health
Assunto da revista:
MEDICINA TROPICAL
/
SAUDE PUBLICA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Holanda