Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi
Abstract Background Although malaria is highly prevalent throughout Malawi, little is known of its transmission dynamics. This paper describes the seasonal activity of the different vectors, human biting indices, sporozoite rates and the entomological inoculation rate in a low-lying rural area in so...
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ftdoajarticles:oai:doaj.org/article:f32395f1131f4f7f85f7362919e1f3bb 2023-05-15T15:17:12+02:00 Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi Mzilahowa Themba Hastings Ian M Molyneux Malcolm E McCall Philip J 2012-11-01T00:00:00Z https://doi.org/10.1186/1475-2875-11-380 https://doaj.org/article/f32395f1131f4f7f85f7362919e1f3bb EN eng BMC http://www.malariajournal.com/content/11/1/380 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-11-380 1475-2875 https://doaj.org/article/f32395f1131f4f7f85f7362919e1f3bb Malaria Journal, Vol 11, Iss 1, p 380 (2012) Malaria Africa Malawi Plasmodium Anopheles falciparum Malariae Gambiae Transmission EIR Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 article 2012 ftdoajarticles https://doi.org/10.1186/1475-2875-11-380 2022-12-31T01:44:54Z Abstract Background Although malaria is highly prevalent throughout Malawi, little is known of its transmission dynamics. This paper describes the seasonal activity of the different vectors, human biting indices, sporozoite rates and the entomological inoculation rate in a low-lying rural area in southern Malawi. Methods Vectors were sampled over 52 weeks from January 2002 to January 2003, by pyrethrum knockdown catch in two villages in Chikhwawa district, in the Lower Shire Valley. Results In total, 7,717 anophelines were collected of which 55.1% were Anopheles gambiae sensu lato and 44.9% were Anopheles funestus. Three members of the An. gambiae complex were identified by PCR: Anopheles arabiensis (75%) was abundant throughout the year, An. gambiae s.s. (25%) was most common during the wet season and Anopheles quadriannulatus occurred at a very low frequency (n=16). An. funestus was found in all samples but was most common during the dry season. Anopheles gambiae s.s. and An. funestus were highly anthropophilic with human blood indices of 99.2% and 96.3%, respectively. Anopheles arabiensis had fed predominantly on humans (85.0%) and less commonly on cattle (10.9%; 1.2% of blood meals were of mixed origin). Plasmodium falciparum (192/3,984) and Plasmodium malariae (1/3,984) sporozoites were detected by PCR in An. arabiensis (3.2%) and An. funestus (4.5%), and in a significantly higher proportion of An. gambiae s.s. (10.6%)(p<0.01). All three vectors were present throughout the year and malaria transmission occurred in every month, although with greatest intensity during the rainy season (January to April). The combined human blood index exceeded 92% and the P. falciparum sporozoite rate was 4.8%, resulting in estimated inoculation rates of 183 infective bites/ person per annum, or an average rate of ~15 infective bites/person/month. Conclusions The results demonstrate the importance of An. gambiae s.s., An. arabiensis and An. funestus in driving the high levels of malaria transmission in the south of Malawi. ... Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Malaria Journal 11 1 |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Malaria Africa Malawi Plasmodium Anopheles falciparum Malariae Gambiae Transmission EIR Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
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Malaria Africa Malawi Plasmodium Anopheles falciparum Malariae Gambiae Transmission EIR Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 Mzilahowa Themba Hastings Ian M Molyneux Malcolm E McCall Philip J Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
topic_facet |
Malaria Africa Malawi Plasmodium Anopheles falciparum Malariae Gambiae Transmission EIR Arctic medicine. Tropical medicine RC955-962 Infectious and parasitic diseases RC109-216 |
description |
Abstract Background Although malaria is highly prevalent throughout Malawi, little is known of its transmission dynamics. This paper describes the seasonal activity of the different vectors, human biting indices, sporozoite rates and the entomological inoculation rate in a low-lying rural area in southern Malawi. Methods Vectors were sampled over 52 weeks from January 2002 to January 2003, by pyrethrum knockdown catch in two villages in Chikhwawa district, in the Lower Shire Valley. Results In total, 7,717 anophelines were collected of which 55.1% were Anopheles gambiae sensu lato and 44.9% were Anopheles funestus. Three members of the An. gambiae complex were identified by PCR: Anopheles arabiensis (75%) was abundant throughout the year, An. gambiae s.s. (25%) was most common during the wet season and Anopheles quadriannulatus occurred at a very low frequency (n=16). An. funestus was found in all samples but was most common during the dry season. Anopheles gambiae s.s. and An. funestus were highly anthropophilic with human blood indices of 99.2% and 96.3%, respectively. Anopheles arabiensis had fed predominantly on humans (85.0%) and less commonly on cattle (10.9%; 1.2% of blood meals were of mixed origin). Plasmodium falciparum (192/3,984) and Plasmodium malariae (1/3,984) sporozoites were detected by PCR in An. arabiensis (3.2%) and An. funestus (4.5%), and in a significantly higher proportion of An. gambiae s.s. (10.6%)(p<0.01). All three vectors were present throughout the year and malaria transmission occurred in every month, although with greatest intensity during the rainy season (January to April). The combined human blood index exceeded 92% and the P. falciparum sporozoite rate was 4.8%, resulting in estimated inoculation rates of 183 infective bites/ person per annum, or an average rate of ~15 infective bites/person/month. Conclusions The results demonstrate the importance of An. gambiae s.s., An. arabiensis and An. funestus in driving the high levels of malaria transmission in the south of Malawi. ... |
format |
Article in Journal/Newspaper |
author |
Mzilahowa Themba Hastings Ian M Molyneux Malcolm E McCall Philip J |
author_facet |
Mzilahowa Themba Hastings Ian M Molyneux Malcolm E McCall Philip J |
author_sort |
Mzilahowa Themba |
title |
Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
title_short |
Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
title_full |
Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
title_fullStr |
Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
title_full_unstemmed |
Entomological indices of malaria transmission in Chikhwawa district, Southern Malawi |
title_sort |
entomological indices of malaria transmission in chikhwawa district, southern malawi |
publisher |
BMC |
publishDate |
2012 |
url |
https://doi.org/10.1186/1475-2875-11-380 https://doaj.org/article/f32395f1131f4f7f85f7362919e1f3bb |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Malaria Journal, Vol 11, Iss 1, p 380 (2012) |
op_relation |
http://www.malariajournal.com/content/11/1/380 https://doaj.org/toc/1475-2875 doi:10.1186/1475-2875-11-380 1475-2875 https://doaj.org/article/f32395f1131f4f7f85f7362919e1f3bb |
op_doi |
https://doi.org/10.1186/1475-2875-11-380 |
container_title |
Malaria Journal |
container_volume |
11 |
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1 |
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1766347460221861888 |