Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Sep 6;10(1):443.
doi: 10.1186/s13104-017-2793-4.

Insecticide use pattern and phenotypic susceptibility of Anopheles gambiae sensu lato to commonly used insecticides in Lower Moshi, northern Tanzania

Elinas J Nnko  1 , Charles Kihamia  1 , Filemoni Tenu  2 , Zul Premji  1 , Eliningaya J Kweka  3   4
Affiliations

Insecticide use pattern and phenotypic susceptibility of Anopheles gambiae sensu lato to commonly used insecticides in Lower Moshi, northern Tanzania

Elinas J Nnko et al. BMC Res Notes. .

Abstract

Background: Evidence of insecticide resistance has been documented in different malaria endemic areas. Surveillance studies to allow prompt investigation of associated factors to enable effective insecticide resistance management are needed. The objective of this study was to assess insecticide use pattern and phenotypic susceptibility level of Anopheles gambiae sensu lato to insecticides commonly used in malaria control in Moshi, northern Tanzania.

Methods: A cross-sectional survey was conducted to assess insecticide usage pattern. Data was collected was through closed and open ended questionnaires The WHO diagnostic standard kit with doses of 0.1% bendiocarb, 0.05% deltamethrin, 0.75% permethrin and 4% DDT were used to detect knockdown time, mortality and resistance ratio of wild A. gambiae sensu lato. The questionnaire survey data was analyzed using descriptive statistics and one-way analysis of variance while susceptibility data was analysed by logistic regression with probit analysis using SPSS program. The WHO criteria was used to evaluate the resistance status of the tested mosquito populations.

Results: A large proportion of respondents (80.8%) reported to have used insecticide mainly for farming purposes (77.3%). Moreover, 93.3% of household reported usage of long lasting insecticidal nets. The frequently used class of insecticide was organophosphate with chloropyrifos as the main active ingredients and dursban was the brand constantly reported. Very few respondents (24.1%) applied integrated vector control approaches of and this significantly associated with level of knowledge of insecticide use (P < 0.001). Overall knockdown time for A. gambiae s.l was highest in DDT, followed by Pyrethroids (Permethrin and deltamethrin) and lowest in bendiocarb. Anopheles gambiae s.l showed susceptibility to bendiocarb, increased tolerance to permethrin and resistant to deltamethrin. The most effective insecticide against the population from tested was bendiocarb, with a resistance ratio ranging between 0.93-2.81.

Conclusion: Education on integrated vector management should be instituted and a policy change on insecticide of choice for malaria vector control from pyrethroids to carbamates (bendiocarb) is recommended. Furthermore, studies to detect cross resistance between pyrethroids and organophosphates should be carried out.

Keywords: Anopheles gambiae s.l.; Insecticides; Mortality; Resistance; Resistance ratio; Tanzania.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Conceptual framework which was used during the study planning
See this image and copyright information in PMC

References

    1. Coetzee M, Craig M, le Sueur D. Distribution of african malaria mosquitoes belonging to the Anopheles gambiae complex. Parasit Today. 2000;16:74–77. doi: 10.1016/S0169-4758(99)01563-X. - DOI - PubMed
    1. Coetzee M, Hunt RH, Wilkerson R, Della Torre A, Coulibaly MB, Besansky NJ. Anopheles coluzzii and Anopheles amharicus, new members of the Anopheles gambiae complex. Zootaxa. 2013;3619:246–274. doi: 10.11646/zootaxa.3619.3.2. - DOI - PubMed
    1. Mnzava A, Kilama W. Observations on the distribution of the Anopheles gambiae complex in Tanzania. Acta Trop. 1986;43:277–282. - PubMed
    1. Kweka E, Mahande A, Nkya W, Assenga C, Lyatuu E, Mosha F, et al. Vector species composition and malaria infectivity rates in Mkuzi, Muheza District, north-eastern Tanzania. Tanzan J Health Res. 2008;10:46–49. doi: 10.4314/thrb.v10i1.14341. - DOI - PubMed
    1. Temu EA, Minjas JN, Tuno N, Kawada H, Takagi M. Identification of four members of the Anopheles funestus (Diptera: Culicidae) group and their role in Plasmodium falciparum transmission in Bagamoyo coastal Tanzania. Acta Trop. 2007;102:119–125. doi: 10.1016/j.actatropica.2007.04.009. - DOI - PubMed

LinkOut - more resources