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
. 2011 Feb 9:4:16.
doi: 10.1186/1756-3305-4-16.

Vectorial status and insecticide resistance of Anopheles funestus from a sugar estate in southern Mozambique

R Graham Kloke  1 , Eduardo Nhamahanga, Richard H Hunt, Maureen Coetzee
Affiliations

Vectorial status and insecticide resistance of Anopheles funestus from a sugar estate in southern Mozambique

R Graham Kloke et al. Parasit Vectors. .

Abstract

Background: The dual problems of rising insecticide resistance in the malaria vectors and increasing human malaria cases since 2001 in southern Mozambique are cause for serious concern. The selection of insecticides for use in indoor residual spraying (IRS) programmes is highly dependent on the extent to which local mosquitoes are susceptible to the approved classes of insecticides. The insecticide resistance status and role in malaria transmission of Anopheles funestus was evaluated at the Maragra Sugar Estate in southern Mozambique where an IRS vector control programme has been in operation for seven years using the carbamate insecticide bendiocarb.

Results: No Anopheles species were captured inside the sugar estate control area. Anopheles funestus group captured outside of the estate represented 90% (n = 475) of the total collections. Of the specimens identified to species by PCR (n = 167), 95% were An. funestus s.s. One An. rivulorum was identified and seven specimens did not amplify. The Anopheles gambiae complex was less abundant (n = 53) and of those identified (n = 33) 76% were An. arabiensis and 24% An. merus. Insecticide susceptibility tests showed that wild-caught and F-1 family An. funestus were resistant to deltamethrin (32.5% mortality) and lambda-cyhalothrin (14.6% mortality), less so to bendiocarb (71.5% mortality) and fully susceptible to both malathion and DDT (100%). Bendiocarb and pyrethroid resistance was nullified using 4% piperonyl butoxide (Pbo), strongly suggesting that both are mediated by P450 monooxygenase detoxification. ELISA tests of An. funestus for Plasmodium falciparum, gave a sporozoite rate of 6.02% (n = 166). One unidentified member of the An. gambiae complex tested positive for P. falciparum sporozoites.

Conclusion: Anopheles funestus was found to be the most abundant and principle vector of malaria in this area, with members of the An. gambiae complex being secondary vectors. Despite the continual use of bendiocarb within the estate for seven years and the level of An. funestus resistance to this insecticide, the IVC programme is still effective against this and other Anopheles in that no vectors were found inside the control area. However, the Mozambique National Malaria Control Programme ceased the use of DDT and bendiocarb in this area of its operations in 2009, and replaced these insecticides with a pyrethroid which will increase insecticide resistance selection pressure and impact on control programmes such as the Maragra IVC.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Map of southern Mozambique showing Manhica north of the capital of Maputo.
Figure 2
Figure 2
Google Earth map showing the Maragra sugar estate south of Manhica in southern Mozambique.
See this image and copyright information in PMC

References

    1. World Health Organization. World Malaria Report. Geneva, Switzerland; 2008.
    1. Casimiro S. Susceptibility and Resistance to Insecticides Among Malaria Vector Mosquitoes in Mozambique. University of KwaZulu/Natal, MSc Thesis, South Africa; 2003.
    1. Charlwood JD, Mendis C, Thompson R, Begtrup K, Cuamba N, Dgedge M, Gamage-Mendis A, Hunt RH, Sinden RE, Høgh B. Cordon sanitaire or laissez faire: differential dispersal of young and old females of the malaria vector Anopheles funestus Giles (Diptera: Culicidae) in southern Mozambique. Afr Entomol. 1998;6:1–6.
    1. Brooke BD, Kloke G, Hunt RH, Temu EA, Koekemoer LL, Taylor ME, Coetzee M. Bioassay and biochemical analyses of insecticide resistance in southern African Anopheles funestus. Bull Entomol Res. 2001;91:265–272. - PubMed
    1. Casimiro S, Hemmingway J, Sharp BL, Coleman M. Monitoring the Operational Impact of Insecticide Usage for Malaria Control on Anopheles funestus from Mozambique. Malar J. 2007;6:142. doi: 10.1186/1475-2875-6-142. - DOI - PMC - PubMed

Publication types