Journal of Mosquito Research 2015, Vol.5, No.14, 1-8
1
Research Article Open Access
Insecticide resistance, Host preference and
Plasmodium falciparum
parasite rates
in Anopheles mosquitoes in Mwea and Ahero rice schemes
Ngala C.J.
1,
, Kamau L.
2,3
, Mireji Paul O.
4
, Mburu J.
5
, Mbogo C.
3,6
1. Department of Biomedical Sciences – Pwani University, P.O. Box 195-80108, Kilifi, Kenya 2 Centre for Biotechnology Research and Development, Kenya
Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
3. Public Health Department, Kenya Medical Research Institute-Wellcome Trust-University of Oxford Programme, GPO, Nairobi, Kenya
4. Department of Biochemistry and Molecular Biology, Egerton University, P.O. Box 536, Egerton, Kenya
5. Department of Animal Sciences, Egerton University, P.O Box 536, Egerton, Kenya
6. Kenya Medical Research Institute-Wellcome trust Research Programme-P.O Box 230-80108, Kilifi, Kenya
Corresponding author email
Journal of Mosquito Research, 2015, Vol.5, No.14 doi: 10.5376/jmr.2015.05.0014
Received: 24 Jun., 2015
Accepted: 25 Jul., 2015
Published: 07 Sep., 2015
Copyright
©
2015 Ngala et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Ngala C.J., Kamau L., Mireji Paul O., Mburu J. and Mbogo C., 2015, Prevalence of Malaria Amongst Children 0 - 4 Years in Olugbo, Odeda Local
Government, Ogun State, Nigeria, Journal of Mosquito Research, Vol.5, No.14 1
-
8
(doi
Abstract
The ability of
Anopheles
mosquito to transmit malaria in nature is partly enhanced by; resistance of mosquito to insecticides,
feeding preference for human host and infection by
Plasmodium falciparum
. An assessment was conducted to determine the status of
these parameters in
Anopheles
populations in Mwea and Ahero rice irrigation schemes in Kenya. This was important in order to
understand their potential influence on local malaria transmission. A total of 1,200 female
Anopheles
mosquitoes (gravid and blood fed)
were sampled from both sites by indoor and outdoor methods.
Anopheles
samples identification to their respective species in the field
was done using morphological features and taxonomic keys. In Mwea scheme, all the 600
Anopheles
mosquitoes collected were
An.
gambiae
s.l out of which 195 were gravid. In Ahero, 250
An. gambiae
s.l (out of which 81 were gravid) and 350
An. funestus
(out of
which 181 were gravid) were collected. Gravid
Anopheles
mosquitoes were allowed to oviposit to give F
1
generations in the insectary.
These F
1,
(four replicates of 25 mosquitoes per species per insecticide) were assessed for susceptibility to permethrin, deltamethrin,
dichlorodiphenyltrichloroethane (DDT), bendiocarb or fenitrothion using standard WHO protocol. Susceptible
An. gambiae
s.s
Kisumu strain (25 mosquitoes per the 100 test mosquitoes) was used as positive control. The 1,200 field samples were further identified
to their respective species using rDNA-PCR using their legs and wings. Source (s) of blood meal in 405
An. gambiae
s.l from Mwea,
169
An. gambiae
s.l and 269
An. funestus
from Ahero were determined using blood meal Elisa. The presence of
Plasmodium
falciparum
Welch, 1897 in the salivary glands was assessed by sporozoite Elisa in all the field collected samples. All
Anopheles
mosquito samples from Mwea were
Anopheles arabiensis
Patton, 1905, while those from Ahero were a mixed species of
Anopheles
arabiensis
(41.7%)
, Anopheles funestus sensu stricto
Giles, 1900 (57%)
, Anopheles rivulorum
Leesoni, 1935 (0.66%)
, Anopheles
leesoni
Evans, 1931 (0.3%) and
Anopheles parensis
Gillies, 1935 (0.3%). Mosquito samples from both study sites showed reduced
susceptibility to the test insecticides.
An. arabiensis
mosquitoes from Mwea had a human blood meal index at 0.22 (n=405).
P.
falciparum
circumsporozoite infection in
An. arabiensis
from Mwea were reported in Murinduko village at 1.5% (n=200). In Ahero,
human blood meal indices were at 0.00 (n=169) and 0.17 (n=269) for
An. arabiensis
and
An. funestus
respectively.
P. falciparum
circumsporozoite infections in
An. funestus
sampled from Kamagaga and Wagai villages in Ahero were at 5% (n=147) and 2.2%
(n=183) respectively.
Keywords
Anopheles;
Plasmodium falciparum
; Insecticide resistance; Host preference
Introduction
World Health Organization estimates that malaria is
responsible for about 655,000 deaths annually, with
P.
falciparum
as the leading causative agent (Gathany,
2012). Malaria is also an important disease in foci
located in irrigation-based agricultural areas where
Anopheles gambiae
Giles, 1902 and
Anopheles
arabiensis
Patton, 1905 mosquitoes are predominant
vectors. This is because they can readily proliferate
due to the abundance of paddies (Mwangangi et al.,
2007). Integrated Malaria Management (IMM) is one
of the vector borne disease management strategies
encompassing the use of insecticides, environmental
modifications to discourage mosquito breeding, health
education and chemotherapy. This strategy has
significantly reduced malaria transmission and burden
on these foci (Dolo et al., 2004). The important
principle with this strategy is the collective contribution
