Ability of mosquitoes to ingest microfilariae (mf), promote their maturation to the infective
stage, and their survival rate to parasite maturation for transmission to humans seems to
differ according to geographic mosquito strains. The proportion of ingested m f that develops
successfully into L3 may decrease (limitation) or increase (facilitation) with higher mf
uptake. Transmission intensity depends on a number of factors such as the level of infection
in the human population, vectorial capacity, vectorial competence, and climatic factors.
Results obtained from a preliminary study after three years of mass drug administration
(MDA) showed a decrease in annual transmission potential (ATP) o f Anopheles funestus but
no change in An. gambiae s.s. This study was conducted to determine the vector competence
of these two Anopheles species in the transmission of Wuchereria bancrofti at low m f levels.
Mass screening for mf was done using IOOjllI finger-prick blood and consented positive
individuals who volunteered and slept under mosquito nets that had one side opened. Wild
mosquitoes that fed on them were collected hourly from 21:00 to 06:00 hours GMT.
Approximately half of the mosquitoes were killed immediately and dissected to count the
number of mf ingested. The remaining mosquitoes were maintained for 13 days to observe
parasite maturation after which they were dissected. Along side the mosquito collection,
lOOjutl finger-prick blood was collected hourly to observe m f level in peripheral blood. The
overall prevalence of mf in the study community (N = 1083) was 1.6%. The levels of mf
varied from 0 to 59 mf7 100jLtl blood, with a geometric mean intensity of 1.1 mf7 ml. Some
variation in intensity with age-group was observed, however neither the intensities in age
group (P = 0.40) nor the intensities in the male and female subjects (P = 0.91) were
significant. Out of the 564 mosquitoes collected, 62.1% were Anopheles species, 32.3%
Mansonia species, 5% Aedes species and 0.7% Culex species. Anopheles funestus and An. gambiae formed 8 8 .6 % and 9.1% of Anopheles caught respectively. Both m f level in
peripheral blood and biting rates of the Anopheles mosquitoes peaked between 00:00 and
03:00 hours. Six mosquitoes each of Anopheles (1.7%) and Mansonia (3.3%) were found
infected but none was infective after day 13 of maintenance. Molecular studies showed all
Anopheles gambiae s.l. to be An. gambiae s.s. out of which 70% were M form. All infected
Anopheles gambiae were M forms. A total of 8 6 % of the An. funestus were identified as An.
funestus s.s. with 6 % being An. leesoni. Although these Anopheles species were not
competent in promoting the maturation of the parasites when mf is low, a repeat of this study
targeting larger mosquito numbers is required to ascertain the role played especially by M
forms of An. gambiae in the transmission of lymphatic filariasis when parasite levels in the
community are low. Considering the fact that the study was conducted in the natural setting,
this finding will help as to whether the combination therapy with ivermectin and albendazole
is enough to eliminate the disease or vector management has to be integrated for the success
of the GPELF in areas like Ghana where Anopheles gambiae and An. funestus are the main
CDR, C (2021). Vector Competence Of The Anopheles (Diptera: Culicidae) Populations For Wuchereria Bancrofti (Spirurida: Filariidae), After Mass Drug Administration In The Gomoa District Of Ghana. Afribary.com: Retrieved May 06, 2021, from https://afribary.com/works/vector-competence-of-the-anopheles-diptera-culicidae-populations-for-wuchereria-bancrofti-spirurida-filariidae-after-mass-drug-administration-in-the-gomoa-district-of-ghana
Coalition, CDR. "Vector Competence Of The Anopheles (Diptera: Culicidae) Populations For Wuchereria Bancrofti (Spirurida: Filariidae), After Mass Drug Administration In The Gomoa District Of Ghana" Afribary.com. Afribary.com, 05 Apr. 2021, https://afribary.com/works/vector-competence-of-the-anopheles-diptera-culicidae-populations-for-wuchereria-bancrofti-spirurida-filariidae-after-mass-drug-administration-in-the-gomoa-district-of-ghana . Accessed 06 May. 2021.
Coalition, CDR. "Vector Competence Of The Anopheles (Diptera: Culicidae) Populations For Wuchereria Bancrofti (Spirurida: Filariidae), After Mass Drug Administration In The Gomoa District Of Ghana". Afribary.com, Afribary.com, 05 Apr. 2021. Web. 06 May. 2021. < https://afribary.com/works/vector-competence-of-the-anopheles-diptera-culicidae-populations-for-wuchereria-bancrofti-spirurida-filariidae-after-mass-drug-administration-in-the-gomoa-district-of-ghana >.
Coalition, CDR. "Vector Competence Of The Anopheles (Diptera: Culicidae) Populations For Wuchereria Bancrofti (Spirurida: Filariidae), After Mass Drug Administration In The Gomoa District Of Ghana" Afribary.com (2021). Accessed May 06, 2021. https://afribary.com/works/vector-competence-of-the-anopheles-diptera-culicidae-populations-for-wuchereria-bancrofti-spirurida-filariidae-after-mass-drug-administration-in-the-gomoa-district-of-ghana