Evaluation of Insecticides Susceptibility and Malaria Vector Potential of Anopheles annularis s.l. and Anopheles vagus in Assam, India

Abstract

During the recent past, development of DDT resistance and reduction to pyrethroid susceptibility among the malaria vectors has posed a serious challenge in many Southeast Asian countries including India. Current study presents the insecticide susceptibility and knock-down data of field collected Anopheles annularis sensu lato and An. vagus mosquito species from endemic areas of Assam in northeast India. Anopheles annularis s.l. and An. vagus adult females were collected from four randomly selected sentinel sites in Orang primary health centre (OPHC) and Balipara primary health centre (BPHC) areas, and used for testing susceptibility to DDT, malathion, deltamethrin and lambda-cyhalothrin. After insecticide susceptibility tests, mosquitoes were subjected to VectorTest™ assay kits to detect the presence of malaria sporozoite in the mosquitoes. An. annularis s.l. was completely susceptible to deltamethrin, lambda-cyhalothrin and malathion in both the study areas. An. vagus was highly susceptible to deltamethrin in both the areas, but exhibited reduced susceptibility to lambda-cyhalothrin in BPHC. Both the species were resistant to DDT and showed very high KDT50 and KDT99 values for DDT. Probit model used to calculate the KDT50 and KDT99 values did not display normal distribution of percent knock-down with time for malathion in both the mosquito species in OPHC (p<0.05) and An. vagus in BPHC (χ2 = 25.3; p = 0.0), and also for deltamethrin to An. vagus in BPHC area (χ2 = 15.4; p = 0.004). Minimum infection rate (MIR) of Plasmodium sporozoite for An. vagus was 0.56 in OPHC and 0.13 in BPHC, while for An. annularis MIR was found to be 0.22 in OPHC. Resistance management strategies should be identified to delay the expansion of resistance. Testing of field caught Anopheles vectors from different endemic areas for the presence of malaria sporozoite may be useful to ensure their role in malaria transmission.

Insecticide susceptibility of Anopheles stephensi to DDT and current insecticides in an elimination area in Iran

“…Moreover it seems that repeated use of pyrethroid insecticides as agricultural pesticides has resulted in a selection pressure on mosquito populations in the study area leading to the development of insecticide resistance. Similar trends have been reported from Middle East different regions, Indian subcontinent, and many African malaria endemic countries [23, 24, 27]. The use of pyrethroids as pesticides in agriculture and bed-net treatment has been recognized as factors responsible for the natural selection of resistant mosquitoes in sub-Saharan Africa [26, 28].…”

“…Synthetic pyrethroids including deltamethrin and lambda-cyhalothrin are being widely used in various public health programmes to control mosquitoes in many countries. However, in the recent years the efficacy of these insecticides against potential malaria vectors has been found to be reduced in endemic areas [24, 25]. In this regard, resistance of the malaria vectors to pyrethroids have been reported from some Afrotropical regions including Mozambique, Uganda, southern Africa, Benin and Ghana [26].…”

Effects of Areca Catechu L. Seed Extract on Mortality Anopheles Vagus Larvae

“…On pre mature phase, the larva habitat is relatively restricted and unable to avoid the control act. The Anopheles larva in India is controlled with larvacide chemical such as temephos, fention, malathion, cloropyriphos and methopren (Dhiman, 2016). The prevention of Anopheles resistence, unwanted effect on non target organism, environmental and human safety can be achived with alternative insecticide from vegetation based (bioinsecticide) (Tomass, 2011).…”

Studi Bioekologi Vektor Malaria di Daerah (Yang Mendapat Sertifikat) Eliminasi Malaria di Kabupaten Jembrana, Bengkalis dan Bulukumba

“…Anopheles vagus juga telah terkonfirmasi sebagai vektor malaria di India dan cenderung bersifat zoophilic, exophilic dan exophagic walaupun pernah ditemukan menghisap darah manusia. 20 Beberapa negara lain di Asia yang juga melaporkan An. vagus sebagai vektor malaria adalah Cambodia, China, Laos, Malaysia, Myanmar, Nepal, Philipina, Srilanka, Thailand, dan Vietnam.…”