Species Identification and Resistance Status of Anopheles gambiae s.l. (Diptera: Culicidae) Mosquitoes in Guinea

Abstract

Insecticide resistance is one of the primary threats to the recent gains in malaria control. This is especially true in Guinea, where long-lasting insecticidal nets are currently the primary vector control intervention. To better inform the national malaria control program on the current status of insecticide resistance in Guinea, resistance bioassays were conducted, using Anopheles gambiae s.l. Giles, in three sites. Molecular analyses were also done on An. gambiae s.l. to determine the species and find whether the target-site mutations kdr and Ace1R were present. Susceptibility tests revealed resistance to DDT and pyrethroids, although mosquitoes were susceptible to deltamethrin in two of the three sites tested. Mosquitoes were susceptible to bendiocarb, except in Kissidougou, Guinea. The kdr-west mutation was widespread and the frequency was 60% or more in all sites. However, the Ace1R mutation was present in low levels. Insecticide susceptibility should continue to be monitored in Guinea to ensure insecticide-based vector control methods remain effective.

An assessment of adult mosquito collection techniques for studying species abundance and diversity in Maferinyah, Guinea

“…This study provides the first entomological survey in Guinea that compares the mosquito species abundance and diversity using a range of different adult mosquito traps. Other studies in West Africa have utilised some of these traps individually, such as CDC light traps (LT) in Guinea (22) and Sierra Leone (43), and gravid traps (GT) in Ghana (9). This is also the first study that compares the performance of a Stealth trap (ST) with other mosquito traps to catch mosquitoes in a field setting.…”

“…aegypti , the major YFV vector in urban areas, was not found in the rural areas (13), suggesting other mosquito species were likely involved in transmission. Despite signficant transmission of malaria, lymphatic filariasis and sporadic outbreaks of arboviruses, relatively few medical entomological studies to date have been undertaken in Guinea (14–22). Therefore, there is a need to undertake entomological surveys using diverse collection methods to determine the most appropriate mosquito trapping methods to use for surveillance.…”

Characterizing the molecular and metabolic mechanisms of insecticide resistance in Anopheles gambiae s.l. in Faranah, Guinea

“…A sub-sample of 60 mosquitoes was randomly selected to be tested for West African L1014F kdr mutation, given the high frequency of this allele and its fixation in many parts of Guinea and West Africa [10, 14]. The PCR master mix was prepared according to MR4 guidelines [15].…”

“…The United States President’s Malaria Initiative (PMI) estimates that intervention coverage remains low with only 48% of households owning at least one insecticide-treated net (ITN) per every two members [9]. Given the reliance on LLINs for malaria control, the detection of nationwide pyrethroid resistance is of concern [10]. In order to safeguard malaria control efforts in the country, we characterized current insecticide resistance levels and underlying mechanisms, to inform the design of appropriate management strategies and mitigate future selection for resistance.…”

Investigating the relationship between insecticide resistance, underlying molecular mechanisms and malaria prevalence in Anopheles gambiae s.l. from Guinea

“…Between 2013-2017, the NMCP, with support from the President's Malaria Initiative (PMI) and the Global Fund, have procured and distributed over 27.6 million pyrethroid LLINs 24 . Because the current vector control strategy relies almost exclusively on LLIN use 25 , nationwide pyrethroid resistance, is of significant concern 26 . To better inform future malaria control efforts in Guinea, there is a pressing need to characterize levels of operationallysignificant insecticide resistance, as well as determine the effect this phenomenon has on the vectorial capacity of local mosquitoes to transmit malaria.…”