Insecticide resistance status of Aedes aegypti and Aedes albopictus mosquitoes in Papua New Guinea

Abstract

Background Aedes aegypti and Ae. albopictus are important vectors of infectious diseases, especially those caused by arboviruses such as dengue, chikungunya and Zika. Aedes aegypti is very well adapted to urban environments, whereas Ae. albopictus inhabits more rural settings. Pyrethroid resistance is widespread in these vectors, but limited data exist from the Southwest Pacific Region, especially from Melanesia. While Aedes vector ecology is well documented in Australia, where incursion of Ae. albopictus and pyrethroid resistance have so far been prevented, almost nothing is known about Aedes populations in neighbouring Papua New Guinea (PNG). With pyrethroid resistance documented in parts of Indonesia but not in Australia, it is important to determine the distribution of susceptible and resistant Aedes populations in this region. Methods The present study was aimed at assessing Aedes populations for insecticide resistance in Madang and Port Moresby, located on the north and south coasts of PNG, respectively. Mosquitoes were collected using ovitraps and reared in an insectary. Standard WHO bioassays using insecticide-treated filter papers were conducted on a total of 253 Ae. aegypti and 768 Ae. albopictus adult mosquitoes. Subsets of samples from both species (55 Ae. aegypti and 48 Ae. albopictus ) were screened for knockdown resistance mutations in the voltage-sensitive sodium channel ( Vssc ) gene, the target site of pyrethroid insecticides. Results High levels of resistance against pyrethroids were identified in Ae . aegypti from Madang and Port Moresby. Aedes albopictus exhibited susceptibility to pyrethroids, but moderate levels of resistance to DDT. Mutations associated with pyrethroid resistance were detected in all Ae . aegypti samples screened. Some genotypes found in the present study had been observed previously in Indonesia. No Vssc mutations associated with pyrethroid resistance were found in the Ae. albopictus samples. Conclusions To our knowledge, this is the first report of pyrethroid resistance in Ae . aegypti mosquitoes in PNG. Interestingly, usage of insecticides in PNG is low, apart from long-lasting insecticidal nets distributed for malaria control. Further investigations on how these resistant Ae . aegypti mosquito populations arose in P...

Decreased bioefficacy of long-lasting insecticidal nets and the resurgence of malaria in Papua New Guinea

“…While insecticide resistance will have a detrimental effect on LLIN bioefficacy [15,16] regular insecticide resistance monitoring activities have shown no signs of emerging pyrethroid resistance in the anopheline mosquito populations in PNG since the beginning of the LLIN distributions [17]. This stands in contrast to recently found high levels of pyrethroid resistance in Aedes aegypti populations in PNG [18], Reduced bioefficacy of LLINs can also be a result of substandard manufacturing process and distributions of substandard LLINs have occurred before e.g., in Rwanda (2015) and Solomon Islands (2014) [19,20]. WHO requirements for LLINs include that 80% of nets that have been in use for 3 years or less exhibit an 80% 24h-mortality or 95% knock-down rate of susceptible mosquitoes in standardised cone-bioassays [21].…”

Frequency of kdr mutations in the voltage-sensitive sodium channel (VSSC) gene in Aedes aegypti from Yogyakarta and implications for Wolbachia-infected mosquito trials

“…Cooccurrence of V1016G and F1534C was reported in populations from Thailand [47], Myanmar [46], Malaysia [48], and Indonesia [49,50,51,52]. Meanwhile, co-occurrence of V1016G and S989P point mutations was detected in Thailand [47], Myanmar [46], Indonesia, [49,50,52], and Papua New Guinea [53]. In addition, co-occurrence of triple mutations V1016G/F1534C/S989P in heterozygous form has been identi ed commonly in A. aegypti from Thailand [54], Myanmar [46], and Indonesia [49] [50,52].…”

Frequency of kdr mutations in the voltage-sensitive sodium channel (VSSC) gene in Aedes aegypti from Yogyakarta and implications for Wolbachia-infected mosquito trials

“…aegypti from Southeast Asia: V1016G/F1534C, V1016G/S989P and V1016G/F1534C/S989P. Co-occurrence of V1016G and F1534C was reported in populations from Thailand [47], Myanmar [46], Malaysia [48] and Indonesia [49][50][51][52] and co-occurrence of V1016G and S989P point mutations was detected in Thailand [47], Myanmar [46], Indonesia, [49,50,52] and Papua New Guinea [53]. In addition, co-occurrence of triple mutations V1016G/F1534C/S989P in heterozygous form has been identi ed commonly in Ae.…”