Polymerase chain reaction detection of human host preference andPlasmodiumparasite infections in field collected potential malaria vectors

Abstract

This study was carried out to determine the human host preference and presence of Plasmodium parasite in field collected Anopheles mosquitoes among four villages around a military cantonment located in malaria endemic Sonitpur district of Assam, India. Encountered malaria vector mosquitoes were identified and tested for host preference and Plasmodium presence using PCR method. Human host preference was detected using simple PCR, whereas vectorial status for Plasmodium parasite was confirmed using first round PCR with genus specific primers and thereafter nested PCR with three Plasmodium species specific primers. Out of 1874 blood fed vector mosquitoes collected, 187 (10%) were processed for PCR, which revealed that 40.6% had fed on human blood; 9.2% of human blood fed mosquito were harbouring Plasmodium parasites, 71.4% of which were confirmed to Plasmodium falciparum. In addition to An. minimus, An. annularis and An. culicifacies were also found positive for malaria parasites. The present study exhibits the human feeding tendency of Anopheles vectors highlighting their malaria parasite transmission potential. The present study may serve as a model for understanding the human host preference of malaria vectors and detection of malaria parasite inside the anopheline vector mosquitoes in order to update their vectorial status for estimating the possible role of these mosquitoes in malaria transmission. The study has used PCR method and suggests that PCR-based method should be used in this entire malarious region to correctly report the vectorial position of different malaria vectors.

Potential malaria vectorAnopheles minimus(species A) still persisting in North East India

“…is endophillic and prefers to rest hiding on darker areas of walls, ceilings, cloths folding and temporary structures inside the human dwellings after taking blood meal. This species has very high affinity for human blood and has reported anthropophilic index of > 90% in North East India (Dev et al 1996(Dev et al , 2010Dhiman et al, 2012). Considering this, the present collections intended to collect An.…”

“…Although the region inhabits 3.5% of country population but contributes 17.5% of total malaria deaths reported in India. Although several Anopheles species have been incriminated as malaria vector in the region during the recent years (Dhiman et al, 2012(Dhiman et al, , 2016Dev et al, 2010) and associated with the transmission of both P. falciparum and P. vivax in the endemic pockets, but historically An. dirus (monsoon species) and An.…”

“…Studies have suggested that both these vectors have been either disappeared (Saxena et al, 2014;Dev et al, 2015) or prevailing in very low numbers which may not be sufficient to maintain perennial malaria transmission (Yadav et al, 2017;Dhiman et al, 2012). Furthermore, secondary malaria vectors which had insignificant epidemiological importance earlier were incriminated harboring malaria parasites and maintaining uninterrupted malaria transmission in the region (Dhiman et al, 2012, Yadav et al, 2017. Although many investigations (Dev et al, 2015;Yadav et al, 2017) could not collect An.…”

Biology, distribution and control of Anopheles (Cellia) minimus in the context of malaria transmission in northeastern India

“…minimus is primarily an endophagic species having a strong predilection for human host with reported anthropophilic index > 90% across its geographical range both in Odisha and northeastern states [20, 27, 59]. It has a nocturnal biting activity and searched the human host all through the night, beginning at 19:00 h and peaked at midnight onwards till 04:00 h (Table 1).…”

High prevalence of pfcrt K76T and mdr1 N86Y mutations in Sonitpur district of Assam, India

“…fluviatilis and An. annularis support the annual transmission in the northeastern states (Dev et al 2003a;Dhiman et al 2012). Malaria control in India largely relies upon the active case detection and treatment using chemoprophylaxis.…”