Infectivity of Symptomatic Malaria Patients to Anopheles farauti Colony Mosquitoes in Papua New Guinea.

Lincoln Timinao,Louis Schofield,Leanne J Robinson,Thomas R Burkot,Rebecca Vinit,Ivo Mueller,Michelle Katusele,Stephan Karl,Cyrille Czeher,Moses Laman,Ingrid Felger,Elma Nate,Tamarah Koleala

doi:10.3389/fcimb.2021.771233

Abstract

Plasmodium transmission from humans to mosquitoes is an understudied bottleneck in the transmission of malaria. Direct membrane feeding assays (DMFA) allow detailed malaria transmission studies from humans to mosquitoes. Especially for Plasmodium vivax, which cannot be cultured long-term under laboratory conditions, implementation of DMFAs requires proximity to P. vivax endemic areas. In this study, we investigated the infectivity of symptomatic Plasmodium infections to Anopheles farauti colony mosquitoes in Papua New Guinea (PNG). A total of 182 DMFAs were performed with venous blood collected from rapid diagnostic test (RDT) positive symptomatic malaria patients and subsequently analysed by light microscopy and quantitative real time polymerase chain reaction (qPCR). DMFAs resulted in mosquito infections in 20.9% (38/182) of cases. By light microscopy and qPCR, 10 – 11% of P. falciparum and 32 – 44% of P. vivax positive individuals infected An. farauti. Fifty-eight percent of P. vivax and 15% of P. falciparum gametocytaemic infections infected An farauti.

Highlights

Transmission between the human host and the mosquito vector is a crucial step in the malaria parasite life cycle
Not significant we did observe a higher proportion of infections by individuals diagnosed with rapid diagnostic test (RDT) as Parasite lactate dehydrogenase (pLDH) positive than those diagnosed as Histidine rich protein 2 (HRP2) positive (35.1% vs 27.3%, p=0.43) (Table 4)
P. vivax infections diagnosed by light microscopy were significantly more infectious to mosquitoes compared to P. falciparum infections (44.2% vs. 11.4%, p

Summary

Introduction

Transmission between the human host and the mosquito vector is a crucial step in the malaria parasite life cycle. DMFAs can be used to study the infectiousness of different human malaria reservoirs, and estimate their contribution towards transmission (Graves et al, 1988; Diallo et al, 2008). This can include symptomatic, patent infections as in the present study and asymptomatic, often low-density infections (Kiattibutr et al, 2017). There is evidence that there is no clustering of gametocytes in the skin as initially perceived making DMFAs a reliable tool for infection studies (Meibalan et al, 2019; Talman et al, 2020)

Methods

Results

Conclusion