Investigating the blood-host plasticity and dispersal of Anopheles coluzzii using a novel field-based methodology

Parasites & Vectors

Mojca Kristan¹  Kathleen O’Reilly¹  James Orsborne¹  Thomas Walker¹  Laith Yakob¹  Claire L. Jeffries¹  Chris Drakeley²  Abdul Rahim Mohammed³  Yaw A. Afrane³  Luis Furuya-Kanamori⁴  Eduardo Massad⁵ 

[1] Department of Disease Control, London School of Hygiene & Tropical Medicine;Department of Immunology & Infection, London School of Hygiene & Tropical Medicine;Department of Medical Microbiology, College of Health Sciences, University of Ghana;Department of Population Medicine, College of Medicine, Qatar University;School of Applied Mathematics, Fundacao Getulio Vargas;

关键词: Blood-meal analysis;    Host preference;    Mosquito;    Biting preference;    Blood index;   

DOI  :  10.1186/s13071-019-3401-3

来源: DOAJ

【 摘 要 】

Abstract Background The biting behaviour and dispersal of insect vectors in the field underlies the transmission of many diseases. Here, a novel collection methodology coupled with the molecular analysis of blood-meal sources and digestion rates is introduced with the aim of aiding the understanding of two critical and relatively understudied mosquito behaviours: plasticity in blood-host choice and vector dispersal. Results A collection strategy utilising a transect of mosquito traps placed at 50 m intervals allowed the collection of blood-fed Anopheles coluzzii from a malaria-endemic village of southern Ghana where human host availability ranged from zero (a cattle pen), increasing until humans were the dominant host choice (the middle of the village). Blood-meal analysis using PCR showed statistically significant variation in blood-meal origins for mosquitoes collected across the 250 m transect: with decreasing trend in Bovine Blood Index (OR = 0.60 95% CI: 0.49–0.73, P < 0.01) and correspondingly, an increasing trend in Human Blood Index (OR = 1.50 95% CI: 1.05–2.16, P = 0.028) as the transect approached the village. Using qPCR, the host DNA remaining in the blood meal was quantified for field-caught mosquitoes and calibrated according to timed blood digestion in colony mosquitoes. Time since blood meal was consumed and the corresponding distance the vector was caught from its blood-host allowed the estimation of An. coluzzii dispersal rates. Within 7 hours of feeding, mosquitoes typically remained within 50 m of their blood-host but at 60 hours they had dispersed up to 250 m. Conclusions Using this methodology the remarkably small spatial scale at which An. coluzzii blood-host choice can change was demonstrated. In addition, conducting qPCR on host blood from field-caught mosquitoes and calibrating with timed experiments with colonised mosquitoes presents a novel methodology for investigating the dispersal behaviour of vectors. Future adaptations to this novel method to make it broadly applicable to other types of setting are also discussed.

【 授权许可】

Unknown