Patterns of anopheline feeding/resting behaviour and Plasmodium infections in North Cameroon, 2011–2014: implications for malaria control

Abstract

Background Effective malaria control relies on evidence-based interventions. Anopheline behaviour and Plasmodium infections were investigated in North Cameroon, following long-lasting insecticidal net (LLIN) distribution in 2010. Methods During four consecutive years from 2011 to 2014, adult mosquitoes were collected indoors, outdoors and in exit traps across 38 locations in the Garoua, Pitoa and Mayo-Oulo health districts. Anophelines were morphologically and molecularly identified, then analysed for blood meal origins and Plasmodium falciparum circumsporozoite protein ( Pf -CSP). Blood from children under 5 years-old using LLINs was examined for Plasmodium infections. Results Overall, 9376 anophelines belonging to 14 species/sibling species were recorded. Anopheles gambiae ( s.l. ) [ An. arabiensis (73.3%), An. coluzzii (17.6%) and An. gambiae ( s.s. ) (9.1%)] was predominant (72%), followed by An. funestus ( s.l. ) (20.5%) and An. rufipes (6.5%). The recorded blood meals were mainly from humans (28%), cattle (15.6%) and sheep (11.6%) or mixed (45%). Pf -CSP rates were higher indoors (3.2–5.4%) versus outdoors (0.8–2.0%), and increased yearly ( χ 2 < 18, df = 10, P < 0.03). Malaria prevalence in children under 5 years-old, in households using LLINs was 30% (924/3088). Conclusions The present study revealed the variability of malaria vector resting and feeding behaviour, and the persistence of Plasmodium infections regardless the use of LLINs. Supplementary interventions to LLINs are therefore needed to sustain malaria prevention in North Cameroon.

Assessment of Novel Lehmann’s Funnel Entry Trap Prototypes Performance to Control Malaria Mosquito Populations

“…gambiae was the main species collected in both sites. Female Anopheles mosquitoes regularly take blood meal every 3 days to mature their eggs and owing to this obligation and depending on the cues smelt, they need to enter to human habitats or animal housing [6][7][8]. During this study, LFET prevented and protected people from a signi cant proportion of unfed female mosquitoes likely searching a blood meal, 39% of total An.…”

“…Malaria parasite transmission is mediated by females of Anopheles mosquitoes in Sub-Saharan of Africa. These female mosquitoes to have progeny and survive, need to seek for blood meal in order to lay eggs, and that blood meal takes place most of the time late and indoors on humans [6][7][8].…”

“…The anthropophilic and endophilic behaviours of malaria vectors force them to enter the house for having blood meal on humans [6,7] whereas this renders them vulnerable and tacklable in many ways. So even malaria being mostly transmitted indoors, some studies in East Africa, have shown a malaria residual transmission occurring outdoor by mosquitoes feeding outside on humans [9][10][11].…”

Fenitrothion Bio-Efficacy on Different Intradomicile Surface Types Against Anopheles (Nyssorhynchus) Albimanus in the Main Malaria Endemic Regions of Panama

“…Within the context of malaria control, the use of physical barriers (nets on windows and doors) as well as the insecticide action, induce a stress in anopheline mosquitoes interfering with blood feeding or with resting on interior walls until their eggs are fully matured. Studies indicate that behavioral modi cations could include a change in feeding times, a switch from feeding exclusively on humans to feeding on other animals or an increase in the exophilic behavior [71]. These behavioral changes could rise due to selection pressure induced by LLINs and IRS and lead to mosquito vectors feeding at earlier times and/or in the peridomicile or extra-domiciles.…”

Assessment of novel Lehmann’s Funnel Entry Trap prototypes performance to control malaria mosquito populations

“…Malaria transmission is mediated by female Anopheles mosquitoes. Female mosquitoes seek blood meals late at night in human dwellings [6][7][8], where they are vulnerable. Although malaria is mostly transmitted indoors, some studies in East and West Africa have shown malaria transmission occurring outdoors by mosquitoes that escape insecticides or other indoor control methods [9][10][11][12].…”