The Importance of Mosquito Behavioural Adaptations to Malaria Control in Africa

Abstract

Over the past decade the use of long-lasting insecticidal nets (LLINs), in combination with improved drug therapies, indoor residual spraying (IRS), and better health infrastructure, has helped reduce malaria in many African countries for the first time in a generation. However, insecticide resistance in the vector is an evolving threat to these gains. We review emerging and historical data on behavioral resistance in response to LLINs and IRS. Overall the current literature suggests behavioral and species changes may be emerging, but the data are sparse and, at times unconvincing. However, preliminary modeling has demonstrated that behavioral resistance could have significant impacts on the effectiveness of malaria control. We propose seven recommendations to improve understanding of resistance in malaria vectors. Determining the public health impact of physiological and behavioral insecticide resistance is an urgent priority if we are to maintain the significant gains made in reducing malaria morbidity and mortality.

Potential of household environmental resources and practices in eliminating residual malaria transmission: a case study of Tanzania, Burundi, Malawi and Liberia

“…Moreover, women and children gather much of the firewood in SSA countries which exposes them to frequent mosquito bites in the forests 8 . Additionally,the shift in mosquito behaviour from indoor late-night biting to outdoor early-evening biting 11 coincides well with major outdoor cooking activities in most homesteads of SSA countries. Charcoal use lowered malaria risk between 11%-49% with significance of this reduction presented in Tanzania.…”

“…For example both interventions have been observed to stimulate insecticide avoidance and early-exit behaviors among indoor-feeding vectors 6 as well as causing the emergency of insecticide-resistant mosquitoes 9,10 . They have also led to an increase in mosquito populations which feed and rest outdoors as well as those that become active early in the morning or evening when people have no protection 11 .…”

Resting Behaviour of Deltamethrin-Resistant Malaria Vectors, Anopheles arabiensis and Anopheles coluzzii, from North Cameroon: Upshots from a Two-Level Ordinary Logit Model

“…In other studies, An. arabiensis populations have shown some variations in biting or resting behaviour at different locations, with some of these variations being explained by seasons or historical use of insecticides [42].…”

Evolution, Current Status and Prospects of Phyto-Repellents against Mosquitoes

“…The resistance mechanisms in mosquitoes towards repellents are wide-ranging comprising behavioural, physiological, and molecular dimensions [7]. Radical behavioural change in host searching pattern, with a shift from nocturnal to crepuscular biting habit of Anopheles mosquitoes over the time has been reported, which in turn, propounds challenge in malaria vector control program using long lasting insecticidal nets, being employed at community levels [101,102]. The best understood molecular mechanism of resistance to repellents/insecticides is the modification of the target molecules of the repellents/insecticides, so as to avoid their action.…”