Are malaria mosquitoes starting to actively...

In the News

Project builds case for dedicated health impact assessments

A visiting scientist from an IHI implementing partner in Switzerland, Dr. Fritz Brugger, presents at the event in Dar es Salaam. PHOTO/IHI (Dar es Salaam) IHI and partners hosted a …

IHI recruits Motor Vehicle Mechanic

IHI is looking for a Motor Vehicle Mechanic to fill a vacant position in our workshop. S/he must be specialized in servicing and repairing all systems contained within automotive vehicles. …

Recent Projects

Development of a new tool for malaria mosquito surveillance to improve vector control

Malaria transmission is influenced not only by vector abundance, but as well by demographic traits such as vector species and age structure, as these influence the intensity by which the …

Demonstrating complete disruption of residual malaria transmission by eliminating Anopheles funestus mosquitoes from rural Tanzanian villages

In rural south-eastern Tanzania, where malaria prevalence has reduced by >60% since 2000, low-to-moderate transmission still persists despite very high coverage with long-lasting insecticidal bednets. Like in most residual transmission …

Evaluating the potential for the development of mosquito behavioural avoidance to compromise Insecticide-Treated Nets in southern Tanzania

Background: The mass distribution of Long lasting Insecticide Treated Nets (LLINs) and Indoor Residual Spraying (IRS) programmes throughout sub-Saharan Africa have generated massive reductions in malaria transmission. The success of these strategies lie in their exploitation of a key vulnerability of the Anopheles mosquitoes that transmit malaria:  their strong behavioural predisposition to feed at night when people are sleeping, and rest inside their houses.  LLINs and IRS continue to prove highly successful for targeting mosquitoes that feed and rest indoors, but are less effective against mosquitoes with more flexible feeding and resting behavior. Consequently with the expansion of LLIN and IRS programmes, there has been a substantial ecological shift in the composition of mosquito vectors from endophilic species such as An. gambiae s.s., towards those such as An. arabiensis that have more variable feeding and resting behaviours. An. arabiensis can avoid contact with insecticides by feeding on other animal species, biting and resting outdoors and/or earlier in the evening.  In recent years, in the Kilombero Valley of Tanzania, the proportion of malaria transmission due to An. arabiensis has increased significantly and it now dominates transmission. There is growing evidence that An. arabiensis are capable of modifying their behaviour in the presence of vector control measures.

About this Project: In view of the potentially devastating epidemiological consequences of the development of behavioural avoidance strategies within mosquito vector populations, we conduct an in-depth investigation of the potential for this phenomenon to arise within the major malaria vector An. arabiensis in Tanzania, and evaluate its potential impact on the long-term sustainability of vector control measures. Working in four villages within the Kilombero Valley of Tanzania, namely Lupiro, Kidugalo, Minepa and Sagamaganga where malaria transmission is now dominated by An. arabiensis, we conduct detailed entomological investigations. Longitudinal surveillance of mosquito vector behaviours was established over a 5 year period (2011-2016) during which LLIN coverage levels are expected to grow to near 100% to test for the emergence of behavioural shifts in the timing and location of mosquito feeding and resting that may reduce the effectiveness of vector control.  In parallel, detailed ecological monitoring is conducted to identify the contribution of environmental factors to variation to these mosquito behaviors (e.g. inside versus outside, early or late evening biting), and evaluate their implications for human exposure risk in different settings.

Lead Scientists

Nicodem Govella

Katharina Kreppel

Heather Ferguson

Deo Maliti

Partners

University of California-Berkeley
University of Glasgow

Funders

National Institute of Health (NIH/NIAID-United States) through University of California

Projects Location

A PIXELBASE DESIGN
© Ifakara Health Institute (IHI), 2016