BiteBarrier Provides Strong Protection Against Malaria and Arbovirus Mosquitoes

Researchers at the Ifakara Health Institute, in collaboration with NM-AIST, Swiss Tropical and Public Health Institute, University of Basel, Liverpool School of Tropical Medicine, University of Notre Dame, and University of Massachusetts Amherst, investigated a new approach to mosquito control using a device called BiteBarrier^[1]. BiteBarrier is a spatial emanator – a device that releases a volatile chemical, transfluthrin, into the air to repel or kill mosquitoes. The aim of the study was to evaluate how well BiteBarrier works against different mosquito species, including those that are resistant to common insecticides, over an extended period.

The study was conducted in a “semi-field system,” which is essentially a controlled outdoor environment that mimics real-life indoor and outdoor settings. This allowed the researchers to observe mosquito behavior and measure the effectiveness of BiteBarrier under more realistic conditions than a laboratory setting. Five mosquito species were tested: Anopheles gambiae sensu stricto (s.s.) – a major malaria vector – in both insecticide-susceptible and knock-down resistance (KDR) forms; Anopheles funestus and Culex quinquefasciatus, both resistant to pyrethroid insecticides; and Aedes aegypti, a key vector of dengue fever.

Two methods were used to assess BiteBarrier’s protective effect. The first measured the “landing rate” – how many mosquitoes landed on people or surfaces. The second, and more reliable, measured the “feeding success” – how many mosquitoes actually managed to take a blood meal from a person. demonstrated that feeding success provided more accurate results than simply counting landings, as not all landings result in a bite.

The results were encouraging. BiteBarrier provided over 93% protection against mosquito bites indoors and 80% protection outdoors, regardless of whether the mosquitoes were susceptible to insecticides or had developed resistance. Importantly, the device also caused substantial mosquito mortality – 47% indoors and 26% outdoors – over the eight-week study period. This is significant because it suggests BiteBarrier can both prevent bites and reduce the overall mosquito population.

These findings build on earlier work highlighting the need for integrated vector management (IVM) strategies^[3]. IVM emphasizes using a combination of tools to control mosquitoes, rather than relying on a single method. The increasing insecticide resistance observed in many mosquito populations^[3] underscores the importance of diversifying control approaches. Spatial repellents, like BiteBarrier, offer a complementary strategy that can work alongside existing methods like insecticide-treated nets and indoor spraying.

The study also aligns with the growing recognition of the potential for spatial repellents to fill critical gaps in mosquito control^[4]. Previous discussions among stakeholders, including the World Health Organization (WHO), have focused on establishing guidelines for the development and evaluation of these products.^[4] notes a key need for epidemiological data demonstrating the public health impact of spatial repellents in different settings to support policy recommendations. The research conducted by the Ifakara Health Institute and its partners provides valuable evidence in this regard.

The BiteBarrier’s effectiveness against both susceptible and resistant mosquito species is particularly noteworthy. This suggests it could be a useful tool in areas where insecticide resistance is widespread, a growing problem in many malaria-endemic regions^[3]. The eight-week duration of protection also indicates that it could provide a sustained level of control, reducing the need for frequent re-application.