Key Results & Achievements

To understand more about the potential acceptability of a repellent-based control strategy in Latin America, a series of qualitative studies were carried out in Colombia to examine the attitudes of women of reproductive age and their partners towards Zika virus and its prevention.

“As a medical entomologist I am excited to be working on this programme because this current Zika epidemic appeared very quickly and taken us by surprise. We need to think of new techniques to outsmart the Aedes mosquito.”

Dr. James Logan, London School of Hygiene & Tropical Medicine

Qualitative study on acceptability of impregnated clothing

The data generated from the studies suggested that people who are consistently exposed to the threat of arboviral diseases may be reluctant to adopt new mosquito bite-reduction practices. This added impetus to the development of technologies that can achieve results with minimal impact on people’s daily routines, such as wash-in repellents, that do not require significant behavior change and are not perceived to be toxic or dangerous to use during pregnancy.

A report on the attitudes of women in the Colombian cities of Villavicencio and Cali was completed. This concerned arbovirus risk perception, with an emphasis on Zika virus, and practices relating to mosquito bite prevention. Focus was on personal protective technologies. In total, 19 focus groups were conducted, involving a total of 149 women of reproductive age. In addition, there were 14 one-to-one interviews conducted with male partners of women of reproductive age. Insights gained from the results of this study will contribute to the development of a repellent, that:

  • has a non-chemical odour; ideally through the use of plant derivatives;
  • has spatial capacity to protect uncovered areas of the wearer;
  • is applicable to various fabrics;
  • is low-cost;
  • is durable, with long periods between re-application.

A second qualitative study was conducted in two cities in Brazil, which also identified cost as a major consideration, and suggested that users would prefer repellents to be applied to clothing rather than incorporated into the fabric itself. The need for a spatial effect of the repellent was communicated by the study participants.

Wash-in detergents

The focus group study confirmed the potential utility of a repellent product that can be applied at home to the users’ clothing. Investigations were conducted into the technical feasibility of developing both wash-in repellent laundry additives and post-laundry textile sprays. Work continues around this task and analysis on which product will prove safe is being pursued.

Wash-resistant clothing

Plant-derived Delta-undecalactone (dUDL) was identified as a potential repellent, and chemical carriers were investigated to improve longevity of the protective effect. Various cyclodextrins, acting as carrier molecules, were developed by Cyclolab and tested with differing levels of success. Essential oils were incorporated into the formulations to help masking the dUDL odour. Lavender oil was effective in making the smell more pleasant whilst retaining the protective effect.

Novel plastic wearable technologies

Plant-derived Delta-undecalactone (dUDL) was identified as a potential repellent, and chemical carriers were investigated to improve longevity of the protective effect. Various cyclodextrins, acting as carrier molecules, were developed by Cyclolab and tested with differing levels of success. Essential oils were incorporated into the formulations to help masking the dUDL odour. Lavender oil was effective in making the smell more pleasant whilst retaining the protective effect.

Modelling prevention

A model from by Kizewski & Darling (2010) was adapted to determine the level of repellent protection required to have an impact on reducing disease in an outbreak scenario. The conclusion was that with an intervention using a repellent that is 75% effective, and a target population uptake rate of 90%, the infection rate could be reduced to ~16%, and to 5% if uptake is 100%.

The Global Vector Hub

In order to provide accurate and up-to-date information on disease vectors and effective control measures despite the ongoing Covid-19 pandemic, an early version of the Global Vector Hub online platform was launched in June 2020. This allows for quick access to essential information, resources, official guidelines and training materials. A fully functional version will be launched later in 2020, which includes further capabilities on networking and the exchange of information and data within the global vector community.

Participating Organisation

Group leader: Prof. James Logan, London School of Hygiene & Tropical Medicine

Senior Researcher: Dr. Thomas Ant