Dengue fever is a major global health threat. It is spreading rapidly, and its incidence has increased 30-fold in the last 50 years. The Americas region, due to its tropical and sub-tropical geography, is where the highest number of infections have been recorded, exceeding 10.5 million cases so far in 2024. Today, more than half of the world's population is at risk, and another billion people are expected to be exposed to dengue in the coming decades due to climate change. Changes in temperatures and rainfall influence mosquitoes’ capacity to breed, impacting the spread of viruses that they carry.

Dengue fever is hyperendemic in Honduras and has triggered emergencies reaching alarming levels in the country. Doctors Without Borders/Médecins Sans Frontières (MSF) has been responding to outbreaks since 1998. So far in 2024, more than 160,000 cases have been reported in the country.

One year ago, MSF started an innovative and unprecedented activity to prevent the transmission of dengue and other arboviruses. This project was launched as existing prevention tools are not sufficient to protect the population from dengue, and there are no specific treatments or vaccines currently available that provide sufficient protection against infection.

For the first time in Honduras, together with local communities, the Ministry of Health, the National Autonomous University of Honduras and the World Mosquito Program, MSF released eight million Aedes aegypti mosquitoes carrying Wolbachia. It is a natural bacterium that reduces the mosquitoes' ability to transmit the dengue, Zika and chikungunya viruses, for six months. These releases were carried out to reduce the number of people affected by dengue and to offer complementary vector control alternatives to the State of Honduras.

One year after the start of the activity, the first results, which are very encouraging.