Wie die Welt das sich ausbreitende Dengue-Fieber erfolgreich bekämpft
Singapore has long done a fine job of fighting dengue. It helps that it is rich enough to pay armies of public-health workers to traipse through its streets, searching out the standing water in which mosquitoes breed, pipetting puddles and issuing fines. The city-state models outbreaks and then deploys platoons of insecticide sprayers in hazmat suits to the predicted epicentres. Latin American countries have hazmat armies too, but with modest budgets and vast areas to cover, they have not done much to slow dengue’s explosive growth in the region. Slums are hard places in which to track down mosquito breeding-grounds.
So it is wise to consider other approaches. Since 2016 Singapore has been running another, higher-tech dengue programme. Every week it releases 5m mosquitoes infected with wolbachia bacteria. This prevents them or their offspring from transmitting the virus that causes dengue and costs about $35m a year, or $6 per resident. Combined with new vaccines under development, it provides a way of fighting dengue that does not rely on legions of standing-water spotters. Trials of wolbachia infection in Colombia have seen a 94% drop in dengue incidents in the area where the mosquitoes are released. The world’s largest wolbachia-mosquito factory is due to start operations in the Brazilian city of Curitiba this year.