Dengue: A Global Overview
Three billion people around the world live in tropical and subtropical regions where the four strands –or serotypes– of the denge virus (see map) exist. Each year, between 50 to 100 million people are infected through the bite of the female Aedes aegypti and other similar species, such as Aedes albopictus.
In the last decades, the rapid growth of urban populations, coupled with poor environmental sanitation services and a lack of adequate water-storage resources, has favoured the spread of mosquito vectors. At the same time, the increase in international air traffic has contributed towards the geographic dissemination of the viruses. These factors have led to a re-emergence of dengue fever, dengue hemorrhagic fever and dengue shock syndrome epidemics. Hyperendemicity (when few members of a single community are not infected) has also increased in several urban centres.
There are currently over 100 countries where dengue is endemic and the number is rising. With no available vaccine or specific drugs to treat it, dengue causes 24 thousand deaths and serious complications among over 500 thousand people each year. This disease is among the most frequent causes of child hospitalization in hyperendemic countries and is a significant financial burden for many lower-income families.
Dengue in Latin America
In 2010, over 1.8 million people became ill from dengue in Latin America, where the number of cases doubles each year. The Pan American Health Organisation considers dengue one of the main public health problems in the Americas.
Across the region, dengue prevention and control has followed models inherited from the top-down programmes of the 1960s and 70s that sought to eliminate the vectors in urban and suburban areas through the use of larvicides such as temephos (not approved for use in drinking water in the United States, where it is produced) and insecticides such as DDT.
The initial impact of these campaigns created the false impression that dengue could be conquered easily; but as funding for these programmes dried up Aedes aegypti and dengue spread through the Americas with increased strength. In the 90s, control strategies began to focus on community action, mainly due to the breakdown of top-down control programmes in the region, the decentralisation of healthcare systems and the lack of sufficient technical staff to match the disease’s geographic spread.
The lack of sustainable results during the last decades has led to the search for more innovative ways of involving the community in the fight against dengue: Camino Verde is one of them.