Dengue

About the disease:

Dengue Fever is a disease caused by a mosquito-borne flavivirus. It is transmitted by mosquitoes of the Aedes genus (primarily Aedes aegypti but also Aedes albopictus and some others) and four serotypes of the virus exist. Infection with the dengue virus can result in mild illness or life-threatening disease (and the disease is classified by the WHO into two categories – uncomplicated or severe). It is the most common of the arbovirus diseases and deemed only second in importance to malaria (surpassing the importance of malaria in certain geographic areas).

Distribution of dengue around the world: Dengue is currently endemic in more than 110 countries with 2.5 billion people living in areas where it is present (generally speaking it is limited to between latitudes of 35° North and 35° South). It is estimated that 50 to 100 million people are infected annually. Of these half a million require hospitalization, with deaths exceeding 10,000 per year. There has been a dramatic increase in the incidence of dengue in recent years and this is attributed to increased urbanisation, population growth and climate change.

The importance of Vector Control:

The Aedes vectors bite primarily during the day and have a strong preference for people rather than sourcing blood meals from animals. Aedes aegypti prefers to lay its eggs in small artificial containers and tends to have a close proximity to man. Treatment or destruction of breeding sites is thus a key method to reduce the incidence of disease. Given the logistical challenges with eliminating and/or treating all breeding sites in an urban environment (and especially during epidemics) the application of space-spray insecticides is also a recognised method to reduce the threat and spread of the disease.