Dengue is a major public-health concern throughout tropical and sub-tropical regions of the world. It is the most rapidly spreading mosquito-borne viral disease, with a 30-fold increase in global incidence over the past 50 years. The World Health Organization (WHO) estimates that 50 - 100 million dengue infections occur each year and that almost half the world’s population lives in countries where dengue is endemic. Recent evidence has put this figure three times higher, at 390 million. Currently, close to 75% of the global dengue burden is borne by the Asia-Pacific region, but dengue is a global concern. Fueled by population growth and urbanization, migration, poverty and ineffective use of resources for control, dengue shows a steady increase in all countries reporting the disease; the 2010-2011 wet season reported exceptional levels, with record incidences recorded in many countries. Not only is the number of cases increasing as the disease spreads to new areas, but explosive outbreaks are occurring. The threat of a possible outbreak of dengue fever now exists in Europe and local transmission of dengue was reported for the first time in France and Croatia in 2010 and imported cases were detected in three other European countries. A recent (2012) outbreak of dengue on Madeira islands of Portugal has resulted in over 1800 cases and imported cases were detected in five other countries in Europe apart from mainland Portugal. Video.
Over the last 50 years, this infectious disease has increased in importance to the point where it is the most widespread arboviral disease worldwide; affecting over half of the world’s population. Prevention of dengue and response to outbreaks without the availability of a vaccine, depend entirely on vector control; a method to limit or eradicate carriers of disease such as insects. Yet there are no methods available that have been proven to impact on dengue vector populations at levels that reduce dengue transmission. Identifying effective dengue vector control tools, suitable for deployment and sustained correct usage in the high-density urban communities of the tropics, remains a high priority. Dengue outbreaks can last for the duration of a wet season (typically around five months) and the challenge is to deliver protection that will remain effective for that duration.
The images above were taken in 2014 from an ongoing trial devised and managed by the Liverpool School of Tropical Medicine in collaboration with University Gadjah Mada, Centre for Tropical Medicine, Yogyakarta, Indonesia. The trial's aim was to determine the efficacy of a number of approaches that might be a suitable response to a Dengue outbreak, whilst also satisfying the need for more long-term protection.