DENGUE is the world's fastest growing vector-borne disease. An estimated 50-100 million dengue infections occur annually in over 100 endemic countries. Ever since its detection in the early 1950s, there has been a 30-fold increase in dengue incidence. Almost half of the world's population is currently considered at risk of contracting dengue. The South-East Asia Region contributes to more than half of the global burden of dengue. About 52% of the world's population at risk resides in this Region. The disease is endemic in 10 of the 11 Member States and India, Indonesia, Myanmar, Sri Lanka and Thailand are among the 30 most endemic countries in the world. More than 400,000 cases of dengue were reported in this Region in 2013.

The good news is that deaths due to dengue have been brought down substantially. This is because of greater awareness amongst treating physicians on the proper use of WHO protocols in providing care to dengue patients. This is also attributed to increased knowledge amongst communities to seek early treatment for symptoms that resemble those of dengue.

However, the worrying part is that the number of cases has been increasing year after year. To understand it, we need to comprehend and keep pace with the changing epidemiology of dengue, especially the multiple ecological factors that influence its spread. Being a vector-

borne disease, ever-increasing numbers and varieties of mosquito-breeding habitats are being created with rapid and poorly planned urbanisation, globalisation, consumerism, poor solid waste and water management and increasing population movement without adequate measures to prevent vector breeding. Climate change is also influencing ecology that encourages vector breeding.

Dengue and other vector-borne diseases share common socioeconomic determinants that include reduced access to health services, housing, sanitation and water supplies as well as poverty. Efficient, effective and sustainable prevention and control of vector-borne diseases requires not only the application of biomedical tools, but also interventions to address these factors.

The accumulation of modern non-biodegradable products such as automobile tyres, plastic containers and tin products because of actions or inactions of sectors other than health provides a conducive environment for prolific breeding of Aedes aegypti and Aedes albopictus vectors of dengue. Hence, effective and sustainable prevention and control of dengue requires interventions that address these factors in an integrated and multisectoral approach.

Recognising the importance of a multisectoral approach and to advocate utmost need for Health-in-All-Policies, the health ministers of the South-East Asia Region, in their recent meeting in September 2014, adopted the Dhaka Declaration on Vector-borne Diseases. The Declaration encourages a "whole of government" approach against diseases such as dengue. The theme of World Health Day 2014 focused on vector-borne diseases to acknowledge their public health importance, raise global awareness and increase commitment on controlling them.

Global evidence conclusively shows that dengue control can never be achieved or sustained without community empowerment and ownership. Unfortunately, there is lack of awareness on the role of vectors in the community and the vital contributions that they can make to prevent dengue by mitigating vector breeding in their respective surroundings. Even the best public health system in the world will not accomplish the desired task of containing dengue without the active participation of communities in

this endeavour. Communities must work with public health authorities and also prevent accumulation of material where water gets stored, thus allowing mosquitoes to breed. The simple preventive step of protecting mosquito bites by wearing clothes completely covering the body can help a lot in cutting short the transmission of this infection.

For many infectious diseases, good vaccines are available. Extensive work is ongoing to have a safe, efficacious and affordable vaccine against dengue too. WHO has been supporting these R&D efforts. A few candidate vaccines are now in advanced stages of clinical trials. We look forward to their early availability to public health systems in developingcountries.

Till vaccines become available, dengue control activities have to be a synergistic combination of multisectoral activities based on sound public health actions, including integrated vector management and active participation of individuals, families and communities in reducing the sources where mosquitoes breed. The battle against dengue can be won only through concerted actions by all.

It is indeed the responsibility of every citizen to fight dengue.

The writer is Regional Director, WHO South-East Asia Region.