MANILA, PHILIPPINES – The World Health Organization (WHO) in the Western Pacific Region and key partners including the Asian Development Bank (ADB) are observing World Health Day on 7 April with a call for greater vigilance and action in tackling a range of vector-borne diseases such as malaria, dengue, chikungunya, lymphatic filariasis, and schistosomiasis.
Vectors such as mosquitoes, ticks, mites, fleas, sandflies and freshwater snails are organisms that can transmit dangerous parasites, viruses, or bacteria from one infected person or animal to another, causing serious diseases in humans.
One sixth of the illness and disability suffered worldwide is due to vector-borne diseases, with more than half the world’s population currently estimated to be at risk of these diseases. The poorest segments of society and least-developed countries are most affected.
Malaria remains the vector-borne disease with the highest death toll in humans, estimated to have caused about 207 million infections globally in 2012 and to have claimed 627,000 lives.
The world’s fastest growing vector-borne disease, however, is dengue, also spread by mosquitoes, with a 30-fold increase in incidence over the last 50 years, topping 100 million cases across 100 countries in 2012. An estimated 500,000 people with severe dengue require hospitalization each year, a large proportion of whom are children; about 2.5% of those affected die. The Asia-Pacific region reports more than 75% of the global dengue burden.
“This year’s World Health Day theme of Small bite, big threat is a timely reminder that vector-borne diseases affect billions of people globally, including millions in all 37 countries and areas in our Region,” noted Dr Shin Young-soo, WHO Regional Director for the Western Pacific.
“While we’ve made significant strides against some of these diseases, malaria in particular, we need much more national, regional and global political commitment, resources and multisectoral collaboration," he added. "We also need much more public awareness about these diseases, as people need to know how to protect themselves better. We hope that World Health Day 2014 serves as a springboard for greater action on all these fronts.”
Vector-borne diseases are commonly found in tropical and sub-tropical regions. The spread of these diseases is determined by a complex combination of social, economic and environmental factors, including the impact of globalization on travel and trade, haphazard urbanization, a lack of access to safe drinking water and sanitation, and environmental challenges including climate change. Some diseases, such as dengue and its close cousins chikungunya and Zika virus, are fast emerging in countries where they were previously not seen.
WHO brings together countries to develop, discuss, and agree on global strategies and regional action plans for malaria, dengue and neglected tropical diseases. The organization provides technical advice and expertise not only to shape these strategies and action plans, but also on how best to implement them. WHO also encourages research and development efforts regarding prevention tools and medication.
Protection from bugs and bites is key: repellents, bed nets treated with insecticides, and window screens can all help, as can making sure there’s no standing water in or around the home.
As a joint WHO-ADB dengue control initiative in Cambodia and the Lao People’s Democratic Republic has assessed, introducing larvae-eating fish like guppies into water storage containers can also control mosquito breeding. It is encouraging to note that a dengue vaccine is currently in the pipeline.
“All vector-borne diseases take a human toll. But they also have significant development impact,” said ADB Vice President Stephen P. Groff. “That is why we’ve helped establish the Asia Pacific Leaders Malaria Alliance, or APLMA, to bring countries together to fight malaria on multiple fronts.”
ADB hosts the secretariat of APLMA and supports high-level advocacy and APLMA’s two taskforces: one to ensure that regional financing for the fight against malaria remains strong, and the other to increase regional access to quality malaria medicines and commodities, and reduce the availability and use of low-quality or counterfeit anti-malarial medicines.
Elimination of these neglected diseases is possible. The People’s Republic of China, Republic of Korea, and Solomon Islands have already eliminated lymphatic filariasis, which is transmitted to humans through mosquitos and causes severe pain and disfiguring disability. Between 2000 and 2011, in the Western Pacific Region, malaria cases dropped by 46% and ; deaths from malaria dropped by 73%.
But many challenges remain. Some diseases are on the rise, especially dengue and chikungunya. Anti-malarial drug resistance – especially artemisinin resistance – and insecticide resistance remain major concerns. Reaching marginalized communities and ensuring universal access to prevention and treatment of vector-borne diseases is a formidable task.
“WHO and ADB cannot work on these issues alone – partnerships are vital,” concluded Dr Shin. “Partnerships with governments, development partners, industry and civil society – to strengthen our collective focus and expand our investment. Partnerships with communities and individuals – so we can each play our role in protecting ourselves. Let’s work together to ensure that the big threat from vector-borne diseases is reduced significantly in the years ahead.”