The Global Dengue Crisis
Before 1970 only 9 countries experienced severe Dengue epidemics. It is now endemic in 100 countries including Africa, the Americas, the Eastern Mediterranean, South-East Asia, and the Western Pacific.The America, South-East Asia and Western Pacific regions are the most seriously affected. That includes the Philippines. In 2015, 2.35 million cases of dengue were reported in the Americas alone, of which 10,200 cases were diagnosed as severe dengue causing 1.181 deaths.
Says the World Health Organisation, WHO, “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 as local transmission was reported for the first time in France and Croatia in 2010 and imported cases were detected in 3 other European countries. In 2012, an outbreak of dengue on the Madeira islands of Portugal resulted in over 2 000 cases and imported cases were detected in mainland Portugal and 10 other countries in Europe. Among travellers returning from low- and middle-income countries, dengue is the second most diagnosed cause of fever after malaria.”
In the Philippines, it is the 7th biggest killer of children of children up to four years old and the second leading cause of death in children between 5 and 9, and the sixth leading cause of death among child between the ages of 10 and 14.
An estimated 500,000 people with severe dengue require hospitalization each year around the world, and with an estimated 2.5% case fatality, annually. Globally, a 28% decline in case fatality have been recorded between 2010 and 2016 with significant improvement in case management through capacity building at country level.
It is now prevalent along a wide swathe of tropical and subtropical areas, as this map from the World Health Organisation shows:
So, Dengue is a growing problem. It is affecting areas where preventative measures such as eliminating sources of standing water, the mosquitoes breeding ground, or insecticide fogging may not be practical or economic: When Shell was building its gravity structure for natural gas in Subic Bay for its Malampaya project, the area was misted every night to eliminate mosquitoes. When the US Navy has its base in Subic Bay there was regular fogging of areas around the base for malaria prevention. Such measures may not be practical for smaller, low-income communities.
An alternative is the sterile insect method, in which sterile male insects mate with females – the core vector – reducing their potential for mating and spreading insect-borne diseases. It is a developing technique and a discussion of its benefits and drawbacks can be found here.
The newest kid on the block is Dengue vaccine. The first such vaccine is Dengvaxia, produced by Sanofi-Pasteur.