In 2014, billionaire philanthropist Bill Gates got the infectious-disease community talking when he posted on his blog a chart ranking different species of animal and the number of people each kills every year.
Sharks ranked last on his list (15th) with 10 kills and snakes, third with 50,000 kills, but mosquitos turned out to be the deadliest to humans, killing 725,000 individuals a year. This is 250,000 more than the killings attributed to fellow humans (ranked second with 475,000 kills annually). The only times humans beat mosquitoes are during periods of war.
Gates argued that mosquitoes carry numerous deadly diseases that include malaria, dengue fever virus, yellow fever, Chikungunya virus, Japanese encephalitis, West Nile virus, Lymphatic filariasis, Rift Valley fever virus and more recently, Zika virus disease.
These mosquito-borne infections don’t just kill as they also debilitate millions more, costing billions in lost productivity in communities where these debilitating infections run rampant.
This is why Health Assistant Secretary and DOH spokesperson Eric Tayag reminded everyone not to relax one’s efforts or vigilance in fighting the resurgence of dengue cases in several areas of the country.
“Now is no time to let down. Keep on your guard. Even with the newest medical breakthroughs like the dengue vaccine that we now have in the market, let us not stop the vector control measures that we have been doing for years to protect ourselves and families. Be extra cautious and be mindful of the different areas where mosquitos thrive especially now that we are experiencing heavy downpours,” Tayag said during a recent press conference held in Manila.
Tayag reminded that dengue is difficult to manage and so a very intense drive is required: Dengue-carrying mosquitos (Aedes) are extremely hardy as they could need just a little bit of water to lay their eggs. Each mosquito can lay eggs about three times in its lifetime, and about 100 eggs are produced each time.
Moreover, these eggs can lie dormant in dry conditions for up to about nine months, after which they can hatch if exposed to favorable conditions, i.e. whenever there’s rain.
Under optimal conditions, the eggs of an Aedes mosquito can hatch into larvae in less than a day. It takes about four days for the larvae to develop into pupae, from which adult mosquitos will emerge after two days. Three days after the female adult mosquito has bitten a person and taken in blood, it will lay eggs, and the cycle begins again.
Rise
Tayag said the DOH Epidemiology Bureau has indicated that dengue cases have risen by 22.9 percent in the last six months—66,299 cases compared to 53,938 cases recorded during the same period last year.
While most cases came from Calabarzon with 8,059 (12.2 percent of total cases); Northern Mindanao with 6,447 (9.7 percent); Central Visayas with 6,422 (9.7 percent); Soccsksargen (South Cotabato, Cotabato, Sultan Kudarat, Sarangani and General Santos City) with 6,063 (9.1 percent); and Central Luzon with 6,048 (9.1 percent), the most alarming cases came from the area of Baguio.
The city already treated 1,199 from January to July, higher than the 239 treated for the same period in 2015. Benguet province, where Baguio City belongs, already recorded 1,483 dengue patients from January to July, exceeding the 437 patients treated there last year.
Other areas where there have been alarming increases of dengue cases were Eastern Visayas (168.5 percent), Davao Region (149 percent), Central Visayas (132 percent), and Western Visayas (101 percent).
But not all is bad news as there were also areas where cases have decreased: Cagayan Valley (60 percent), Ilocos Region (34 percent), Metro Manila (23 percent) and Zamboanga Peninsula (21 percent).
Reach out
“The DOH wants to reach out to the scientific community to participate in its efforts to define and find out the benefits of dengue vaccination in our country setting even as the department explores other means to eliminate dengue as a public health threat in this administration,” said Tayag.
The DOH has piloted a free anti-dengue vaccination program and at the moment, administered the first of the three doses of dengue vaccine (from April to July 2016) to eligible public schoolchildren, only 489,003 were covered and are limited to select public schools in Regions 3 (Central Luzon), 4-A (Calabarzon) and the National Capital Region.
The second and third doses will be given six months and 12 months after the first dose, respectively.
Sadly, this dengue vaccine, which is available commercially, is still too expensive for the average households as each person needs three injections of the vaccine, which costs between P4,000 and P5,500 per dose.
For the vaccination campaign, the DOH will be spending P3.5 billion.