The World Health Organization (WHO) estimates about 50 to 100 million dengue infections occur each year and require 500,000 hospitalizations, and more than 40 percent of the world’s population is living at risk for infection.
Dengue infection was a relatively minor, geographically restricted disease, which originated in monkeys and was transmitted to humans between 100 and 800 years ago. It was only in the middle of the 20th century when dengue spread to other countries.
According to the Centers for Disease Control and Prevention, “The disruption of the second world war – in particular the coincidental transport of Aedes mosquitoes around the world in cargo – are thought to have played a crucial role in the dissemination of the viruses. DHF was first documented only in the 1950s during epidemics in the Philippines and Thailand. It was not until 1981 that large numbers of DHF cases began to appear in the Carribean and Latin America, where highly effective Aedes control programs had been in place until the early 1970s.”
Dengue fever occurs following the bite of an infected mosquito Aedes aegypti, which breeds in clean water and has a flight range of only 100-200 meters. The oosquitoes generally acquire the virus while feeding on the blood of an infected person. The symptoms of infection usually begin four to seven days after the mosquito bite and typically last three to 10 days.
However, some people never have significant symptoms but can still infect mosquitoes. “Aedes mosquitoes may acquire the virus when they feed on an individual during incubation period,” the WHO says.Infected humans are the main carriers and multipliers of the virus, serving as a source of the virus for uninfected mosquitoes.
Dengue only spreads through the bite of an infected mosquito. Unfortunately, there are four different but related strains of dengue virus. There can be a repeat occurrence of dengue if a different strain is involved and being affected by one strain offers no protection against the others.
Dengue fever is a severe, flu-like illness accompanied by severe headache, pain behind the eyes, muscle and joint pains, nausea, vomiting, swollen glands or rash that affects infants, young children and adults, but seldom causes death. However, severe dengue is a potentially deadly complication due to plasma leaking, fluid accumulation, respiratory distress, severe bleeding, or organ impairment.
The WHO explains. “Symptoms usually last for two to seven days, after an incubation period of four to 10 days after the bite from an infected mosquito. Warning signs occur three to seven days after the first symptoms in conjunction with a decrease in temperature and include: severe abdominal pain, persistent vomiting, rapid breathing, bleeding gums, fatigue, restlessness, blood in vomit.”
“The next 24 to 48 hours of the critical stage can be lethal; proper medical care is needed to avoid complications and risk of death,” the WHO points out. “Dengue is the world’s most important viral disease transmitted by mosquitoes,” declares Dr. Duane Guble, health administrator of the US Centers for Disease Control and Prevention.
With the rising number of infections and fatalities due to dengue, this mosquito-borne disease is undeniably a global health concern, and curbing the spread of the disease is one of the main goals of all the countries that are suffering from its dangers.
Dengvaxia: A medical breakthrough
In December 2015, Sanofi Pasteur, the vaccines division of Sanofi, announced that the Philippines have granted marketing approval to Dengvaxia® , making it the first vaccine to be licensed for the prevention of dengue in Asia. The Philippines’ Food and Drug Administration approved Dengvaxia® , tetravalent dengue vaccine, for the prevention of disease caused by all four dengue types in individuals from nine to 45 years of age living in endemic areas.
“Approval of the first dengue vaccine in Asia, which bears 70 percent of global disease burden , is a major milestone in dengue prevention and public health,” notes Olivier Charmeil, President and CEO of Sanofi Pasteur. “Approval of Dengvaxia® in the Philippines, following closely the first approval in Mexico, is further evidence of Sanofi Pasteur’s long-standing commitment to introduce this innovative new vaccine first in countries where dengue is a major public health threat.”
On April 4, the Department of Health, together with the Department of Education (DepEd), and the Department of the Interior and Local Government (DILG) launched the dengue vaccine in in Marikina City. It was continued in Iba, Zambales where His Excellency, President Benigno Aquino III, together with Health Secretary Janette P. Loreto-Garin led the immunization to selected 9 years old students.
The Philippines is the first country to implement dengue vaccination through school-based immunization approach and aims to vaccinate about 1 million Grade 4 pupils aged nine years old and above enrolled in public schools in Regions III, IV-A, and NCR.
Dengvaxia® vaccine’s anticipated impact on dengue fever disease burden is expected to stem from the vaccine’s proven ability to prevent 8 out of 10 dengue hospitalizations and up to 93 percent of severe dengue cases–including dengue hemorrhagic fever–in study participants 9 years and older, as demonstrated during 25 months of follow-up of phase III efficacy studies.
As of March 2016, Dengvaxia® was licensed in Mexico, the Philippines, Brazil and El Salvador for prevention of dengue from all four serotypes in individuals nine to 45 years of age living in endemic areas. Regulatory review processes for Dengvaxia® are continuing in other countries where dengue is a public-health priority. Both public and private vaccinations have already begun in the Philippines and discussions are underway in the other approval countries for launches later this year.
Sanofi Pasteur’s vaccine is the culmination of over two decades of scientific innovation and collaboration, as well as 25 clinical studies in 15 countries around the world. Over 40,000 volunteers participated in the Sanofi Pasteur dengue vaccine development program (phase I, II and III), with 29,000 volunteers receiving the vaccine. Large-scale efficacy studies of Dengvaxia®, including 25-month follow up, were successfully completed in 2014. ,
Pooled efficacy and integrated safety analyses from the 25-month Phase III efficacy studies and their ongoing long-term follow-up were published online in The New England Journal of Medicine on July 27th 2015, documenting the vaccine’s consistent efficacy and longer-term safety profile in the study population of nine to 16 years of age. In the pooled efficacy analysis in this age group, Dengvaxia® was shown to reduce dengue fever due to all four serotypes in two-thirds of the participants and prevent 8 out of 10 hospitalizations and up to 93 percent of severe dengue cases.1
Dengvaxia® is the first vaccine in the world licensed for the prevention of dengue fever. The vaccine is produced in a dedicated production site in France, with a full-scale production capacity of 100 million vaccine doses annually.
Dengue prevention tips
1 Clean up your backyard. Mosquitoes love to stay in the dark and damp areas. So if your garage is littered with boxes and assorted garbage, clean them up or throw them away. Don’t let them become mosquito havens. Schedule a weekend clean-up day.
2 Empty containers with stagnant water. The dengue-carrying mosquitoes breed in stagnant water. This means that flower pots, garbage cans, aquariums, unused swimming pools, tires and other piles are potential breeding grounds for mosquitoes. So after the rains fill them with water, throw the water away. Next time, keep these containers closed and upside down. Flower vase should also be replaced weekly.
3 Check your surroundings for stagnant water. Some ornamental plant leaves have this “whorl” or cup-like shape that can hold water. Beautiful to behold but deadly in design. Turn them over and throw the water away. Upturned coconut shells are also notorious for holding water. Non-moving rivers, especially in squatter areas, are full of mosquito eggs.
4 Close your doors and windows. Some people open their doors in the morning for a whiff of fresh air. They also believe that mosquitoes would leave the house and go into the sunlight. “But my advice is to keep your doors shut at all times,” he advices. If it’s too stuffy, then place a screen door that keeps the flies and mosquitoes outside.
5 Spray insecticide regularly. To rid your house of mosquitoes, flies and cockroaches, spray insecticides every few days. Make sure you spray those dark corners, crevices, and cabinets. You’ll be amazed at the number of pests you’ll find dead in the morning. Just make sure that household members are not exposed to the insecticide as they are not the target. Just spray selected rooms when people are not around.
6 Wear pants, pajamas, long sleeves, and socks. Mosquitoes are attracted to your breath as you exhale so they know how to reach you even in the dark. “I guess they love bare, plump skin, especially the kids who don’t shoo them away and let them suck as much blood as they want,” Dr. Ong believes.
7 Apply insect-repellants or use mosquito nets. If your kids are going hiking, camping or off to school, you can apply insect-repellants like Off-Lotion. Kids like to play outdoors and are prime targets of these mosquitoes. You can wipe it on selected areas of the clothing like collars, sleeves and pants. Avoid applying lotion on the eyes, mouth or hands.
8 Kill those mosquitoes. When it comes to dengue, it’s either kill or be killed. Instruct everyone to kill as many mosquitoes and flies as they can. Once you’ve got them trapped in your bathroom, show no mercy. Mosquitoes belong to the forest, not in your home.
9 Involve the whole community. The best way to defeat dengue is if the whole community is aware of the threat. Ask your community leaders to schedule a clean-up day. The danger is in those empty houses and lots, which are excellent breeding places for mosquitoes. Become a volunteer to monitor and clean up your surroundings.
10 Spread the word: Dengue fever is here. You’ll never know where dengue will strike next so better be prepared. Inform your neighborhood. Share the good news that a vaccine is already available for protection against dengue. with Henrylito Tacio
1 comment
Great insights! Cleaning up our front and backyard indeed isn’t really just increasing our home value. But also prevents pests and other insects that may cause diseases to humans.