After a five-week decline from mid-November to December 2019, the incidence of dengue infections began rising again – with the number of dengue cases increasing, and expected to continue increasing, according to the National Environment Agency (NEA).
Plus, there is another added headache in store: A new, less common strain, Dengue virus serotype 3 (DENV-3), is emerging. For the past 30 years, mosquitotransmitted viruses have typically switched between DENV-1 and DENV-2. However, DENV-3 has emerged in more clusters across the island over these past few months (as of March 2020).
Why is this of concern? A switch in the serotype – in this case, to DENV-3 – usually
precedes an outbreak. “There are several reasons for this,” explains Dr. Maria Tang of International Medical Clinic (IMC) “Fewer people have been infected with the DENV-3 virus, which results in lower herd immunity in the population and a higher rate of transmission.”
Here’s what to know to help protect your family:
How is it Transmitted?
The dengue virus is transmitted by the bite of an infected female Aedes mosquito, most commonly Aedes aegypti. “In order for transmission to occur, the mosquito must feed on an infected person during the fiveday period when there is large amount of virus present in the blood,” says Dr. Tang. “This period is before the person shows any signs or symptoms. The incubation in humans is four to 10 days before the onset of symptoms.”
What are the Symptoms?
- The main symptoms are:
- A high fever that can reach 41 Celsius (105.8 Fahrenheit)
- Severe headache and/or pain behind the eyes
- Bone, muscle and joint pain
- Swollen glands
- Nausea and vomiting
- Rash (usually three to four days after the fever starts)
- Bleeding nose and gums
- Easy bruising
How to Reduce the Risks?
The Aedes mosquito breeds indoors in clean stagnant water easily found in our homes. And, it only needs a very small amount of water – the size of a 20-cent coin – to breed. Reduce mosquito habitats by doing the following:
- Turn pails and watering cans over
- Change water in vases
- Empty pet bowls and flowerpot plates
- Loosen soil from potted plants to prevent stagnant water on hardened soil surfaces
- Clear roof gutters and blocked drains
- Clean out air-conditioning trays
What Else to Do?
Because these mozzie carriers tend to feed in daylight in the early morning or late afternoon, you should avoid playing or exercising outdoors during sunrise or sunset. “Mosquitoes seek out chemicals in your breath and sweat, especially carbon dioxide, and are attracted to movement and heat,” says Dr. Tang.
When you are outdoors, use mosquito repellents containing 10- to 30-percent DEET concentration. “SPF can increase the concentration of the repellent, so apply your sunscreen first and wait 10 minutes before applying DEET,” recommends the doctor, who notes, “DEET is safe to use in children above 2 months old, provided it is not stronger than 30-percent concentration.” (Tip: IMC stocks RID, imported from Australia.)
In addition, try to wear long-sleeved tops and pants when outside. Use window and door screens to prevent mosquitoes from entering your home, and floor fans and air-conditioning to deter mosquitoes indoors.
If you are concerned, make sure to visit a doctor. And, for up-to-date data on dengue cases, go to the National Environment Agency (NEA)’s Dengue & Zika page.
By Sara Lyle Bow / From The Finder Kids, Volume 28, March 2020 / Photos: 123RF.com
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