Dengue: Things one should know

As Bangladesh continues to struggle to contain the dengue outbreak, the social media has been flooded with unfounded information about the mosquito-borne disease and ways to fight it.

Dengue has, so far, officially claimed 29 lives in the country this year, although media reports suggest the number is way higher.

There is no specific treatment for dengue or severe dengue, the WHO says, but early detection and access to proper medical care lowers fatality rates below 1 per cent.

Physician Mazharul Islam, former chief medical officer at Feni Sadar Hospital, told UNB that aedes aegypti, the mosquito responsible for dengue, mostly bites during the daytime. “They’re mostly active during couple of hours after sunrise and several hours before sunset. But you shouldn’t let your guard down as they can bite anytime,” he said.

The Centres for Disease Control and Prevention says mosquitoes that spread dengue, chikungunya and Zika bite during the day and night.

Dengue is caused by a virus of the Flaviviridae family. There are four distinct, but closely related, serotypes of the virus that cause dengue (DEN-1, DEN-2, DEN-3 and DEN-4).

Aedes aegypti is the primary vector of dengue. It mainly acquires the virus while feeding on the blood of an infected person. The virus is passed on to humans through the bites of an infective female aedes mosquito.

The mosquito can be identified by the white bands on its legs and a silver-white pattern of scales on its body.

Flight range studies suggest that most female aedes aegypti may spend their lifetime in or around the houses where they emerge as adults. They usually fly an average of 400 metres. This means that people, rather than mosquitoes, rapidly move the virus within and between communities and places, the WHO says.

Symptoms typically begin three to 14 days after the infection, and may include a high fever, headache, vomiting, muscle and joint pains, and rashes. When a mosquito bites a person infected with a dengue virus, the virus enters the mosquito. It is the female mosquito that bites. It needs nutrients in the blood to produce eggs.

The papaya leaf, coconut oil myths

You too have probably heard it – drink lots of papaya-leaf juice to increase platelet count if you have dengue. Or remember how people told you to use coconut oil to deter aedes mosquitoes.

Do not believe everything you are told since there is no scientific basis for the two ‘methods’.

Some refer to a recent open-labelled trial from Malaysia that showed significant higher platelet count after 40-48 hours of first dose of papaya-leaf juice. Others have also reported encouraging findings.

“The role of papaya leaves cannot be scientifically substantiated based on a few positive preliminary reports,” Mazharul notes.

It has also not been scientifically proven that coconut oil can keep aedes aegypti at bay. “Awareness is the key,” the physician says. “Keep your houses and surrounding areas clean, use adequate mosquito repellent and cover yourself. Stay safe!”