Why is dengue fever back in the news again? Why are we seeing it in areas
where it did not exist before? And what about treatment? What about vaccination? Here to talk about all of this is Dr. Raman Velayudhan. Welcome, Raman. Talk to us about dengue fever,
what causes it and how does it spread? Dengue fever is a virus fever caused by the bite of Aedes mosquito. In majority of the cases,
these are mild symptoms with body pain, headache and rashes,
which lasts for a few weeks. However, about 5% o
f the cases are severe where the patient needs hospital care. The main symptoms of severe dengue are vomiting, bleeding of the gums, plasma leakage,
and sometimes organ failures. These cases need to be managed
in the hospital to prevent death. However, most of the patients recover from it. But the delay in admission can cause unnecessary fatalities. So in many cases, the patient takes time
to come and that delay is a crucial point. Dengue is transmitted from one person
to the other by the bite o
f the mosquito. You know, when I was growing up in New Delhi, I never heard about dengue
until a certain point. And then dengue cases started appearing. We are seeing it in places where
it did not exist before, like Spain or Bhutan. Why is this happening? Well, dengue is spread very fast, mainly because of international travel and the adaptation of the mosquito
into an urban pocket. Climate change is yet another factor which
has contributed to the spread of dengue. And this has two extremes,
whe
re the flooding of areas also causes mosquitoes to multiply. But at the same time, if there is scarcity
of water, the mosquitoes manage to survive in containers of stored water. So the more water you store,
the more areas for it to breed. So this has all helped the mosquito to adapt and spread the disease
to newer areas and new countries. Over 100 countries are endemic
for this disease and approximately 4 billion
people are at risk of it. The mosquito has adapted
so well that it is continuing to
spread to newer areas where
the climatic conditions are suitable. Are there any treatments or vaccine? Does that work for dengue fever? There are currently no treatments
for dengue. Most of the cases are managed at home,
mainly to prevent the main symptoms of dengue,
which are fever or joint pains. So tablets are given for controlling that. Paracetamol is given as a medicine for this, while ibuprofen and aspirin are discouraged
since that can lead to bleeding. Currently there is only one vaccin
e which is approved
and that is recommended for age group between 6 to 16 in high transmission settings. There are several new developments
which include better diagnostic kits, medicines and mosquito control tools. They will be made available
as the studies and results are published. Currently, there are no other effective
methods which are in use, but we are using traditional methods
to control the mosquitoes. Raman, talk to us about why dengue fever is so hard to control
and how can we protec
t ourselves? The dengue fever is hard to control because this mosquito has adapted
extremely well to urban centres. Secondly, their eggs can remain dry
for several months and hatch as soon as they come
in contact with water. Thirdly, this mosquito is continuing
to spread to newer areas where conditions are favourable to them, and this includes
urban and semi-urban pockets. The dengue mosquito bites
during the daytime. Hence, we have to protect ourselves with repellents and other personal
protec
tion measures. So before we go to work
or before children go to school, they must be provided with repellents. So they are protected
from the bite of this mosquito. Other measures include preventing mosquito
breeding in and around your homes, covering your water storage containers, and at the same time, those who have dengue, or people who tend to sleep during the day,
should use a mosquito net. Thank you, Raman. That was Science in Five today. Until next time, then. Stay safe, stay healthy
and
stick with science.
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