Dengue for dummies

Dengue epidemics are escalating in India. Here's (mostly) everything that you need to know.
30 Sep 2015
0 mins read
Wanted for murder: The Aedes aegypti mosquito the primary vector for Dengue (Source: James Gathany [Public domain], Wikimedia Commons)
Wanted for murder: The Aedes aegypti mosquito the primary vector for Dengue (Source: James Gathany [Public domain], Wikimedia Commons)

I keep seeing news about dengue everywhere. Why is it such a big deal?
India is experiencing a dengue outbreak now. As of September 13, 2015 about 22,000 people in India have been diagnosed with the disease; nearly 2000 of these cases are in Delhi alone. Thankfully, fatalaties this year are at 0.2 percent, which is considered 'very low'. Outbreaks of this magnitude do place a strain on health services. Much of what is  being reported is about how hospitals and the government are struggling to diagnose and treat patients. Sadly, some reporting has fuelled a panic which overwhelms strained hospital resources and may also block the truly needy from accessing health care. So watch the news, take precautions, but don't panic.

There was nothing like this when I was young, was there?
No, there was. Dengue has been around for a very long time. The virus was isolated in Japan in 1943, and so confirmed diagnoses only extend that far. In India, the first confirmed outbreak was in 1963 in Calcutta. Since then, it has never really gone away but here's a map.
The various types of the dengue virus (there are four of them) can cause a range of afflictions from dengue fever (DF) which is mild, to the potentially fatal dengue haemorrhagic fever (DHF). While dengue fever outbreaks have been recorded since the 1960s, the latter only surfaced in India in 1988. It was not till 1996 that we had the first major epidemic of dengue haemorrhagic fever in Delhi.

But I don't live in Delhi, so I should be okay, right?
It's not really confined to Delhi. If you look at the map, it covers nearly the entire country. Moving to Ladakh is not the solution either. With climate change, mosquitoes are boldly going where they have not gone before.So no matter where you are, be careful.

I was in a meeting and shook hands with this chap. The next day, I learnt that he was down with dengue. Does that mean I'll get it now?
No, not by shaking his hand. Dengue is transferred through the blood. While it can be transferred by transfusion of infected blood, the most prevalent means of transmission by far is mosquitoes. This is  why the WHO has specified vector control as a 'critical' strategy to control dengue. Specifically, they recommend 'source reduction' meaning making sure your backyard does not contain any stagnant water that mosquitoes may breed in.
By the way, a human is  capable of infecting a mosquito from upto 12 hours before he or she shows any symptoms and for as long as 3-5 days from that period. Once infected, a mosquito remains a carrier for life.
So you should only worry if you were sitting in a room full of mosquitoes, which you wouldn't be doing dengue outbreak or not!

So what should I do to protect myself?
Follow the steps you normally would to protect yourself from mosquito bites. Reduce mosquitoes around your home, wear protective clothing and use a repellent. And here's a more comprehensive list of measures for yourself and your community.

How do I reduce mosquitoes around my home?

This is where water management comes into the picture. Mosquitoes lay their eggs in stagnant water. This means that you need to be scrupulous about not allowing water to collect around your house.  Making sure your rainwater harvesting and other tanks are covered and properly maintained is an important part of this. A system of channels and recharge pits is a good way of ensuring no water accumulates in low-lying areas. But mosquitoes don't need much space. This means that you need to be vigilant about things like drainage saucers under potted plants, plastic bags and containers lying in the open,  coconut shells, tyres and other trash- these can all harbour mosquito larvae.

How will I know if I have dengue?
Here are a list of symptoms of dengue fever:

  • Abrupt onset of high fever
  • Severe frontal headache
  • Pain behind the eyes which worsens with eye movement
  • Muscle and joint pains
  • Loss of sense of taste and appetite
  • Measles-like rash over chest and upper limbs
  • Nausea and vomiting

The following symptoms are indicative of dengue haemorrhagic fever. If you notice these, you should immediately go to a doctor:

  • Red spots on the skin
  • Bleeding from the nose or gums
  • Frequent vomiting, especially with blood
  • Black stools
  • Sleepiness
  • Abdominal pain
  • Excessive thirst
  • Pale, cold, clammy skin
  • Difficulty in breathing

And I should stock up on antibiotics, right?
Definitely not! Dengue is caused by a virus and antibiotics are not effective against them. They only treat bacterial infections. Indiscriminate use of antibiotics leads to antimicrobial resistance which has now become a serious global problem. Dengue fever is treated symptomatically with judicious doses of  paracetamol, rest and more-than-usual amounts of liquid, especially coconut water or an oral rehydration solution that can prevent  electrolyte imbalance. According to the World Health Organisation: 'Thirst and dehydration result from high fever, anorexia and vomiting; thus fluid intake by mouth should be ample. An electrolyte replacement solution or fruit juice is preferable to plain water. Oral rehydration solution, as for the treatment of diarrhoeal disease, is recommended'. You can download a complete set of recommendations for the management of dengue.

I always take Aspirin for pain and fever. Now I can't get any! What's going on?
Besides not taking antibiotics, the most important thing you must NOT do is to take Aspirin, Brufen or Ibubrufen. These 'non-steroidal anti-inflammmatory drugs' (NSAIDs) decrease blood clotting and can aggravate haemorrhage in vulnerable patients. If you were wondering why there is a ban on these over-the-counter drugs in your city during a dengue outbreak, now you know. Do NOT take any of these drugs. Here's a list of NSAIDs by their brand names.

To sum up, avoid mosquito-bites, stay hydrated, don't take aspirin for a fever and go to a doctor if you see any of the warning symptoms.

Most importantly, in the words of the great Douglas Adams, “Don't panic”!

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