Dengue fever symptoms and prevention for parents

Dengue starts as a sudden high fever with a bad headache, pain behind the eyes and aching joints. The WHO warns that the dangerous phase usually comes after the fever falls, not while it is high. Prevention is mostly about still water in and around your home. For pain and fever, use paracetamol only, never ibuprofen or aspirin.

Malaysia has dengue all year round. KKM recorded 123,133 cases and 100 deaths in 2023, and the Aedes mosquito that spreads it lives in our porches, drains and flowerpots.

What dengue looks like

The WHO describes a fever that comes on suddenly and climbs high, with a severe headache, pain behind the eyes, muscle and joint aches, nausea, vomiting, swollen glands and a rash. The joint pain is why it was once called breakbone fever.

Children often show less. A toddler may simply run a high temperature, go off her food and become clingy, with no complaint of pain because she cannot describe it. That makes any unexplained fever lasting more than two days worth a clinic visit here, in a way it might not be in a country without dengue.

Symptoms usually appear four to ten days after the bite. Many infections are mild or cause no symptoms at all, which is part of how the virus keeps spreading.

The warning signs that mean emergency care now

This part is worth remembering, because it is not what you would expect. Severe dengue tends to develop in the 24 to 48 hours after the fever comes down, just when a family starts to relax.

Go straight to the nearest hospital emergency department, or call 999, for any of these:

• Severe stomach pain, or tenderness when you press the belly
• Vomiting that will not stop
• Bleeding from the gums or nose, or blood in vomit or stools
• Fast or laboured breathing
• Extreme tiredness, restlessness, or a child who is hard to wake
• Cold, clammy or blotchy skin
• Passing very little urine, or dry diapers for many hours

Severe dengue is a medical emergency, and how quickly fluids are started makes the difference. Do not wait until the morning.

Why a second infection worries doctors more

Four types of dengue virus circulate. Recovering from one gives lasting immunity to that type only, and the WHO notes that a later infection with a different type carries a higher risk of severe dengue.

So a family that has had dengue before is not protected. If anything, it needs to be more careful.

Dengue while you are pregnant

Dengue in pregnancy is managed closely, not just watched. WHO and CDC guidance describes risks including preterm birth and low birth weight, and the virus can pass to the baby if you are infected close to the delivery.

Call your doctor or go to your klinik kesihatan the same day a fever starts, wherever you are having your antenatal care. A blood test can confirm dengue, and your monitoring plan changes once it does.

Paracetamol is the painkiller to use. Ibuprofen and other anti-inflammatory painkillers are out, both in pregnancy and in dengue. If you take low-dose aspirin prescribed for your pregnancy, call your doctor about the fever rather than stopping or continuing it on your own.

Clearing breeding spots at home

Aedes breeds in small amounts of clean, still water. That is why a home with no pond can still produce mosquitoes. Ten minutes a week of searching and clearing does most of the work.

Then look for the spots particular to your home. The tray under the dish rack. A water tank or tempayan without a tight lid. The bucket left in the porch after the last downpour. The dish under the fridge. Water pooling in a covered car porch or on a flat roof.

Health officers inspect homes in dengue areas, and under the Destruction of Disease-Bearing Insects Act 1975 a household where Aedes larvae are found can be fined. The cheaper habit is the weekly check.

KKM's iDengue shows dengue hotspots and case counts across the country. Checking whether your area is a hotspot takes a minute and tells you how hard to work at this.

Protecting a baby from bites

Aedes bites during the day, with peaks in the early morning and late afternoon. Repellent only in the evening misses most of the risk.

The American Academy of Pediatrics advises no insect repellent at all on babies under 2 months, and considers products with up to 30% DEET acceptable for children older than that. Our article on DEET in mosquito repellent goes through the strengths and the alternatives.

For the youngest babies, cover up rather than spray:

• A mosquito net over the cot and the stroller
• Long, light sleeves and trousers in breathable cotton in the late afternoon
• Screens on windows, and a fan running, since Aedes is a weak flier in moving air
• Repellent put on your own hands first and then on her skin, never near her eyes or mouth, for babies old enough to use it

Most bites are just itchy, though a scratched one can become infected in this climate. See a doctor if a bite becomes hot, swollen and painful, or if your baby has a fever.

Getting tested, and what happens next

Your klinik kesihatan or GP can order the blood tests that confirm dengue, and a fever lasting beyond two days is reason enough to ask. Note when the fever started, because the test chosen depends on how many days in you are.

There is no medicine that kills the dengue virus. Care means fluids, rest, paracetamol and regular blood counts to watch the platelets, with admission to hospital if the counts fall or warning signs appear. Most people recover fully and feel drained for a couple of weeks afterwards.

While someone at home has dengue, keep them under a net during the day. A mosquito that bites them and then bites you is how one case becomes a cluster. Tell your neighbours too, so they can check their own homes.

Is there a vaccine?

Yes, with limits. Malaysia's Drug Control Authority gave conditional approval to Qdenga for people aged 4 and over. It is given as two doses three months apart, is available at private clinics and hospitals, and is not part of the National Immunisation Programme. It is a live vaccine, so it is not given during pregnancy or breastfeeding. Your doctor can tell you whether it suits your family.

Clearing water at home still matters with or without the vaccine. It protects the people in your household who cannot have it, including your baby.