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, and the WHO warns that the dangerous phase usually arrives after the fever falls rather than during it. Prevention is mostly about stagnant water in and around your home. Paracetamol only, never ibuprofen.

Singapore has year-round transmission, and the Aedes mosquito that carries it lives in our corridors and planter boxes rather than in some distant swamp.

What dengue looks like

The WHO describes a fever that comes on abruptly and climbs high, with 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 turn clingy, with none of the described 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 would not be in a country without dengue.

Symptoms generally appear four to ten days after the bite. Many infections are mild or silent, which is part of how the virus keeps circulating.

The warning signs that mean A&E tonight

This is the part to remember, because it is counter-intuitive. Severe dengue tends to develop in the 24 to 48 hours after the fever subsides, just when a family relaxes.

Go straight to A&E, or to KKH's children's emergency if it is your child, 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 stool
• Fast or laboured breathing
• Extreme tiredness, restlessness or a child who is hard to rouse
• Cold, clammy or mottled skin
• Passing very little urine, or dry diapers for many hours

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

Why a second infection worries doctors more

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

So a household that has already had dengue is not protected. If anything it needs to be more careful.

Dengue while you are pregnant

Dengue in pregnancy is managed actively, not observed. The risks described in WHO and CDC guidance include preterm birth and low birth weight, and transmission to the baby around the time of delivery is possible if you are infected close to then.

Call your obstetrician the same day a fever starts, whether you are seeing KKH, NUH or a private clinic. A blood test can confirm it, and the monitoring plan changes once it does.

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

Clearing the breeding spots in a flat

Aedes breeds in small volumes of clean, still water, which is why a Singapore home with no pond at all can still produce mosquitoes. The National Environment Agency sets out five habits, published as the Mozzie Wipeout, and they take only a few minutes a week.

Add the ones particular to our flats. The tray under the drying rack. Bin lids on the service balcony. A forgotten bucket in the yard after the last downpour. Water collecting in the dish beneath a bidet spray or a washing machine standpipe.

NEA publishes a cluster map and a case count, updated through the week. Checking whether your block is in an active cluster takes a moment and tells you how hard to work at this.

Project Wolbachia, NEA's release of Wolbachia-carrying male Aedes mosquitoes, now covers a growing number of estates and suppresses the local population. It is a supplement to clearing your own home rather than a replacement.

Protecting a baby from bites

Aedes bites during the day, with activity rising in the early morning and again in the late afternoon. Evening repellent alone misses most of the risk.

The AAP advises no insect repellent at all on infants under 2 months, and considers products containing up to 30 percent DEET acceptable for children older than that. Our longer piece on whether DEET repellents are safe for kids works through the concentrations and the alternatives.

For the youngest babies, cover rather than spray:

• A mosquito net over the cot and over the stroller
• Long, light sleeves in the late afternoon, in breathable cotton
• Window screens, and a ceiling fan running, since Aedes flies poorly in moving air
• Repellent applied to your hands and then to her skin, never near her eyes or mouth

Bites themselves are mostly a nuisance, though a scratched one can get infected in this climate. Common baby rashes covers telling an infected bite from the many other things that appear on baby skin, and our piece on protecting your baby from mosquito bites goes through repellents by age.

The lotion pictured at the top of this page is a moisturiser. It is not an insect repellent, and it does not protect against mosquito bites or dengue.

Getting tested, and what happens next

Polyclinics and GPs can order the blood tests that confirm dengue, and a fever lasting beyond two days is reason enough to ask for one. Bring a note of when the temperature started, because the test chosen depends on how many days in you are.

There is no antiviral for dengue. Treatment is fluids, rest, paracetamol and daily blood counts to watch platelets, with admission if the counts fall or warning signs appear. Most people recover fully, and feel wrung out for a fortnight afterwards.

While someone at home is infected, keep them under a net during the day. A mosquito that bites them and then bites you is how one case becomes a cluster, and how a block ends up on the NEA map. Good hygiene habits round out the picture, which protecting your baby from germs covers.