DEET or picaridin — which is better?

Both are effective and recommended. DEET is the most studied first choice and higher strengths last longer; picaridin is a good alternative that many find less greasy and odorous. Choose one, use an adequate concentration, and reapply as the label directs.

Do I still need repellent if I am taking malaria tablets or have had vaccines?

Yes. Tablets and vaccines reduce risk but are not complete, and they do not cover diseases like dengue, Zika and chikungunya. Bite avoidance protects against several infections at once and should always be combined with any tablets or vaccines.

Sunscreen or repellent first?

Apply sunscreen first, let it absorb, then apply repellent on top. Reapply repellent as directed, especially after sweating or swimming.

Are repellents safe for children and in pregnancy?

DEET-based repellents are generally considered suitable in pregnancy, breastfeeding and for children, with UK travel guidance permitting up to about 50% DEET in these groups — always follow the product label and get tailored advice for infants and during pregnancy.

I have come back from a malaria area and now have a fever — what should I do?

Treat this as urgent. Malaria can become life-threatening quickly. See a doctor promptly (or go to A&E) and clearly state where and when you travelled so you can be tested for malaria straight away. In an emergency call 995.

Insect Bite Prevention for Travellers: Repellents & Nets

Written & reviewed by the BestDoctors.sg editorial team · Last updated 25 Aug 2026 · General information, not medical advice

Many serious travel infections — malaria, dengue, Zika, chikungunya, Japanese encephalitis and others — are spread by insect bites, chiefly mosquitoes. For several of these there is no vaccine or tablet that gives complete protection, so avoiding bites is the single most important defence, and it protects against several diseases at once. No single measure is fully protective, so the key is to combine repellent, clothing, nets and sensible accommodation choices.

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In a medical emergency, or for severe or sudden symptoms such as breathing difficulty, chest pain, fainting or stroke signs, call 995 immediately.

Fever after travel to a malaria area is a medical emergency — malaria can be rapidly fatal. Seek care promptly, during or up to weeks or months after travel, and tell the doctor your travel history so you can be tested urgently.

Which diseases are bite-borne

Mosquitoes spread malaria, dengue, Zika, chikungunya, JE, yellow fever and more, while ticks, sandflies and other insects spread certain other infections relevant to some destinations and activities. Vaccines exist for some (such as JE and yellow fever) and tablets for malaria prevention, but for dengue, Zika and chikungunya, bite avoidance is the main protection — a reason not to rely on vaccines or tablets alone.

How repellents work

Repellents make skin less detectable to biting insects, reducing landing and biting; they reduce but do not eliminate risk, and do not replace antimalarial tablets where malaria is a risk. Recommended active ingredients are DEET (the most studied first choice, with higher concentrations lasting longer — UK guidance commonly cites up to about 50% for adults in malaria areas), picaridin (an effective, often more pleasant alternative), and some formulations of IR3535 or oil of lemon eucalyptus. Apply repellent to all exposed skin after sunscreen (sunscreen first, then repellent on top), reapply per the label and more often with sweating or swimming, and do not spray under clothing.

Day-biting versus night-biting

Timing matters because different mosquitoes carry different diseases. Aedes mosquitoes, which spread dengue, Zika and chikungunya, bite mainly in the daytime, peaking in early morning and late afternoon, so daytime protection matters. Anopheles mosquitoes, which spread malaria, bite mainly at night, which is why bed nets and covering up after dark matter in malaria areas, while Culex mosquitoes (JE) tend to bite in the evening and night in rural areas. In areas with both dengue and malaria, all-day protection is needed.

Nets, clothing and accommodation

Insecticide-treated bed nets are important where malaria or night-biting mosquitoes are present, especially if rooms are not screened or air-conditioned — tuck the net under the mattress and check for holes. Wear loose, long-sleeved tops and long trousers in light colours, and consider treating clothing and gear with permethrin (applied to fabric, not skin). Choose air-conditioned or well-screened rooms with intact screens, and use a plug-in insecticide or knockdown spray indoors where appropriate. Combining these layers — repellent, covering clothing, treated net and screened room — is far more effective than any one alone.

Red flags and Singapore context

Fever after travel to a malaria area is a medical emergency, because malaria can progress rapidly and be fatal; anyone who develops fever, chills or a flu-like illness during or up to weeks or months after such travel must seek care promptly and state their travel history so malaria can be tested for urgently. Fever after travel to a dengue area also needs assessment, with immediate care for dengue warning signs such as severe abdominal pain, persistent vomiting, bleeding, or lethargy. Remember that Singapore itself has dengue and chikungunya, so removing stagnant water and avoiding bites apply at home too, and a returning traveller who is infected can seed local transmission. Call 995 for an emergency.

A practical daily routine

Bite prevention works best as a simple daily habit rather than an afterthought. In the morning, apply repellent to all exposed skin after sunscreen, and reapply through the day as the label directs, more often if you are sweating or swimming. In areas with daytime-biting Aedes mosquitoes, keep this up all day; where malaria or JE is a risk, be especially diligent from dusk onwards, covering up with long sleeves and trousers in the evening. At night, sleep in an air-conditioned or well-screened room, or under an insecticide-treated bed net tucked under the mattress if the room is not sealed. Treating clothing and gear with permethrin adds another layer for higher-risk trips. Check your accommodation for intact window and door screens on arrival, and use a plug-in insecticide indoors where appropriate. These same habits are worth keeping up back home during dengue season, since Singapore has Aedes mosquitoes too, and a returning traveller who is infected can seed local spread, so keeping up repellent and covering up for a week or two after returning from a dengue area is a sensible precaution.

When to see a doctor

Before travel, see a travel clinic or GP for a risk assessment, repellent and net advice, malaria tablets and vaccines — ideally four to six weeks ahead. Urgently during or after travel, seek care for any fever or flu-like illness after visiting a malaria area and mention your travel, and get immediate care for dengue warning signs.

Sources

NHS Fit for Travel — Insect Bite Avoidance: fitfortravel.nhs.uk
CDC Travelers’ Health — Avoid Bug Bites: cdc.gov
HealthHub (Singapore) — Travel Medicine and Vaccination: healthhub.sg
NEA (Singapore) — Prevent Aedes Mosquito Breeding: nea.gov.sg

General information only. This guide is general travel-health information and is not a diagnosis or personalised medical advice. See a doctor or travel clinic — ideally 4–6 weeks before travel — for advice tailored to your destination and health. Any animal bite, scratch or lick in a rabies-risk area needs immediate wound washing and urgent medical care — do not wait. Fever after travel to a malaria or dengue area is urgent — seek care promptly and mention your travel. Call 995 (or local emergency services abroad) for sudden breathlessness or chest pain, confusion, seizures, or collapse.

Insect Bite Prevention for Travellers in Singapore