Preventing Malaria

What is malaria?

Malaria is a serious infection. It is common in tropical countries such as parts of Africa, Asia, and South America. It is caused by a parasite (germ) called plasmodium that lives in mosquitoes. The parasite is passed to humans from a mosquito bite.

There are four types of plasmodium that cause malaria. Plasmodium falciparium is usually the most serious of the four. Each year over 2000 people in the UK develop malaria which has been caught whilst abroad. About nine people die from malaria in the UK each year.

Preventing malaria - four steps

1. Be aware of the risks, and avoid them if possible.
2. Avoid mosquito bites.
3. Take anti-malarial medication regularly exactly as prescribed.
4. If symptoms of malaria develop (such as fever), seek medical help urgently.

The risk of malaria
The risk varies between countries, and the type of trip. For example, back-packing or travelling to rural areas is generally more risky than staying in urban hotels. In some countries the risk varies between seasons - malaria is more common in the wet season. The main type of parasite, and the amount of resistance to medication, varies in different countries. Although risk varies, all travellers to malaria-risk countries should take precautions to prevent malaria. Anopheline mosquitoes which transmit malaria also commonly fly from dusk to dawn and therefore evenings and nights are the most dangerous time for transmission.

You can avoid mosquito bites, or reduce the number of bites, by the following:

• Sleep in rooms that are properly screened. For example, rooms with close fitting gauze over windows and doors.
• Spray the bedroom with insecticide just before evening. This kills mosquitoes that may have come into the room during the day.
• If you sleep outdoors or in an unscreened room, use mosquito nets impregnated with an insecticide (such as permethrin). The net should be long enough to fall to the floor all round your bed and be tucked under the mattress. Check the net regularly for holes. Impregnate with fresh insecticide every six months.
• Use an electric mat to vaporise insecticide overnight. Burning a mosquito coil is an alternative.
• Apply insect repellent to clothing or exposed skin. Diethyltoluamide (DEET) is safe and effective, but take advice on the best repellent in the area you visit.
• Mosquitoes are most active at dusk and in the evening. If you go out after dusk apply insect repellent to exposed parts of the skin. If the temperature allows, wear long sleeved clothing, trousers, and socks. Light colours are better as they are less attractive to mosquitoes.

Anti-malarial medication
Antimalarial medication helps to prevent malaria. The best medication to take depends on the country you visit. This is because the type of parasite varies between different parts of the world. Also, in some areas the parasite has become resistant to some medicines. Some general points are below.

• Seek advice for each new trip abroad. Do not assume the medication that you took for your last trip will be advised for your next trip, even to the same country. There is a changing pattern of resistance to some medicines by the parasites. Doctors, nurses, pharmacists, and travel clinics are updated regularly on the best medication to take for each country.
• Take the medication exactly as advised. This may include starting medication up to a week or more before a planned trip. This allows the level of medicine in your body to become effective. It also gives time to check for any side-effects before travelling. Continue with medication for the time advised after returning to the UK (often for four weeks).
• The most common reason for malaria to develop in travellers is because the anti-malarial medication is not taken correctly. For example, some doses may be missed, forgotten, or the tablets may be stopped too soon after returning from the journey.
• Medication to protect against malaria is not funded by the NHS. You can buy some anti-malarial medicines at pharmacies without a prescription. Those that are 'prescription only' require a private prescription, and the cost paid by the traveller. A pharmacist can advise on prices.
• Side-effects are usually minor or uncommon with anti-malarial medicines. However, always read the information sheet which comes with a particular medicine. Usually it is best to take the medication after meals to reduce possible side-effects.
• If you experience any side-effects or worrying signs contact your GP. If this may be due to the malaria medication your prescription may be changed. In some cases you may want to start taking the tablets at least 2-3 weeks before your travel so that any side effect can be detected in good time.
• Medication is only a part of protection. It is not 100% effective and does not guarantee that you will not get malaria. The advice above on avoiding mosquito bites is just as important, even when you are taking anti-malarial medication.

Symptoms of malaria
Symptoms are similar to 'flu. They include fever, shivers, sweating, backache, joint pains, headache, vomiting, diarrhoea, and sometimes delirium.

Symptoms may take a week or more to develop after being bitten by a mosquito. Occasionally, it takes a year or more for symptoms to develop. Therefore, suspect malaria in anyone with a feverish illness who has travelled to a malaria area within the past year - in particular, if symptoms occur within three months.

Special situations

• Pregnant women are at particular risk of severe malaria, and should, ideally, not go to malaria-risk areas. Full discussion with a doctor is advisable if you are pregnant and intend to travel. Most anti-malarials are thought to be safe to the unborn child. Some, such as mefloquine, should be avoided in the first 12 weeks of pregnancy.
• Non-pregnant women taking mefloquine should avoid becoming pregnant. Continue with contraception for three months after the last dose.
• If you have epilepsy, kidney failure, some forms of mental illness, and some other uncommon illnesses, you may have a restricted choice of antimalarial medication. This may be due to your condition, or to possible interactions with other medication that you may be taking.
• If you do not have a spleen (if you have had it removed), or your spleen does not work well, then you have a particularly high risk of developing severe malaria. Ideally, you should not travel to a malaria-risk country.
• Travellers going to remote places far from medical facilities sometimes take emergency medication with them. This can be used to treat suspected malaria until proper medical care is available.

In summary

• Malaria is a serious illness, and is sometimes fatal.
• Your chance of developing malaria is much reduced by taking anti-malarials and avoiding mosquito bites.
• However, malaria is still possible. Seek medical help if symptoms of malaria occur when you are abroad, or within a year of returning even if you take, or have taken, anti-malarial tablets.

Further Information

All travellers going abroad are advised to get 'Health Advice for Travellers' by the Dept. of Health. Available at main post offices, or by phoning the Health Literature Line on 0800 555 777, or download from the web: www.dh.gov.uk/PolicyAndGuidance/HealthAdviceForTravellers/fs/en

The Medical Advisory Services for Travellers Abroad (MASTA) provide a personalised health advice on vaccines and immunisations as well as malaria and yellow fever prevention. See their website for details www.masta.org

Details of the above two services plus other useful travel health sites are on the travel page at www.patient.co.uk

Malaria Foundation International - www.malaria.org

© EMIS and PIP 2006   Updated: June 2006   PRODIGY Validated

The authors and editors of this article are employed to create accurate and up to date content reflecting reliable research evidence, guidance and best clinical practice. They are free from any commercial conflicts of interest.

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