Malaria - prevention

Produced by Rebecca Canvin, Bupa Health Information Team, January 2012.

This factsheet is for people who are going to a country with malaria, or who would like information about how to protect themselves against malaria.

Malaria is a serious and potentially life-threatening disease, which can be prevented. It’s spread by the bite from a female mosquito, which infects people with a parasite called Plasmodium.

About malaria

Malaria is an infection that can cause serious illness and can be life threatening. You get malaria from the bite of an infected female anopheles mosquito. The anopheles mosquitoes that carry malaria usually bite at dusk and during the night. Mosquitoes carry a parasite called Plasmodium, which infects your red blood cells.

If you’re bitten by a mosquito carrying malaria, it usually takes between seven and 18 days to develop symptoms. However, for some people the symptoms may not develop for up to a year. You may have:

• a fever, sweating and chills
• muscle pain and tenderness
• a headache
• diarrhoea
• a cough
• general discomfort

Malaria can develop very quickly and needs immediate treatment. If malaria isn’t treated, you may have more serious health problems, for example fits, loss of consciousness, kidney failure and blood clotting problems. If you have any of these symptoms, or feel unwell at all and you have been to a country where there is malaria, it’s important to get medical help straightaway.

There are four important types of malaria including Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale and Plasmodium malariae. Of these, Plasmodium falciparum causes the most infections and is the most severe form.

Which countries have malaria?

The mosquitoes that carry malaria are found in more than 100 different countries. This includes countries in Africa, Asia, Central and South America, Haiti and the Dominican Republic and parts of the Middle East. In these countries malaria is very common. As many as 250 million people across the world get malaria every year.

You can’t catch malaria in the UK. However, around 1,500 people are treated for the infection every year in the UK, having got it while travelling or developing the disease when they arrive into the UK from countries where malaria is found.

Immunity to malaria

People who live in an area with malaria can gradually build up some immunity to the disease, because they are continuously exposed to it. However, any immunity you may have built up when living in a country with malaria quickly goes away once you leave it.

People travelling to countries where there is malaria usually don’t have any immunity. Therefore it’s important to take steps to prevent the disease. You can prevent malaria by following the ABCD of malaria prevention.

• Awareness of risk – find out if the country you’re visiting has malaria.
• Bite avoidance – take steps to avoid getting bitten by mosquitoes.
• Check – if you need malaria prevention tablets.
• Diagnosis – see a doctor straightaway if you have any symptoms while you’re abroad, or for a year after you come back.

Avoiding bites

The key to preventing malaria is to avoid being bitten by mosquitoes. There are some factors that increase your risk of being bitten. The main ones are listed below.

• The country you’re visiting is warm and wet. Mosquitoes are commonly found in places where the temperature is between 20ºC and 30ºC and there is a lot of moisture in the air (high humidity).
• You’re staying in a place that is less than 2000m above sea level. Mosquitoes aren’t found at high altitudes.
• You’re going on a long trip or visit. The longer you stay, the more likely you are to get bitten.
• You’re staying in a rural area or village, rather than a town or city.
• It's rainy season time of year. Mosquitoes breed in water, so there are more around when it's wet.
• You’re staying in hotels or hostels where there is no air-conditioning.
• Being outside between dusk and dawn. This is the main time of day when mosquitoes bite.

You can reduce your risk of being bitten by ensuring you’re well prepared and following a number of precautions. The main ones are listed below.

• Use a mosquito net impregnated with an insecticide over your bed at night. Make sure it’s tucked in under the mattress and that there are no holes in it.
• Spray your room with an insecticide before you go to bed.
• Use an electrical device in your room at night to vaporise an insect repellent tablet.
• Wear loose-fitting tops with long sleeves, trousers and socks if you’re out at dusk or at night. You can also wear clothes that have insect repellent already in them.
• Apply an insect repellent containing diethyltoluamide (DEET) to your skin and clothes. Stronger preparations last for longer and need to be put on less often, for example 50 percent DEET will last for up to 12 hours on your skin, whereas 20 percent DEET will last for three hours. If you’re allergic to DEET, you can use lemon eucalyptus oil, although it's not as effective. Don’t use oil of citronella.
• Cover bedroom doors and windows with fine mesh netting.
• Use air-conditioning or a fan in your room, as mosquitoes are less active in cooler temperatures.

Medicines to prevent malaria

There are a number of different medicines that can help to prevent malaria, although you also need to follow the advice for preventing mosquito bites. Your GP will prescribe you a medicine based on your health, where you’re travelling to, what you will be doing there and how long you will be there.

See your GP or visit a travel health clinic before you travel, ideally six to eight weeks before. You will need to take the medicines before you travel, while you’re away and when you come back. It’s very important to finish the course of medicines prescribed for you.

If you’re travelling to a remote place where you won’t have easy access to medical help, your GP may prescribe emergency standby treatment for you. You can use this if you develop the symptoms of malaria and are unable to get to a doctor. Ask your GP for more information.

No medicine for preventing malaria is totally effective, but you can greatly reduce your risk of getting the disease if you take the right medicine. Malaria in most parts of the world is now resistant to chloroquine so most people requiring prophylaxis will be prescribed either doxycycline, proguanil with atovaquone or mefloquine. Some of the common medicines are listed below.

• Doxycycline. You may be asked to take doxycycline if you’re going to an area of the world where malaria is resistant to chloroquine or if you can’t take mefloquine. Side-effects can include diarrhoea, thrush and heartburn. Children under 12 years and pregnant or breastfeeding women shouldn't take doxycycline.
• Proguanil with atovaquone. You may be asked to take these medicines together instead of mefloquine and doxycycline if you’re travelling in areas where malaria is resistant to chloroquine. The side-effects can include headaches and sickness and diarrhoea. Malarone only needs to be taken while you are in a malaria area and doesn't need to be continued after you return home, unlike other antimalarials.
• Mefloquine. You may be asked to take mefloquine if you’re going to an area of the world where malaria is resistant to chloroquine. Mefloquine is given once weekly and should be started one to two weeks before travelling to ensure there are no severe side-effects and to obtain adequate drug concentrations before travelling. The side-effects of mefloquine include sickness and diarrhoea, headache, dizziness and disturbed sleep. Mefloquine can also cause anxiety, depression and panic attacks. These side-effects are more common in women who take this medicine. For this reason your GP may suggest other medicines if you have had depression or other mental health problems. You shouldn’t become pregnant when you’re taking mefloquine, or for three months after.
• Chloroquine. In most areas of the world malaria has become resistant to chloroquine, so your GP is likely to prescribe this if your risk of developing malaria is low. Your GP may also prescribe chloroquine with other medicines to prevent malaria. The side-effects of chloroquine include sickness and diarrhoea and headache. You shouldn't take this medicine if you have epilepsy, and it can make psoriasis worse.
• Proguanil. In most areas of the world malaria has become resistant to proguanil so it’s usually given along with another medicine, such as chloroquine. The side-effects of proguanil include diarrhoea or constipation and mouth ulcers. Proguanil can increase the effects of warfarin.

Malaria and pregnancy

Ideally, if you're pregnant you shouldn't travel to an area where there is a risk of malaria. This is because you’re at greater risk of severe malaria.

If you do have to travel then it’s important to follow the guidelines to avoid mosquito bites and take medicines as prescribed. Being pregnant makes you more likely to get bitten, so protecting yourself is very important. If you can, stay indoors between dusk and dawn. You can also take chloroquine and proguanil during pregnancy, though other medicines may be unsafe. Ask your GP or travel health clinic for more information.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.