Malaria is a parasitic infection that is spread from person to person through the bite of a mosquito. Malaria is a serious disease, and people who have not grown up in a malarial area, children and pregnant women are particularly at risk of rapid deterioration and death. Malaria is preventable and treatable, but it is very important that treatment is given quickly, if it is to be successful.
There are five species of malaria responsible for malaria disease in humans. Plasmodium falciparum causes the most severe disease, and P. vivax and P. ovale may cause a less severe but relapsing illness. P. malariae is the fourth significant species, and P. knowlesi is known to occasionally cause disease in humans.
Disease Information Sheets
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How common is it?
Malaria is widespread in many tropical and subtropical countries: Half of the world’s population is at risk and in 2012 there were 104 malaria-endemic countries. In 2010 malaria caused 490,000-836,000 deaths, mostly among children in Africa, and there were 150-290 million cases. Every year there are approximately 2000 cases reported in UK travellers, with several deaths. Similar numbers are reported in travellers from the USA.
The malaria-transmitting mosquitos require warmth and water to survive and replicate, however malaria is a disease of poverty - many countries with suitable climates have successfully eradicated the disease, including much of southern Europe. The mosquito cannot survive above about 2000m, so higher altitude areas are likely to be malaria-free.
Are travellers and/or expat workers at risk?
Yes. The risk of malaria depends on the local intensity of transmission and the individual’s exposure to mosquitoes. Both short and long-term visitors are at risk, although the risk is directly proportional to the length of stay in an endemic area, so long-term visitors are at even greater risk than those staying for shorter periods.
Only one mosquito bite is required to contract potentially fatal malaria, and some species of malaria-transmitting mosquito have bites that are not particularly itchy, and may go unnoticed.
What is the illness?
There is a 7-15 day incubation period between being bitten and becoming ill.
The first symptoms are fever, headache, chills and vomiting, but these may be mild and difficult to recognise as malaria.If not treated within 24 hours malaria can progress to severe illness and death very rapidly, due to anaemia, respiratory distress, cerebral disease or multiple organ failure.
The fever typically recurs on a 2-3 day cycle, although it can be continuous.
Can it be treated?
Yes - antimalarial medication is very effective if given promptly. Once severe, high quality intensive care may be critical for survival. Some travellers to remote areas are advised to carry Standby Emergency Treatment with them..
How can it be prevented?
There is no vaccine.
Prevention is by avoiding mosquito bites, particularly at dawn and dusk and during nighttime hours.
Spray exposed skin with 30% DEET
Treat clothing with insecticide; wear long sleeves and trousers
Sleep under an insecticide-treated bed net
Avoid camping/staying near stagnant water; fill puddles if possible
Take malaria chemoprophylaxis - tablets to reduce the risk of disease.
The type of chemoprophylaxis that is suitable varies according to the person and the location.
Some tablets must be started three weeks prior to entering the risk area and continued for four weeks after return to a non-risk area.
Malaria is found in tropical areas, particularly Sub-Saharan Africa and South East Asia.