What is Malaria?
Malaria is a serious tropical disease spread by mosquitoes. If malaria is not diagnosed and treated promptly, it can be fatal. Malaria is caused by a tiny single cell organism called a Plasmodium that attacks and invades red blood cells. The World Malaria Report, published by the World Health Organization (WHO) in 2013, states that in 2012 there were 207 million cases of malaria worldwide and 627,000 deaths, over 90% in Africa. Malaria is not found in the UK, although about 1,400 travellers were diagnosed with malaria after returning to the UK from risk areas in 2012.
Malaria is a serious threat to health.
How is malaria transmitted?
By mosquitoes. The types of mosquitoes that carry malaria, Anopheles, tend to bite at night. It is particularly important to avoid being bitten between dusk and dawn. Transmission between humans can only occur through blood transfusion or at birth from mother to child.
Where is malaria a problem?
Most tropical countries have malaria but some parts carry a greater risk. North Africa and the Middle East carry a very low risk, whereas Sub-Saharan Africa, Amazonian South America and parts of SE Asia have a very high risk.
How can I avoid getting malaria?
There is no fool proof method, but there are three ways, in addition to drugs, that you can reduce the risk.
1. Use insect repellents
Apply repellent creams, sprays or lotions. Products with DEET are widely available and there are a number of alternatives. Frequent application of repellents to exposed skin can be supplemented by use of DEET soaked towelling bands on the wrists and ankles or strong repellents sprayed onto areas of clothing.
2. Insect Barriers
Wear loose fitting clothing that covers your arms and legs during the evening and if your bedroom does not have effective screens on the windows then sleep under bed mosquito nets, preferably impregnated with permethrin or one of the other insecticides approved for this purpose. Bed nets should be re-treated every 3 months.
3. Use knock down insecticide sprays
Check your room every night, mosquitoes may be most obvious resting on upper walls and ceiling areas and also spray nightly under your bed and in the dark corners of your bedroom. To help further, consider using a vaporising electric mat or mosquito coil.
Drug Prophylaxis (= anti-malaria drugs)
No drug is 100% effective and malaria may still occasionally develop while you are taking anti-malaria tablets or after completion. The drug to recommend depends amongst other factors on where you are going, for how long, your age (e.g. children) and pregnancy. For these reasons the advice we give is individually tailored to each traveller. If you are going for more than a month and will be more than 24 hours away from competent medical help, you may need standby self-treatment. The following is a summary of information on the currently most widely used anti malaria preventative treatments;
Mefloquine (trade name Lariam) – dose for adults is one tablet (250 mg) weekly beginning 1 week before travel and continued weekly during the period of risk and for 4 weeks on leaving the malaria risk area. It is used on its own for travellers going for less than one year to places where malarial parasites are resistant to other drugs. It should be taken with food. We usually avoid it if you have a history of mental ill health, epilepsy, or are in the first three months of pregnancy. The most common side effects include loss of balance and dizziness, headache, sleep disturbance such as abnormal dreams, insomnia or drowsiness, gastrointestinal symptoms including nausea and loss of appetite. Very occasionally more severe problems such as hallucinations, seizures, panic attacks and anxiety can occur. Begin mefloquine at least 1 week before departure and try to schedule doses to avoid the weekly dose being taken on the day of travel. A three weeks trial before departure is worth considering for first time users and if side effects develop a switch to an alternative anti-malaria drug is possible.
Chloroquine (trade name Avloclor) – adult dose is two tablets (2x155 mg) weekly starting 1 week before travel and continued weekly during period at risk and for 4 weeks on leaving the malaria risk area. Side effects are usually mild and most commonly are of headache or gastrointestinal upset. Much less frequent adverse effects are of visual disturbance, seizures or skin reactions. In many areas of the world malaria parasites have developed a degree of resistance to chloroquine. It is safe for use in pregnancy. Chloroquine is usually combined with:
Proguanil (trade name Paludrine) – adult dose is two tablets (2x100 mg) daily starting 1 week before travel and continued daily during risk period and for 4 weeks on leaving the malaria risk area. Occasionally proguanil causes mouth ulcers and skin reactions. Proguanil can also be used in pregnancy along with a folic acid vitamin supplement.
Doxycycline – adult dose is one tablet (100 mg) daily starting 1 or 2 days before travel and continued daily during period at risk and for 4 weeks on leaving the malaria risk area. Sun exposure may cause a photosensitive rash in at least 3-5% of users. Heartburn and diarrhoea are common gastrointestinal side effects. It is not for use in children under 12 years or in pregnancy or if breast-feeding.
Atovaquone/proguanil (trade names; Malarone, Mafamoz or Reprapog) – dose is one tablet daily starting 1 day before travel and continued daily during period at risk and for 7 days on leaving the malaria risk area. It is currently licensed in the UK for both treatment and prevention of malaria in adults and children. Side effects are infrequently reported but may include mild headache, mouth ulcers, nausea, diarrhoea and abdominal pain.
What about children?
Children need smaller doses of anti-malarial drugs but their bodies break down drugs more energetically and they need higher doses than their weight would suggest. Only chloroquine is available as syrup and atovaquone/proguanil is available as paediatric tablets, the rest are available in adult tablets which need to be broken into half or a quarter to get the dose about right.
Small children often make taking anti-malarials a test of their parents’ resolve! Syrup or crushed tablets mixed with juice can be squirted over the back of the tongue with a syringe. Uncrushed tablets in honey may be palatable, or tablets may be pushed to the back of the tongue with a little finger.
Are special measures needed during pregnancy?
Malaria may present a more serious illness during pregnancy with increased risk to both mother and baby and sometimes the best advice is to avoid travel to a malaria region. It is generally accepted that chloroquine and proguanil are safe for use in pregnancy. Breast-feeding or planned conception are areas requiring special consideration when planning malaria prevention measures.
What if I am on medication for a pre-existing health problem?
Malaria advice needs to be tailored for the individual traveller taking account of any details of medical history including prescribed medications.
When should I start anti-malaria tablets?
This will depend on the drug prescribed and also on whether a trial (e.g. mefloquine or doxycycline) for first time users of the anti-malarial is being taken.
How long should I take the tablets after I leave?
For four weeks for all anti-malarials except atovaquone/proguanil which is taken for only seven days. Most anti-malaria tablets act mainly by destroying parasites when they appear in the blood, after the initial liver replication phase, 1-3 weeks after a mosquito bite. Atovaquone/proguanil kills parasites whilst they are developing in the liver and only needs to be taken for a further 7 days after the latest possible exposure i.e. 7 days after leaving a malaria risk area.
What should I do if I become ill during the trip or after I return?
Symptoms of malaria usually first present 1-3 weeks after becoming infected. Symptoms include:
- - a high temperature (fever)
- - sweats and chills
- - headaches
- - vomiting
- - muscle pains
- - diarrhoea
Very occasionally malaria may occur up to many months after infection. In any circumstance when malaria is suspected an urgent blood test for diagnosis should be arranged by your doctor and treatment started immediately when necessary.
Emergency “Standby”Treatment of Malaria: