Infection Plasmodium falciparum is the most severe form and causes the majority of the deaths and the most severe symptoms. Problems with resistance against malaria drugs are also almost entirely found in P. falciparum infections. P. falciparum is the most common infection in Africa.
Symptoms Fever, headache, muscle and joint pains. Later reduced consciousness, kidney failure and coma. The death rate in travellers returning to Europe and diagnosed in Europe is between 0.5% and 4%.
Diagnosis Microscopy of a blood sample (thick and thin blood smear), rapid test finding a malaria specific protein in the blood and in some specialised laboratories detection of parasite DNA.
Treatment There are several drugs available. If the patient has taken drugs for prophylaxis the drug chosen for treatment should not be the same as used for prophylaxis.
If the infection is severe the treatment is given intravenously.
Prevention Prophylaxis with a drug is primarily given to prevent disease from P.falciparum malaria.
No prophylactic drug is entirely effective and no malaria drug without side effects.
It is therefore important that the drug for prophylaxis is chosen with regard to the risk of being infected with malaria is balanced against the risk of side effects.
Risk of infection P.falciparum is the most important malaria in Africa and P.vivax the most important type in Asia.
The risk is proportional to the length of stay in the area with malaria and long-term travellers, along with residents are therefore a special high-risk group.
Lariam is more effective against chloroquine resistant malaria than chloroquine and paludrine. There has been some discussion about side effects from lariam, but two thirds to three quarters of all users apparently have few problems.
Malarone is a new drug combination and can be used for both prophylaxis and treatment. For prophylaxis the dose is 1 tablet daily from the day before entry to 7 days after departure from the malaria risk area.
Malarone is primarily an alternative to lariam and doxycycline. Malarone is also an alternative to chloroquine and paludrine for short stays, if you want to avoid taking tablets 4 weeks after departure from the malaria risk area.
Doxycycline is an antibiotic which can be used to prevent malaria resistant to other drugs. There is less experience with doxycycline than with lariam and malarone. The side effects are mostly an allergic rash on areas exposed to sunlight.
Side effects Comparing chloroquine and paludrine and lariam the risk of mild side effects are about the same, but lariam users have up to four times higher risk of experiencing neuropsychiatric side effects of which difficulty with sleeping is the most common.
Overall 2% to 5% of all users, no matter which drug they use, experience symptoms, which are suspected to be side effects from the drugs and lead to cessation of medication.
Our attitude to malaria prophylaxis
In general the traveller should be offered the most effective drug taking the destination, mode of travel and length of stay into consideration.
In areas with very low risk like for instance Thailand, drugs are not recommended for prophylaxis, only traditional methods like repellents and impregnated mosquito nets.
In area with a high degree of resistance against chloroquine, like tropical Africa and part of South America and South East Asia, we recommend
Malarone as first choice for short-term travellers, and
lariam for long term travellers, both with
doxycycline as an alternative.
Protection should be as good as possible, but it is unacceptable to have the travel spoiled by side effects, if the risk of infection is low.
Traditional protection The malaria mosquito primarily bites between dusk and dawn. The risk of infection can be much reduced by preventing mosquito bites, for instance by sleeping in closed, air-conditioned rooms or rooms with screened windows.
Mosquito nets An insecticide impregnated mosquito net (bed net) around the bed during night offer a good protection, at least 50% reduced risk, if used properly.
Synthetic pyrethroids like permethrin, deltamethrin or lambda-cyhalothrin are usually used for impregnation, which last 6 to 12 months.
The net must be without holes and must be tucked under the mattress or sleeping bag to provide a sealed sleeping space.
The net must to packed during daytime to avoid mosquitoes entering during daytime.
The net should be supplemented with a repellent after dusk before going to bed under the impregnated net.
Repellents can be DEET (usually 20%), Autan and Mossi-guard which are synthetic and protects at least 4 hours.
Some repellents are made of natural oils like citronella and eucalyptus, but usually provide shorter effective protection. An exception is Mossiguard, which has been shown to be equal to DEET 20% in a 50% solution.