Overview
Malaria is an illness caused by Plasmodium parasites. Five types can infect people. Plasmodium falciparum causes the most severe disease, and Plasmodium vivax is the type most often seen outside sub-Saharan Africa.
The parasite is carried by female Anopheles mosquitoes, which bite mainly between dusk and dawn. When such a mosquito bites, the parasite enters the blood, multiplies in the liver and then in the red blood cells, and that is when fever begins.
Symptoms
Symptoms usually begin about 10 to 15 days after the bite, though with some types they appear months or even years later. The first signs are easy to mistake for any other fever:
- Fever, often with shaking chills and then sweating
- Headache and aching muscles
- Tiredness and weakness
- Nausea, vomiting or loose motions
Fever in waves every day or two is typical, but it is not always there. Severe malaria shows as extreme tiredness, confusion or reduced consciousness, fits, difficulty breathing, dark urine, yellow eyes, or abnormal bleeding.
When to see a doctor
See a doctor within a day or two for any fever with chills or body aches, and mention travel in the past year to an area where malaria occurs. Fever in pregnancy, in a baby or in a young child should be seen the same day.
Causes
Malaria spreads when an infected female Anopheles mosquito bites a person. The mosquito picks the parasite up from someone who already has malaria.
It can also pass on through a blood transfusion, shared needles, or from mother to baby in pregnancy. It does not spread from person to person in daily contact.
Risk factors
- Living in or travelling to an area where malaria occurs, especially in the rainy season
- Babies and children under five
- Pregnancy
- HIV or another condition that weakens immunity
- Sleeping outdoors or without a mosquito net
Complications
Most people treated early recover completely. Untreated falciparum malaria can turn severe, with:
- Reduced consciousness or coma
- Repeated fits
- Severe anaemia
- Difficulty breathing
- Kidney failure, jaundice and abnormal bleeding
Malaria in pregnancy also raises the chance of premature delivery and low birth weight.
Prevention
- Sleeping under an insecticide-treated mosquito net
- Mosquito repellent on exposed skin in the evening and at night
- Long sleeves and full trousers after dusk
- Screens on windows and doors, and indoor spraying by the health department
- Emptying and scrubbing containers of standing water
- Preventive tablets before travel to a high risk area, if a doctor advises them
Diagnosis
Malaria is confirmed by looking for the parasite in a blood sample, under a microscope or with a rapid test that answers in minutes. The test also shows which type of parasite is present, which decides the treatment.
A first test can be negative early on, so it may be repeated if the fever continues. Other blood tests often run alongside, for anaemia and for other causes of fever such as dengue.
Treatment
Malaria is treated with prescription antimalarial medicines. For falciparum malaria, artemisinin-based combination treatment is the standard. Vivax malaria is treated with a different medicine, often followed by a further one that clears parasites resting in the liver and prevents a relapse months later. Pregnancy changes the choice, so tell the doctor.
Severe malaria is treated in hospital with injectable medicine and fluids, and sometimes a blood transfusion or support for the kidneys and breathing. Fever and aches are eased with paracetamol. The full course must be completed even after the fever has gone.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Any fever in the rainy season is malaria, so a course of tablets from the chemist will sort it out.”What is true?
Fact
The World Health Organization advises that a suspected case is confirmed by a blood test, either microscopy or a rapid test, before treatment. Many rainy season fevers turn out to be dengue, typhoid or flu, which are treated quite differently. Taking antimalarial tablets on a guess delays the right treatment and helps the parasite become resistant.
Myth“Malaria is caught from drinking dirty water or from eating the wrong food.”What is true?
Fact
Malaria spreads through the bite of an infected mosquito. It is not passed on by water, food, or ordinary contact with someone who has it. The only other routes are blood transfusion, shared needles, and passage from mother to baby in pregnancy.
Myth“Once the fever settles, the rest of the tablets can be stopped.”What is true?
Fact
The fever usually settles well before the course is finished, and stopping early can let the illness return. Some types of malaria also need a further medicine afterwards to clear parasites that stay in the liver and can cause a relapse months later.
Myth“Malaria is just a fever, nothing to worry about.”What is true?
Fact
Most people recover fully with prompt treatment, but malaria caused by Plasmodium falciparum can progress to severe illness and death within a day if it is not treated. That is why fever with drowsiness, fits, breathlessness or dark urine is an emergency.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
My fever went away on its own. Do I still need a test?
Yes. Malaria fever often comes in waves, so a gap of a day without fever means very little. A blood test is quick, and finding malaria early is what keeps it from turning severe.
Can malaria come back after treatment?
It can, in two ways. Vivax and ovale malaria leave parasites resting in the liver that can wake up months later, which is why a further medicine is often added to clear them. Malaria can also simply be caught again from another mosquito bite, so bite protection still matters after recovery.
Can I just take tablets from the chemist instead of getting tested?
It is better not to. The World Health Organization advises confirming malaria with a blood test before treating it, because several other illnesses cause the same fever and need different medicines. Antimalarial tablets taken on a guess also delay the correct treatment and help the parasite become resistant.
