Malaria - Symptoms, Prevention & Treatment

Malaria is a disease caused by tiny parasites called Plasmodium that are transmitted to humans through the bites of infected mosquitoes. It’s a major global health concern, particularly in tropical and subtropical regions of the world.

When an infected mosquito bites a person, it injects the malaria parasites into their bloodstream. These parasites then travel to the liver, where they multiply and mature.

After this stage, they re-enter the bloodstream and invade red blood cells, causing them to rupture. This leads to recurring cycles of fever, chills, and flu-like symptoms.

Wearing protective clothing, using insect repellent and taking antimalarial medications before, during and after travelling to countries with a high risk of malaria are ways to prevent infection. 

Diagnosing malaria typically involves a blood test to identify the presence of malaria parasites. Antimalarial medications are used to treat the disease and can vary depending on the type of malaria and its severity.

Symptoms

Malaria symptoms can vary and depend on the type of malaria parasite that’s causing the infection. The most common symptoms include:

• High fever
• Chills and sweats
• Fatigue and weakness
• Headache 
• Muscle and joint pain
• Nausea and vomiting
• Abdominal pain
• Anaemia

Causes

Malaria is caused by tiny parasites called Plasmodium. They are passed to humans when an infected female mosquito bites them. 

These parasites are the ones responsible for causing malaria in humans. There are different types of Plasmodium parasites, with Plasmodium falciparum being the most dangerous.

The malaria-carrying parasites first enter the bloodstream. From there, they travel to the liver, multiply, and then infect red blood cells.

Although rare, malaria can also be transmitted through blood transfusions or organ transplants from infected donors. Infected mothers can pass it to their babies during pregnancy as well.

Malaria cannot be spread through casual contact like hugs or handshakes, or through coughing or sneezing. It only spreads through mosquito bites or, rarely, through blood or organ donations.

Countries with malaria zones

It can take just 1 bite from an infected mosquito to catch malaria, and it’s very common in certain parts of the world. It’s important to note that malaria is not found here in the UK and you can’t catch it from others.

Malaria is found in areas like:

• Large areas of Africa and Asia
• Central and South America
• Dominican Republic and Haiti
• Parts of the Middle East
• Some Pacific islands

Before you travel, it’s essential to check the malaria risk of the area you’re travelling to. 

Who is at risk

Certain groups of people are at higher risk of contracting malaria than others. Malaria is most commonly found in tropical and subtropical regions of the world; people living in or travelling to these areas are at higher risk.

Individuals who spend a lot of time outdoors, especially during peak mosquito activity times (typically during the evening and night), have a higher risk of being bitten by infected mosquitoes and contracting malaria.

People who have little or no previous exposure to malaria parasites are more susceptible to the disease. This includes individuals living in non-endemic regions who travel to malaria-affected areas.

Malaria can affect people of all ages, but young children, particularly those under the age of five, have less developed immune systems and are more vulnerable to severe forms of the disease. Those over the age of 65 are at a higher risk, too.

Pregnant women have a higher risk of developing severe malaria and experiencing complications. Malaria infection during pregnancy can also pose risks to the unborn baby, such as low birth weight and premature birth.

Those with weakened immune systems, such as those living with HIV/AIDS or undergoing immunosuppressive treatments, have a higher risk of developing severe malaria if infected. Those who have no spleen are also more susceptible.

Diagnosis

The most common method used to diagnose malaria is a blood test. A small sample of blood will be taken from your vein or obtained by finger prick. The blood sample will be sent to a laboratory for analysis.

In the laboratory, the blood sample will be examined under a microscope to look for the presence of malaria parasites. This helps identify the specific species of the parasite and determine the stage of infection.

Alternatively, in some cases, a rapid diagnostic test (RDT) may be used instead of or in addition to microscopic examination. RDTs detect malaria antigens in the blood and provide quick results. It is a simple test similar to a pregnancy test and does not require laboratory equipment.

When to call 111/an emergency doctor

You must book an urgent GP appointment, see an emergency doctor or call 111 if you have travelled to a country where malaria is found and you have malaria symptoms. Additionally, you should tell anyone you travelled with to seek medical attention right away.

Get medical advice quickly if you have malaria symptoms while you're travelling.

Treatment

The type of malaria treatment depends on the strain of malaria you’ve been infected with, and some medication will be ineffective against certain types. 

Once you’ve been diagnosed with malaria, it’s vital that treatment is started immediately. If left untreated, malaria can be fatal. 

Your healthcare provider will decide which type of malaria treatment is best for you, but below are some medicines you may be offered.

Medical treatments

Artemisinin-Based Combination Therapies (ACTs) are the most effective and commonly recommended treatment for malaria caused by Plasmodium falciparum, the most dangerous malaria parasite. 

ACTs combine an artemisinin derivative with another antimalarial drug to ensure a more effective and rapid clearance of the parasites.

Chloroquine was previously a widely used antimalarial drug, especially for treating malaria caused by Plasmodium vivax and Plasmodium malariae. 

However, resistance to chloroquine has become widespread in many regions, and it may no longer be effective in those areas.

Quinine and quinidine are alternative medications used for treating severe or complicated malaria. They are typically given in a hospital setting.

Primaquine is a medication used to treat malaria caused by Plasmodium vivax or Plasmodium ovale. It’s effective in eliminating dormant liver-stage parasites (hypnozoites) to prevent relapses.

Prevention

The prevention of malaria is crucial in areas where the disease is present. To prevent malaria, several key measures can be taken. 

Using mosquito nets is a highly effective way to reduce mosquito bites during sleep, particularly for vulnerable groups like young children and pregnant women. 

Applying mosquito repellents containing DEET on exposed skin and wearing long-sleeved clothing and pants can provide additional protection. 

If you’re travelling to an area with a high risk of malaria, you must take an antimalarial before, during and after travelling to prevent infection. To find out which type of antimalarial is right for you, read our guide to learn everything you need to know about antimalarials.