Malaria Tests

What are malaria tests?

Malaria tests look for signs of a malaria infection in a sample of your blood. These infections are caused by malaria parasites, which are tiny single-celled life forms. There are several types of these parasites. 

If you have a malaria infection, the parasites will stay in your liver for a few days or even a few months before moving to your blood. There, they will live and reproduce in your red blood cells and make you feel sick. This happens because malaria parasites destroy the red blood cells when they live in them.

In most cases, people get malaria when they are bitten by mosquitoes that are infected with the parasite. This is rare in the United States. Mosquitoes infected with malaria are mostly found in warm, humid parts of the world such as parts of Africa south of the Sahara Desert. In the U.S., most cases are in people who have traveled to these kinds of climates where mosquitoes spread a lot of disease.

In some cases, malaria is spread through contact with the blood of an infected person. This may happen during blood transfusions, organ transplantations, or from sharing needles and other items used to inject drugs. If you're pregnant when you have malaria, it's possible to give it to your fetus. Malaria can't be spread like a cold or flu or through sex or being near someone who has malaria.

If you do have malaria, early symptoms can be mild. However, if it isn't treated quickly, the infection can become life-threatening. Luckily, medicines can usually cure the disease.

Other names: malaria blood smear, malaria rapid diagnostic test, malaria by PCR

What are they used for?

Malaria tests are used to diagnose malaria and tell which of the different types of malaria you have. These include:

• Blood smear tests. For these, a drop of your blood is put on a special slide. A laboratory professional will examine the slide under a microscope to look for parasites. These tests can identify all types of malaria parasites.
• Rapid diagnostic tests (RDT). These look for certain proteins that come from malaria parasites. They can provide results in under 15 minutes, but an RDT can't accurately show which type of malaria parasite you have. So, if an RDT shows that you have malaria, a blood smear is needed, too.
• Molecular tests. These look for genetic material from malaria parasites in your blood sample. A PCR test (polymerase chain reaction) is a type of molecular test that's used to check for malaria, but usually only if you have serious symptoms. It can also help health care providers find out which type of parasite is in your blood. 

Your provider will usually order more than one of these tests. They may also order other blood tests, such as a complete blood count (CBC), to see if a malaria infection has caused any additional health problems. What tests they order will depend on your symptoms.

The results of your malaria tests are important because:

• The earlier you start treatment for malaria, the less likely it is that the infection will become serious
• Identifying the type of malaria parasite can help your provider decide which treatment you need

Malaria testing can also help to control the spread of the disease. That's because if you have malaria and a mosquito bites you, that mosquito can then spread malaria to anyone else they bite. So, identifying and treating malaria infections early can lower the chances that the malaria parasite will spread to others.

Why do I need a malaria test?

You may need this test if you have symptoms of malaria and you've been in an area where malaria is common. Depending on the type of malaria parasite, symptoms usually begin between 7 to 30 days after an infected mosquito bites you. However, in some cases symptoms can take up to a year to show up. So, if you have symptoms of malaria within 12 months of a trip to a place where malaria is common, remind your provider about your travels.

The first symptoms of malaria are often like having the flu, and may include:

• Fever
• Chills
• Fatigue
• Headache
• Muscle pain
• Nausea and vomiting

If you are infected with certain types of malaria parasites, you may have symptoms which come and go every two or three days.

Without treatment, malaria can quickly become a life-threatening disease. As it gets worse, the symptoms will depend on the type of parasite you have. They may include:

• Anemia
• Jaundice
• Kidney failure
• Seizures
• Mental confusion
• Coma

What happens during a malaria test?

Your provider will examine you and ask about your symptoms and recent travels. If your provider thinks you could have malaria, you will have a blood test to check for signs of malaria parasites.

During a blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a malaria test.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

If the results of your malaria test are negative, it means that no signs of malaria parasites were found in your blood sample. But this doesn't rule out malaria. That's because the number of malaria parasites in your blood can vary over time. If you have a negative result, more blood samples are usually taken every 12–24 hours for a total of 3 sets of tests. If these test results are all negative, you probably don't have malaria.

If the results of your malaria test are positive, it means you have malaria. Your provider will prescribe medicine right away. The medicine you take will depend on:

• The type of malaria parasite you have
• Whether the parasite has become resistant to certain medicines
• Your symptoms and medical history
• Whether you are pregnant

When treated early, malaria can usually be cured. If your provider strongly believes you have a serious case of malaria, you may start treatment before test results confirm you have the disease.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about malaria tests?

If you will be traveling to an area where malaria is common, talk with your provider before you go. You may be able to take medicine that can help prevent malaria.

You can also take steps to protect yourself against mosquito bites. This may reduce your risk of getting malaria and other infections transmitted by mosquitoes. 

If you are pregnant or planning to become pregnant, you should take steps to reduce your risk of getting a malaria infection. If you can't avoid traveling to an area that may put you at risk for a malaria infection, or if you live in one of these areas, you should:

• Apply an insect repellent containing DEET on your skin and clothing. DEET is safe and effective for pregnant women.
• Wear long-sleeved shirts and pants.
• Use screens on windows and doors.
• Sleep under a mosquito net.