What to Know About Getting Tested for Malaria

When a mosquito with malaria bites you, a parasite gets into your blood and destroys oxygen-carrying red blood cells. You’ll usually feel sick within days or weeks. But some parasites can live in your body for a year without problems.

The first symptoms of malaria often look like the flu or a virus. Because of this, you may not get help right away. But a delay in treatment can lead to death. Early tests give you the best shot at recovery.

Types of Tests

Thick and thin blood smears. These are the most common and accurate malaria tests. A lab technician, doctor, or nurse will take some of your blood and send it to a lab to be stained to make any parasites show clearly. The technician spreads it on a glass slide and looks at it with a microscope. A thin blood smear, also called a blood film, is one drop of blood spread across most of the slide. A thick smear drops the blood on a small area. A normal test does two of each.

The number of malaria parasites in your blood can change each day. So your test might say you don’t have malaria even if you do. For that reason, you may need your blood drawn several times over 2-3 days for the best results.

Rapid diagnostic test. Also called RDT or antigen testing, this is a quick option when blood draws and smears aren't available. Blood taken from a prick on your finger is put on a test strip that changes color to show whether you have malaria or not.

This test usually can't tell which of the four common species of malaria parasites caused your infection. Nor can it tell whether the infection is minor or major. Your doctor should follow up all results with blood smears.

Molecular test. Also known as polymerase chain reaction test, it can identify the type of parasite, which helps your doctor decide which drugs to prescribe. This test is a good choice if your blood has low number of parasites or if the results of your blood smear are vague.

Antibody test. Doctors use this to find out if you've had malaria in the past. It looks for antibodies that show up in the blood after an infection.

Drug resistance test. Some malaria parasites are resistant to drugs. But doctors can test your blood to see if certain drugs will work.

Blood test. In addition to other tests, you may also have your blood drawn for a blood count and chemistry panel. This can tell your doctor how serious your infection is and if it's causing other problems, like anemia or kidney failure.

WebMD Medical Reference Reviewed by Jennifer Robinson, MD on February 28, 2018

Sources

SOURCES:

Cleveland Clinic: "Malaria."

Mayo Clinic: "Malaria."

CDC: "Malaria Diagnosis (United States)," "Malaria Diagnosis (U.S.) – Serology."

Lab Tests Online: "Malaria."

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