What to expect from a blood test for malaria

A laboratory may examine a blood film under a microscope or use a rapid test to look for malaria parasites. The result can help identify whether malaria is present and, when parasites are found, may help determine the type and amount present. A negative result does not always settle the question if fever or other symptoms continue soon after travel to a malaria area; the clinician may arrange repeat samples because parasites can be easier to detect at another point in the illness.

Tell the clinician about recent travel, fever pattern, chills, medicines, and any malaria prevention tablets. Follow instructions about food and drink, although many blood tests do not require fasting. After the sample, keep pressure on the site briefly and mention persistent bleeding, swelling, or increasing pain. Do not delay care while waiting for a result if you feel unwell after possible mosquito exposure.

Seek urgent medical help for fever with confusion, unusual sleepiness, trouble breathing, repeated vomiting, seizures, fainting, or rapidly worsening weakness. Malaria can become serious quickly, particularly after travel in a malaria area, so explain the travel history at the first assessment even if the initial blood test is negative.

Ask which malaria test was used, whether another sample is needed, when the result is expected, and which symptoms should prompt immediate review. You can also ask how the result changes treatment and whether other causes of fever need checking.