What Does a Malaria Rapid Test (RDT) Result Mean?

What it means

Malaria is an infection caused by tiny parasites spread by mosquito bites. A rapid diagnostic test, or RDT, is a small plastic cassette, a little like a home pregnancy test. A drop of blood from a finger prick is added, and coloured lines show whether malaria parasite proteins (antigens) are present. Malaria, especially the type called falciparum, can become serious quickly, so fever after time in a malaria area needs prompt medical attention.

RDTs are used where a microscope and trained staff are not always available, and they give an answer during the same visit. Many tests show which type of malaria was found: one line for Plasmodium falciparum (often labelled Pf or HRP2) and another line for other types (often labelled Pan or Pv). The result helps the health worker decide straight away whether malaria treatment is needed.

An RDT is different from a blood smear, where a trained person looks at stained blood under a microscope. A smear can count how many parasites are present, which an RDT cannot.

Where you may see it

• Clinic records and fever forms in malaria areas
• Travel clinic or emergency results for fever after travel
• Community health worker records
• Lab reports listing "Pf" and "Pan" lines as positive or negative