Positive RDT After Malaria Treatment

QUESTION

I have Pv malaria repeated 2 times in two month then doctor give arthemether, lumefantrine tablet for three days twice in a day and primaquine tablet for 14 days..after this treatment malaria show positive on rapid test by a faint line….what is this?

ANSWER

It sounds like your doctor has treated you appropriately. What the line on the rapid test means depends a bit on the type of test it was. Some of these rapid tests look for parts of the malaria parasite which the body recognizes as causing disease (called antigens)—sometimes, these antigens can persist a bit in the body even after the malaria infection has been cured. Therefore, that could explain a slight positive result in a  rapid test soon after treatment. It will be important to follow this up with a second rapid test, maybe in a week, just to make sure you do not have an active infection. You should also be aware that Plasmodium vivax can remain dormant in the liver (primaquine is used to kill these dormant forms), and if primaquine treatment does not work, you will still be ay risk of relapse but you will not have any malaria parasites in the blood, and thus even a rapid test will be negative.