Positive RDT After Malaria Treatment

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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.

Pregnant Women and Malaria

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QUESTION

Why are pregnant women and children at the highest risk of getting malaria?

ANSWER

The reason why pregnant women and children are at greater risk of contracting malaria is due to their reduced levels of immunity. Children living in malarial areas have less immunity than adults because they have had less exposure to malaria, and so their immune systems have not had a chance to develop antibodies to protect against the disease. Pregnant women, although they may normally have good immunity, witness changes in their immune systems during pregnancy in order for the woman to carry the child.

Given that a baby is genetically distinct from its mother, the mother’s immune system has to be modulated in order to ensure that the body’s defenses do not act against the baby, as they would some other foreign object such as an infection. While this immune modulation allows the mother to carry her foetus, it does leave her vulnerable to other infections, such as malaria. In areas of high malaria transmission, the mother may still retain enough immunity to not present with severe symptoms of malaria. In these cases, the dangers of malaria in pregnancy come from resulting anemia in the mother, as well as passage of malaria antigens or the parasite itself through the placenta and to the foetus, which can result in problems for the baby.

Interestingly, a study came out last year which showed evidence that using long-lasting insecticide treated bednets increased malaria prevalence in older children and adults, probably because the nets protected against even sub-clinical exposure to malaria and therefore the levels of natural immunity in people using the nets declined over time, leaving them more susceptible to infection. However, this result has been controversial, as in other studies community-wide coverage of bednets has reduced overall malaria incidence due to reduced transmission.