QUESTION

If a person treated for malaria after being infected from a malaria endemic country of West Africa and cured then he travel back to his country which does not known for malaria endemic region of the world. Question is: Is there any chance of re-occurrence even he is not being exposed to malaria spreading mosquito for some time may be year?
Is it true Malaria parasites stays in liver as hibernation for a long period and attack after many months or year?
If so what treatment can prevent it?

Please advise.

ANSWER

There are several different types of malaria which are found in West Africa, and the most common and deadly form, Plasmodium falciparum, is not able to hibernate in the liver. However, two other types of malaria are able to lay dormant in the liver – these two kinds are called Plasmodium vivax and P. ovale. Both are not nearly as common as P. falciparum in West Africa, though P. ovale has been reported at prevalences of over 10% in some areas, which is double its usual prevalence elsewhere in the world. Weeks, months or even years after an initial infection with P. vivax or P. ovale, the patient may experience what is known as a relapse, which is when the dormant liver forms become active again and re-invade the blood stream, causing a renewal of malaria symptoms. These relapses can be treated with normal anti-malarial drugs (even chloroquine, in many cases), but a different drug is required to kill the dormant liver forms and prevent future relapse. This drug is called primaquine, and may not be suitable for people with certain types of G6DP deficiencies, so you should talk to your doctor about having a test for this condition before taking primaquine.