A new method for testing the activity of drugs against dormant malaria parasites

15 January 2014

BPRC - 1. A new method for testing the activity of drugs against dormant malaria parasites

The malaria parasite Plasmodium vivax (P. vivax ) is one of the most frequent causes of (severe) malaria worldwide. Technically it is very difficult to perform experiments with P. vivax, due to the inaccessibility of some of its developmental forms. A culture system with monkey malaria parasites and monkey cells offers the opportunity to overcome these issues.

Vivax-malaria is very difficult to fight, because the parasite can lodge in the liver in the form of hypnozoites: dormant stages, which can become active weeks to years after a bite of an infected mosquito and cause renewed disease. New drugs against vivax-malaria are urgently needed, because to date only one registered drug is available that (sometimes causing severe side effects) can kill the dormant stages of this parasite.

Culture Systems for testing the activity of drugs against the dormant stages of P. vivax are currently missing due to a lack of a constant, well-characterized access to this parasite. Therefore, researchers of the BPRC have developed a culture system with monkey cells and the monkey version of vivax-malaria. This monkey malaria parasite is almost identical to P. vivax and also forms dormant stages in the liver. Using this newly developed culture system, it has become possible to test whether medicines are not only active against developing, but also against the (precursors of) dormant forms of the parasite.

The newly developed test has identified a new compound that can kill the precursors of the dormant stages. Further characterisation of this compound is needed to determine if this drug can eventually be applied in the clinic.

This research, published in the journal Antimicrobial Agents and Chemotherapy, for the first time enables extensive testing of the activity of compounds against the (precursors of) dormant stages of the vivax-type malaria parasites.