Counterfeit and substandard antimalarial drugs in Cambodia.

Counterfeit and substandard antimalarial drugs can cause death and contribute to the growing malaria drug resistance problem, particularly in Southeast Asia. Since 2003 in Cambodia the quality of antimalarial drugs both in the public and private health sector is regularly monitored in sentinel sites. We surveyed 34% of all 498 known facilities and drug outlets in four provinces. We collected 451 drug samples; 79% of these were not registered at the Cambodia Department of Drugs and Food (DDF). Twenty-seven percent of the samples failed the thin layer chromatography and disintegration tests; all of them were unregistered products. Immediate action against counterfeit drugs was taken by the National Malaria Control Program (NMCP) and the DDF. They communicated with the Provincial Health Department about the presence of counterfeit antimalarial drugs through alert letters, a manual, annual malaria conferencing and other training occasions. Television campaigns to alert the population about counterfeit drugs were conducted. Moreover, the NMCP has been promoting the use of good quality antimalarial drugs of a blister co-packaged combination of artesunate and mefloquine in public and private sectors. Appropriate strategies need to be developed and implemented by relevant government agencies and stakeholders to strengthen drug quality assurance and control systems in the country.

Positive control wells: a potential answer to remote-area quality assurance of malaria rapid diagnostic tests.

Malaria rapid diagnostic tests (RDTs) are a potential breakthrough in the provision of accurate diagnosis in remote areas, but widescale use is hampered by uncertainty over accuracy under field conditions. Positive control wells, which contain recombinant malaria parasite antigen, are a novel method for addressing this need for quality assurance. The potential of a commercially available positive control well, reconstituted with blood, was assessed for use in routine monitoring of RDT sensitivity in a remote malaria-endemic region. When maintained at 4 degrees C, the wells produced a consistent level of parasite lactate dehydrogenase (pLDH) antigen activity, as detected by pLDH-detecting RDTs, but activity reduced after cumulative exposure to temperatures likely to be encountered over a few months in a malaria-endemic area. This limitation was successfully overcome in the field through centralized, controlled storage. Monitoring of RDT sensitivity was successfully incorporated into routine supervisory visits to remote clinics. However, improved temperature stability of the wells would enhance their potential. The threshold at which the wells' signal reduced RDT sensitivity requires further investigation. The wells show potential to overcome an important obstacle to the wide implementation of accurate parasite-based diagnosis and appropriate treatment. Further assessment of their place in malaria management is warranted.