WHO drug resistance fear for ACTs

The World Health Organization has warned that the improper use of artemisinin against malaria is threatening to neutralize the efficacy of  its preferred malaria treatment. Surveillance systems supported by the  WHO in the Cambodia-Thailand border areas indicate that resistance is  building up against artemisinin-based combination therapies (ACTs), due  to several factors, including counterfeit or substandard drugs.

One problem identified by the health body is the continued use of  artemisinin monotherapy, which increases the chances of the parasite  developing immunity, despite attempts to persuade manufacturers to  switch to ACTs. The WHO said: "monotherapy fosters resistance because it  is easier for the parasite to adapt and eventually overcome the  obstacles presented by a single drug than a combination of drugs  delivered together." ACTs are over 90% effective against malaria when  used appropriately, the WHO added. In 2007, Cambodia and Thailand shared  over 75,000 malaria cases, but only 300 deaths, compared with over 1,000  per year in Thailand alone in the 1990s.

A 2006 study, led by Paul Newton of the UK's Oxford University, found  that 68% of artemisinin drugs tested in Cambodia, Laos, Myanmar and  Vietnam were substandard. The Bill & Melinda Gates Foundation has  awarded a $25.0-million grant to ensure that local treatment of malaria  is effective and practices that are likely to help the parasite achieve  drug resistance are avoided.