Some 35% of antimalarial drugs sold in six major African cities failed basic quality tests according to a study published today in PLoS ONE, a peer-reviewed open-access journal. The cities were in Ghana, Kenya, Nigeria Rwanda, Tanzania and Uganda. The study further found that artemisinin monotherapies, which the World Health Organisation explicitly rejects as substandard, remain common in Africa. Substandard antimalarial drugs cause an estimated 200,000 avoidable deaths each year.