Poor quality medicines are a real and urgent threat that could undermine decades of successful efforts to combat HIV/AIDS, malaria and tuberculosis, according to the editors of a collection of journal articles published today. Scientists report up to 41 percent of specimens failed to meet quality standards in global studies of about 17,000 drug samples. Among the collection is an article describing the discovery of falsified and substandard malaria drugs that caused an estimated 122,350 deaths in African children in 2013. Other studies identified poor quality antibiotics, which may harm health and increase antimicrobial resistance. However, new methodologies are being developed to detect problem drugs at the point of purchase and show some promise, scientists say.