A fifth of medicines in Africa could be substandard or fake, according to a major research project, raising the alarm over a problem that could be contributing to the deaths of countless patients.

Researchers from Bahir Dar University in Ethiopia analysed 27 studies in the review and found, of the 7,508 medicine samples included, 1,639 failed at least one quality test and were confirmed to be substandard or falsified.

Claudia Martínez, the head of research at the Access to Medicine Foundation, an Amsterdam-based non-profit group, described the finding as a major public health concern.

“If patients are getting medicines that are substandard or outright fake, it can result in their treatment failing or even preventable deaths,” she said.