Credit: Dr Sian Owen and Dr Rocio Canals University of Liverpool scientists have exploited the combined power of genomics and epidemiology to understand how a type of Salmonella bacteria evolved to kill hundreds of thousands of immunocompromised people in Africa. Bloodstream infections caused by a drug-resistant type of Salmonella Typhimurium called ST313 are a major public health concern in Africa, where the disease is endemic and causes ~50,000 deaths each year. What was missing was an understanding of the timing of the major evolutionary events that equipped African Salmonella to cause bloodstream infections in humans. In a new paper published in