As many as 85 percent of cases are in low- and middle- income countries.
Children were most at risk with four in 10 cases in children under the age of five.
Researcher and assistant professor Kristina Rudd said: “I’ve worked in rural Uganda, and sepsis is what we saw every single day.
“My colleagues treating patients on the ground in low- and middle-income countries every day have been saying this for years, that sepsis is a major problem.
“So in a way I wasn’t actually that surprised – on the other hand I didn’t expect it to be double the previous estimate.”
There are around 48,000 deaths from sepsis in the UK each year, the report shows.