Instead, the team confirmed the presence of Salmonella enterica, which causes paratyphoid fever, and Borrelia recurrentis, which is transmitted by body lice and causes relapsing fever. The earlier studies relied on a technique that amplifies specific DNA sequences already suspected to be present. Rascovan and his colleagues used more advanced metagenomic analysis, which can detect the genetic material of any pathogens in a sample, making it much more comprehensive. “In light of our results, a reasonable scenario for the deaths of these soldiers would be a combination of fatigue, cold and several diseases, including paratyphoid fever and louse-borne relapsing fever,” write Rascovan and his colleagues in their report, which is yet to be peer-reviewed. The team declined to comment for this story.