Bloomberg -- A fever-triggering illness that has killed about 30 percent of infected patients in rural China has been traced to a new virus. Researchers, who designated the culprit as the SFTS bunyavirus, believe the disease is transmitted by ticks that count most mammals in the Asia-Pacific region as hosts, according to a study today in the New England Journal of Medicine. SFTS is short for severe fever with thrombocytopenia syndrome.