Since June 2009, investigators have documented the presence of the virus in 171 patients from six regions in central and northeastern China, and the infection proved fatal in 12% of cases.
A causal relationship between the virus and the illness has yet to be established. However, epidemiologic, clinical, and laboratory data strongly implicate the virus in the febrile illness, the researchers reported online in the New England Journal of Medicine.
“Our finding that [the bunyavirus] is the probable cause of a previously unknown severe febrile disease is one of the fruits of heightened surveillance of infectious diseases in China,” De-Xin Li, MD, of the Chinese Center for Disease Control and Prevention in Beijing, and co-authors wrote in conclusion ….
Mosquitoes and ticks were found in the homes of most of the patients. The investigators found no viral RNA in any of 5,900 mosquitoes tested but did isolate viral RNA from 10 of 186 (5.4%) ticks of the species Haemaphysalis longicornis found on domestic animals belonging to patients.
There is little apparent chance of a major epidemic, however. From Bloomberg:
There is no evidence of human-to-human transmission, the researchers said.
“These are not viruses that are airborne or easily transmitted,” Heinz Feldmann, chief of the Laboratory of Virology for the National Institute of Allergy and Infectious Diseases in Hamilton, Montana, said in a telephone interview. “It’s very unlikely it would spread into areas where the virus is not present.
“The risk of a global outbreak or even a larger epidemic is remote,” said Feldmann, who wrote an accompanying editorial in the journal.