H7N9 bird flu may be spread through human faeces, research suggests

The H7N9 bird flu that emerged on the mainland in March may be spreading through human faeces, as university researchers found the virus in the stools of four out of six people killed by the bug in Zhejiang .

Theoretically, the virus could spread in the same way as severe acute respiratory syndrome (Sars) did during the 2003 outbreak in Amoy Gardens, Kowloon Bay - through sewage pipes - University of Hong Kong microbiologist Yuen Kwok-yung, a top researcher behind the cross-border study, told the South China Morning Post.

"This has important implications on the infection control strategies for H7N9 virus infection, as the influenza virus in stools may contaminate the surrounding environment," Yuen and his team reported.

But the team also suggested that the fact the virus may be transmitted via faeces was the reason why, so far, few cases of human-to-human infection had been recorded, Yuen said.

HKU conducted the joint study with Zhejiang University's First Affiliated Hospital in Hangzhou and published the results in the Clinical Infectious Diseases journal on Tuesday. They tested 12 patients who were admitted to the intensive care unit between April 10 and 23. Half of them have died.

During post-mortem tests, stool samples collected from four of the six fatalities returned positive results for the H7N9 strain.

The rate - 67 per cent - was much higher compared with those found for human flu or H5N1 bird flu, which ranged from 5 per cent to 33 per cent, the report said.