Challenges and hope loom in H7N9 fight

Although infections in three people in a family have been confirmed, there are encouraging signs that the spread of the H7N9 avian influenza virus could be brought under control.

From April 13 to 23, H7N9 cases in China doubled to 108. As of Tuesday, 22 of the total cases have ended in death and 14 patients have been discharged from hospitals after treatment.

In addition to the rising number of patients, the H7N9 virus is also spreading to more regions, with a cluster of infections in a family confirmed, said Feng Zijian, director of the emergency response center of the Chinese Center for Disease Control and Prevention (CCDCP).

In Shanghai, the infected family cluster involved three patients -- a father and his two sons. The investigation into the cause of their infections remains under way.

"There is no conclusion about whether they were infected through people-to-people transmission or if they were all exposed to poultry or an environment contaminated by the H7N9 virus," Feng said.

Feng added that the infections in the family do not mean the H7N9 virus is able to be transmitted through people. "That is the consensus of both the CCDCP and international public health and disease control agencies."

RISKS AND HOPE

"We are still puzzled about why some patients were infected despite having no contact with poultry. The world knows little about this new type of virus," said Zhong Nanshan.

Zhong, director of the Guangzhou Institute of Respiratory Diseases, is credited with helping to identify and then curb the 2003 outbreak of severe acute respiratory syndrome (SARS).

Of all the H7N9 cases confirmed by the CCDCP, about 40 percent of infected patients had not been exposed to live poultry or poultry markets.

"Despite no people-to-people infections being confirmed, we can not rule out that out as a possibility. During the bird migration in the spring, there are also other possibilities of new viruses being produced through gene reassortment," Zhong said.

Meanwhile, the increasing number of H7N9 patients being discharged from Chinese hospitals is offering encouragement to both medical staff and the public in the fight against the virus.

Special report: H7N9 avian influenza