Children wearing face masks to protect themselves from infection during the 2003 severe acute respiratory syndrome (SARS) outbreak.
It may be time to get really scared about bird flu. China’s Centre for Disease Control and Prevention (CDC) has announced that it believes human-to-human transmission of the H7N9 virus, although “highly sporadic”, is possible.
Feng Zijian, director of the CDC’s health emergency centre, said that while the virus does not spread easily between humans, “long-term and unprotected exposure to the infected person might result in another human infection”. He added that this does not necessarily mean that the virus has mutated into a human influenza virus capable of being transmitted easily between groups of people.
The CDC is currently investigating whether human-to-human transmission was involved in one of the earliest reported cases of H7N9 in China. An 87 year old Shanghai man and one of his sons died from the virus, another son has recovered, according to the National Health and Family Planning Commission. Two other potential cases of human-to-human transmission are also under investigation, again in Shanghai, which involve a father and son, and a husband and wife.
The total number of confirmed cases in the country has risen to 82, 17 of which have proved fatal, a mortality rate of 20 percent.
Approximately 40 percent of those who tested positive for H7N9 have had no recent contact with poultry, according to Dr Zeng Guang, chief of epidemiology at the CDC.
“How were they infected? It is still a mystery,” Dr Zeng told the Beijing News.
Feng Zijian pointed out that during the last bird flu outbreak in 2008, many victims could not remember whether they had come in contact with poultry. Feng told reporters he believed that all those infected with H7N9 must have come in contact with bird directly, or with a contaminated environment.
A four year old Beijing boy who was found to be infected with the virus but asymptomatic has baffled doctors, who have worried publicly that the possibility of ‘carriers’ may make the virus harder to track. The boy remains in quarantine.