Via the Centre for Health Protection in Hong Kong: Scientific Committee on Emerging and Zoonotic Diseases meets on risk assessment and local response to human infection of avian influenza A(H7N9) virus. Excerpt:
The Scientific Committee on Emerging and Zoonotic Diseases (SCEZD) of the Centre for Health Protection (CHP) of the Department of Health today (April 30) convened a meeting to assess the risk and local response in view of the recent human cases of avian influenza A(H7N9) in the Mainland.
The SCEZD reached a consensus view that the emergence of human infections with the novel avian influenza virus reported in the Mainland since March 31 is of concern as further human sporadic infections and expansion of geographic spread in the Mainland and other countries/areas is anticipated.
At the meeting, the members of the SCEZD agreed that the current epidemic strain of the avian influenza A(H7N9) virus is a novel reassortant avian influenza virus which does not cause illnesses in birds, but has gained some abilities to cross species barriers, causing sporadic poultry-to-human transmission which may result in severe disease in infected people.
Genetic and epidemiological findings showed that patients are likely to be infected through exposure to infected poultry or its contaminated environment such as wet markets. However, the exact source and mode of spread still require further investigations.
While family clusters of infection suggest that limited human-to-human transmission may have occurred in close contacts, exposure to a common source can also be one of the explanations. Hence, the members are of the view that there is no evidence of sustained human-to-human transmission at present but the main concern is whether the virus will further adapt to enable efficient human-to-human transmission, which may result in a pandemic.
Turning to the local response, the SCEZD concurred with the view that the enhanced preventive and control measures for human infection with avian influenza should be continued. Surveillance for human avian influenza A(H7N9) infection is crucial. Although the risk of human-to-human transmission appears to be low, the actual risk is currently unknown and control measures, such as appropriate infection control precautions, isolation of suspected cases and quarantine of close contacts of confirmed cases, should be enforced.
As for treatment of patients infected with the avian influenza A(H7N9) virus, the members considered that the avian influenza A(H7N9) virus is expected to be sensitive to the neuraminidase inhibitors, oseltamivir (Tamiflu) and zanamivir (Relenza). Confirmed or highly suspected cases should receive antiviral treatment with a neuraminidase inhibitor as early as possible.
