Headlines - New Avian Influenza A(H7N9) Virus

On March 31, 2013, Chinese authorities informed the World Health Organization (WHO) that several cases of infection with a new H7N9 influenza virus had been identified since mid-February. This is a reassortant virus containing genes from the A(H7N9) and A(H9N2) viruses. This is the first time this strain of influenza virus has been identified in humans.

As of April 9, 2013, 28 human cases of a new variant of avian influenza A(H7N9), including 8 deaths, have been reported with no epidemiological link between them in 4 different provinces of China. No imported cases have been recorded to date in France.

The emergence of a new influenza virus in humans calls for the utmost caution, especially since the clinical forms observed are severe and the source of infection and route of transmission remain largely unknown.

The risk of the virus spreading in Europe is considered low at this stage. However, the entry into France of certain patients arriving from China cannot be ruled out: surveillance has been stepped up accordingly.

Therefore, clinicians are advised to remain highly vigilant for any severe respiratory infection occurring in a person within 10 days of a stay in China and to report possible (i) or confirmed (ii) cases, or clusters of hospitalized severe acute respiratory infections, preferably by phone, to:

• the French Institute for Public Health Surveillance at 08 20 42 67 15 or alerte@invs.fr

• the Poitou-Charentes Health Surveillance and Alert Unit at 05 49 42 30 30 or ars-pch-alerte@ars.sante.fr

Case definitions for infection with the novel avian influenza virus A(H7N9): (i) Probable case:

• Any person who has traveled to or stayed in China and who, within 10 days of returning, has presented with: - clinical signs of severe acute respiratory infection - with no other identified cause that could explain the condition.

• Any contact (e.g., family, caregivers) of a possible or confirmed case who has developed an acute respiratory infection, regardless of severity, within 10 days of the last contact with the possible/confirmed case while the latter was ill (i.e., symptomatic)

(ii) Confirmed case:

A case with respiratory specimens indicating the presence of the novel avian influenza virus A(H7N9).