Recombinomics: Likely Clade 7 Fatal H5N1 Case In Beijing

Commentary

Likely Clade 7 Fatal H5N1 Case In Beijing
Recombinomics Commentary 12:01
January 6, 2009

Huang Yanqing, who died at 7:20 a.m. yesterday in a Beijing hospital, handled the innards of nine ducks bought from a market in Hebei province, which surrounds Beijing

"The woman fell ill on Dec. 24, was hospitalised on Dec. 27 and died on Monday (at) 7.20 am,"

She had contact with 116 people, Xinhua said, citing the local health bureau.

A nurse recovered from the fever she’d developed after coming in contact with the deceased woman

The above comments are from media reports describing and H5N1 confirmed fatality (19F) in Beijing. The presumed source of the H5N1 was waterfowl from a local market in Hebei, although China has not recently reported H5N1 in the Beijing region.

The last reported H5N1 in China was at two locations in Jiangsu province last month (see satellite map). That H5N1 was vaccine resistant and sequence data indicated in was clade 7. Clade 7 was linked to a 2006 outbreak in Shanxi, which was also difficult to control, which was likely linked to a cluster of non-synonymous changes flanking receptor binding domain position 190 (H3 numbering) - see A/chicken/Shanxi/2/2006. Receptor bind domain changes remain a serious cause for concern.

In 2003, the mainland’s first confirmed H5N1 cases was a patient who died in Beijing and was infected with clade 7 (A/Beijing/01/2003). In addition, clade 7 isolates were obtained from poultry in Hebei in 2005, as well as Jiangsu and Jilin in 2002. More recently clade 7 was linked to poultry outbreaks in Vietnam in August of 2008.

The time and location of this event raises concerns that this patient was also infected by clade 7. The concerns are increased by the report of a symptomatic health care were who was in contact with the patient, suggesting human to human transmission. More information on the cause of the fever in the nurse would be useful.

Similarly, sequence data on the H5N1 would be useful. The proposed H5N1 vaccine target for clade 7 is a chicken isolate from Vietnam, A/chicken/Vietnam/NCVD-016/2008, raising concerns that the current case in Vietnam is also clade 7.

These isolates will be largely resistant to current human and poultry vaccines that target clade 1 or one of the three clade 2 sub-clades (2.1, 2.2, 2.3).

Release of the sequence of the proposed clade 7 WHO vaccine target would also be useful.

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