H7N9 Zaozhuang Shandong Cluster Raises Concerns

Recombinomics Commentary 03:15
April 29, 2013

Patients Zhang, male, 36 years old, who lives in Zaozhuang City, and engaged in the work of building materials wholesale. Fever, cough 6 days, hold breath after 1 day the Zaozhuang City hospital on the evening of April 21, admitted to hospital with severe pneumonia
 
In Shandong, experts confirmed an H7N9 bird flu case in the city of Zaozhuang on Sunday. The patient, a four-year-old boy surnamed Zhang, developed a fever on Saturday.

The above translation (in red) describes the first confirmed H7N9 case(36M) in Zaozhuang, Shandong Province, who developed symptoms on April 15 (see map).  The comments (in blue) describe the confirmation of H7N9 in his son (4M), who developed symptoms on April 27.  The 12 day gap in disease onset dates strongly signals human to human transmission.  Similar time gaps exist for family members in other H7N9 bird flu clusters, including the Minghan familial cluster where disease onset dates between son and father was 8 days (both cases died).

Although the disease onset date gaps provided compelling evidence of human yo human (H2H) transmission, the evidence for sustained H2H transmission is the identity in three genes found on A/Hangzhou/1/2013 and A/Jiangsu/01/2013, which included L226I

The dramatic spread of confirmed cases in recent days (see map) also supports widespread H 2 H transmission.