Paradigm Shift Intervention Monitoring
twitter
Commentary
Novel H7N9 Hong Kong Ex-Shenzhen - Human H9N2
& H10N8
Recombinomics Commentary
December 30, 2014 12:00
The case is an export from Shenzhen (where there was no direct contact with chickens in live markets) and has symptomatic contacts who are negative on initial test. Another case from Shenzhen (35F) has been confirmed and her daughter has mild symptoms (test results not released at this time). Both confirmed adult cases are in critical condition.
The sequence was quickly released by CHP (collected December 25), which is to be commended. It is a novel reassortant, with internal genes from human H9N2 and H10N8 cases, raising concerns of human adaptation. The H7 sequence has abolished the glycosylation site with T160A and has receptor binding domain change, Q226L, both of which are common in human H7N9 cases. However, the PB2 sequence is most closely related to avian H9N2 sequences, except it has the human adaptation E627K. In addition, two other internal genes (PB1 and NP) are closely related to the human H9N2 case (86M) in late 2013, A/Hong Kong/308/2014, while the PA sequence is closely related to the human H10N8 sequence, A/Jiangxi-Donghu/346/2013 (73F also from late 2013).
Thus, the novel H7N9 sequence has 4 internal genes. One, PB2, has human adaptation marker E627K, while two others (PB1 and NP) are from a human H9N2 case, and the fourth, PA, is from a human H10N8 case. These human genes in association with human adaptation markers in H7 and the reports of symptomatic contacts in a case with no direct link to poultry, raises serious concerns.
Release of the sequences from the other Shenzhen case and testing or restesting symptomatic contacts would be useful.
Recombinomics
Presentations
Recombinomics
Publications
Recombinomics
Paper
at Nature Precedings