Table 4.
Hemagglutination inhibition (HI) and microneutralization (MN) antibody titers against influenza A(H7N9) among close contacts, March 2013 to February 2014
| Provinces | Date first case confirmed | No. of blood sample | Time of collection | HI titer | MN titer c, | |
|---|---|---|---|---|---|---|
| Healthcare contacts | Shanghai | March 30, 2013 | 14 singlea | March 2013 | 1 sample: 40All others <20 | All <10 |
| Anhui | March 30, 2013 | 16 pair b | April 2013 | All <20 | ||
| Jilin | Feb 21, 2014 | 31 pair | February 2014 | All <20 | ||
| Non‐healthcare contacts | Shandong | April 23, 2013 | 10 pair | April 2013 | 1 sample: 202 sample: 401 sample: 8016 sample<20 | All <10 |
| Anhui | March 30, 2013 | 54 pair33 single | April 2013 | All <20 | ||
| Hebei | July 20, 2013 | 5 pair | July 2013 | All <20 | ||
| Jilin | Feb 21, 2014 | 15 pair | February 2014 | All <20 | ||
| Total | 309 samples |
a
Single blood samples were collected from close contacts during convalescent period of the index patient they were exposed to.
b
Pair blood samples were collected from close contacts during both acute and convalescent period of the index patient they were exposed to.
c
MN test was conducted for those sera with HI titer ≥20 only.