Table 2 Seroprevalences of antibodies (HI titer ≥1: 80) to H7N9 and H5N1 viruses in poultry workers, swine workers and the general population in three cross-sectional surveys (2013–2015).

From: Avian influenza A(H7N9) and (H5N1) infections among poultry and swine workers and the general population in Beijing, China, 2013–2015

Period

Characteristics

H7N9

p value

H5N1 clade 2.3.4

P value

H5N1 clade 2.3.2.1

p value

November 2013

Participant category

      

 Poultry workers

0/1258 (0)

0.317

0/1258 (0)

1.000

0/1258 (0)

0.334

 Swine workers

0/1332 (0)

 

1/1332 (0.1)

 

2/1332 (0.2)

 

 General population

1/1200 (0.1)

 

0/1200 (0)

 

0/1200 (0)

 

Sex

      

 Male

0/1933 (0)

0.490

1/1933 (0.1)

1.000

2/1933 (0.1)

0.166

 Female

1/1855 (0.1)

 

0/1855 (0)

 

0/1855 (0)

 

Age group

      

 <50 years

1/2200 (0.0)

1.000

1/2200 (0.0)

1.000

2/2200 (0.1)

0.513

 ≥50 years

0/1585 (0)

 

0/1585 (0)

 

0/1585 (0)

 

Having underlying disease

      

 No

1/3489 (0.0)

1.000

1/3489 (0.0)

1.000

2/3489 (0.1)

1.000

 Yes

0/301 (0)

 

0/301 (0)

 

0/301 (0)

 

April 2014

Participant category

      

 Poultry workers

4/1056 (0.4)

0.008

17/1056 (1.6)

<0.001*

2/1056 (0.2)

0.091

 Swine workers

0/1254 (0)

 

1/1254 (0.1)

 

0/1254 (0)

 

 General population

0/1188 (0)

 

0/1188 (0)

 

0/1188 (0)

 

Sex

      

 Male

2/1686 (0.1)

1.000

3/1686 (0.2)

0.007*

1/1686 (0.1)

1.000

 Female

2/1807 (0.1)

 

15/1807 (0.8)

 

1/1807 (0.1)

 

Age group

      

 <50 years

3/2018 (0.1)

0.643

12/2018 (0.6)

0.447*

0/2018 (0)

0.178

 ≥50 years

1/1471 (0.1)

 

6/1471 (0.4)

 

2/1471 (0.1)

 

Having underlying disease

      

 No

4/3278 (0.1)

1.000

17/3278 (0.5)

1.000

2/3278 (0.1)

1.000

 Yes

0/219 (0)

 

1/219 (0.5)

 

0/219 (0)

 

April 2015

Participant category

      

 Poultry workers

4/1123 (0.4)

0.023

2/1123 (0.2)

0.417

1/1123 (0.1)

0.209

 Swine workers

0/998 (0)

 

1/998 (0.1)

 

2/998 (0.2)

 

 General population

0/1135 (0)

 

0/1135 (0)

 

0/1135 (0)

 

Sex

      

 Male

1/1595 (0.1)

0.625

0/1595 (0)

0.250

1/1595 (0.1)

1.000

 Female

3/1658 (0.2)

 

3/1658 (0.2)

 

2/1658 (0.1)

 

Age group

      

 <50 years

2/1871 (0.1)

1.000

2/1871 (0.1)

1.000

3/1871 (0.2)

0.267

 ≥50 years

2/1377 (0.1)

 

1/1377 (0.1)

 

0/1377 (0)

 

Having underlying disease

      

 No

4/2950 (0.1)

1.000

3/2950 (0.1)

1.000

3/2950 (0.1)

1.000

 Yes

0/305 (0)

 

0/305 (0)

 

0/305 (0)

 
  1. Note. Data are expressed as proportion (%) of participants, unless otherwise indicated.
  2. *Compared using Pearson’s χ2 test.
  3. Compared using Fisher’s exact test.