Serological Surveillance of the H1N1 and H3N2 Swine Influenza A Virus in Chinese Swine between 2016 and 2021

Table 1

Serological survey of the feeding stages of IAV-S in the swine population in China, 2016-2021.

Pigs of different ages	EA H1N1	Pdm/09 H1N1	H3N2	EA H1N1 and pdm/09 H1N1	EA H1N1 and H3N2	Pdm/09 H1N1 and H3N2	EA H1N1, pdm/09 H1N1 and H3N2	Total
Piglets	1400/4613 (30.35)^a	308/4613 (6.68)	4/4613 (0.09)	1384/4613 (30.00)	2/4613 (0.04)	1/4613; (0.02)	1/4613; (0.02)	3100/4613 (67.20)
Nursery pigs	800/4060 (19.70)	313/4060 (7.71)	0	565/4060; (13.92)	0	0	0	1678/4060 (41.33)
Fattening pigs	1507/4231 (35.62)	300/4231 (7.09)	0	528/4231; (12.48)	3/4231 (0.07)	1/4231; (0.02)	0	2339/4231 (55.28)
Gilts	1160/7018 (16.53)	500/7018 (7.12)	4/7018 (0.06)	1352/7018 (19.26)	6/7018 (0.09)	4/7018; (0.06)	6/7018; (0.09)	3032/7018 (43.20)
Sows	3877/15121 (25.64)	1538/15121 (10.17)	15/15121 (0.10)	1895/15121 (12.53)	16/15121 (0.11)	8/15121; (0.05)	10/15121; (0.07)	7359/15121 (48.67)
Boars	1242/5300 (23.43)	246/5300 (4.64)	1/5300 (0.02)	665/5300; (12.55)	10/5300 (0.19)	4/5300; (0.08)	6/5300; (0.11)	2174/5300 (41.02)
Total	9986/40343 (24.75)	3205/40343 (7.94)	24/40343 (0.06)	6389/40343 (15.84)	37/40343 (0.09)	18/40343 (0.04)	23/40343; (0.06)	19682/40343 (48.79)

^a: positive samples; : sample number; : positive rate.