Table 2.

HIV incidence among MSM in sentinel surveillance surveys in Jiangsu province, China, 2016–2021.

Year	Negative (N)	Adjusted negative (N′)	Requested LAg-avidity-EIA testing (P)	Actual LAg-avidity-EIA testing (P′)	Recent (R)	Incidence (%) (95% CI) (I)
2016	2,172	2,143	223	220	60	7.4 (5.5–9.2)
2017	2,435	2,375	204	199	46	5.0 (3.6–6.5)
2018	2,379	2,379	196	196	70	7.9 (6.1–9.8)
2019	2,226	2,160	202	196	56	6.9 (5.1–8.6)
2020	2,387	2,387	192	192	79	9.0 (7.0–11.0)
2021	2,444	2,431	189	188	58	6.3 (4.7–8.0)

The number of unambiguous previously diagnosed cases was 8, 13, 28, 39, 26, and 24, respectively, in 2016, 2017, 2018, 2019, 2020, and 2021; The number of Western Blot indeterminate samples was 1, 4, 1, 2, 6, and 0, respectively; The reasons for not testing LAg-Avidity-EIA (difference between P and P′) were samples missing or poor quality.