Poultry-exposed people around Poyang Lake showed varied avian influenza antibody reactivity, 2018–2025

A cross-sectional serological surveillance study of occupationally exposed people around Poyang Lake found that hemagglutination-inhibition antibody reactivity to seven avian influenza virus subtypes varied by subtype, surveillance location and year between 2018 and 2025. The study analyzed 2,437 valid serum samples, including 1,599 from Jiujiang and 838 from Nanchang. Participants were backyard poultry keepers, their household members and live poultry market workers with direct poultry contact. The findings show antibody reactivity in the sampled population but do not, by themselves, establish subtype-specific human infection or local circulation of the viruses.

The study’s abstract reports that 108 samples, or 4.43%, met the predefined positivity threshold for H5N6, while 107, or 4.39%, met the threshold for H9N2. During 2018–2020, 25 of 914 samples (2.74%) met the threshold for H7N9. From 2021 through 2025, 22 of 1,523 samples (1.44%) met the threshold for H3N8, including nine of 100 samples collected in Nanchang in the 2024 surveillance year (9.00%). Four of 1,523 samples (0.26%) met the threshold for H10N3, and all four were from Jiujiang in 2024. For H5N8, four of 314 samples (1.27%) met the threshold in 2020. None of the 600 samples tested for H5N1 in the 2024 and 2025 surveillance years met its predefined threshold.

Samples were collected annually during winter and spring at surveillance sites in Nanchang County and in Duchang and Wuning counties, Jiujiang, Jiangxi Province. The National Influenza Center performed hemagglutination-inhibition assays using test antigens representing H5N6, H9N2, H7N9, H3N8, H10N3, H5N8 and H5N1. Positivity was defined as a titre of at least 1:20 for H3N8, H5N8, H5N1, H7N9 and H10N3, and at least 1:40 for H5N6 and H9N2. The abstract identifies peaks in H5N6 positivity in Jiujiang in 2021 and Nanchang in 2022, and in H9N2 positivity in Jiujiang in 2021 and Nanchang in 2023. It also identifies the H3N8 finding in Nanchang and the H10N3 finding in Jiujiang in the 2024 surveillance year as warranting further investigation.

Because this was an observational, cross-sectional study, the results describe antibody reactivity among selected occupationally exposed participants rather than clinically diagnosed infections. The number of samples tested differed among subtypes, locations and years, limiting direct comparisons across those groups. The article is presented in an accepted, citable version that the publisher says may undergo further edits before replacement by the final Version of Record. The authors concluded that continued serological surveillance, interpreted alongside poultry and environmental virological data, may inform risk assessment.

Subject of Research: Serological surveillance of avian influenza antibodies among poultry-exposed populations around Poyang Lake, China

Article Title: 2018–2025 Serological study on avian influenza among occupationally exposed populations in the Poyang Lake area — the region with the highest environmental surveillance positive rate in China

Article References: Nie, C., Li, Y., Xie, W., Qian, K., Xu, T., He, F., Deng, Z., Wei, W., Hou, Y., Tu, X., Xiang, T., & Song, W. (2026). 2018–2025 Serological study on avian influenza among occupationally exposed populations in the Poyang Lake area — the region with the highest environmental surveillance positive rate in China. BMC Public Health. https://doi.org/10.1186/s12889-026-29921-6

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29921-6

Keywords: avian influenza, serological surveillance, Poyang Lake, hemagglutination inhibition, occupational exposure, poultry workers, H5N6, H9N2, H3N8, H10N3, Jiangxi, China