Multiplex serological profiling reveals diverse avian and mammalian influenza A virus exposure in swine

Foong Ying Wong; Peter Cronin; Rong Zhang; Arata Hidano; Jurre Y Siegers; Dolyce H W Low; Hannah Holt; William Leung; Dina Koeut; Bunnary Seng; Sovanncheypo Chao; Ty Chhay; Sothrya Tum; San Sorn; Monidarin Chou; Kimrong Bun; Phalla Y; Leangyi Heng; Marcus G Mah; Giselle G K Ng; Jiayi Li; Heidi Auerswald; Michael A Zeller; Richard J Webby; Erik A Karlsson; James W Rudge; Gavin J D Smith; Yvonne C F Su

doi:10.1016/j.isci.2026.115743

Multiplex serological profiling reveals diverse avian and mammalian influenza A virus exposure in swine

iScience. 2026 Apr 16;29(5):115743. doi: 10.1016/j.isci.2026.115743. eCollection 2026 May 15.

Authors

Foong Ying Wong¹, Peter Cronin¹, Rong Zhang¹, Arata Hidano², Jurre Y Siegers³, Dolyce H W Low¹, Hannah Holt², William Leung², Dina Koeut⁴, Bunnary Seng⁴, Sovanncheypo Chao⁴, Ty Chhay⁵, Sothrya Tum⁴, San Sorn⁴, Monidarin Chou⁶, Kimrong Bun³, Phalla Y³, Leangyi Heng³, Marcus G Mah¹, Giselle G K Ng¹, Jiayi Li¹, Heidi Auerswald³, Michael A Zeller¹, Richard J Webby⁷, Erik A Karlsson³, James W Rudge², Gavin J D Smith¹, Yvonne C F Su¹

Affiliations

¹ Programme in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore.
² Department of Global Health and Development, London School of Hygiene and Tropical Medicine, London, UK.
³ Virology Unit, Institute Pasteur du Cambodge, Phnom Penh, Cambodia.
⁴ National Animal Health and Production Research Institute, General Directorate of Animal Health and Production, Ministry of Agriculture, Forestry and Fisheries, Phnom Penh, Cambodia.
⁵ Livestock Development for Community Livelihood, Phnom Penh, Cambodia.
⁶ University of Health Sciences, Phnom Penh, Cambodia.
⁷ Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA.

Abstract

Animal-origin influenza viruses pose significant pandemic threats, with swine serving as key hosts. Serological surveillance in pigs remains limited in regions with intense human-animal-avian contact. Between March 2020 and July 2022, we collected 4,069 pig serum samples in Cambodia, of which 1,321 (32.5%) were influenza A virus (IAV) seropositive by ELISA. We developed a multiplex microsphere immunoassay comprising a broad panel of hemagglutinin (HA) and neuraminidase (NA) antigens. Seroprevalence was highest for pandemic H1N1/pdm09 (35.3-45.7%) and lower for classical swine H1 (16.4-17.7%) and European avian-like swine H1 (∼15%) lineages. Lineage-specific or shared exposures to multiple lineages were observed, indicating complex infection histories. H3 responses varied by clade, while antibodies to avian H5, H7, and H9 were detected in <8% of IAV-positive sera. These findings underscore the ongoing zoonotic risk posed by diverse IAVs circulating in pigs and highlight the need for integrated serological and genomic surveillance.

Keywords: Microbiology; Virology.