Antibody dynamics after melioidosis infection in Thailand: a retrospective cohort study

Summary: Background: Melioidosis is a life-threatening infectious disease caused by Burkholderia pseudomallei , endemic to southeast Asia and northern Australia. Serological tests targeting haemolysin co-regulated protein 1 (Hcp1) and O-polysaccharide (OPS) antigens have shown promise for diagnosis and surveillance, but their interpretation is limited by an incomplete understanding of antibody persistence following infection. To address this gap, we aimed to characterise post-infection decay dynamics of Hcp1 and OPS-specific IgG and IgA antibodies to improve diagnostic interpretation and population-level seroepidemiological inference.