Integrated surveillance for lymphatic filariasis and other infectious diseases with a nationwide non-communicable disease STEPwise survey in the small Pacific Island Nation of Niue, 2025.

The small Pacific island nation of Niue was validated by the WHO in 2016 as having eliminated lymphatic filariasis (LF) as a public health problem; however, no post-validation surveillance (PVS) has been conducted since. In 2025, LF-PVS was integrated into a near-census national WHO STEPwise non-communicable disease (NCD) risk factor survey, a cost-effective approach for estimating LF prevalence and assessing whether elimination had been sustained. Finger-prick blood samples were tested for LF antigen and antibodies; antigen-positive samples were screened for microfilariae. One participant was antigen-positive (0.1%, 95% CI 0.02-0.88), and no microfilariae were detected, indicating sustained elimination. Ten participants were antibody-positive (five Wb123, four Bm14, one dual-positive). Semi-structured interviews provided operational insights, indicating that integrating LF-PVS into the WHO STEPwise NCD risk factor survey was resource-efficient, logistically feasible, and acceptable to both health workers and the community. This study is the first to examine the integration of NCD and communicable disease surveillance in the Pacific.