Measles RNA detection in wastewater solids

Measles incidence has increased in recent years as vaccination rates have dropped globally. However, there are challenges in surveillance of measles; measles presents similarly to other diseases and can be misdiagnosed. The lag between infectivity and symptom onset also poses a challenge for surveillance, as measles is highly infectious and significant transmission can occur before case identification. Wastewater monitoring of measles RNA could help to fill gaps in clinical surveillance. In this study, we developed a novel assay to detect wild-type measles virus in wastewater; through both in silico and in vivo tests, we demonstrated assay specificity and sensitivity. We conducted both retrospective and prospective monitoring in a sewershed adjacent to ongoing outbreak areas in the region in the United States from December 2024 – May 2025. In total, 11 of 105 (10.5%) of samples were positive for measles with a median concentration of 6,900 gene copies per dry gram of wastewater solids. Overall, we demonstrate that measles is detectable in wastewater during an ongoing outbreak and that wastewater monitoring of measles can result in early warning over clinical surveillance.