Local wastewater monitoring as a complementary tool in a mumps outbreak investigation in the Netherlands: A...

A recent outbreak of mumps showed a concerningly low number of classical disease notifications, prompting evaluation of the efficacy of local wastewater monitoring.

Suspected mumps cases were recorded by local General Practitioner practices (n = 13) for 20 weeks, and laboratory-reported notifications were collected. Local wastewater monitoring using passive samplers was deployed downstream of a confirmed case and their school, and in wastewater pumping stations serving the involved and neighbouring towns. Wastewater samples were analysed using reverse transcription polymerase chain reaction.

General Practitioners reported 50 suspected patients, of which 24 were confirmed. The passive sampler near the confirmed case detected virus RNA directly postdiagnosis, followed by a negative signal afterwards, while samplers at the school and the local pumping station detected rising concentrations as more cases were reported. Samplers in neighbouring towns showed further spread, including a town with no reported cases.

This study demonstrates the first successful proof-of-concept for local wastewater monitoring of mumps and indicates a possible correlation between wastewater and clinical monitoring. These results suggest a role for local wastewater monitoring using passive samplers in creating situational awareness during an outbreak, even when cases are not reported.