BACKGROUND: Norovirus is the most common cause of acute gastroenteritis (AGE) in the United States, accounting for an estimated 19-21 million illnesses and 570-800 deaths a year. Infections usually cause mild illness in healthy adults, but can be severe in older adults. Norovirus outbreaks are common in communal settings such as long-term care facilities (LTCFs). Tracking of AGE outbreaks in Wisconsin LTCFs by the Wisconsin Division of Public Health (DPH) began in 2003 and reporting to the National Outbreak Reporting System (NORS) in 2009. LTCFs report AGE outbreaks to their local health department (LHD), which then reports outbreaks to DPH by phone, fax or email. The number of AGE outbreaks in LTCFs reported to DHS rose from 52 in 2006 to 217 in 2015. The DPH guidance document for controlling and reporting AGE outbreaks in LTCFs was last revised in 2009. A surveillance evaluation was conducted to inform a quality improvement plan (QIP).
METHODS: An evaluation was conducted of the system using data collect during 2006—2015 using the CDC’s Updated Guidelines for Evaluating Public Health Surveillance Systems. Evaluation of the system’s performance was completed through analysis of electronic surveillance data and interviews with stakeholders.
RESULTS: During the evaluation time period, 1,528 outbreaks of AGE in LTCFs were reported to DPH. The surveillance system is well accepted among LHDs (96% reporting), but only 10% of LTCFs had reported an outbreak during the evaluation period. Reporting timeliness is good, with average interval of initial illness onset to LHD notification of 5 days, LHD to DPH notification of 2 days, and DPH to NORS notification of 6 days. The system is useful in identifying trends in seasonality and etiology but reporting and data management inefficiencies were identified; a baseline measurement determined DPH staff spend approximately 70 hours a year (22 minutes/outbreak X 200 outbreaks/year) notifying partners of these outbreaks. Stakeholders expressed interest in an electronic reporting option to replace current methods and requested updates to the guidance document.
CONCLUSIONS: Overall the system provides DPH staff and NORS with useful data, is generally well accepted (with acceptance increasing over time), and facilitates DPH staff providing recommendations to LTCFs. A QIP was initiated to address deficiencies identified by the evaluation and includes developing an electronic reporting method, eliminating redundancies, and improving and updating recommendation documents.