Early Warning System for Flu Epidemics in Acute Care Settings

[indigo girl]

http://www.annals.edu.sg/pdf/39VolNo4Apr2010/V39N4p341.pdf

It is interesting that they included conjunctivitis as a possible symptom of flu in this study. It is not usually one of the symptoms that would be mentioned. We did a thread on conjunctivitis and flu over here: Swine Flu and Conjunctivitis - Nursing for Nurses

ARI stands for acute respiratory illness.

Following the nosocomial outbreaks of SARS, TTSH implemented an on-line staff sickness absenteeism surveillance system. The web-based user interface includes pre-populated demographic and employment details of hospital personnel, including name and work area. In each work area, there are at least 2 designated staff in charge of daily submission of data on medical certificates (MCs) for sickness absenteeism. Data captured include start and end dates of MC, area of work, and the reason for the staff being on MC, either as a diagnosis [e.g., pneumonia, URTI (upper respiratory tract infection)] or a set of self-reported symptoms (fever, cough, breathlessness, and diarrhoea). On a daily basis, a team of epidemiologists monitors healthcare worker reports of URTI, gastroenteritis and conjunctivitis, with clusters being identified and actively investigated. Hospital personnel may be advised on enhanced infection control measures and staying away from work if necessary.

Our unique syndromic surveillance system has been in operation for 6 years with consistently high compliance rates from healthcare personnel reporting of about 80%. We suggest that surveillance of sickness absenteeism in healthcare staff, using algorithms for highlighting staff ARI MC clusters, can serve as a useful and cost effective tool for detecting influenza epidemics. Since laboratory surveillance is not routinely performed for staff presenting with ARIs, syndromic surveillance becomes our best means for the early detection of unusual and emerging diseases and events, and could complement other means of uncovering outbreaks. Our rapid assessment suggests that the number of staff ARI clusters did correlate better with influenza A activity in 2007 than the total count of staff ARIs (Fig. 1). In fact, in May 2008, a cluster of ARI did occur among healthcare staff working in a medical ward in TTSH.8 Online reporting on the web-based staff MC surveillance system enabled early identification and investigation of the cluster. Staff with acute symptoms were tested for influenza and other respiratory pathogens, and sent home. Sixty per cent of the staff with ARI tested positive for influenza A. Subsequent investigations revealed that although all infected staff had received influenza vaccination in September to October 2007, there had been a drift in the circulating influenza A strain. The circulating strain was antigenically related to A/Brisbane/10/2007(H3N2), which was not in the 2007 northern hemisphere influenza vaccine, but was included in the 2008 southern hemisphere (SH) influenza vaccine. Consequently, a hospitalwide staff

immunisation programme with the 2008 SH influenza vaccine was implemented. Without the existence of the staff surveillance system, that particular influenza outbreak and the mismatch between circulating strain and vaccine might have been missed.

...the TTSH staff surveillance system was one innovation arising out of the SARS outbreak which we believe deserves greater attention. Certainly, the above analysis was meant to facilitate no more than a crude and rapid assessment of the system's ability to detect influenza outbreaks ahead of the H1N1-2009 epidemic. The recent H1N1-2009 epidemic also provided data which might validate the system's usefulness, although preliminary analysis based on confirmed cases in TTSH staff suggests that there were few clusters of healthcare worker cases, possibly due to the widespread use of face masks for patient care during the epidemic.9 Additional work to further evaluate the system is currently in progress.

(hat tip Avian Flu Diary)