Rapid Control of a Scabies Outbreak at a Tertiary Care Hospital Without Ward Closure

Background: Crusted scabies is highly transmissible, often misdiagnosed and has been associated with numerous outbreaks in both acute and long term care facilities which can be difficult to control.      

Objective: To describe the interventions used to control a hospital outbreak of scabies rapidly, without disruption of services.

Methods: The descriptive epidemiology of the outbreak is presented.  All interventions are described in accordance with the ORION statement for outbreak reports.

Results: The index patient was a 58 year old renal transplant patient with unrecognized crusted scabies admitted 3 times to St. Michael's Hospital, a 550 bed tertiary care hospital, in Jan/Feb 2009 (Figure 1).  On her 3rd admission she was isolated due to a recognized scabies outbreak at the referring facility.  A skin biopsy confirmed the diagnosis of crusted scabies.

An outbreak management team (OMT) initiated contact tracing with prophylaxis of exposed patients and staff; notification of facilities where exposed patients had been transferred; treatment of the index patient; and hospital-wide surveillance for scabies that included communications encouraging symptomatic healthcare workers to report for treatment.  Within days 3 patients and 5 staff with scabies were identified. Some of the affected staff had been symptomatic for > 2 weeks. 

The OMT declared an outbreak.  Treatment of all patient and staff cases and prophylaxis of family members was undertaken.  Given the potential for unrecognized exposure mass prophylaxis was initiated on both involved wards (an 80 bed medicine ward and 26 bed nephrology ward).  All patients were prophylaxed with 5% permethrin on the same evening shift.  In the morning, rooms were cleaned; linen, clothes and privacy curtains were changed; and the patients showered and donned clean gowns.  Staff worked using gowns and gloves and were sent home with 5% permethrin at the end of their shift; this process continued until all staff received prophylaxis, including staff that only had transient contact with the outbreak units (e.g. phlebotomists).  Neither ward was closed to admissions.  Patient and staff prophylaxis was completed within 1 and 4 days, respectively.  One additional case was identified in a staff member that omitted prophylaxis.  Over the next 6 months, no further cases occurred at our facility. In total, 597 staff and 385 patients received prophylaxis for scabies.

Conclusions: Unrecognized crusted scabies remains the most common trigger for hospital scabies outbreaks.  When widespread exposure occurs within a facility, our experience suggests that mass prophylaxis of all potentially exposed staff and patients is an effective strategy to rapidly stop transmission.  We describe how this can be safely achieved without ward closure.  Rapid identification of exposed patients transferred prior to such prophylaxis is critical to protect other facilities.