An outbreak of scabies in a teaching hospital: Lessons learned

OBJECTIVE: To investigate an outbreak of scabies in an inner-city teaching hospital, identify pathways of transmission, institute effective control me asures to end the outbreak, and prevent future occurrences. DESIGN: Outbreak investigation, case-control study, and chart review. SETTING: Large tertiary acute-care hospital. RESULTS: A patient with unrecognized Norwegian (crusted) scabies was admitt ed to the acquired immunodeficiency syndrome (AIDS) service of a 940-bed ac ute-care hospital. Over 4 months, 773 healthcare workers (HCWs) and 204 pat ients were exposed to scabies. Of the exposed HCWs, 147 (19%) worked on the AIDS. service. Risk factors for being infested with scabies among HCWs inc luded working on the AIDS service (odds ratio [OR], 5.3; 95% confidence int erval [CI95], 2.17-13.15) and being a nurse, physical therapist, or HCW wit h extensive physical contact with infected patients (OR, 4.5; CI95, 1.26-17 .45). Aggressive infection control precautions beyond Centers for Disease C ontrol and Prevention barrier and isolation recommendations were instituted , including the following: (1) early identification of infected patients; ( 2) prophylactic treatment with topical applications for all exposed HCWs; ( 3) use of two treatments I week apart for all cases of Norwegian scabies; ( 4) maintaining isolation for 8 days and barrier precautions for 24 hours af ter completing second treatment for a diagnosis of Norwegian scabies; and ( 5) oral ivermectin for treatment of patients who failed conventional therap y. CONCLUSIONS: HCWs with the most patient contact are at highest risk of acqu iring scabies. Because HCWs who used traditionally accepted barriers while caring for patients with Norwegian scabies continued to develop scabies, we found additional measures were required in the acute-care hospital. HCWs w ith skin exposure to patients with scabies should receive prophylactic trea tment. We recommend (1) using heightened barrier pre cautions for care of p atients with scabies and (2) extending the isolation period for 8 days or 2 4 hours after the second treatment with a scabicide for those patients with Norwegian scabies. Oral ivermectin was well tolerated for treating patient s and HCWs who failed conventional treatment. Finally, we developed a surve illance system that provides a "barometric measure" of the infection rate i n the community. If scabies increases in the community, a tiered triage sys tem is activated to protect against transmission among HCWs or hospital pat ients (Infect Central Hosp Epidemiol 2001;22:13-18).