An outbreak of scabies: a forgotten parasitic disease still present in Switzerland

Scabies, a contagious parasitic dermatosis, has a worldwide distribution but is considered a "disease of the poor" in resourcerich countries. However, it can cause major public health problems following outbreaks in industrialised countries. The following study describes a large outbreak of scabies involving several health care institutions in the canton of Neuchâtel, Switzerland.

After reporting a case of crusted scabies hospitalised for several months (for other comorbidities) in various health care institutions, a "scabies task force" was created in order to detect further cases by contact tracing. Suspected cases were reported to public health authorities, with notification of the health care institutions where cases or exposed patients had been transferred, and information to general practitioners and dermatologists of the entire area (100,000 inhabitants),

Three health care institutions (a rehabilitation clinic, a 200-bed acute care hospital, a small hospital with a haemodialysis unit) were involved. Overall, 24 cases of scabies were detected, 12 among inpatients after exposure within the health care institutions, and 12 among household or other close contacts. 116 health care providers exposed to cases within the health care institutions were investigated with negative results for scabies. After the creation of the task force, no further transmission of scabies was observed. Prolonged misdiagnosis of crusted scabies as well as frequent transfers of cases between various health care institutions facilitated the outbreak. Barrier precautions for health care workers caring for patients with skin lesions even in the absence of a diagnosis of transmissible disease appeared to be efficacious since no transmission to health care workers could be detected.

This is the first reported observation of a large scabies outbreak involving health care institutions in Switzerland. Our outbreak demonstrates that it is not an obsolete disease and that a high index of suspicion must be maintained in order to promptly detect difficult cases and to curb potential outbreaks.