Investigation of a Scabies Outbreak in a Nursing Home in Mueang District, Nonthaburi Province, Thailand, August 2023 to April 2024

Abstract

On February 8, 2024, the Division of Epidemiology was notified of a scabies outbreak at a nursing home in Mueang District, Nonthaburi Province. An investigation team was deployed to confirm the diagnosis and outbreak, describe its epidemiological features, identify the source, and provide proper control measures. A descriptive study was conducted, with active case finding using a structured questionnaire. Suspected cases were defined as individuals with at least one rash lesion between August 1, 2023, and April 30, 2024. Probable cases were those diagnosed by a dermatologist, while confirmed cases had laboratory confirmation. Environmental surveys and laboratory testing were performed. A total of 19 cases were identified, including 1 confirmed case, with an attack rate of 54.3%. The cases included 8 males and 11 females (male-to-female ratio: 1:1.4), with a median age of 64 years (range: 17–89). Among the cases, 11 were residents and 8 were staff members, distributed across both floors of the facility. The index case, a staff member, developed symptoms on September 14, 2023, after sharing a room with a trainee who had itchy rashes. Sarcoptes scabiei was confirmed in one laboratory sample. The outbreak was likely linked to caregiving processes, as staff rotated rooms and had direct physical contact with residents. In conclusion, the investigation confirmed a scabies outbreak involving both residents and staff, with no severe cases or fatalities. The outbreak was likely introduced by an infected individual without prior screening. It is recommended that new staff undergo scabies screening before starting work to prevent future outbreaks.