Investigation of Strongyloides stercoralis in an Intermediate Care Facility for Developmentally Disabled Individuals, New York, Nov. - Dec. 2023.

Background: Strongyloidiasis is a parasitic infection caused by the nematode Strongyloides stercoralis and can often be asymptomatic.

Methods: An investigation was initiated by the local health department following notification of 3 cases of Strongyloides in a facility for individuals with developmental disabilities in November 2023. Residents and staff were tested using IgG antibody by a commercial laboratory. A site visit was conducted, and staff were interviewed.

Results: Among 62 residents and 140 staff tested, 11 (17.7%) residents and 6 (4.3%) staff were positive for Strongyloides IgG antibodies. Age ranged from 29 to 68 years. Most affected residents were male (72%) and located on the 3^rd floor (82%) (odds ratio 2.88 (CI 0.49,30.23)). Almost all residents were incontinent and non-ambulatory. Infection control practices were assessed; a compliance rate of 4% was observed for staff hand hygiene opportunities and 14% for environmental cleaning in resident rooms. Positive cases were treated, and the last case was reported in December 2023.

Discussion: This was a large outbreak of strongyloidiasis in a long-term care setting in which transmission was likely attributable to workers and/or environmental contamination.

Conclusions: The source of Strongyloides remains unknown; however, adherence to appropriate infection control practices may help to mitigate future outbreaks.