Open Forum Infect Dis

BackgroundThe genus Acanthamoeba are free-living amebae found worldwide in water, including tap water, and soil that can cause rare but severe infections of the eye, skin, and central nervous system. Acanthamoeba spp. generally cause disease in immunocompromised persons, including those with HIV, hematologic malignancies, and solid organ transplants. The route of transmission and incubation period are not well known in humans, but animal studies have shown that disease can be produced via the intranasal, intrathecal, and intravenous routes. We describe 5 cases of Acanthamoeba disease among immunocompromised patients who practiced nasal rinsing prior to becoming ill.MethodsThe Centers for Disease Control and Prevention (CDC) offers a clinical consultation service for free-living ameba infections and maintains a Free-living Ameba laboratory with confirmatory diagnostic testing capabilities. When an Acanthamoeba case is confirmed in the United States, details about the case are collected on a standardized case report form which includes questions about the case\u2013patient\u2019s water and soil exposure prior to becoming ill. Questions about nasal rinsing were added to the form in 2011.ResultsFive Acanthamoeba case patients in CDC\u2019s free-living ameba database were reported to have performed nasal rinsing prior to becoming ill. The median age was 60 years (range 36\u201373 years) and 3 of 5 patients were female. Two were solid-organ transplant patients (heart and kidney), 2 had chronic lymphocytic leukemia, and 1 had HIV. Three patients presented only with encephalitis and died. The 2-organ transplant patients had a combination of rhinosinusitis, osteomyelitis, and skin lesions. One survived and the other died, the cause of which was unrelated to Acanthamoeba. All reported using tap water to perform nasal rinsing, most for sinus congestion using a neti pot or similar device and one for religious purposes.ConclusionAcanthamoeba is an inhabitant of water, including treated tap water. Immunocompromised patients, like those presented here, might be at risk for infections caused by Acanthamoeba transmitted via tap water used for nasal rinsing. Clinicians caring for immunocompromised patients should advise their patients not to use tap water for nasal or sinus rinsing.DisclosuresAll authors: No reported disclosures.20182018-11-26T00:00:00ZPMC6253004675