Methods: The 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-patient’s water and soil exposure prior to becoming ill. Questions about nasal rinsing were added to the form in 2011.
Results: Five Acanthamoeba case-patients in CDC’s free-living ameba database were reported to have performed nasal rinsing prior to becoming ill. The median age was 60 years (range 36–73 years) and 3/5 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 two 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.
Conclusion: Acanthamoeba 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.
I. Ali, None