Draft Chromosome Sequences of a Clinical Isolate of the Free-Living Ameba Naegleria fowleri

ABSTRACT We present the chromosome sequences of a Naegleria fowleri isolate from a human primary amebic meningoencephalitis (PAM) case. The genome sequences were assembled from Illumina HiSeq and PacBio sequencing data and verified with the optical mapping data. This led to the identification of 37 contigs representing 37 chromosomes in N. fowleri.

A Newborn with Brain-Eating Ameba Infection

Naegleria fowleriis a thermophilic free-living ameba that is found in warm, fresh water and causes primary amebic meningoencephalitis (PAM) in humans with high mortality rate. Here we report a case of newborn admitted with destructive clinical features of PAM after having bath with unchlorinated well water on a summer day.

354. The Epidemiology and Clinical Features of Acanthamoeba Disease in the United States, 1956–2018

Background Acanthamoeba is a free-living ameba found worldwide in soil and water that can cause severe illness. Transmission is thought to be through the skin, eyes, or lungs; Acanthamoeba can cause disseminated infection (Acanthamoeba disease) in addition to the more widely recognized Acanthamoeba keratitis. Infections however are rare, and only case reports or small case series have been published. We review Acanthamoeba disease cases from the Centers for Disease Control and Prevention (CDC) free-living ameba registry to characterize the disease in the United States. Methods CDC maintains a free-living ameba (FLA) registry of laboratory-confirmed Acanthamoeba cases (excluding keratitis) sourced from published case reports, CDC case report forms, and CDC laboratory results. SAS© version 9.4 software was used to calculate descriptive statistics and frequencies. Results We identified 163 cases of Acanthamoeba disease between 1956 and 2018. Of cases with documented outcome, 85% were fatal (105/124). Most (88%) cases were in patients who were immunocompromised (136/155): 66 people living with HIV (of whom 49 were classified as having AIDS); 33 recipients of organ transplantation; 30 people diagnosed with malignancy. The most common manifestation of disease was encephalitis (49%). Other clinical presentations included cutaneous lesions (20%) and rhinosinusitis (6%); 40 cases involved multiple organ systems. Median patient age was 42 years (range 0–83 years). Males accounted for 71% (114/160) of cases. California (29) and Texas (14) had the most case reports; 30 other states reported cases. The source of exposure was unknown in most cases (75%); soil and water were documented in 14 and 17 cases, respectively. Conclusion Acanthamoeba disease in the United States is primarily characterized by encephalitis and cutaneous lesions that affect predominately immunocompromised individuals. Acanthamoeba as a cause of encephalitis in immunocompromised patients should be considered by clinicians, which may lead to earlier diagnosis and treatment. Disclosures All Authors: No reported disclosures

Epidemiology and Clinical Characteristics of Primary Amebic Meningoencephalitis Caused by Naegleria fowleri: A Global Review

Background Primary amebic meningoencephalitis (PAM) is a rapidly progressive and often fatal condition caused by the free-living ameba Naegleria fowleri. To estimate the global occurrence, characterize the epidemiology, and describe the clinical features of PAM, we report a series of PAM cases published in the international literature and reported to the Centers for Disease Control and Prevention (CDC). Methods We performed a literature search of PAM case reports published through 2018. Additionally, we included cases reported through the CDC’s Free-Living Ameba surveillance or diagnosed via CDC’s Free-Living and Intestinal Amebas Laboratory. Cases were classified as confirmed, probable, or suspect on the basis of confirmatory testing, presentation, exposure, and disease course. Results A total of 381 PAM cases were identified. Seven reported survivors were classified as confirmed. The most commonly reported exposure associated with PAM was swimming/diving, and the most common class of water source was lakes/ponds/reservoirs. Patients were predominantly male (75%), with a median age of 14 years. Confirmed and probable cases were similar in their survival, course of illness, and cerebrospinal fluid (CSF) findings. Conclusions PAM is a rare but deadly disease with worldwide occurrence. Improved clinician awareness, resulting in earlier diagnosis and treatment, may contribute to increased survival among PAM patients. The case definition of probable used in this study appears to capture cases of PAM, as evidenced by similarities in outcomes, clinical course, and CSF profile to confirmed cases. In the absence of confirmatory testing, clinicians could use this case definition to identify cases of PAM.

Potential Transmission of Acanthamoeba spp. from Contact Lens Solution and Tap Water in Jakarta, Indonesia

BACKGROUND: Acanthamoeba spp. can cause corneal infection or keratitis that can be transmitted through contamination of contact lenses and water. AIM: The objective of this study was to determine the risk factors, transmission potential of Acanthamoeba spp. from the contact lenses cleaning solutions including the household water sources to the contact lens wearers. METHODS: The study was conducted between January 2019 and May 2019. An examination of Acanthamoeba was carried out by collecting contact lenses from 53 graduate students in a college in Jakarta. Their cleaning solutions of contact lenses and household water were also obtained. Each sample was separately examined for Acanthamoeba spp. in the Parasitology Laboratory of the Faculty of Medicine, Universitas Indonesia, on page – salt agar culture. RESULTS: The findings show 2 and 3 contact lens samples positive for Acanthamoeba spp. and other free-living ameba (FLA), respectively. In addition, from the cleaning solution and tap water samples revealed, there are 5 (9.4%) and 34 (64.1%) cultures positive for Acanthamoeba spp. and other FLA, respectively. CONCLUSION: A positive sample of Acanthamoeba spp. originating from the same source of the contact lens and tap water, indicating an association of Acanthamoeba spp. from contact lenses and tap water with the cleaning solutions of the contact lenses. Thus, there is might be a risk of transmission of Acanthamoeba sp. from household water to the cleaning solutions of contact lenses.

865. Acanthamoeba Disease Associated With the Practice of Nasal Rinsing in Immunocompromised Patients

Background The 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. 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 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. 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. Disclosures All authors: No reported disclosures.

Improved Method for the Detection and Quantification ofNaegleria fowleriin Water and Sediment Using Immunomagnetic Separation and Real-Time PCR

Primary amebic meningoencephalitis (PAM) is a rare and typically fatal infection caused by the thermophilic free-living ameba,Naegleria fowleri. In 2010, the first confirmed case of PAM acquired in Minnesota highlighted the need for improved detection and quantification methods in order to study the changing ecology ofN. fowleriand to evaluate potential risk factors for increased exposure. An immunomagnetic separation (IMS) procedure and real-time PCR TaqMan assay were developed to recover and quantifyN. fowleriin water and sediment samples. When one liter of lake water was seeded withN. fowleristrain CDC:V212, the method had an average recovery of 46% and detection limit of 14 amebas per liter of water. The method was then applied to sediment and water samples with unknownN. fowlericoncentrations, resulting in positive direct detections by real-time PCR in 3 out of 16 samples and confirmation ofN. fowlericulture in 6 of 16 samples. This study has resulted in a new method for detection and quantification ofN. fowleriin water and sediment that should be a useful tool to facilitate studies of the physical, chemical, and biological factors associated with the presence and dynamics ofN. fowleriin environmental systems.