Geographic Range of Recreational Water-Associated Primary Amebic Meningoencephalitis, United States, 1978-2018.

Naegleria fowleri is a free-living ameba that causes primary amebic meningoencephalitis (PAM), a rare but usually fatal disease. We analyzed trends in recreational water exposures associated with PAM cases reported during 1978-2018 in the United States. Although PAM incidence remained stable, the geographic range of exposure locations expanded northward.

Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of tissue and blood protozoal infections in the pre- and post-transplant period. Significant new developments in the field have made it necessary to divide the previous single guideline published in 2013 into two sections, with the intestinal parasites separated from this guideline devoted to tissue and blood protozoa. The current update reflects the increased focus on donor screening and risk-based recipient monitoring for parasitic infections. Increased donor testing has led to new recommendations for recipient management of Toxoplasma gondii and Trypanosoma cruzi. Molecular diagnostics have impacted the field, with access to rapid diagnostic testing for malaria and polymerase chain reaction testing for Leishmania. Changes in Babesia treatment regimens in the immunocompromised host are outlined. The risk of donor transmission of free-living amebae infection is reviewed. Changing immigration patterns and the expansion of transplant medicine in developing countries has contributed to the recognition of parasitic infections as an important threat to transplant outcomes. Medications such as benznidazole and miltefosine are now available to US prescribers as access to treatment of tissue and blood protozoa is increasingly prioritized.

Fatal Granulomatous Amebic Encephalitis in a Heart Transplant Patient: Clinical, Radiographic, and Autopsy Findings.

Granulomatous amebic encephalitis is a rare necrotizing infection of the CNS that occurs most commonly in immunocompromised individuals and is usually fatal. It is difficult to diagnose as the clinical symptoms and radiographic findings are often mistaken for other bacterial, viral, fungal, or protozoan infections. Herein, we present the case of a 69-year-old heart transplant recipient who suffered fulminant neurological decline ∼5 months after transplant. Extensive radiographic and laboratory testing did not provide a definite anatomic diagnosis and, despite aggressive clinical treatment, he died. An autopsy examination demonstrated numerous brain abscesses which contained amebic trophozoites and cysts. An indirect immunofluorescence assay performed at the Centers for Disease Control confirmed the presence of Acanthamoeba species. To the best of our knowledge, only 13 other cases of Acanthamoeba amebic encephalitis have been reported in patients who have received solid organ transplants and this is the second case reported in a heart transplant recipient. This case emphasizes that amebic encephalitis should be in the differential diagnosis for immunocompromised patients with new brain lesions found on radiographic imaging.

Primary Amebic Meningoencephalitis Associated With Rafting on an Artificial Whitewater River: Case Report and Environmental Investigation.

Background: Naegleria fowleri is a thermophilic ameba found in freshwater that causes primary amebic meningoencephalitis (PAM) when it enters the nose and migrates to the brain. Patient exposure to water containing the ameba typically occurs in warm freshwater lakes and ponds during recreational water activities. In June 2016, an 18-year-old woman died of PAM after traveling to North Carolina, where she participated in rafting on an artificial whitewater river. Methods: We conducted an epidemiologic and environmental investigation to determine the water exposure that led to the death of this patient. Results: The case patient's most probable water exposure occurred while rafting on an artificial whitewater river during which she was thrown out of the raft and submerged underwater. The approximately 11.5 million gallons of water in the whitewater facility were partially filtered, subjected to ultraviolet light treatment, and occasionally chlorinated. Heavy algal growth was noted. Eleven water-related samples were collected from the facility; all were positive for N. fowleri. Of 5 samples collected from the nearby natural river, 1 sediment sample was positive for N. fowleri. Conclusions: This investigation documents a novel exposure to an artificial whitewater river as the likely exposure causing PAM in this case. Conditions in the whitewater facility (warm, turbid water with little chlorine and heavy algal growth) rendered the water treatment ineffective and provided an ideal environment for N. fowleri to thrive. The combination of natural and engineered elements at the whitewater facility created a challenging environment to control the growth of N. fowleri.

Primary amoebic meningoencephalitis caused by Naegleria fowleri: an old enemy presenting new challenges.

First discovered in 1899, Naegleria fowleri is a protist pathogen, known to infect the central nervous system and produce primary amoebic meningoencephalitis. The most distressing aspect is that the fatality rate has remained more than 95%, despite our advances in antimicrobial chemotherapy and supportive care. Although rare worldwide, most cases have been reported in the United States, Australia, and Europe (France). A large number of cases in developing countries go unnoticed. In particular, religious, recreational, and cultural practices such as ritual ablution and/or purifications, Ayurveda, and the use of neti pots for nasal irrigation can contribute to this devastating infection. With increasing water scarcity and public reliance on water storage, here we debate the need for increased awareness of primary amoebic meningoencephalitis and the associated risk factors, particularly in developing countries.

Cerebral trypanosomiasis in a renal transplant recipient.

Chagas disease is a lifelong, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. The main form of disease transmission is vector borne, but vertical transmission, such as by organ transplantation from a chronically infected donor, is also possible. The brain tumor-like form can occur years after infection and has been described in patients with acquired immunodeficiency syndrome, and in a very few cases in transplant recipients. We describe the case of a kidney transplant patient who was human immunodeficiency virus negative and infected with T. cruzi, and developed cerebral trypanosomiasis that was successfully treated with benznidazole at 7 mg/kg/day for 60 days. The risk of Chagas disease transmission should not be underestimated in renal transplant patients, even in non-endemic areas. Chagas disease can present as a tumor-like brain lesion, very difficult to differentiate from other opportunistic infectious or neoplastic processes. Frequent monitoring for T. cruzi infection is essential to promptly implement treatment, which, in our patient, proved to be effective and safe.

Infections with free-living amebae.

Acanthamoeba spp., Balamuthia mandrillaris, and Naegleria fowleri are mitochondria-bearing, free-living eukaryotic amebae that have been known to cause infections of the central nervous system (CNS) of humans and other animals. Several species of Acanthamoeba belonging to several different genotypes cause an insidious and chronic disease, granulomatous amebic encephalitis (GAE), principally in immunocompromised hosts including persons infected with HIV/AIDS. Acanthamoeba spp., belonging to mostly group 2, also cause infection of the human cornea, Acanthamoeba keratitis. Balamuthia mandrillaris causes GAE in both immunocompromised and immunocompetent hosts mostly in the very young or very old individuals. Both Acanthamoeba spp. and B. mandrillaris also cause a disseminated disease including the lungs, skin, kidneys, and uterus. Naegleria fowleri, on the other hand, causes an acute and fulminating, necrotizing infection of the CNS called primary amebic meningoencephalitis (PAM) in children and young adults with a history of recent exposure to warm fresh water. Additionally, another free-living ameba Sappinia pedata, previously described as S. diploidea, also has caused a single case of amebic meningoencephalitis. In this review the biology of these amebae, clinical manifestations, molecular and immunological diagnosis, and epidemiological features associated with GAE and PAM are discussed.

Tap water or "sterile" water for sinus irrigations: what are our patients using?

BACKGROUND: Nasal saline irrigations are a valuable, widely used adjunct for the management of chronic rhinosinusitis. Due to potential concerns regarding infection, patients are commonly recommended to use distilled, bottled, or boiled tap water when mixing these solutions. Anecdotally, patients frequently inform otolaryngologists that they use tap water for irrigation preparation. The purpose of this study was to assess patient adherence to preparation guidelines. METHODS: This study was a cross-sectional, anonymous survey of 100 consecutive patients using nasal saline irrigations for chronic rhinosinusitis on the instruction of the senior author. Patients received their instructions in a standardized manner including printed handouts and had been instructed to use distilled, bottled, or boiled tap water. RESULTS: Patients almost uniformly reported improvement in their symptoms with the use of saline irrigations. No single water preparation was used by a majority of patients. However, tap water was used by 48% and the most common reason cited for using tap water was convenience. Of the patients using bottled, distilled, or boiled tap water, 65% described the process as "mildly" or "moderately" inconvenient. A large majority (70%) of patients report not adhering to cleaning instructions for their sinus rinse bottles. CONCLUSION: Despite standardized instructions for the preparation of saline irrigation solutions, many patients use untreated tap water. The extremely rare, but typically fatal, risk of meningoencephalitis from Naegleria fowlerii makes this a potential health hazard.

Granulomatous amoebic encephalitis caused by Balamuthia mandrillaris.

A 51-year-old immunocompetent Japanese woman presented with a rare case of granulomatous amoebic encephalitis (GAE) caused by Balamuthia mandrillaris. She was brought to our hospital with epilepsy. Magnetic resonance imaging of the brain revealed a homogeneously enhanced solitary mass in the left frontal lobe. Histological diagnosis was made by a biopsy, which suggested lymphomatoid granulomatosis. After that, her neurological condition got worse. New masses were found and had spread across the whole brain. She died 2 months later of cerebral hernia. Autopsy revealed that the patient had GAE caused by Balamuthia mandrillaris. GAE is usually fatal, and is difficult to diagnose except at autopsy. Therefore, awareness of this disease is important, and earlier diagnosis and the development of a better therapeutic strategy will improve clinical outcome.

Demostración del ameboflagelado Naegleria fowleri como agente etiológico de meningoencefalitis amébica primaria en Santiago de Cuba / Demonstration of flagellum ameba Naegleria fowleri as etiological agent of primary amebic meningoencephalitis in Santiago de Cuba

En los últimos años se ha demostrado que el amebo-flagelado Naegleria fowleri es el causante de la meningoencefalitis amébica primaria (MEAP). En Cuba ha sido mencionada la sospecha de su presencia en un líquido céfalo-raquídeo (LCR) de una ameba cuya locomoción y circunstancias sugería que pudiera ser esta ameba. Se realizó el análisis en fresco y en cultivo, con Test de Flagelación de 64 muestras de LCR seleccionadas al azar a partir de las 173 que presentaron las características de transparencia y negatividad a bacterias, requisitos iniciales en búsqueda de este agente, partiendo de una muestra inicial de 1 488 muestras de LCR procedentes de pacientes con meningoencefalitis clínicamente establecidas. De estos 64 LCR, 2 resultaron positivos a la evaluación por los diferentes métodos lo que permitió teñirlos con Giemsa, demostrar su capacidad de flagelación y su resistencia a TMT. Las características citoquímicas de los líquidos concordaban con lo planteado en la literatura y uno de los pacientes sobrevivió, el otro falleció. La patogenicidad de los ameboflagelados aislados de esas dos muestras de LCR se comprobó en el modelo animal ratón albino suizo y fueron observados al microscopio electrónico. Lo anterior confirma microbiológicamente por primera vez en el país este agente etiológico, aunque ya había elementos clínicos y de laboratorio de sospecha en casos anteriores

During the last years it has been demonstrated that the flagellae-carring ameba Naegleria fowleri is the aethiologic agent of the primary amoebic meningoencephalitis (PAME), in Cuba the suspicion of its presence has been mentioned in a Cefalo Raquideal Fluid (CRF) of an ameba whose locomotion and circumstances suggested that it could be this organism. The present work carries out the analysis in fresh CRF samples and after culture, performing the Flagelation Test of the 64 CRF that presented the characteristics of transparency and negativity to bacterial culture ,needed to suspicion of this flagellae-carring ameba, leaving of an starting sample of 1488 CRF.From this analysed sample of CRF only two were positive to the observation of amebas what allowed to tint them with Giemsa and also with Lugol, to demonstrate their flagelation capacity and their resistance to TMT in the corresponding test. The citochemical characteristics of the liquids agreed with that outlined in the literature for this organisms,and one of the patients survived, the other one died. The patogenicity of the isolated flagellae-carring amebas was proven in the animal model of Swiss albino mouse and both isolated strains were observed by the electronic microscope. This results are the basis for considering the present report the first one confirming N.Fowleri as aetiologic agent in two cases of PAME in Cuba

Primary amoebic meningoencephalitis: a new case from Venezuela.

Primary amoebic meningoencephalitis (PAM) is not often seen. To date, less than 300 cases have been communicated to the medical literature since the disease was first discovered in 1965. Six of these reports originated in Venezuela. The authors describe a new spontaneous case of PAM in a 33-year-old previously healthy Western-Venezuelan man.

Molecular identification of Trypanosoma cruzi I tropism for central nervous system in Chagas reactivation due to AIDS.

Trypanosoma cruzi lineages, microsatellite allelic polymorphism, and mithocondrial gene haplotypes were directly typified from peripheral blood and cerebrospinal fluid specimens of a Bolivian patient with Chagas disease with accompanying AIDS and central nervous system severe involvement. Of note, the patient's blood was infected by a mixture of T. cruzi I and T. cruzi IId/e polyclonal populations while the cerebrospinal fluid showed only a monoclonal T. cruzi I population. Our findings do not corroborate the original assumption of innocuity for T. cruzi I in the southern cone of the Americas and highlight lineage I tropism for central nervous system causing lethal Chagas reactivation.

A multicenter case-control study of risk factors for equine protozoal myeloencephalitis.

OBJECTIVE: To identify risk factors for equine protozoal myeloencephalitis (EPM) among horses examined at 11 equine referral hospitals. DESIGN: Case-control study. ANIMALS: 183 horses with EPM, 297 horses with neurologic disease other than EPM (neurologic controls), and 168 horses with non-neurologic diseases (non-neurologic controls) examined at 11 equine referral hospitals in the United States. PROCEDURES: A study data form was completed for all horses. Data were compared between the case group and each of the control groups by means of bivariate and multivariate polytomous logistic regression. RESULTS: Relative to neurologic control horses, case horses were more likely to be > or = 2 years old and to have a history of cats residing on the premises. Relative to non-neurologic control horses, case horses were more likely to be used for racing or Western performance. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that cats may play a role in the natural epidemiology of EPM, that the disease is less common among horses < 2 years of age relative to other neurologic diseases, and that horses used for particular types of competition may have an increased risk of developing EPM.

Disseminated acanthamoeba infection in a renal transplant recipient: a case report.

Acanthamoeba species are free-living amoebae that are the causative agents of chronic granulomatous meningoencephalitis, amoebic keratitis, pulmonary lesions, cutaneous lesions and sinusitis. Immunocompromised individuals are particularly susceptible to infections with Acanthamoeba, which can be disseminated at times. We herewith report the autopsy findings of disseminated Acanthamoeba infection in a 36-year-old female, a renal transplant recipient on immunosupressants for last four years. Central nervous system showed Acanthamoeba associated chronic granulomatous meningoencephalitis, with predominant perivascular infiltrate of amoebic cysts, trophozoites and inflammatory cells. Both lungs and pancreas also showed infiltration with Acanthamoeba.