Swimming with death: Naegleria fowleri infections in recreational waters

Recreation & Tourism Studies Program, University of North Dakota, University Mail Stop #7116, Grand Forks, ND 58202, USA.
Travel Medicine and Infectious Disease (Impact Factor: 1.67). 07/2010; 8(4):201-6. DOI: 10.1016/j.tmaid.2010.06.001
Source: PubMed


Naegleria fowleri is a free-living amoeba commonly found in warm freshwater environments such as hot springs, lakes, natural mineral water, and resort spas frequented by tourists. N. fowleri is the etiologic agent of primary amoebic meningoencephalitis (PAM), an acute fatal disease of the central nervous system that results in death in approximately seven days. Previously thought to be a rare condition, the number of reported PAM cases is increasing each year. PAM is difficult to diagnose because the clinical signs of the disease are similar to bacterial meningitis. Thus, the key to diagnosis is physician awareness and clinical suspicion. With the intent of creating awareness among travel medicine practitioners and the tourism industry, this review focuses on the presenting features of N. fowleri and PAM and offers insight into the prevention and treatment of the disease.

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Available from: Travis W Heggie, Nov 19, 2014
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    • "and B. mandrillaris cause chronic granulomatous encephalitis [3]. N. fowleri is commonly found in warm freshwater environments such as hot springs, lakes, natural mineral water, and resort spas frequented by tourists [4]. Infection can occur when N. fowleri enter the nasal passages, attach to the olfactory mucosa, and migrate along the olfactory nerve tracts, crossing the cribriform plate to the brain [5]. "
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    ABSTRACT: After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.
    Full-text · Article · Apr 2013 · The Korean Journal of Parasitology
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    • "Infection in humans is rare, but rapid, with a mortality rate of approximately 99% (Visvesvara and Stehr-Green 1990). The majority of individuals infected with PAM fail to be diagnosed promptly or correctly, and thus most cases are diagnosed post-mortem (Heggie 2010). In diagnosed patients, the treatment involves the use of amphotericin B administered both intravenously and intrathecally along with miconazole or fluconazole and rifampin (da Rocha-Azevedo et al. 2009). "
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    ABSTRACT: Naegleria fowleri is a unicellular eukaryote causing primary amoebic meningoencephalitis, a neuropathic disease killing 99% of those infected, usually within 7-14 days. Naegleria fowleri is found globally in regions including the US and Australia. The genome of the related nonpathogenic species Naegleria gruberi has been sequenced, but the genetic basis for N. fowleri pathogenicity is unclear. To generate such insight, we sequenced and assembled the mitochondrial genome and a 60-kb segment of nuclear genome from N. fowleri. The mitochondrial genome is highly similar to its counterpart in N. gruberi in gene complement and organization, while distinct lack of synteny is observed for the nuclear segments. Even in this short (60-kb) segment, we identified examples of potential factors for pathogenesis, including ten novel N. fowleri-specific genes. We also identified a homolog of cathepsin B; proteases proposed to be involved in the pathogenesis of diverse eukaryotic pathogens, including N. fowleri. Finally, we demonstrate a likely case of horizontal gene transfer between N. fowleri and two unrelated amoebae, one of which causes granulomatous amoebic encephalitis. This initial look into the N. fowleri nuclear genome has revealed several examples of potential pathogenesis factors, improving our understanding of a neglected pathogen of increasing global importance.
    Full-text · Article · Mar 2013 · Journal of Eukaryotic Microbiology
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    • "However, it has to be stressed that exposure to waterborne pathogens does not always result in infection, nor does infection always lead to clinical illness (Pond, 2005). While the most frequent adverse health outcome associated with exposure to contaminated recreational water is enteric illness (WHO, 1992), there are a number of bacteria, viruses, protozoa and algae associated with more severe health outcomes (Karanis et al., 2002; Muniesa et al., 2006; Karanis et al., 2007; Reynolds et al., 2008; Monahan et al., 2009; Heggie, 2010; Lèvêque et al., 2010; Baldursson and Karanis, 2011). Nearly half of the population in developing countries suffers from health problems associated with the consumption of contaminated water, due to inadequate water quality and water treatment facilities (WHO, 2003). "
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    ABSTRACT: During a 12 month period (June 2007-May 2008), the prevalence and susceptibility of Salmonella serovars and their relation to specific pathogenic and indicator bacteria in river and coastal waters was investigated. A total of 240 water samples were collected from selected sites in Acheron and Kalamas Rivers and the Ionian Sea coast in north western Greece. The samples were analyzed for Salmonella spp., Listeria spp., Campylobacter spp., Escherichia coli O157, Staphylococci, Pseudomonas spp., Total Coliforms, Fecal Coliforms, Fecal Streptococci, Total Heterotrophic Flora at 20°C and at 37°C, fungi and protozoa (Cryptosporidium, Giardia). Susceptibility tests to nine antimicrobials (ampicillin, amikacin, amoxicillin/clavulavic acid, cefuroxime, ciprofloxacin, cefoxitin, tetracycline, ticarcillin/clavulanic acid, ampicillin/sulbactam) were performed using the disk diffusion method for Salmonella isolates. We isolated 28 serovars of Salmonella spp. identified as Salmonella enteritidis (23), Salmonella thompson (3) and Salmonella virchow (2). Multi-drug resistant Salmonella serovars were isolated from both river and marine waters, with 34.8% of S. enteritidis and 100% of S. virchow being resistant to more than 3 antibiotics. Also we isolated 42 strains of Listeria spp. identified as L. monocytogenes (20), L. innocua (9), L. seeligeri (2) and L. ivanovii (11). All the Listeria isolates were susceptible to the tested antibiotics. No Campylobacter spp., E. coli O157, Cryptosporidium and Giardia were detected. The overall ranges (and average counts) of the indicator bacteria were: Total Coliforms 0-4×10(4)cfu/100ml (3.7×10(3)cfu/100ml), Fecal Coliforms 0-9×10(3)cfu/100ml (9.2×10(2)cfu/100ml), Fecal Streptococci 0-3.5×10(4)cfu/100ml (1.4×10(3)cfu/100ml), Total Heterotrophic Flora at 20°C 0-6×10(3)cfu/ml (10(3)cfu/ml) and at 37°C 0-5×10(3)cfu/ml (4.9×10(2)cfu/ml). Weak or non significant positive Spearman correlations (p<0.05, r(s) range: 0.13-0.77) were obtained between Salmonella, Listeria, fungi and indicator bacteria. The results underline the complexity of the interrelations between pathogens and indicator bacteria, and the necessity to assess the presence of resistant bacteria in the aquatic environments.
    Full-text · Article · Aug 2012 · International journal of hygiene and environmental health
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