Primary Amebic Meningoencephalitis in Florida: A Case Report and Epidemiological Review of Florida Cases
Epidemic Intelligence Service, Centers for Disease Control and Prevention, USA.Journal of environmental health (Impact Factor: 0.96). 04/2013; 75(8):26-31.
Primary amebic meningoencephalitis (PAM) is a rare but nearly always fatal infection of the central nervous system caused by the thermophilic, free-living ameba Naegleria fowleri. Since its first description in 1965 through 2010, 118 cases have been reported in the U.S.; all cases are related to environmental exposure to warm freshwater; most have occurred in children and adolescents and are associated with recreational water activities, such as swimming, diving, or playing in freshwater lakes, ponds, or rivers. Over one-fourth of all national PAM cases have occurred in Florida. The authors describe here a fatal case of PAM in a resident of northeast Florida and the ensuing environmental and public health investigation; they also provide a review of all cases of PAM in Florida from 1962 to 2010 and discuss public health responses to PAM in Florida, highlighting opportunities for positive collaboration between state and local environmental health specialists, epidemiologists, and the Centers for Disease Control and Prevention.
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- [Show abstract] [Hide abstract] ABSTRACT: Parasitic infections of the CNS are a public health challenge to the developing world. During the past few decades, increased tourism, migratory movements, and the AIDS epidemic have facilitated the spread of formerly geographically restricted parasitic infections that now affect thousands of people living in developed countries. Parasites are classified into protozoa and helminths, and the latter are further divided into cestodes (tapeworms), nematodes (roundworms), and trematodes (flukes). Parasitic infections are highly pleomorphic due to the unpredictable nature of the immunological reaction of the host against parasites as well as the many pathological lesions that these organisms may cause. Parasitic infections of the CNS may cause subacute or chronic meningitis, encephalitis, space-occupying brain lesions, stroke, and myelopathy. Diagnosis may be difficult due to nonspecificity of clinical manifestations and neuroimaging findings and the poor reliability of some of the most commonly used serologic tests. While the introduction of potent antiparasitic drugs has improved the prognosis in many patients, therapy still remains anecdotal for most of these conditions.
- [Show abstract] [Hide abstract] ABSTRACT: Naegleria is a free-living amoeba, and pathogenic Naegleria may pose a health risk to people exposed to recreational water. Our objective in this study was to determine if there are pathogenic amoebae in environmental water samples from Changchun, Northeastern China. During July to September 2012, a total of 70 water samples were collected from Changchun, Northeastern China, and Naegleria was enriched by in vitro culture and detected by PCR using Naegleria genus-specific primers. Resulting PCR products were sequenced and phylogenetically analyzed to identify Naegleria species. Naegleria was detected in 65 (92.9%) of 70 water samples. DNA sequence and phylogenetic analyses based on the internal transcribed spacer (ITS) rDNA sequences revealed four Naegleria species, including N. pagei (n = 24) and N. Australiensis (n = 18), N. clarki (n = 13) and N. gruberi (n = 10), in which N. australiensis is pathogenic to mice. But the pathogenic species N. fowleri was not detected. This is the first report on Naegleria species in Northeastern China, showing that almost all environmental water samples were contaminated with Naegleria, including N. pagei, N. Australiensis, N. clarki and N. gruberi, which should be considered a potential public health threat.
- [Show abstract] [Hide abstract] ABSTRACT: Increasing numbers of Primary Amoebic Meningoencephalitis (PAM) cases due to Naegleria fowleri are becoming a serious issue in subtropical and tropical countries as a Neglected Tropical Disease (NTD). To establish a rapid and effective diagnostic tool, a PCR-based detection technique was developed based on previous PCR methods. Four kinds of primer pairs, Nfa1, Nae3, Nf-ITS, and Naegl, were employed in the cultured amoebic trophozoites and a mouse with PAM experimentally developed by N. fowleri inoculation (PAM-mouse). For the extraction of genomic DNA from N. fowleri trophozoites (1×10(6)), simple boiling with 10μl of PBS (pH 7.4) at 100°C for 30min was found to be the most rapid and efficient procedure, allowing amplification of 2.5×10(2) trophozoites using the Nfa-1 primer. The primers Nfa1 and Nae3 amplified only N. fowleri DNA, whereas the ITS primer detected N. fowleri and N. gruberi DNA. Using the PAM-mouse brain tissue, the Nfa1 primer was able to amplify the N. fowleri DNA 4 days post infection with 1ng/μl of genomic DNA being detectable. Using the PAM-mouse CSF, amplification of the N. fowleri DNA with the Nae3 primer was possible 5 days post infection showing a better performance than the Nfa1 primer at day 6. Copyright © 2015 Elsevier GmbH. All rights reserved.