National primary drinking water regulations: Long Term 1 Enhanced Surface Water Treatment Rule. Final rule.
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In this document, EPA is finalizing the Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR). The purposes of the LT1ESWTR are to improve control of microbial pathogens, specifically the protozoan Cryptosporidium, in drinking water and address risk trade- offs with disinfection byproducts. The rule will require systems to meet strengthened filtration requirements as well as to calculate levels of microbial inactivation to ensure that microbial protection is not jeopardized if systems make changes to comply with disinfection requirements of the Stage 1 Disinfection and Disinfection Byproducts Rule (DBPR). The LT1ESWTR applies to public water systems that use surface water or ground water under the direct influence of surface water and serve fewer than 10,000 persons. The LT1ESWTR builds upon the framework established for systems serving a population of 10,000 or more in the Interim Enhanced Surface Water Treatment Rule (IESWTR). This rule was proposed in combination with the Filter Backwash Recycling Rule (FBRR) in April 2000. (+info)
Sources and species of cryptosporidium oocysts in the Wachusett Reservoir watershed.
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Understanding the behavior of Cryptosporidium oocysts in the environment is critical to developing improved watershed management practices for protection of the public from waterborne cryptosporidiosis. Analytical methods of improved specificity and sensitivity are essential to this task. We developed a nested PCR-restriction fragment length polymorphism assay that allows detection of a single oocyst in environmental samples and differentiates the human pathogen Cryptosporidium parvum from other Cryptosporidium species. We tested our method on surface water and animal fecal samples from the Wachusett Reservoir watershed in central Massachusetts. We also directly compared results from our method with those from the immunofluorescence microscopy assay recommended in the Information Collection Rule. Our results suggest that immunofluorescence microscopy may not be a reliable indicator of public health risk for waterborne cryptosporidiosis. Molecular and environmental data identify both wildlife and dairy farms as sources of oocysts in the watershed, implicate times of cold water temperatures as high-risk periods for oocyst contamination of surface waters, and suggest that not all oocysts in the environment pose a threat to public health. (+info)
Cryptosporidium muris infection in an HIV-infected adult, Kenya.
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We describe a case of Cryptosporidium muris infection in an HIV-infected adult with diarrhea in Kenya. Sequence analysis of an 840-bp region of the 18S rRNA gene locus demonstrated the isolate had 100% nucleotide identity with C. muris recovered from a rock hyrax, 98.8% with a C. muris "calf" isolate, 95.5% with C. serpentis, but only 87.8% with C. parvum "human" type. (+info)
Manufacturer's recall of rapid assay kits based on false positive Cryptosporidium antigen tests--Wisconsin, 2001-2002.
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The Wisconsin Division of Public Health and the Wisconsin State Laboratory of Hygiene (WSLH) reported that a recent cluster of cryptosporidiosis cases in a three-county area in southeastern Wisconsin was the result of false-positive tests. During December 1, 2001-February 1, 2002, approximately 30 cases of cryptosporidiosis were diagnosed at a laboratory in southeastern Wisconsin using the Becton, Dickinson, and Company (Franklin Lakes, New Jersey) ColorPAC Cryptosporidium/Giardia rapid assay (lot number 219370, expiration date 2002-06-05). Seventeen stool specimens, which were collected from 11 patients and tested positive by the rapid assay, were re-evaluated at WSLH. Six of these stool specimens were in EcoFix (Meridian Bioscience Inc., Cincinnati, Ohio), eight were in Cary-Blair transport media, and three were formalin fixed. All 17 specimens tested negative for Cryptosporidium at WSLH using the hot safranin stain and MeriFluor (Meridian Bioscience Inc., Cincinnati, Ohio) Cryptosporidium/Giardia direct fluorescent antibody kit with concentrated specimens. (+info)
Simple method for long-term copro-preservation of Cryptosporidium oocysts for morphometric and molecular analysis.
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Preservation of Cryptosporidium oocysts in faecal specimens containing 75% ethanol is suitable for subsequent morphometric and molecular analysis. No significant morphologic alteration occurred after storage at ambient temperatures, ranging from 22 to 38 degrees C, for more than 2 years. After washing, sugar floatation and DNA extraction, a nested polymerase chain reaction targeting the small subunit ribosomal RNA gene successfully amplified Cryptosporidium DNA in all 15 isolates examined. The sensitivity of detection by polymerase chain reaction (PCR) was found to be as high as 1.25 oocysts per reaction (mean=3.01, SD=1.14). Importantly, a 2.2-kb of the complete DNA sequence of a gene encoding Cryptosporidium thrombospondin-related adhesive protein (TRAP-C1) was also consistently amplified by PCR in all isolates. The PCR-amplified product can be used as a good template for sequencing. Therefore, this simple procedure should be useful for epidemiological analysis of clinical samples from outbreaks, endemic or sporadic cases of cryptosporidiosis when long-term storage of oocysts is required. (+info)
PCR-restriction fragment length polymorphism analysis of a diagnostic 452-base-pair DNA fragment discriminates between Cryptosporidium parvum and C. meleagridis and between C. parvum isolates of human and animal origin.
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Genomic DNAs from human Cryptosporidium isolates previously typed by analysis of the 18S ribosomal DNA locus (Cryptosporidium parvum bovine genotype, C. parvum human genotype, Cryptosporidium meleagridis, and Cryptosporidium felis) were used to amplify the diagnostic fragment described by Laxer et al. (M. A. Laxer, B. K. Timblin, and R. J. Patel, Am. J. Trop. Med. Hyg., 45:688-694, 1991). The obtained 452-bp amplified fragments were sequenced and aligned with the homologous Cryptosporidium wrairi sequence. Polymorphism was exploited to develop a restriction fragment length polymorphism method able to discriminate Cryptosporidium species and C. parvum genotypes. (+info)
Novel cryptosporidium genotypes in sporadic cryptosporidiosis cases: first report of human infections with a cervine genotype.
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In this study, we genotyped parasites from the fecal specimens of sporadic cryptosporidiosis cases in British Columbia from 1995 to 1999. Genotyping was conducted by polymerase chain amplification of the internal transcribed spacer region, a hypervariable region in the 18S rRNA gene and the Cryptosporidium oocyst wall protein gene. Subsequent analysis was by restriction fragment length polymorphism and DNA sequencing. We identified two new Cryptosporidium genotypes in humans. One of these genotypes has been found recently in deer in New York state. The other genotype has not been identified in humans or animals. These results have important implications for drinking water quality strategies, especially for communities that obtain drinking water supplies from surface sources located in forested regions with deer populations. (+info)
Molecular analysis of Cryptosporidium species isolated from HIV-infected patients in Thailand.
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Cryptosporidium isolates from diarrhoeal stools of human immunodeficiency virus (HIV)-infected patients in Thailand were genetically analysed by sequencing the variable region in the 18S rRNA gene. Twenty-nine isolates from four children and 25 adults attending King Chulalongkorn Memorial Hospital in Bangkok during 1996 and 2000 were analysed. All patients suffered from chronic watery diarrhoea and had low CD4+ lymphocytes (mean +/- SD=105.5 +/- 133.2 cells/microl). Four Cryptosporidium species were identified, i.e. C. parvum (genotype 1), C. meleagridis, C. muris and C. felis occurring in 24, 3, 1 and 1 isolates, respectively. Oocysts of C. muris were significantly larger than oocysts of other species; C. felis was the smallest in these populations (P < 0.01). Sequences of the ITS1, 5.8S rRNA and ITS2 regions of C. muris and C. meleagridis identified in this study displayed unique sequences from those of other known species. Based on a limited number of isolates analysed, only C. meleagridis and C. muris were found in HIV-infected children, whereas the genotype 1 of C. parvum predominated in HIV-infected adults. (+info)