Dataset Information

Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

ABSTRACT: Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing. All samples underwent "head to head" re-testing using both RCA and direct fluorescence assay (DFA). Community level results from three sites indicated that 54.4% (166/305) of Meridian ImmunoCard STAT! positives and 87.0% (67/77) of Remel Xpect positives were confirmed by DFA. When samples were retested by RCA at state laboratories and compared with DFA, 83.3% (155/186) of Meridian ImmunoCard STAT! positives and 95.2% (60/63) of Remel Xpect positives were confirmed. The percentage of confirmed community results varied by site: Minnesota, 39.0%; New York, 63.9%; and Wisconsin, 72.1%. The percentage of confirmed community results decreased with patient age; 12.5% of community positive tests could be confirmed by DFA for patients 60 years of age or older. The percentage of confirmed results did not differ significantly by sex, storage temperature, time between sample collection and testing, or season. Findings from this study demonstrate a lower confirmation rate of community RCA positives when compared to RCA positives identified at state laboratories. Elucidating the causes of decreased test performance in order to improve overall community laboratory performance of these tests is critical for understanding the epidemiology of cryptosporidiosis in the United States (US).

SUBMITTER: Roellig DM

PROVIDER: S-EPMC5234809 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

Roellig Dawn M DM Yoder Jonathan S JS Madison-Antenucci Susan S Robinson Trisha J TJ Van Tam T TT Collier Sarah A SA Boxrud Dave D Monson Timothy T Bates Leigh Ann LA Blackstock Anna J AJ Shea Shari S Larson Kirsten K Xiao Lihua L Beach Michael M

PloS one 20170113 1

Cryptosporidium is a common cause of sporadic diarrheal disease and outbreaks in the United States. Increasingly, immunochromatography-based rapid cartridge assays (RCAs) are providing community laboratories with a quick cryptosporidiosis diagnostic method. In the current study, the Centers for Disease Control and Prevention (CDC), the Association of Public Health Laboratories (APHL), and four state health departments evaluated RCA-positive samples obtained during routine Cryptosporidium testing ...[more]

PMID: 28085927

Similar Datasets

Project description:The protozoan parasite Cryptosporidium is an important cause of diarrheal disease (cryptosporidiosis) in humans and animals, with significant morbidity and mortality especially in severely immunocompromised people and in young children in low-resource settings. Due to the sexual life cycle of the parasite, transmission is complex. There are no restrictions on sexual recombination between sub-populations, meaning that large-scale genetic recombination may occur within a host, potentially confounding epidemiological analysis. To clarify the relationships between infections in different hosts, it is first necessary to correctly identify species and genotypes, but these differentiations are not made by standard diagnostic tests and more sophisticated molecular methods have been developed. For instance, multilocus genotyping has been utilized to differentiate isolates within the major human pathogens, Cryptosporidium parvum and Cryptosporidium hominis. This has allowed mixed populations with multiple alleles to be identified: recombination events are considered to be the driving force of increased variation and the emergence of new subtypes. As yet, whole genome sequencing (WGS) is having limited impact on public health investigations, due in part to insufficient numbers of oocysts and purity of DNA derived from clinical samples. Moreover, because public health agencies have not prioritized parasites, validation has not been performed on user-friendly data analysis pipelines suitable for public health practitioners. Nonetheless, since the first whole genome assembly in 2004 there are now numerous genomes of human and animal-derived cryptosporidia publically available, spanning nine species. It has also been demonstrated that WGS from very low numbers of oocysts is possible, through the use of amplification procedures. These data and approaches are providing new insights into host-adapted infectivity, the presence and frequency of multiple sub-populations of Cryptosporidium spp. within single clinical samples, and transmission of infection. Analyses show that although whole genome sequences do indeed contain many alleles, they are invariably dominated by a single highly abundant allele. These insights are helping to better understand population structures within hosts, which will be important to develop novel prevention strategies in the fight against cryptosporidiosis.

Project description:Whole genome sequencing (WGS) of Cryptosporidium spp. has previously relied on propagation of the parasite in animals to generate enough oocysts from which to extract DNA of sufficient quantity and purity for analysis. We have developed and validated a method for preparation of genomic Cryptosporidium DNA suitable for WGS directly from human stool samples and used it to generate 10 high-quality whole Cryptosporidium genome assemblies. Our method uses a combination of salt flotation, immunomagnetic separation (IMS), and surface sterilisation of oocysts prior to DNA extraction, with subsequent use of the transposome-based Nextera XT kit to generate libraries for sequencing on Illumina platforms. IMS was found to be superior to caesium chloride density centrifugation for purification of oocysts from small volume stool samples and for reducing levels of contaminant DNA.The IMS-based method was used initially to sequence whole genomes of Cryptosporidium hominis gp60 subtype IbA10G2 and Cryptosporidium parvum gp60 subtype IIaA19G1R2 from small amounts of stool left over from diagnostic testing of clinical cases of cryptosporidiosis. The C. parvum isolate was sequenced to a mean depth of 51.8X with reads covering 100 % of the bases of the C. parvum Iowa II reference genome (Bioproject PRJNA 15586), while the C. hominis isolate was sequenced to a mean depth of 34.7X with reads covering 98 % of the bases of the C. hominis TU502 v1 reference genome (Bioproject PRJNA 15585). The method was then applied to a further 17 stools, successfully generating another eight new whole genome sequences, of which two were C. hominis (gp60 subtypes IbA10G2 and IaA14R3) and six C. parvum (gp60 subtypes IIaA15G2R1 from three samples, and one each of IIaA17G1R1, IIaA18G2R1, and IIdA22G1), demonstrating the utility of this method to sequence Cryptosporidium genomes directly from clinical samples. This development is especially important as it reduces the requirement to propagate Cryptosporidium oocysts in animal models prior to genome sequencing.This represents the first report of high-quality whole genome sequencing of Cryptosporidium isolates prepared directly from human stool samples.

Project description:As in many other European countries, a nationwide screening program for colorectal cancer (CRC) has recently been introduced in the Netherlands. As a side effect, such a screening program will inherently yield an increase in the demand for surveillance after removal of polyps/adenomas or CRC. Although these patients are at increased risk of metachronous colorectal neoplasia, solid evidence on CRC-related mortality reduction as a result of colonoscopy-based surveillance programs is lacking. Furthermore, colonoscopy-based surveillance leads to high patient burden, high logistic demands and high costs. Therefore, new surveillance strategies are needed. The aim of the present study, named Molecular stool testing for Colorectal CAncer Surveillance (MOCCAS), is to determine the performance characteristics of two established non-invasive tests, i.e., the multitarget stool DNA test Cologuard® and the faecal immunochemical test (FIT) in the detection of CRC and advanced adenomas as an alternative for colonoscopy surveillance.In this observational cross-sectional cohort study, subjects aged 50 to 75 years will be approached to collect (whole-) stool samples for molecular testing and a FIT prior to their scheduled surveillance colonoscopy. The results of the tests will allow calculation of test sensitivities and specificities in the context of surveillance. This will provide the required input for the Dutch ASCCA model (Adenoma and Serrated pathway to Colorectal CAncer) to simulate surveillance strategies differing in frequency and duration. The model will allow predictions of lifetime health effects and costs. Multiple centres in the Netherlands will participate in the study that aims to include 4,000 individuals.The outcome of this study will inform on the (cost-) effectiveness of stool based molecular testing as an alternative for colonoscopy in the rapidly expanding surveillance population.ClinicalTrials.gov ( https://clinicaltrials.gov/ ): NCT02715141 . Retrospectively registered 17 February 2016.

Dataset Information

Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

Publications

Community Laboratory Testing for Cryptosporidium: Multicenter Study Retesting Public Health Surveillance Stool Samples Positive for Cryptosporidium by Rapid Cartridge Assay with Direct Fluorescent Antibody Testing.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets