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B A Rush

Publications and source records attributed to B A Rush.

5 recordsLinked to original sources

Evaluation of an enzyme immunoassay kit for detecting cryptosporidium in faeces and environmental samples.

AIMS: To evaluate a commercially available enzyme immunoassay based on a monoclonal antibody to a genus specific Cryptosporidium (IDEIA Cryptosporidium; Dako) antigen for detecting Cryptosporidium oocysts in faecal and environmental samples. METHODS: 435 human faecal samples and post-filtration deposits from 10 reservoir samples, and from six tap water samples seeded with Cryptosporidium oocysts, were examined by EIA according to the manufacturer's instructions, and by microscopic examination of phenolauramine stained smears. Samples giving discrepant results were examined by specific immunofluorescence, before and after concentration of oocysts. RESULTS: Sixteen (3.6%) faecal samples were positive by both microscopy and EIA; five (1.1%) were positive by microscopy of auramine-phenol stained smears (but were not confirmed by specific immunofluorescence) and negative by EIA; one (0.2%) was positive by EIA alone, but confirmed by specific immunofluorescence; and 362 (83.2%) were negative by both microscopy and EIA. Compared with immunofluorescence positive faecal samples, the sensitivity of conventional microscopy and EIA were 94% and 100%, and specificity 76.4% and 100%, respectively. Fifty one (11.7%) were not examined by microscopy due to detection of other pathogens in a previous sample from that patient, but were found to be negative by EIA. Ten reservoir water samples (not suspected of being linked to cases of cryptosporidiosis) were negative by both microscopy and EIA. Of six samples of tap water seeded with varying concentrations of Cryptosporidium oocysts, two (10(2) and 10(3) oocysts/l) were positive by both microscopy and EIA, two (10 and 1/l) by EIA alone, and two (0.1/l and unseeded water) were negative by both microscopy and EIA. CONCLUSIONS: The kit is simple and rapid to use and offers a less subjective method than microscopy for detecting Cryptosporidium in faecal samples submitted to a busy diagnostic laboratory.

Animals↗

An enzyme immunoassay for detecting Cryptosporidium in faecal and environmental samples.

An enzyme immunoassay (EIA) with a monoclonal antibody to cryptosporidium oocysts was developed and evaluated for the examination of faecal and environmental samples. The EIA was as sensitive as microscopy for detecting Cryptosporidium but also produced some positive results which could not be confirmed by a modified Ziehl-Neelsen technique or by immunofluorescence microscopy. These specimens reacted also with heterologous antibodies in EIA, suggesting false positive results.

Animals↗

A probable waterborne outbreak of cryptosporidiosis in the Sheffield area.

There was a marked peak in human cases of cryptosporidiosis in the Sheffield area in May and June 1986. Extensive epidemiological investigations failed to find a common source of food or a consistent history of animal contact, but did suggest that a waterborne outbreak of cryptosporidiosis may have occurred. Cryptosporidium oocysts were found in untreated water and in fish from a reservoir complex implicated by epidemiological analysis. Laboratory investigations confirmed that cattle on a farm adjacent to the reservoir complex were a possible source of contamination.

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Efficiency of sand filtration for removing cryptosporidium oocysts from water.

Purified oocysts of Cryptosporidium were applied to the top of a sand filter which had been constructed in the laboratory. The filter was eluted with distilled water; fractions were collected and examined for Cryptosporidium by modified Ziehl-Neelsen technique and immunofluorescence microscopy and by an enzyme immunoassay. The results indicate that oocysts of Cryptosporidium do not easily pass through the sand filter, and that some disintegration of oocysts may occur during filtration.

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