Blood Parasitology
ACCREDITATION STATUS:
UKAS Accreditation in accordance with ISO 17043: 2010
CLINICAL APPLICATION:
Identification of malaria parasites and other blood parasites. In infections with P. falciparum the percentage parasitaemia has implications for prognosis and the pattern of treatment employed.
PURPOSE OF PROGRAMME:
To assess a laboratory's ability to identify the parasite(s) present in the sample, identify different stages of parasites and estimating a parasitaemia when appropriate.
MATERIAL PROVIDED: Thick and thin blood films, bone marrow films or tissue dabs
DISTRIBUTIONS PER YEAR: 8 times a year
SAMPLES PER DISTRIBUTION: 1 to 2
FREQUENCY OF DISTRIBUTION: Twice every quarter
PROGRAMME OF ANALYSIS:
Results are entered online via the UK NEQAS website. Trials are live for 3 weeks. Results can be entered at any time during this period. Specimens for overseas participants are despatched 1 week earlier than those of UK participants to allow for postal delays. The intended results of the parasitology distributions are provided immediately after the closing date for that distribution. These are based on pre-distribution investigations in the UK NEQAS Parasitology laboratory situated at the Hospital for Tropical Diseases. Following analyses of results, a full summary of results from all laboratories and country specific performance (where there are more than 10 participants in a country) is provided.
DATA ANALYSIS:
The statistical design of evaluating performance originated from “Quality Control of the isolation rate of pathogens in medical microbiological laboratories”, HE Tillet and PB Crone, J. Hygiene.(1976) 359. The statistical design is robust and takes the minimum number of participants and the number of Distributions and specimens per annum into account. For information on individual laboratory scoring, refer to UKNEQAS Microbiology web page: www.ukneqasmicro.org.uk. . The statistical design of the scheme includes: summary statistics, performance statistics and detection of outliers.
PERFORMANCE SCORING:
The ability to confirm or exclude the presence of parasites (both pathogenic and non-pathogenic), to correctly identify and speciate the parasite(s) present with the aid of the clinical details supplied. In order for the participants to evaluate their performance, a score is awarded for each result reported.
PERFORMANCE MONITORING:
The schemes are designed to provide information allowing participants to gain an insight into their performance and to take individual action to investigate and remedy any defects revealed. Repeat specimens are available free of charge to any laboratory that experienced problems with the original. For UK laboratories, advice and help is available to those with continual poor performance in the scheme. The participants are sent a report of their individual results with current specimens, their report achieved, and their cumulative results over a 12 month period expressed as the numbers of standard errors above or below the mean score. Every 12 months, participants receive details of all the specimens despatched during the year.
PERSISTENT POOR PERFORMANCE:
Performance is monitored over a rolling set number of distributions (the number of distributions included in the cumulative performance analysis is scheme dependent) and is based on the number of standard deviations from the mean of the participants' annual score. (See the UKNEQAS for Microbiology Web page http://www.ukneqasmicro.org.uk for more information on the statistical analyses).
Parasitology
The External Quality Assessment Scheme for Parasitology was founded in 1986 by Professor Peter Chiodini at Department of Clinical Parasitology at the Hospital for Tropical Diseases, London. In 1986 the Service became known as the UK National External Quality Assessment Service for Parasitology. UK NEQAS for Parasitology is hosted by Public Health England. For the most up-to-date scheme information (including any pilot schemes) please contact the centre directly.
Contact Details
- The Halo
- 1 Mabledon Place
- London
- WC1H 9AZ