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Cryptosporidium Reference Unit

Contact Us

Cryptosporidium Reference Unit
Public Health Wales Microbiology 
Singleton Hospital
SA2 8QA    

Public Health Wales Microbiology 
DX 6070300
Swansea 90 SA

Tel:  01792 285341 (for results, consultation and advice during office hours)
Tel (out of hours): 01792 205666 (ask for on-call consultant microbiologist)
Laboratory hours: 0845-1700 (Monday to Friday)


Senior Staff
  • Consultant Clinical Scientist and Head of Unit: Professor Rachel Chalmers
  • Principal Clinical Scientists: Dr Kristin Elwin and Dr Guy Robinson
  • Consultant Medical Microbiologist: Dr Angharad Davies
  • Biomedical Scientist: David Cooper LIBMS

Supported by a Research Scientist and a Biomedical Support Worker

    Core Reference Services and Guide to Investigations

    • Differential diagnosis and confirmation of referred isolates of Cryptosporidium
    • Specialist testing for the detection of Cryptosporidium in immunocompromised patients at high risk 
    • Typing of referred isolates to support outbreak/cluster investigations and for epidemiological surveillance 
    • Evaluation of new laboratory methods for Cryptosporidium 
    • Provision of positive control and training materials 
    • Consultation advice on diagnostic methods and management of cryptosporidiosis 
    • Advice on the investigation, epidemiology, control and prevention of Cryptosporidium  
    • R & D activities in relation to our reference functions



    Samples required Tests performed

    Turnaround time

    (depends on complexity and current workload)



    DNA (min 20µl) - by prior arrangement



    2 working days

    Specialist testing of immunocompromised patients at high risk from Cryptosporidium


    (minimum 2 scoops)

    Other specimen types as indicated

    Microscopy (including immunofluorescence)

    PCR-based tests

    2 working days


    PCR offered weekly

    Typing of Cryptosporidium* isolates (species/genotype) for epidemiological purposes and for the investigation of clusters/outbreaks

    Further characterisation is at the discretion of the Unit Head or following consultation

    *In Wales, Giardia genotyping is also undertaken but may have a longer turnaround time

     Cryptosporidium*-positive stools (minimum 2 scoops, ideally without preservative but if formalin has been added, this should be noted on the form)


    DNA (min 20µl) - by prior arrangement



     PCR-based tests

     5-10 working days (maybe reduced during outbreak investigations)

    Typing from Cryptosporidium-positive water and environmental slides

       Please see our water and environmental services webpage for details


    How to Obtain Services 

    Use the Cryptosporidium Reference Unit form above. For Giardia please use the form supplied by the reference unit.

    Sample transportation

    • Samples should be sent in packaging appropriate to current legislation, accompanied by a referral form (available to download above) detailing putative diagnosis, patient or sample details and relevant (clinical) history. 
    • Send either by Royal Mail, HAYSDX or other Courier Services
    • Cryptosporidium positive stools for typing may be batched prior to sending to us if this is more convenient for you. Please store faeces in a refrigerator 
    • Category 3 organisms: Requests for work on samples also known to contain organisms in ACDP Hazard Group 3 must be clearly marked.


    Stool testing service is free of charge to all NHS Trust, UKHSA and Public Health Wales laboratories in England and Wales, to whom Cryptosporidium positive control stools for microscopy and enzyme immunoassays can be supplied on request,

    Charges for investigations for other purposes are reviewed annually and can be supplied on request.