Discontinuation of complement fixation testing for Mycoplasma, Chlamydia and Coxiella from February 1st 2011.

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Commencing February 1st 2011, the NVRL will no longer perform complement fixation tests (CFT) for the diagnosis of the above bacterial infections (PCR for C.trachomatis will continue as normal ). There are a number of reasons for this decision. Over the past 6 months, the NVRL – in conjunction with laboratories in the UK – has been unable to obtain control antigens for Chlamydia for use in the CFT assay due to a manufacturing problem. Unfortunately, no alternative source of antigen is available. This issue is unlikely to be resolved imminently, and as there has been limited demand for testing in CFTs absence, the NVRL cannot justify retaining this test in the current financial climate.

In relation to Mycoplasma testing, the NVRL has completed a review of CFT versus IgM EIA for the past 12 month period. This review revealed that the overall demand for Mycoplasma CFT was low, and that CFT provided minimal additional diagnostic value to Mycoplasma specific IgM testing. As a consequence, CFT testing will be discontinued, and the NVRL will move to introduce Mycoplasma specific IgG testing in addition to retaining the current IgM assay. (Please read UPDATE FEB 2011)

Finally, the demand for Coxiella burnettii testing in conjunction with the very low number of significant results means the retention of CFT cannot be justified on the basis of this pathogen alone. Therefore, we are recommending that future samples be sent directly from your laboratory to the UK HPA for Coxiella testing

  • Bristol Regional HPA Laboratory (Coxiella Serology), Department of Microbiology, Myrtle Road, Kingsdown, Bristol BS2 8EL

While we appreciate this change in practice may cause some initial mild disruption, we believe it will result in shorter turn-around times, more efficient use of available resources, and therefore an overall improvement in patient care. If you have any questions regarding this change in policy, please do not hesitate to contact the staff in the NVRL. Note of Clarification: Please note, the above notification relates to Chlamydia pneumoniae testing as part of the Atypical Pneumonia screen on blood specimens and does not affect the Chlamydia trachomatis test performed on urines/swabs as part of the STI screen.