B. burgdorferi investigations at the NVRL

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An audit was performed at The National Virus Reference Laboratory (NVRL) on the serological investigation of suspected Borrelia burgdorferi (B. burgdorferi) infection. The audit reviewed the performance of the B. burgdorferi IgM assays in comparison with the B. burgdorferi IgG and combined IgG/IgM assays. All samples in which there was serological evidence for recent B. burgdorferi infections were sent to the Lyme Borreliosis Unit, Southampton, UK for confirmation. A review of the reference results, the majority of which reported that there was no serological evidence for recent infection, strongly suggested that the use of the IgM assay for screening was not appropriate. In addition as many requests for “lyme disease” investigation provided minimal information relating to recent history of tick bite or any relevant clinical information it is probable that a number of investigations for B. burgdorferi were not justified. 

Current information indicates that the use of an IgG test only would identify recent infection more accurately. Therefore, it is proposed that the NVRL will only investigate B. burgdorferi infection using an IgG assay and will only test samples which are accompanied with relevant exposure and clinical history.  If, based upon the serological results, recent infection is suspected, a follow up sample will be requested and if necessary referred to the UK reference laboratory (Rare and Imported Pathogens Laboratory, HPA, Porton Down.

If you would like to discuss this further, please contact Dr. Jeff Connell on 716 1321 or 087 948 4008.

The Health Protection Surveillance Centre have issued Guidelines for the clinical management of patients with Lyme disease