Is persisting Bb infectious?

Cathy Rubin of the Huffington Post has interviewed Monica Embers about her team’s studies of Borrelia burgdorferi in rhesus macaque monkeys. This is a very good summary, with key references, of what we do and don’t know in this field. Monica Embers says:

“While we have shown that intact Borrelia spirochetes can persist following a standard duration of treatment following disseminated infection, we do not know if those spirochetes linger and cause disease or if they are eventually cleared.”

This uncertainty underpins one of the key questions raised by our James Lind Alliance PSP which documented the known uncertainties in diagnosis and treatment of Lyme disease:

  • Are continuing symptoms following conventional recommended treatment due to continued infection, an immune response or other process?

In some cases the answer is clear because a patient has an obvious relapse when ceasing antibiotics and a very clear recovery when starting again followed by an eventual complete recovery. This has been documented by a retrospective UK study Dillon et al 2010 which found “three patients had evidence of persistent infection after treatment and two required intravenous therapy”. There is also an individual record of a Cornish patient requiring several IV treatments.

So clearly part of the answer is “Yes, infection can persist beyond the first course of treatment” and this has been demonstrated in humans, not just monkeys. In the absence of a test which can detect this, we would suggest that as in any other disease doctors listen to their patients and make a clinical judgement.

That does still leave those cases with a less clear cut response to treatment and a less clear cut relapse. However, as the European guidelines for Neuroborreliosis state - “There are no class I comparisons of different treatment durations. In most European treatment studies, the duration ranged from 10 to 14 days and few studies for as long as 28 days.”

Which highlights of course the most important uncertainty in treatment uncovered by the JLA project:

  • What is the best treatment for children and adults presenting with a) early Lyme disease without neurological involvement and not including erythema migrans and b) late Lyme disease of any manifestation? To include consideration of drug(s), dose, duration?

A simple acknowledgement of this key uncertainty would undoubtedly improve patient care. Enrolling every UK patient treated for Lyme disease into a study with long term follow up, using patient based outcomes, would go a long way towards finding pragmatic answers to inform doctors’ and patients’ decisions.