Dueling Topicals

On Sept. 16, I posted some information about a recent paper on the use of topically antibiotics to prevent borreliosis in mice.  The authors concluded “that topical treatment with a formulation containing azithromycin is a promising approach to prevent Lyme borreliosis shortly after a tick bite.”

Now along comes a similar murine study with the oppose conclusion about the effectiveness of topical antibiotics. 

J Infect Dis. 2011 Sep 19. Failure of Topical Antibiotics to Prevent Disseminated Borrelia burgdorferi Infection Following a Tick Bite in C3H/HeJ Mice. Wormser GP, Daniels TJ, Bittker S, Cooper D, Wang G, Pavia CS.

A prior study in mice has shown that the timely application of topical antibiotics to the skin at the tick bite site could eradicate Borrelia burgdorferi infection.  That study, however, did not evaluate antibiotic preparations that are considered suitable for use in humans. In this murine study, topical application of 2% erythromycin and 3% tetracycline preparations that are acceptable for use in humans was found to be ineffective in eliminating B. burgdorferi from the tick bite site or in preventing dissemination to other tissues.  Reasons for the discrepant findings are discussed.

Well, as Einstein supposedly said, “If we knew what we were doing it wouldn’t be called research.”