Tick bites, prevention, and prophylaxis of Lyme disease – What diagnostic tests should be used following tick bite?, pages 19-20, lines 453-467: It states, “We recommend against testing for B. burgdorferi in an Ixodes tick following a bite”. While true that the presence of a pathogen does not reliably predict the likelihood of clinical infection, there still is valuable information to be gained by testing ticks. Primary care physicians, even in Lyme-endemic areas, are not always familiar with the tick species common to a given location or the pathogen(s) they may carry. The stated rationale for the recommendation not to test is that “Even in areas that are highly endemic for Lyme disease, patients presenting with an Ixodes tick bite have a low probability of developing Lyme disease…”. This statement is not referenced and is unsupported by the fact that in highly endemic areas, in the northeastern U.S. in particular, the carriage rate for B. burgdorferi can be 50% or greater and such high carriage rates correlate with a higher incidence of Lyme disease. Tick removal and sending it for testing is a relatively rare event and thus should not contribute significantly to unnecessary antibiotic prescriptions. A major benefit to tick testing is that if no pathogens are found, this information would put the patient’s mind at ease.  If instead, the tick tests positive for one or more pathogens, this will focus the physician’s and patient’s attention on what symptoms to look for and better inform a treatment strategy if such symptoms arise.

The guidelines also suggest that “Anticipatory guidance is recommended so that a prompt diagnosis of Lyme disease (as well as other Ixodes tick transmitted infections) can be made should a patient develop symptoms”. However, given the inadequate familiarity most physicians have regarding ticks and tick-borne agents in their area, let alone in an area(s) to which a patient may have traveled and been bitten, there is no basis for thinking such anticipatory guidance can be provided. It is hard to rationalize why the guidelines would advocate for physicians and patients to make decisions having less rather than more information in hand, especially when the benefits of a prophylactic single dose of Doxycycline are substantial and the risks negligible.