"Lyme borreliosis: a review of data on transmission time
after tick attachment."
Cook MJ.
/International Journal of General Medicine/. 2014 Dec
19;8:1-8. eCollection 2015.
dx.doi.org/10.2147/IJGM.S73791 "...It is frequently stated that the risk of infection is very low if the tick is removed within 24-48 hours, with some claims that there is no risk if an attached tick is removed within 24 hours or 48 hours.
A literature review has determined that in animal models, transmission can occur in <16 hours, and the minimum
attachment time for transmission of infection has never been
established. Mechanisms for early transmission of spirochetes have been proposed based on their presence in different organs of the tick. Studies have found systemic infection and the presence of spirochetes in the tick salivary glands prior to feeding, which could result in cases of rapid transmission. Also, there is evidence that
spirochete transmission times and virulence depend upon the
tick and /Borrelia/ species.
These factors support anecdotal evidence that Borrelia infection can occur in humans within a short time after tick attachment."