Re: Can you contract Lyme from a partner?
At this point the two confirmed ways of transmission are either through tickbite or in utero (mother to fetus). Both of these have been scientifically documented. Tick borne diseases can also be spread through blood transfusion of contaminated blood, which is why patients with active Lyme should not donate blood and patients who have ever had Babesiosis can never donate.
The reason for speculation on other forms of transmission, such as sexual, is because the causative organism, Borrelia burgdorferi, has been isolated in all bodily fluids including semen and breast milk. In a study, the offspring of Bb infected lactating mice were shown to be infected. Also, Bb is a spirochete, the same classification of organism as the one which causes syphillus, and the speculation goes that if syphyllis can be sexually transmitted then perhaps Lyme could too.
On the one hand there is to date no documented case of sexual transmission. However, many of us have seen case after case after case in which both partners in a relationship are infected. There are a number of people who believe they passed it to their partners. Some would say that this could be because they spent time in the same tick infested areas, but there are some couples for whom this is not the case and yet still both are infected. There definitely needs to be more research on this.