Sexual transmission of Borrelia garinii by male Ixodes persulcatus ticks (Acari, Ixodidae)

We investigated the transmission of Borrelia garinii and Borrelia afzelii b etween male and female Ixodes persulcatus ticks. For this purpose the infec tion rate of partners from tick couples was determined by polymerase chain reaction and reverse line blot. In couples, where the male tick was infecte d with B. garinii, four out of nine female partners carried B. garinii. In eight couples, male ticks had a dual infection of B. afzelii and B. garinii and three female partners were infected by Borrelia spirochetes. Two femal e ticks carried B. garinii, and one female tick had a dual infection. No ev idence for transmission of B. afzelii from male to female ticks was found a mong seven couples. In 45 couples where the female tick was infected, not o ne male tick carried spirochetes. The difference in the B. garinii infectio n rate between male and female ticks among these couples is highly signific ant. Our data suggest that transmission of B. garinii from male ticks to fe male ticks does occur. Sexual transmission of this pathogen may play an imp ortant role in the maintenance of B. garinii in I. persulcatus. Exp Appl Ac arol 23: 165-169 (C) 1999 Kluwer Academic Publishers.