borrelia burgdorferi in ticks of the canton tessin (switzerland). | in the northern alps it is hard to find an ixodes ricinus population which does not harbour borrelia burgdorferi. the infection rates range from 5 to 34% for adults and nymphs to 3.1% for larvae. this study shows that the infection rates on the southern side of the alps are similar, at 25% for adults, 36.2% for nymphs and 3.2% for larvae. with respect to tick species other than i. ricinus, we did not succeed in finding any spirochetes in dermacentor marginatus, haemaphysalis punctata, ixodes hex ... | 1990 | 2132440 |