[Incidence of Borrelia burgdorferi sensu lato spirochetes in Ixodes ricinus ticks from a museum collection evaluated by PCR].

Ixodes ricinus ticks (total n = 51:14 larvae, 16 nymphs, 17 females and 11 males) collected at 21 different sites during 1948-1987 were examined individually for the presence of Borrelia burgdorferi sensu lato spirochaetes. Detection of spirochaetes was carried out by polymerase chain reaction (PCR) using primers complementary to chromosomal sequence. Borreliae were found in 3 (3.56%) examined ticks (nymphs) collected at the same site (two in June, 1952 and one in August, 1987). The low number of infected ticks found in this investigation do not reflects real infection rate in tick population.