Lyme Disease in Urban Areas, Chicago

sson B. Cloning of a human parvovirus by molecular screening of respiratory tract samples.tinct patterns of evolution between respiratory syncytial virus subgroups A and B from New Zealand isolates collected over thirty-seven years. 1-year experience with human metapneu-movirus in children aged <5 years. subtyping of infl uenza viruses and respiratory syncytial viruses by multiplex RT– PCR. Detection of human bocavirus in Japanese children with lower respiratory tract infections.man bocavirus infection in young children in the United States: molecular epidemiological profi le and clinical characteristics of a newly emerging respiratory virus. To the Editor: Lyme disease is a multisystem illness caused by infection with the tickborne spirochete Bor-relia burgdorferi. Most infections in the United States occur in the Northeast and upper Midwest, and the mid-western focus now includes Illinois (1,2). Previously, the greatest risk of contracting Lyme disease in the Mid-west was confi ned to the northernmost states (Wisconsin and Minnesota) and did not encroach into heavily populated areas around the city of Chicago. However, we showed recently that B. burgdorferi–infected Ixodes scapular-is ticks were recovered from sites in Cook and DuPage counties (3), but the percentages of infected ticks were low (<5%). Since that time, however, reports of Lyme disease in Cook County have been reviewed and individual I. scapularis tick submissions from Lake County, north of Chicago, have been received. We therefore surveyed new areas north of Chicago (closest was <1 mile from the city limits; farthest was ≈25 miles from the city limits) and examined additional ticks for infection with B. burgdorferi. we collected 172 adult I. scapu-laris ticks from sites to the north and northwest of Chicago (Figure). Adult ticks were collected because nymph-al ticks are more diffi cult to obtain, and the infection rate in adult ticks is similar (1). The tick midguts were removed aseptically, inoculated into tubes containing 1 mL of modifi ed Barbour-Stoenner-Kelly medium (4), incubated at 35ºC, and examined for spirochetes for up to 3 weeks. Spiro-chetes were recovered from 21 (32%) of 65 ticks and 40 (37%) of 107 ticks collected from sites in Cook and Lake counties, respectively. In addition, PCR using primers specifi c for outer surface protein A (5) confi rmed that the spirochetes were B. burgdorferi.