Human leptospirosis cases and the prevalence of rats harbouring Leptospira interrogans in urban areas of Tokyo, Japan
Nobuo Koizumi1, Maki Muto1, Tsutomu Tanikawa2, Hiroshi Mizutani3,{dagger}, Yoshiko Sohmura3, Eiji Hayashi4,{ddagger}, Nobuaki Akao4, Mayu Hoshino1,§, Hiroki Kawabata1 and Haruo Watanabe5
1 Department of Bacteriology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
2 Ikari Corporation, 579 Chibadera, Chuo-ku, Chiba 260-0844, Japan
3 Tokyo Metropolitan Animal Care and Consultation Center, 3-2-1 Jonanjima, Ohta-ku, Tokyo 143-0002, Japan
4 Section of Environmental Parasitology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
5 National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
Correspondence
Nobuo Koizumi
nkoizumi{at}nih.go.jp
Received April 1, 2009
Accepted May 28, 2009
Thirteen patients with leptospirosis were identified, as confirmed by laboratory analysis during the last 5 years in our laboratory, who came from urban areas of Tokyo, Japan. All of the patients came into contact with rats before the onset of illness. Seventeen per cent of Norway rats captured in the inner cities of Tokyo carried leptospires in their kidneys. Most of these rat isolates were Leptospira interrogans serovar Copenhageni/Icterohaemorrhagiae. Antibodies against these serovars and their DNA were detected in the patients. This suggests that rats are important reservoirs of leptospirosis, and that rat-borne leptospires occur in urban areas of Tokyo.
{dagger}Present address: Tokyo Metropolitan Shibaura Meat Sanitary Inspection Station, 2-7-19 Konan, Minato-ku, Tokyo 108-0075, Japan.
{ddagger}Present address: Togane Hospital, 1229 Daikata, Togane, Chiba 283-8588, Japan.
§Present address: Horticultural Institute, Ibaraki Agricultural Center, 3165-1 Ago, Kasama, Ibaraki 3165-1, Japan.
The GenBank/EMBL/DDBJ accession numbers for the flaB sequences of rat isolates and patient samples are AB454100–AB454125.
A table of detection test data and a figure of PFGE results are available as supplementary data with the online version of this paper.