ABSTRACT
The epidemiologic characterization of leptospirosis in the United States has been limited by difficulties associated with both case detection and confirmation. In addition, leptospirosis was eliminated from the list of National Notifiable Diseases in 1995. From 1974 until the cessation of national surveillance, Hawaii consistently had the highest reported annual incidence rate in the United States. From 1974 through 1998, 752 leptospirosis cases were reported in the State of Hawaii. Of these, 353 had exposures within the state and were laboratory confirmed. The mean annual incidence rate was 1.29 per 100,000. Cases were predominately male. Rates were highest in rural areas. Occupational exposures diminished over time while recreational exposures increased. This series represents the first large U.S. leptospirosis surveillance report since 1979. With leptospirosis recently being identified as a re-emerging zoonosis, continued national surveillance and case reporting should be reconsidered.
Subject(s)
Disease Outbreaks , Leptospira/isolation & purification , Leptospirosis/epidemiology , Adult , Age Factors , Aged , Child , Child, Preschool , Disease Reservoirs , Female , Hawaii/epidemiology , Hawaii/ethnology , Humans , Incidence , Infant , Leptospirosis/blood , Leptospirosis/ethnology , Logistic Models , Male , Middle Aged , Multivariate Analysis , Occupational Exposure , Retrospective StudiesSubject(s)
Dog Diseases/diagnosis , Leptospira/classification , Leptospirosis/veterinary , Agglutination Tests/methods , Agglutination Tests/veterinary , Animals , Canada/epidemiology , Dog Diseases/epidemiology , Dog Diseases/microbiology , Dogs , Hawaii/epidemiology , Humans , Leptospira/pathogenicity , Leptospirosis/diagnosis , Leptospirosis/epidemiology , Prevalence , Sensitivity and Specificity , Serotyping , United States/epidemiology , ZoonosesABSTRACT
Leptospirosis is a major public health problem throughout the world. Clinical recognition of leptospirosis is challenging, and the definitive serologic diagnostic assay, the microscopic agglutination test, is time-consuming and difficult to conduct. Various serologic screening tests have been developed, but their performance among ill persons in the United States has not been established. Eight screening tests were compared using 379 serum samples obtained in 1998 and 1999 from a series of 236 patients (33 with confirmed infection). The median number of days between illness onset and specimen collection was 9. The overall sensitivity, by specimen, for each test was as follows: indirect hemagglutination assay (MRL Diagnostics, Cypress, Calif.), 29%; INDX Leptospira Dip-S-Tick (PanBio InDx, Inc., Baltimore, Md.), 52%; Biognost IgM IFA test (Bios GmbH Labordiagnostik, Gräfelfing, Germany), 40%; Biolisa IgM ELISA (Bios GmbH, Labordiagnostik), 48%; Leptospira IgM ELISA (PanBio Pty Ltd., Brisbane, Australia), 36%; SERION ELISA classic Leptospira (Institut Virion*Serion GmbH, Würzburg, Germany), 48%; LEPTO Dipstick(Organon-Teknika, Ltd., Amsterdam, The Netherlands), 34%; Biosave latex agglutination test (LATEX; Bios GmbH Labordiagnostik), 86%. Test specificity ranged from 85 to 100% among all tests except LATEX, for which the specificity was significantly lower, at 10%. Test sensitivity was particularly low (<25%) for all tests (except LATEX) on specimens collected during the first week of illness. This is the most comprehensive field trial of leptospirosis screening tests reported to date. The data indicate that immunoglobulin M detection tests have limited utility for diagnosing leptospirosis during the initial evaluation of patients seen in Hawaii, a time when important therapeutic decisions are made. Improved leptospirosis screening tests are needed.
