Mayo Clinic Proceedings Home

Incidence of Tuberculosis in Olmsted County, Minnesota, 1990-2001


      To describe and compare the incidence and clinical characteristics of tuberculosis in Olmsted County, Minnesota, among US-born and foreign-born persons.


      We performed a retrospective cohort study at the Mayo Clinic in Rochester, Minn, of all residents of Olmsted County (2000 population 124,277) diagnosed as having tuberculosis between January 1, 1990, and December 31, 2001. Potential cases were identified with use of a computerized diagnostic coding database and microbiological laboratory data; all identified medical records were abstracted. Definite cases were those in which Mycobacterium tuberculosis was recovered in culture. Probable cases were those that met predefined clinical or radiographic evidence of tuberculosis and other criteria. Age-specific, sex-specific, and country of origin-specific incidence rates were calculated with use of Olmsted County census data. Variables were compared among risk groups using the Fisher exact test.


      During a 12-year period, 71 cases of tuberculosis (53 definite, 18 probable) were identified, for an incidence of 5.3 per 100,000 person-years. Of these cases, 54 (76%) occurred during the second half of the study (incidence 7.7 per 100,000 person-years). The incidence among US-born persons was similar throughout the study period; however, the incidence among foreign-born persons increased more than 3-fold during the second half of the study period. Twenty-five patients (35%) were former refugees. All isoniazid-resistant infections (12% of isolates) and multidrug-resistant infections (6% of isolates) occurred among foreign-born persons.


      The incidence of tuberculosis increased substantially in Olmsted County between 1990 and 2001, primarily because of an increase in the number of cases among foreign-born persons.


      CDC (Centers for Disease Control and Prevention), CI (confidence interval)
      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Mayo Clinic Proceedings
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


      1. World Health Report 2000: Health Systems: Improving Performance. World Health Organization, Geneva, Switzerland2000: 164
        • Centers for Disease Control and Prevention
        Tuberculosis morbidity among U.S.-born and foreign-born populations—United States, 2000.
        MMWR Morb Mortal Wkly Rep. 2002; 51: 101-104
        • Centers for Disease Control and Prevention
        Recommendations for prevention and control of tuberculosis among foreign-born persons: report of the Working Group on Tuberculosis among Foreign-Born Persons.
        MMWR Recomm Rep. 1998; 47: 1-29
        • McKenna MT
        • McCray E
        • Onorato I
        The epidemiology of tuberculosis among foreign-born persons in the United States, 1986 to 1993.
        N Engl J Med. 1995; 332: 1071-1076
        • Talbot EA
        • Moore M
        • McCray E
        • Binkin NJ
        Tuberculosis among foreign-born persons in the United States, 1993-1998.
        JAMA. 2000; 284: 2894-2900
        • Centers for Disease Control and Prevention
        Core Curriculum on Tuberculosis: What the Clinician Should Know. 3rd ed. US Dept of Health and Human Services, Division of Tuberculosis Elimination, Atlanta, Ga1994
        • Bergstralh EJ
        • Offord KP
        • Chu CP
        • Beard CM
        • O'Fallon WM
        • Melton III, LJ
        Calculating Incidence, Prevalence and Mortality Rates for Olmsted County, Minnesota: An Update. Section of Biostatistics, Mayo Clinic, Rochester, Minn1992 (Technical Report Series, No. 49.)
        • Ronningen BJ
        Immigrants in Minnesota: an increasingly diverse population.
        (Accessibility verified July 16, 2004.)
        • Bloch AB
        • Cauthen GM
        • Onorato IM
        • et al.
        Nationwide survey of drug-resistant tuberculosis in the United States.
        JAMA. 1994; 271: 665-671
        • Minnesota Department of Health Tuberculosis Prevention and Control Program
        The Epidemiology of Tuberculosis Among Foreign-Born Persons in Minnesota, 1999-2003.
        (Accessibility verified August 10, 2004.)

      Linked Article