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Persons using assistive technology might not be able to fully access information in this file. For assistance, please send e-mail to: mmwrq@cdc.gov. Type 508 Accommodation and the title of the report in the subject line of e-mail. Epidemiologic Notes and Reports Expanded Tuberculosis Surveillance and Tuberculosis Morbidity -- United States, 1993Because of the resurgence of tuberculosis (TB) in the United States, in 1987 the Advisory Committee for the Elimination of Tuberculosis recommended the strengthening of TB surveillance to improve monitoring and to assist in targeting groups at risk for disease (1). In addition, because of outbreaks of nosocomial multidrug-resistant TB (MDR-TB) in New York and Florida during 1990-1992 (2), in 1992, the National MDR TB Task Force recommended that drug-susceptibility testing be performed on all initial and final Mycobacterium tuberculosis isolates from each TB patient and that the results be reported to CDC (3). In January 1993, in conjunction with state and local health departments, CDC implemented an expanded surveillance system for TB. This report summarizes final TB surveillance data for 1993, compares findings with previous years, and provides information on expanded surveillance. In November 1992, following approval of the Report of a Verified Case of TB (RVCT) form for reporting TB cases to CDC, TB programs in state and local health departments were asked to use the new surveillance form beginning January 1993. In July 1993, a new computer software package (SURVS-TB) was distributed for data entry, analysis, and transfer of records to CDC. Additional elements of the RVCT included results for human immunodeficiency virus (HIV) testing, occupation, history of substance abuse, homelessness, and residence in a correctional or long-term-care facility. To evaluate the outcomes of antituberculous therapy, information was collected about initial therapy, type of health-care provider, sputum culture conversion, and use of directly observed therapy (DOT). In 1993, 25,313 cases of TB (9.8 cases per 100,000 population) were reported to CDC from the 50 states, the District of Columbia, and New York City (Figure_1), a 5.1% decrease from 1992 (26,673 {10.5 cases per 100,000}) (4) but a 14% increase over 1985 (22,201) (the year with the lowest number of TB cases since national reporting began in 1953). During 1985-1993, there was an excess of approximately 64,000 reported cases, compared with the number predicted based on the trend of decline from 1980 through 1984. During 1993, 33 states reported fewer TB cases than in 1992; in comparison, during 1992, 27 states and the District of Columbia reported fewer cases than in 1991. The states reporting fewer cases in 1993 included those characterized by the greatest increases in cases since 1985 (California, New York, and Texas). Fifteen states and the District of Columbia reported increases in TB cases (Table_1). Compared with 1992, the number of reported TB cases decreased for all age groups except for persons aged less than 15 years. Decreases were greatest for persons aged 15-24 (6.6%) and 25-44 years (7.8%). Among persons aged less than 15 years, the number of cases increased 0.8%; of all cases, the proportion accounted for by persons in this group increased from 6.4% in 1992 to 6.8% in 1993. During 1993, persons born outside the United States and its territories (i.e., foreign-born) composed 29.6% of reported cases, compared with 27.4% in 1992. Selected characteristics were analyzed for cases in states where greater than or equal to 75% of records contained information requested for the first time in 1993 (Table_2). Among these persons, injecting-drug use was reported by 2.4%, noninjecting-drug use by 4.7%, excessive use of alcohol during the preceding 12 months by 13.0%, and homelessness by 5.3%. For patients aged 25-44 years, HIV test results were reported for 33%; 18 reporting areas reported HIV results for greater than or equal to 50% of cases. These 18 reporting areas accounted for 63% of cases in persons aged 25-44 years with HIV results. From January 1, 1993, through May 25, 1994, antibiotic-susceptibility results for M. tuberculosis isolates were reported for 10,941 (54%) of the 20,090 persons with culture-positive TB. For 26 reporting areas, drug-susceptibility results were available for greater than or equal to 75%; however, these areas included only two of the 12 states in which greater than or equal to 1% of cases had isoniazid and rifampin resistance in the previous national survey (5). Reported by: Div of Tuberculosis Elimination, National Center for Prevention Svcs, CDC. Editorial NoteEditorial Note: The findings in this report document a substantial decrease in the number of reported TB cases from 1992 to 1993 (5.1%; p less than 0.001 *), probably reflecting the effectiveness of prevention and control measures implemented during 1989-1993. However, a portion of this decrease may be due to two other factors, including 1) delayed reporting caused by use of the new TB surveillance reporting form and the change from paper records to a computerized system; and 2) underreporting because of modification of the acquired immunodeficiency syndrome (AIDS) surveillance case definition in January 1993 (6). Following the resurgence of TB in 1985 and the recognition of nosocomial outbreaks of MDR-TB in 1991 (2), the Public Health Service increased funding to state and local health departments for TB-prevention and TB-control activities, including DOT -- which has been shown to reduce TB case rates even in the presence of HIV infection -- and screening programs for persons at high risk for TB infection (7-9). In addition, some hospitals implemented recommendations to prevent nosocomial transmission of M. tuberculosis (10). These measures may account for a substantial proportion of the decrease in reported TB cases in 1993. Most states require that laboratories notify the health department about patients with cultures positive for M. tuberculosis; during 1993, 79% of all reported TB cases were culture-positive for M. tuberculosis. In response to the initial report, local health departments conduct investigations to verify the diagnosis of TB and to collect information needed for completion of reporting. The addition of information needed for the new TB surveillance form may have delayed investigation of suspected TB cases and completion of case reports in 1993. Ongoing analysis is assessing the impact of delayed reporting. The expansion of the TB surveillance system during 1993 coincided with the revision of the AIDS surveillance case definition. The revised AIDS case definition classifies as AIDS cases HIV-infection in persons who have either pulmonary TB or extrapulmonary TB (6). As a consequence, HIV-infected persons with pulmonary or extrapulmonary TB may have been reported to the AIDS surveillance program at the local or state health department but not to the TB program. This explanation may account for the apparent decrease in the number of reported TB cases in states characterized by a high incidence of AIDS (California, New York, and Texas) and in persons aged 15-24 and 25-44 years. In the states with the largest TB/AIDS co-morbidity (i.e., California and New York), laws to protect the confidentiality of persons with AIDS have been interpreted to prohibit the disclosure of patients' names to anyone outside the AIDS program, including other programs within the state health department. Information on the HIV status of persons with TB in 1993 is incomplete (missing/unknown for 67% of TB patients in the 25-44-year age group); thus, the impact of HIV on the TB epidemic in the United States can only be indirectly measured in 1993. Collaboration between TB and HIV/AIDS surveillance programs will be necessary to accurately measure the extent of overlap between the TB and HIV epidemics. Maintaining the current decline in TB morbidity and reaching the goal of eliminating TB in the United States will require sustaining prevention and control activities. In particular, health-care providers should attempt to identify all TB cases and report them to health departments and ensure that persons with active TB successfully complete treatment (e.g., DOT). In addition, TB skin-test screening programs that target persons at highest risk (e.g., contacts of persons with active cases) can ensure appropriate use of preventive therapy. References
* Statistical significance assessed by Chi Square test for
dispersion; statistical tests for differences in surveillance
data
must be interpreted in relation to epidemiologic and programmatic
considerations. TABLE 1. Reported tuberculosis cases, by reporting area -- United States, 1992-1993 ===================================================================================== No. reported cases ------------------ Reporting area 1992 1993 % Change -------------------------------------------------------- Areas with decreases Arizona 259 231 -10.8 Arkansas 257 209 -18.7 California 5382 5212 - 3.2 Colorado 104 102 - 1.9 Connecticut 156 155 - 0.6 Florida 1707 1655 - 3.0 Georgia 893 810 - 9.3 Hawaii 273 251 - 8.1 Idaho 26 12 -53.8 Illinois 1270 1242 - 2.2 Louisiana 373 367 - 1.6 Maryland 442 406 - 8.1 Massachusetts 428 370 -13.6 Michigan 495 480 - 3.0 Minnesota 165 141 -14.5 Mississippi 281 279 - 0.7 Nebraska 28 22 -21.4 Nevada 99 98 - 1.0 New Jersey 984 912 - 7.3 New Mexico 88 74 -15.9 New York 4574 3953 -13.6 North Carolina 604 594 - 1.7 North Dakota 11 7 -36.4 Ohio 358 315 -12.0 Oklahoma 216 209 - 3.2 Pennsylvania 758 746 - 1.6 South Dakota 32 16 -50.0 Texas 2510 2396 - 4.5 Utah 78 46 -41.0 Washington 306 286 - 6.5 West Virginia 92 75 -18.5 Wisconsin 106 100 - 5.7 Wyoming 8 7 -12.5 Areas with increases Alabama 418 487 +16.5 Delaware 55 66 +20.0 District of Columbia 146 161 +10.3 Indiana 247 248 + 0.4 Iowa 49 59 +20.4 Kansas 56 80 +42.9 Kentucky 402 405 + 0.7 Maine 24 27 +12.5 Missouri 245 257 + 4.9 Montana 16 22 +37.5 New Hampshire 18 26 +44.4 Oregon 145 154 + 6.2 Rhode Island 54 64 +18.5 South Carolina 387 401 + 3.6 Tennessee 527 556 + 5.5 Virginia 457 458 + 0.2 Areas with no change Alaska 57 57 0 Vermont 7 7 0 Total 26,673 25,313 -5.1 -------------------------------------------------------- ===================================================================================== Return to top. Table_2 Note: To print large tables and graphs users may have to change their printer settings to landscape and use a small font size. TABLE 2. Reported tuberculosis cases, by selected characteristic, number of cases with information about >=75% of cases, and percentage of cases with characteristics -- United States *, 1993 ========================================================================================================== No. areas with information % Cases Characteristic for >=75% of cases with characteristic + ----------------------------------------------------------------------------- Initial drug regimen 50 --- Isoniazid and rifampin --- 14.2 Isoniazid, rifampin, and pyrazinamide --- 39.9 Isoniazid, rifampin, pyrazinamide, and ethambutol or streptomycin --- 32.5 Other --- 13.4 Injecting-drug use 15 2.4 Noninjecting-drug use 15 4.7 Excessive alcohol use & 11 13.0 Homelessness 36 5.3 Residence Correctional institution 47 3.7 Long-term-care facility 45 4.5 Occupation 23 --- Health-care worker --- 3.2 Correctional employee --- 0.2 Migrant worker --- 0.8 Unemployed --- 68.2 Other --- 27.6 ----------------------------------------------------------------------------- * Comprises the 50 states, the District of Columbia, and New York City. + Comprises reporting areas with information on characteristics reported for >=75% of cases. & During preceding 12 months. ========================================================================================================== Return to top. Disclaimer All MMWR HTML versions of articles are electronic conversions from ASCII text into HTML. This conversion may have resulted in character translation or format errors in the HTML version. Users should not rely on this HTML document, but are referred to the electronic PDF version and/or the original MMWR paper copy for the official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices. **Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.Page converted: 09/19/98 |
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