Transmission of Mycobacterium tuberculosis from tuberculosis patients with HIV infection or AIDS.

Contacts exposed to tuberculosis patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus (HIV) infection were compared with contacts of HIV-negative patients for evidence of Mycobacterium tuberculosis transmission, based on a review of records of tuberculin skin tests administered during routine health department follow-up investigations in Miami/Dade County, Florida, from 1985 through 1989. After an adjusted analysis designed to balance background prevalence, tuberculin positivity was 42.0% in 2,158 contacts of HIV-negative patients compared with 28.6% and 31.3% in 363 contacts of HIV-infected patients and 732 contacts of AIDS patients, respectively. Similar results were observed in a subset of 5- to 14-year-old contacts of United States-born black or white tuberculosis patients chosen to minimize the possibility of false-negative tuberculin tests in contacts due to undiagnosed HIV infection. Analysis of contacts as sets showed a more than expected number of sets with none or all contacts infected, but this did not differ by HIV/AIDS group. In this study, tuberculosis patients with AIDS or HIV infection were less infectious to their contacts and, in this community, exposed fewer contacts than HIV-negative tuberculosis patients.

Transmission of multidrug-resistant Mycobacterium tuberculosis during a long airplane flight.

BACKGROUND: In April 1994, a passenger with infectious multi-drug resistant tuberculosis traveled on commercial-airline flights from Honolulu to Chicago and from Chicago to Baltimore and returned one month later. We sought to determine whether she had infected any of her contacts on this extensive trip. METHODS: Passengers and crew were identified from airline records and were notified of their exposure, asked to complete a questionnaire, and screened by tuberculin skin tests. RESULTS: Of the 925 people on the airplanes, 802 (86.7 percent) responded. All 11 contacts with positive tuberculin skin tests who were on the April flights and 2 of 3 contacts with positive tests who were on the Baltimore-to-Chicago flight in May had other risk factors for tuberculosis. More contacts on the final, 8.75-hour flight from Chicago to Honolulu had positive skin tests than those on the other three flights (6 percent, as compared with 2.3, 3.8, and 2.8 percent). Of 15 contacts with positive tests on the May flight from Chicago to Honolulu, 6 (4 with skin-test conversion) had no other risk factors; all 6 had sat in the same section of the plane as the index patient (P=0.001). Passengers seated within two rows of the index patient were more likely to have positive tuberculin skin tests than those in the rest of the section (4 of 13, or 30.8 percent, vs. 2 of 55, or 3.6 percent; rate ratio, 8.5; 95 percent confidence interval, 1.7 to 41.3; P=0.01). CONCLUSIONS: The transmission of Mycobacterium tuberculosis that we describe aboard a commercial aircraft involved a highly infectious passenger, a long flight, and close proximity of contacts to the index patient.

The need for epidemic intelligence.

The past decade has witnessed an unprecedented upturn in tuberculosis morbidity and outbreaks of difficult- to-treat and highly lethal multidrug-resistant tuberculosis. In the early 1990s, a national consensus developed among public health officials to define more comprehensively the problem, and in January 1993, expanded tuberculosis surveillance was implemented nationwide. Carefully selected epidemiologic and case management variables were added to the Report of Verified Case of Tuberculosis form. Information is collected on the health status and treatment of patients, including human immunodeficiency virus status, drug susceptibility test results, and the initial drug regimen. Completion of therapy and use of directly observed therapy are also monitored. The new surveillance system allows a comparison of the quality of care of patients in the public and private sectors. Additional epidemiologic variables include membership in high-risk groups (the homeless, residents of correctional or long-term care facilities, migrant workers, health care workers, and correctional employees) and substance abuse (injecting drug use, non-injecting drug use, and excess alcohol use). The additional information derived from expanded tuberculosis surveillance is crucial to optimal patient management, policy development, resource allocation, as well as program planning, implementation, and evaluation at Federal, State, and local levels.