Tuberculosis and the HIV pandemic. Risk of nosocomial tuberculosis infection
Pedersen, C.; Kolmos, H.J.; Nielsen, J.O.
Ugeskrift for Laeger 159(9): 1233-1238
1997
ISSN/ISBN: 0041-5782 PMID: 9072866 Document Number: 268052
Approximately 4 million people are infected with tuberculosis (TB) in the world, of whom 3.5 million live in sub-Saharan Africa. The incidence of HIV infection among TB patients in several African countries ranges from 20% to 60%. During 1989-92 both American and European major cities reported an increasing number of TB cases among younger people. Studies from New York and San Francisco also revealed that 40% and 30% of newly registered TB cases, respectively, were attributed to new infections rather than the reactivation of latent infection. A study of 6546 patients diagnosed with AIDS during 1979-89 in Europe also found that 14% of them had TB at some time during the course of the disease, mainly in southern Europe and among drug users. Multidrug-resistant Mycobacterium tuberculosis (MDRTB), which is resistant to isoniazid and rifampicin, increased in the US from 0.5% to 3.5% during 1982-91, with 19% of all MTB isolates reported to be MDRTB in New York in April 1991. Among patients not treated earlier, the multidrug-resistant isolates were more frequent among HIV-positive than HIV-negative patients (16% vs. 3%). During 1990-92 there was also a number of nosocomial TB cases reported in the US. The outbreak affected about 200 patients, most of them HIV-positive, and the mortality rate was high (72-89%). In the US, at least 20 health care workers were infected with MDRTB, and 9 (7 of which HIV-positive) died. In a Michigan substance-abuse facility an AIDS patient with MDRTB transmitted the illness to 15 (21%) of 70 health care workers during a 5-week hospitalization. In a Florida hospital, 36% of health care workers were infected during a 2-year period in a unit with HIV-positive patients, whereas none were infected in a thoracic surgery division. The prevention of MDRTB transmission was accomplished by isolating the patients with MDRTB as well as by rapid diagnosis and treatment.