Delayed diagnosis of tuberculosis in patients with human immunodeficiency virus infection

Abstract

purpose: To determine the frequency with which the diagnosis of tuberculosis is delayed in patients with concomitant human immunodeficiency virus (HIV) infection, and to identify reasons for such delays.

patients and methods: We reviewed medical records of 52 consecutive HIV-infected patients with culture-proven tuberculosis seen at a 1,900-bed general hospital serving a predominantly indigent population in Los Angeles, where the prevalences of HIV infection and tuberculosis are high. The late-treatment (LT) group consisted of 25 patients in whom tuberculosis was untreated prior to death (n = 6) or treated more than 22 days after presentation (n = 19). The early-treatment (ET) group comprised 27 patients in whom antituberculous therapy was begun less than 16 days after presentation.

results: Symptoms, physical and laboratory findings, chest roentgenographic abnormalities suggestive of tuberculosis (hilar adenopathy, pleural effusion, miliary pattern, cavitation, predominant upper lobe infiltrate), and frequencies of concomitant nontuberculous disease were similar in LT and ET groups. Delayed diagnosis of tuberculosis was attributable to errors in management in 21 (84%) of 25 LT group patients. The most common error was failure to obtain at least three sputum samples for acid-fast smear and mycobacterial culture in patients with clinical and chest roentgenographic findings compatible with tuberculosis (15 cases). Acid-fast sputum smears were positive in 25 (61%) of 41 cases of pulmonary tuberculosis. Acid-fast smears of stool were positive in eight (42%) of 19 cases. Blood cultures yielded Mycobacterium tuberculosis in 18 (38%) of 48 cases.

conclusions: Delayed therapy of tuberculosis in HIV-infected patients at our medical center was common and was not due to atypical manifestations of tuberculosis. In most cases, delays could have been avoided if adequate numbers of sputum samples for acid-fast smear and mycobacterial culture had been obtained, and if empiric antituberculous therapy had been given to symptomatic patients in whom chest roentgenographic findings were suggestive of mycobacterial disease.