Miliary tuberculosis: epidemiology, clinical manifestations, diagnosis, and outcome

During the early 1970s, attention was called to the changing demographics and poor prognosis of patients with miliary tuberculosis. Thirty-eight non-AIDS patients with miliary tuberculosis seen since 1975 are reviewed. Their average age was 60 years. Two-thirds of the patients had comorbid conditions. Presenting symptoms were nonspecific; fever, anorexia, sweats, and weight loss were the most frequent. Fever, tachypnea, rales, and altered mental status were the most commonly associated signs. Chest radiographs often showed miliary disease, but the remainder of the laboratory abnormalities were nonspecific. Seventy-six percent of sputum cultures, 75% of gastric aspirate cultures, 59% of urine cultures, and 54% of bronchial washings were positive for Mycobacterium tuberculosis. Biopsy specimens, including those obtained by transbronchial biopsy, were frequently abnormal histologically but were rarely culture-positive. Mortality attributable to miliary tuberculosis was 21%. Risk factors for death included female sex and altered mental status. No patient treated initially with a regimen that included streptomycin died whereas 21% of those treated with other regimens died. These data confirm and extend the results of earlier studies and suggest that miliary tuberculosis is a disease of the elderly and immunocompromised and is associated with significant morbidity and mortality. A high index of suspicion and diagnostic persistence are required for diagnosis.