is rare in infants, the proportion of TB patients presenting with disseminated disease is still
higher than in any other age group. In a series from South Africa, miliary TB accounted for 8%
of hospital admissions for TB in children compared with 1% in adults. More than 50% of such
cases occurred in children under the age of one year (7).
Reports from the early 1970s indicated a progressive shift of the epidemiology to adult
populations (8,9). In an autopsy study conducted at a hospital in Northern Ireland, 54% of
patients diagnosed with miliary TB between 1946 and 1949 were less than 20 years of age; in a
latter era (1966–1969), all patients with miliary TB were aged over 30 years (8). The widespread
use of BCG vaccination has resulted in substantial reductions in miliary TB among young
vaccines. The increasing uses of modern radiologic and invasive diagnostic methods have also
contributed to the demographic shift. While infants remain at high risk for the development of
miliary TB, the majority of cases now occur in adults. In accordance with the current
population distribution of TB and the growing population of older adults presenting with age-
related waning or iatrogenic impairment of cellular immunity, the elderly have now become
the most common group to develop miliary disease (2,10). In a study from Scotland, the mean
age of patients with miliary TB was 59.3 years during 1954–1967 but was 73.5 years during
1984–1992 (10). The HIV/AIDS pandemic and an increasing number of patients with iatrogenic
impairments of cellular immunity have led to an additional peak of miliary TB among younger
adults, resulting in a biphasic epidemiologic curve.
Figure 1 Millet seeds.
Table 1 Underlying Medical Conditions
Concurrent childhood infections (measles, tonsillitis)
Malnutrition
HIV/AIDS
Gastrectomy
Alcohol abuse
Malignancy
Corticosteroids or other iatrogenic immunosuppression
Connective tissue disorders (with or without iatrogenic immunosuppression)
End-stage renal disease
Diabetes
Solid organ or bone marrow transplantation
Silicosis
Pregnancy
Miliary Tuberculosis in Critical Care 421