The diagnosis of childhood tuberculosis in an HIV-endemic setting and the use of induced sputum.

SETTING: A hospital in the capital city of Uganda. OBJECTIVES: To determine the proportion of positive induced sputum cultures among probable childhood tuberculosis (TB) cases, to describe the laboratory and radiological features of childhood TB in the context of human immunodeficiency virus (HIV), and to determine the prevalence of HIV infection in these patients. DESIGN: Cross-sectional descriptive study. METHOD: Seven hundred and fifty children with suspected TB were evaluated clinically, by chest radiography and by tuberculin test (Mantoux). Probable cases underwent sputum induction or lymph node biopsy, HIV testing and RNA-PCR tests. RESULTS AND CONCLUSION: The Mantoux test was positive in 55/121 (45%) of the patients; low sensitivity to Mantoux was associated with HIV infection (P = 0.000). Induced sputum yielded 12/101 (12%) positive smears of Mycobacterium tuberculosis and 30/101 (30%) positive cultures. Six of the eight lymph node biopsies were culture-positive, and the histology of seven samples was supportive of TB. Most of the children with probable and confirmed TB presented with similar signs, symptoms and chest radiography patterns, irrespective of HIV status. Elevated ESR had no significant role in the diagnosis of TB in children and even more so in the presence of HIV infection. The HIV infection rate was high among children with TB (49%).

The effect of bacille Calmette-Guérin vaccination at birth on tuberculin skin test reactivity in Ugandan children.

SETTING: In Uganda, bacille-Calmette Guerin (BCG) vaccination coverage at birth is between 82 and 84%. OBJECTIVE: To evaluate the effect of neonatal BCG vaccination on tuberculin skin test positivity in Ugandan children exposed to infectious cases. DESIGN: As part of an ongoing prevalence study of household contacts of new tuberculosis cases, 365 children were evaluated to determine if BCG vaccination at birth had an impact on tuberculin skin testing. The children were classified as contacts (179) and non-contacts (186) depending on the presence of a sputum acid-fast bacilli (AFB) smear-positive adult tuberculosis case in the household. RESULTS: Regardless of prior BCG vaccination, children exposed to a smear-positive adult were more likely to have a positive skin test (purified protein derivative >5mm) (68% versus 36%, P < 0.01). BCG-vaccinated children below 1 year of age without a known household contact with active tuberculosis had a lower frequency of tuberculin skin reactions (29%) compared to their counterparts in the contact households (65%, P = 0.031). CONCLUSION: BCG vaccination at birth had no important effect on the interpretation of the tuberculin skin test reactivity in this group of Ugandan children. The tuberculin skin test remains a valuable tool for the evaluation of household contacts and suspected cases of tuberculosis in BCG-vaccinated children.

Human immunodeficiency virus type 1 activation after blood transfusion.

BACKGROUND: Anemia and transfusion are predictors of disease progression in AIDS patients. This study was designed to examine the effects of blood transfusion on human immunodeficiency virus type 1 (HIV-1) expression. STUDY DESIGN AND METHODS: Assays of plasma viral load were performed before and after transfusion in nine HIV-1-infected patients who required blood transfusion for refractory anemia. RESULTS: There was a modest rise in plasma HIV-1 p24 antigen and plasma HIV-1 RNA beginning 1 to 2 weeks after the blood transfusion. The mean change in plasma p24 antigen for all patients was 9.3 +/- 5.1 (mean +/- SE) pg per mL at Week 2 after transfusion and 18 +/- 11.1 pg per mL at Week 4. Plasma HIV-1 RNA levels were unchanged immediately after transfusion and exceeded pretransfusion levels with a mean rise of 84 +/- 40 percent (SE) at Week 1, 70 +/- 27 percent at Week 2, and 67 +/- 38 percent at Week 4 (p = 0.006, exact permutation test). There was no increase in spontaneous or interleukin 2-induced lymphocyte proliferation or p24 antigen production by patients' lymphocytes that were examined immediately after blood transfusion. CONCLUSION: The transfusion of blood to persons with advanced HIV-1 infection modestly increases plasma levels of HIV-1. The activation of HIV-1 expression by transfusion may help to explain the accelerated course of HIV-1 disease in recipients of blood transfusion.