Tuberculin skin reactivity after neonatal BCG vaccination in preterm infants in Minas Gerais, Brazil, 2001-2002

Abstract

The efficacy of BCG vaccination in preterm babies is unknown, and available data on conversion rates to tuberculin in this age group are scarce and controversial. This study assessed the tuberculin response in preterm infants after BCG vaccination. This randomized cohort study was carried out at the Neonatal Department, University Hospital, Federal University of Minas Gerais in Brazil during 2001 and 2002. The BCG vaccine was administered at birth to 65 full-term (control) and 40 preterm newborns. All of them were tested with 5 tuberculin units of purified protein derivative-S approximately 3 months after vaccination. A typical BCG scar was verified in 96.9% of the control group and in 90.0% of the preterm infants (P = 0.19). Indurations > 5 mm in diameter were recorded in 87.7% of the full-term and 67.5% of the preterm infants (P = 0.02). Indurations > 10 mm were recorded in 70.8% of the full-term and 42.5% of the preterm infants (P = 0.007). For indurations > 5 mm the upper and the lower limits of the 95% confidence interval for the difference between proportions were 8.5% to 31.8%, and for indurations > 10 mm these limits were 18.0% to 38.4%. No adverse reactions were observed in the study population. BCG vaccination could be recommended for preterm infants upon discharge from the neonatal unit to reduce morbidity and mortality in infants at risk for tuberculous infection, and to increase BCG vaccination coverage rates, especially in countries with high prevalence rates of tuberculosis.