Prevalence of BCG scar among BCG-vaccinated children in a southern Nigeria tertiary hospital

Abstract

Background: The burden of tuberculosis is high in Nigeria as in other developing countries. The administration of BCG vaccine to neonates is essential in the control of tuberculosis. A scar usually develops 6 – 8 weeks later at the site of vaccination, which can be used clinically as a proof of vaccination. Not all vaccinated infants however, develop a BCG scar. Objectives: To determine the prevalence of scar formation postvaccination and to unravel, if present, any factors responsible for scar failure. Methods: Two hundred and fourteen children were consecutively recruited from those who presented for immunization in the University of Benin Teaching Hospital, Benin. The bio-data and other relevant information were obtained using a proforma. The anthropometric measurements of the children were obtained and the children were examined for presence of a BCG scar. Results: Two hundred and six subjects (96.3%) had a postvaccination BCG scar. About 72% of the subjects were vaccinated within the first week of life. The age at vaccination was significantly affected by gestational maturation (P=0.003) and birth weight (P=0.0001). Gestational maturation is a strong predictor of BCG scar formation postvaccination (P = 0.007) Conclusion: There is high prevalence of BCG scar formation in this study and gestational maturation is a strong predictor of BCG scar formation.