# Scar among Bacillus Calmette-Guerin Vaccinated Children Presenting to an Immunisation Clinic at a Tertiary Hospital in Nepal: An Observational Study

## TL;DR

This study examines the prevalence of BCG vaccination scarring in children in Nepal and compares clinical characteristics between those with and without scars.

## Contribution

The study provides updated prevalence data on BCG scar formation in a Nepalese population and identifies factors related to scar failure.

## Key findings

- The prevalence of BCG scar formation was 88.34% among 386 children.
- Scar size had a median of 4mm transversely and 3mm vertically.
- Scar failure rates were comparable to those reported in other studies.

## Abstract

Bacillus Calmette-Guerin vaccination is associated with the development of scarring at the vaccination site in most children within 12 weeks of vaccination. However, due to various factors, some children do not develop scars. The aim of the study was to determine the prevalence of scar failure and the differences in clinical characteristics between scar-positive and scar-negative children.

This observational cross-section study was conducted between 12 September 2022 and 15 April 2024 on children attending a vaccination clinic at a tertiary care hospital for 12 or 15-month vaccination. A purposive sampling method was used, and 386 children were enrolled in the study. During medical history, information was collected on Bacillus Clamettte-Guerin vaccination, child and maternal clinical profiles, and hospitalisations for respiratory tract infections in children.

Among 386 infants, prevalence of BCG scar was 341 (88.34%; 95% CI: 91.81 %-91.37%). Vaccination was confirmed in 94.82% by history and card. The median scar size was 4mm (IQR: 2,5 mm) transversely and 3 mm (IQR: 2,5) vertically. Thirty-two (8.30%) infants required hospital admission for respiratory infections; none received anti-tubercular treatment.

The BCG scar formation was higher compare to the scar failure. The scar failure was comparable to other studies.