Sudden Unexpected Infant Death Due to Postvaccinal Disseminated Bacillus Calmette–Guérin Disease: A Case Report with Literature Review

The objective of this study was to present a rare fatal case of sudden unexpected infant death caused by post-vaccinal disseminated Bacillus Calmette–Guérin (BCG) disease and to perform a comprehensive global literature review highlighting clinical, autoptic, forensic, and public health perspectives. A medico-legal autopsy, toxicological screening, and histopathological examinations were conducted on a 5-month-old male infant who died suddenly at home. A structured literature search was performed across PubMed and Google Scholar (1980–2024) to identify published cases of disseminated BCG disease following neonatal vaccination. Postmortem examination revealed a hypotrophic infant with a localized papulonodular neck eruption, a prominent left axillary mass, and multiple necrotic axillary lymphadenopathies associated with hepatosplenomegaly. Histopathology confirmed granulomatous necrotizing lymphadenitis and granulomatous hepatitis consistent with disseminated BCG infection. The literature review yielded 19 representative studies, summarizing global clinical features, diagnostic methods, underlying immunological defects, and high mortality rates. This case highlights the need for awareness of severe but rare complications of BCG vaccination even without a known family history of immunodeficiency disorders.