Characteristics of patients with disseminated Bacillus Calmette-Guérin infection: a retrospective study at Namazi Hospital, Southern Iran, from 1991 to 2022.

Bacillus Calmette-Guérin (BCG) vaccine has an acceptable safety record; however, the vaccination can be accompanied by a variety of complications including local and systemic ones. Disseminated BCG infection is one of these complications, i.e. associated with a higher rate of mortality. In the present study, we aimed to identify the demographic and clinical characteristics of these patients. In this retrospective study, patients with a diagnosis of disseminated BCG infection admitted to Namazi Hospital between January 1991 and January 2022 were included. Demographic, clinical, and paraclinical data of these patients were collected. Statistical Package for Social Sciences was used for data management and analysis. One hundred and eighteen patients with a documented diagnosis of disseminated BCG infection were included in the study. The age range was between 1 and 85 months; however, the majority of them were infants. Immunodeficiency was detected in more than half the patients (51.7%) with severe combined immunodeficiency on the top. Forty-three patients, 36.4%, did not survive the disease. The age of the patients and the status of their immune systems were significantly associated with their outcomes in the hospital course. Disseminated BCG infection may be the first manifestation of an underlying immunodeficiency. The study showed that the common presentations of this condition, such as fever, lymphadenopathy, and failure to thrive, can mimic those of many other pediatric diseases. Given its high mortality rate, affecting over a third of our study population, thorough history-taking and careful examination are essential to avoid missing the diagnosis.