Clinical, Microbiological Profile and Treatment Outcomes of Infants with BCG Adenitis: A Retrospective Study

Background: Bacille Calmette-Guérin (BCG) adenitis is an uncommon complication following BCG vaccination. In rare cases, infants can develop other complications. Controversy exists regarding the diagnosis and management of these cases. Not much information is available in literature regarding their microbiological and immunological characteristics.

Methods: Electronic medical records of children presenting to the Pediatric Infectious Diseases clinic in a tertiary care hospital from January 2011-December 2020 with a diagnosis of BCG adenitis were retrospectively reviewed. Their clinical, microbiological, treatment and follow-up data were noted and analyzed.

Findings: During the study period, 40 infants presented with a probable diagnosis of BCG adenitis with or without disseminated BCG. Median age at symptom onset was 4(2.5-5.9) months. Nine infants had disseminated disease at presentation. Fifteen infants were suspected to have underlying immune deficiency of whom 12 had proven defects in immune function. On multivariable logistic regression analysis, presence of disseminated disease was the only factor predictive of underlying immunodeficiency. Isoniazid monoresistance was seen in seven cases (32%) of the 22 samples sent for TB cultures.

Conclusions: Though BCG adenitis runs a benign course, it could rarely be the first manifestation of an underlying immune defect. There is sizable isoniazid monoresistance, hence sending tissue samples for microbiologic evaluation is necessary to guide anti-tubercular therapy.