Background: The Bacillus Calmette-Guérin (BCG) preparations are live-attenuated derivatives of Mycobacterium bovis. These products are used to vaccinate infants at birth, a practice that may result in a disseminated infection in those patients who have an unidentified immunodeficiency.
Case presentation: Patients who were immunized at birth with BCG and who developed a disseminated infection are reported here to emphasize the importance of taking an extensive medical history before giving the BCG vaccine. Patient 1 has a sibling who had familial hemophagocytic lymphohistiocytosis. Patient 2 has a severe immunodeficiency with profound lymphopenia. Patient 3 has a sibling who had a disseminated BCG infection. Patient 4 has two siblings with an immunodeficiency disorder; one sibling passed away in infancy and one is receiving regular immunoglobulin infusions. Patient 5 has profound lymphopenia and his brother had cytomegalovirus (CMV) pneumonitis and passed away in infancy.
Conclusions: These unfortunate events could have been avoided by compiling the relevant clinical and laboratory information. These cases also underscore the importance of a strict adherence to the BCG vaccine policies. Local and international registries that estimate the birth prevalence of primary immune deficiencies are needed prior to implementing universal BCG vaccination administration.
Keywords: BCG; Danish-SSI 1331 strain; Immunodeficiency; Mycobacterium bovis; Newborns; Tuberculosis; Vaccines.