The incidence rate of lymphadenitis after Bacille Calmette-Guérin (BCG) vaccination

Purpose: Bacille Calmette-Guérin (BCG) lymphadenitis is a relatively frequent local adverse reactions after BCG vaccination. Its incidence rate is usually <1%. However, this rate may be different according to BCG strain, vaccination method or skill, etc. In the Republic of Korea, two BCG strains are used: intradermal Danish-1331 or percutaneous Tokyo-172. We surveyed the incidence rates of BCG lymphadenitis. Methods: This survey was performed in total 25 centers (5 general hospitals, 20 private pediatric clinics). Immunized type of BCG strain in study subjects was verified by directly observing the scar. The occurrence of BCG lymphadenitis was asked to their parent. In cases of BCG lymphadenitis, location, diameter size, progression of suppuration, and treatment method were investigated, as well. Results: The total number of study subjects was 3,342. Among these, the subjects suitable for enrollment criteria (total 3,222; Tokyo strain 2,501, Danish strain 721) were analyzed. BCG lymphadenitis regardless of its size developed in each five of subjects per strains, therefore, its incidence rate was 0.20% in Tokyo and 0.69% in Danish strain, respectively (P =0.086). However, when applying the WHO criteria - the development of lymph node swelling with diameter 1.5 cm or more, the incidence rate of BCG lymphadenitis was 0.16% (4 cases) in Tokyo and 0.42% (3 cases) in Danish strain, respectively. Conclusions: The incidence rate of lymphadenitis in two BCG types, percutaneous Tokyo and intradermal Danish strain BCG, is 0.20% and 0.69%, respectively. Both rates are acceptable.