Comparison of tuberculin skin test results and adverse reactions following BCG vaccination in various infant groups of different ages

Park, In Seung; Han, Dong Ki; Lim, Ho Joon; Oh, Sung Hee; Lee, Hahng

Abstract

Most authorities including WHO recommended immununizing infants with BCG as early as possible in areas prevalent with tuberculosis, however the optimal time for immunization has not well been characterized. Therefore the investigation was undertaken by vaccinating various infant groups of different ages with BCG and subsequently evaluating for adverse effects and tuberculin reactions, in order to contribute to undestanding the optimal time for immunization. Four hundred eighty three infants from the newborn nursery and the well baby clinic of Hanyang University Hospital who had no family history of tuberculosis were divided into three groups; group I of infants immunized within 7 days after birth, group II of infants immunized at about 1 month of age and group III of infants immunized at about 3 months of age. To each infant 0.1 ml of BCG(Institute Merieux, France) was administered intradermaly and approximately 3 months later tuberculin skin test using 5 TU PPD (NIH, Korea) was performed. Adverse reactions following BCG vaccination such as temperature elevation, induration alone or with suppuration at or near the injection site, and lymph node enlargement were also analyzed. The summary of the results is as follows. 1) Distribution of diameters of induration on tuberculin skin test illustrated incomplete bimodal configuration in all three different age groups. The means 2 standard deviations of diameters of indurations distributed on the main bells were 10.07 4.52 mm in group I, 10.65 3.82 mm in group II, and 10.83 5.08 mm in group III, and were not significantly different. 2) Criteria for positive tuberculin reaction was diameters of indurations equal to or greater than 6mm, 2 standard deviations below the mean values of diameters of indurations on the main bells. 3) The positive tuberculin reaction rates of 85.8% in group II and 88.6% in group III were significantly greater than 74.1% in group I. 4) Incidence of complications following BCG vaccination including temperature elevation, induration with suppuration, and localized lymphadenopathy was not different among three groups and the serious complications such as temperature elevation and lymphadenopathy were minimal. The data indicate that it is appropriate to immunize infants with BCG at about one month of age and the incidence of complications following BCG vaccination was not different among three infant groups of different ages.