The Comparison of the Conversion Rate and Duration after Multipuncture BCG vaccination

Jeon, Min Cheol; Kim, Young Hoon; Lee, Joon Sung; Whang, Kyung Tai; Cho, Sung Hoon

Abstract

PURPOSE
During the childhood, Mantoux test is very popular for detecting tuberculous infection and also useful for evaluating the immunity against tuberculosis after BCG vaccination. But the response and conversion rate is affected by the age of vaccination, the quality of vaccine, the duration after vaccination and the frequency of the test. Recently percutaneous multipuncture technique of BCG vaccination was introduced and used because of local side effect and technical problem of intradermal BCG vaccination, however there is only a study of conversion rate and side effect at 3month after multipuncture BCG vaccination. We performed this study to evaluate of the difference of the Mantoux reaction and conversion rate according to duration (3month, 9month and 15month) after vaccination, gestational age, sex, and feeding type.
METHODS
174 neonates (155 of full term infants, 19 of preterm infants) who were born Kangnam St. Mary's Hospital were given multipuncture BCG vaccination within 4weeks after birth between July, 1995 and June 1997. All subjects was performed Mantoux test using 5TU PPD (NIH, Korea) at 3month, 9month and 15month. Injecting BCG and interpretating the result of the Mantoux test was done by the same person.
RESULTS
1) The positive rates of Mantoux test which was done 3month , 9month and 15month after vaccination were 38.7%, 58.1%, 71.6% in the full term infant group and 31.6%, 31.6%, 47.4% in the preterm infant group. 2) The size of induration in Mantoux test, which was done 3month, 9month and 15month after vaccination were 7.3 mm, 9.4 mm, and 10.6 mm in the full term infant group and 5.6 mm, 7.7 mm, 9.2 mm in the preterm infant group. The size of induration was significantly lower in the preterm infant group as compared with that of the full term infant group 9month after vaccination. 3) The positive conversion rate, less than 5 mm to more than 10 mm, was 6.3% (3 infants of 48 infants who were negative Mantoux test 3month became positive 9month) and 26.3% (5 infants of 19 infants who were negative 9month became positive 15month) in the full term infant group, and 33.3% (one infant of 5 infants who were negative 9month became positive 15month). 4) There is no difference in conversion rate of Mantoux test according to the sex, feeding type in both groups5) Complication rate for multipuncture is 3.2%, which is leaded by local ulceration and fever in the full term infant group, and 5.3%, which is only fever in the preterm infant group.
CONCLUSION
In those result the size of induration and conversion rate is increased as the duration after vaccination, then their smaller size in the preterm group 9month after vaccination maybe due to immunological immaturity of preterm group.