Efficiency of BCG vaccination in infants and preschool children

ABSTRACT

Mycobacterium tuberculosis remains one of the pathogens causing the greatest amount of chronic disease and death throughout the world. BCG is the method which can provide without any major difficulties, reliable protection against tuberculous infection through creation of a long lasting immunity in the vaccinated individual. This study was carried out in New Children Hospital, Cairo University on 180 infants and children at different age groups [3 months - 6 years] who had attended to the Outpatient Clinic. All of them were chosen to be BCG vaccinated early at the age of 1 month to 40 days, the age at which BCG vaccination is compulsory in Egypt. They were not suffering, convalescing from any disease or taking any drug that could affect the degree of tuberculin test reaction. Tuberculin test using 2 units P.P.D. was carried out using Mantoux Technique test and was real 48-72 hours later and the mean diameter of induration was measured. Induration of 5 mm or more were considered positive and 4 mm or less were considered negative. The obtained data showed that the collective percentage of tuberculin positive reaction in BCG vaccinated children in the first 6 years of life was only 30.5% and the tuberculin test reaction diminished with age but did not show significant difference with sex. The positivity of tuberculin test showed direct relation to the diameter of BCG scar but no relation was traced between the age and size of the BCG scar