In an attempt to evaluate the effectiveness ofrnneonatal BeG vaccination policy, a tuberculin survey wasrnconducted among different age groups of children inrnLideta awraja, Addis ababa who had received BeGrnvaccination shortly after birth. The survey consisted ofrnassessing the immunization records and nutritional statusrnand conducting clinical histories and physicalrnexaminations. Thereafter, each study subject's site ofrnBeG vaccination on the right shoulder was assessed andrnthe size of the scar graded. Tuberculin PPD tests werernalso performed simultaneously, andrnwere read within 96-120 hours.rntuberculin reactionrnA standard datarncollection form was used to record address, age, sex,rnbody weight, BeG Scar and tuberculin response.rnIn addition, 60 children were revaccinated at thernage of 10 years (within the study period) and tuberculinrntests were performed 2 months after the secondrnvaccination.rnFurthermore, 70 bacteriologically provenrntuberculosis patients were also tuberculin tested at thernbeginning of the study, in order to check the potency ofrntuberculin PPD test and to estimate the diagnostic valuernof the test.rnA total of 895 children were studied between Octoberrn1992 and February 1993. Of these 563 (63%) had a definiternBeG scar while the rest 331 (37%) were without a Scar.rnThe sex distribution in each group was similar. Thernpercentage of tuberculin non reactors in different agerngroups was 39.5% at 2 months, 34.5% at 18 months, 39.1%rnat 5-7 years, and 46% at 9-11 years. The number ofrntuberculin non reactors initially showed a slight declinernfrom age 2 months and then an increase from age 18 monthsrnonward; the overall pattern of induration si ze wasrnvirnstatistically significant different between the agerngroups (P< 0.001). Some 55% of the children without arnBeG scar showed no response to the tuberculin test, whilern67% of those with a scar showed a positive tuberculinrnresponse. A direct correlation was observed betweenrntuberculin reactivity and the size of BeG scar (P6 mm) wasrnobserved in 11% of children despite the absence of thernBeG scar . Children without the BeG scar have 2.53 timesrnthe risk of a negative tuberculinrnthose with a BeG scar (P 4 mm). The tuberculosis patients showedrntuberculin reactions according to an unimodalrndistribution. Of these 12% showed 10 -15mm induration.rnA reaction of 10-15 mm were also observed in 3.3% ofrnchildren without a scar,ll% of children with a large scarrnsize( >5mm) and in 10% Of revaccinated children with outrntuberculosis infection. This revealed that the lack ofrnspecificity of the test.rnOverall, this finding emphasized the poor tuberculinrnresponse in infants at the age of 2 months compared to 18rnmonths after vaccination at birth and the waning effectrnof tuberculin response at the age five years compared torn18 months. It indicates that the BeG induced allergyrntended to disappear in this age group and the need forrnrevaccination. Thus we suggest a further study inrndeciding the age of first vaccination and revaccinationrnat the age of 5 years without tuberculin test.rnIn estimating coverage of vaccination, the presencernof BeG scar used as an indicator may overestimate byrnalmost a factor of two . Hence for accurate estimates wernrecommend determining the rate of tuberculin reactors inrnpopulations who have a BeG scar.