Changes in tuberculin sensitivity among first-grade students of elementary schools in Evros, Greece due to immigration

Abstract

To investigate the tuberculin sensitivity trends among first-grade students of elementary schools tested according to the Greek national school-based screening and vaccination programme. Retrospective analysis of tuberculin skin test (TST) results from 1988 to 2004 in unvaccinated first-grade students in Evros, Greece. All 6-7-year-old children who were unvaccinated for tuberculosis were tested by a highly experienced team. This study tested whether gender (male vs female), national origin (native vs foreign-born children) and place of residence (urban vs semi-urban vs rural) correlated with tuberculin reaction positivity. In total, 8588 children (47.1% girls) were tested. Tuberculin reaction positivity was independent of gender. The difference in TST positivity between native and foreign-born children between 1993 and 2004 was highly significant, with substantially more foreign-born children having a positive Mantoux test (P<0.0001). The percentage of children with a positive TST peaked at 13% in 1995 due to initial admission of foreign-born children, originating from countries of the former Soviet Union, into the Greek educational system. In addition, a positive Mantoux test was more common among children living in rural (8.1%) and semi-urban (6.4%) areas compared with children living in urban areas (3.5%, P<0.0001). The increase in TST positivity noted was due to admission of foreign-born children into the Greek educational system. School-based tuberculosis screening programmes should continue in Greece because the prevalence of tuberculosis appears to show substantial variation between years.