Horizontal transmission of HBV infection among students in Turkey

In this study, the HBsAg carrier state and the role of horizontal transmiss ion were investigated among primary and high school students in southeaster n Anatolia where HBsAg seropositivity is remarkably high. In total, 350 students from primary school first grade, 350 students from f ifth grade, 400 students from high school eleventh grade and 400 healthy ad ults as a control group were studied. In all cases HBsAg and anti-HBs were screened by ELISA. HBsAg positivity was 2.4% in first grade, 6.1% in fifth and 6.7% in elevent h grade students. Anti-HBs positivity was 14% in first grade, 20% in fifth and 21% in eleventh grade students. HBsAg positivity was 9% and anti-HBs, 4 9% in the control group. There is a significant difference between first an d fifth grade students for HBsAS positivity (2.1% vs 6.1% and P < 0.05). Th is difference decreased during the high school years (6.2% and P > 0.05). T here is also a similar statistically significant difference for anti-HBs po sitivity during the primary school years (14% vs 20%, P < 0.05). These findings show that the risk of horizontal transmission of HBV is espe cially important during elementary school years between the ages of 7 and 1 1 y. All infants or at least elementary school first grade students in Turk ey should have HBV vaccinations.