Determination of HBsAg and anti HBs in mothers and their children between 6 months and 3 years of age in Islamabad

ABSTRACT

To determine the presence of hepatitis B surface antigen and antibodies in mothers and their children aged between 6 months-3 years and assess if vaccination at 6 weeks is preventing maternal to child transmission. Sero-epidemiological cross-sectional community-based study conducted in district Islamabad from Dec. 2008- Dec. 2009 in six clusters [Bani gala, Kuri shehr, Bara kahu, Karachi company, I-sector and Koral town]. About 50 paired samples [Maternal and child] were collected from each cluster making a total of 300 mothers and their children. In each cluster, a door to door survey was done to locate houses that had a child between 6 months to 3 years of age and whose mother was willing to participate in the study. Informed written consent was taken from parents [mother/ father] of the enrolled child. Two ml of blood was taken from mother and child and information regarding the HBV vaccination of child and mother was entered in a questionnaire apart from other risk factors for disease transmission. The sera were stored and later analysed for presence of Hepatitis B surface antibodies [anti HBs], Hepatitis B negative for anti HBs were run for HBsAg and those found positive were run for HBsAg. A total of 227 mothers and their 304 children were enrolled in the study which lasted for 6 months. Out of 277 mothers, 39[14%] were anti HBs positive, 29[11.4%] were positive for HBsAg and out of these three [10.3%] were also HBsAg positive. Out of 304 children who were tested for anti HBs, 239 [77%] showed protective levels. Eight children [2.6%] were positive for HBsAg and 02[25%] were also positive for HBeAg. Out of 261 vaccinated children 89% showed, antibodies while 11% did not have antibodies. Five [2%] children were HBsAg positive despite taking the vaccination. Of the 29 mothers who were HBsAg positive, their 03 children were also positive for the virus. Of the 3 mothers that were HBsAg positive but their mothers were negative for this virus indicating other routes of viral transmission or a paternal transmission. Vertical transmission of HBsAg was seen from HBsAg positive mothers to their newborns. HBV infection is seen in 2% vaccinated children indicating that vaccination at 6 weeks are not protecting these children to this deadly virus. Vaccination of Hepatitis B should be done at birth