DETERMINATION OF HEPATITIS B SURFACE ANTIBODIES IN CHILDREN AGED 3 YEARS IN ISLAMABAD. A PILOT STUDY

ABSTRACT 

Aim: To determine the presence of hepatitis B surface antibodies in children aged between 6 months-2 years and assess if vaccination at 6 weeks is preventing maternal to child transmission.   

Study Design: Sero-epidemiological cross-sectional community-based study  

Duration and Settings: The study was conducted in district Islamabad from Dec. 2008- Dec. 2009. We selected six clusters of the district Islamabad (Bani gala, Kuri shehr, Bara kahu, Karachi company, I-sector and Koral town). On an average about 50 paired samples (Maternal and child) were collected from each cluster making a total of 300 mothers and their children.  

Methods: In each catchment, a door to door survey was done to locate houses that had a child between 6 months to 2 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.  Venous samples (2ml) were taken from mother and child and information regarding the HBV vaccination of child and mother was taken apart from other risk factors for disease transmission. The Sera were stored at Citi lab Islamabad and were later analysed for presence of Hepatitis B surface antibodies (anti HBS), Hepatitis B surface antigen (HBsAg) and Hepatitis e antigen (HBeAg). Anti HBs was run on all samples, only those that were negative were run for HBsAg and those found positive were run for HBeAg. 

Results:  A total of 277 mothers and their 304 children were enrolled in the study which lasted 6 months. Out of 277 mothers, 39 (14%) were anti HBs positive. 29 (11.4%) were positive for HBs antigen and out of these three (10.3%) were also HBeAg 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 (table-1). 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 03 mothers that were HBeAg positive, 02 children were also positive showing the possibilities of maternal to child infection. 05 children were HBsAg positive but their mothers were negative for this virus indicating other routes of viral transmission.   

Conclusion:

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.