الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 67 |  |  |
| | | from | 67 | | |
Abstract
Hepatitis B virus (HBV) infection is a public health problem and a major cause of morbidity and mortality particularly in developing countries. Worldwide, it is estimated that more than 2 billion people had been infected with HBV and have serological evidence of past or present HBV infection .Of these approximately 360 million are chronically infected and at risk of cirrhosis and hepatocellular carcinoma. In Egypt, there are nearly 2-3 million chronic carriers. Egypt is considered to be a region of intermediate endemicity (2-8%) for HBV infection. Universal immunization against HBV is considered to be the most effective means of prevention of HBV infection. Egypt was one of the earliest countries to implement HBV vaccination in 1992 in the Expanded Program of Immunization (EPI) at two, four, and six months of age. S. haematobium is endemic in Upper Egypt governorates, the prevalence rate ranged from 4.8% to 13.7% with an average of 7.8%. S. mansoni was rare being consequential in Fayoum only, which had a prevalence of 4.3%. In Egypt, infection with hepatitis B virus (HBV) and hepatitis C (HCV), together with schistosomiasis are major causes of chronic liver disease. Moreover, prevalence of both hepatitis B and C infections have been reported to be higher in patients with hepatosplenic schistosomiasis than in those without , also the effects of schistosomal infection on HBV vaccination were reported. Thus the aim of the present study was to understand and observe the immune response to HBV vaccine in case of schistosomiasis positive and negative children in an endemic area in Upper Egypt. The specific objectives were to assess the immune response to HBV vaccine among schistosome infected children according to the intensity of infection and to compare the immune response to HBV vaccine among children infected with schistosomiasis versus negative children . A case- control study was conducted in a primary school located in Gizeerat Abu Saleh village, 18 Km North East to Beni-Suef City, Beni-Suef Governorate, Egypt. It is an rural area endemic of schistosomiasis. All pupils of the school were examined parasitologically to diagnose S. haematobium infection. This was followed by a case- control study. Cases (Bilharzial group) were 90 children and (Non-bilharzial group) were 90 children. Controls were selected from negative children matching in age. Study population was submitted to the following: 1- Filling a pre-designed interview questionnaire for collection of data, socio demographic, vaccination and medical histories. 2- Detection and titration of HbsAb for all studied children to detect immune response to HBV vaccine (HbsAb concentration of (≥10 mIU/ml) were considered protected and those with (<10 mIU/ml) were considered non-protected 3- All studied children were subjected to testing for anticore antibody (anti-HBc) 4- Hepatitis B surface antigen (HBsAg) was tested for children with HbsAB<10 mlU/ml. 5- Detection of anti-bilharzial antibodies by indirect haemagglutination technique (IHAT),for negative bilharzial children group.
Summary and Conclusion
37
The data of the present study revealed the following: 1- 72.2% of bilharzial children were males and 27.8% were females while 60% of the control group was males and 40% was females. The difference was not statistically significant. 2- The persistence of responsive antibody (HbsAb) levels in children 6-12 years post vaccination was 85% 3- 15.0% of the hepatitis B vaccinated children were unprotected(
HbsAB< (10 mIU/ml). 4- The percentage of non-immune (HbsAb < 10 mIU/ml) in non bilharzial group were (8.9%), compared to 21.1% in bilharzial group 5- All children 6-12 years with (HbsAb< 10 mIU/ml) were negative for HBsAg i.e. No carrier state were found among non-immune, this finding supports the conclusion that a high efficacy of hepatitis B vaccine exists 6- The current data revealed that(27 cases) in non bilharzial group were exposed to HBV (positive anti-core),25 cases of them (92.6%) had boosting (Anti-HBs ≥10 mIU/ml), whereas 9 cases in bilharzial group were exposed and only 66.7% had boosting (Anti-HBs ≥10 mIU/ml) 7- The level of good responders (HbsAb>100 mIU/ml) in non-bilharzial children were (15.6%). which decreased in bilharzial children to (11.1%) 8- Percentages of unprotected males (Anti-Hbs< 10 mIU/ml) were more than unprotected females, (13.0 % vs 2.8%) & (23.1% vs 16.0%) in non bilharzial and bilharzial groups respectively. However the difference was not statistically significant different. 9- Twenty percent of the studied school children had breakthrough infection as they were anti-HBc seropositive while all non-protected children were HbsAg negative. 10- The intensity of bilharzial infection had no effect on the titre of immune response of HBV as 87.5% of those with heavy infection (≥50 Ova /10 ml urine) and 90.5% of non bilharzial children had anti-HBs ≥ 10 mIU/ml. In conclusion, Schistosoma in general had no significant effect on immune response to hepatitis B vaccine with different intensities of bilharzial infection. Although bilharzial children were exposed to hepatitis B and antibody formation was less than non bilharzial children, they were still protected since HBsAg was negative.