It is evident that HBV infection is a serious public health problem in the middle east area. The majority of countries in the region have an intermediate or high indemicity of HBV infection.(1)

The chronic carrier of hepatitis B is an important risk factor in the development of serious diseases, such as chronic persistent hepatitis , chronic active hepatitis, and liver cirrhosis and hepatocelluler carcinoma.(2)

The World Health Organization (WHO) has considered it a disease of public health importance. So it has recommended universal immunization against it by including a vaccine into Expanded Program for Immunization (EPI) schedule for children.(3)

The first Middle East countries to introduce hepatitis B vaccination into their EPI, were Saudi Arabia and Qatar in 1989. These were followed by Oman in 1990, Bahrain, Iraq, Syrian Arabic Republic, UAE in 1991, Egypt in 1992, Palestine in 1993, Jordan and Tunisia in 1995, and the Republic of Yemen in 1998.(4)

Our aim is to measure the prevalence of HB carrier status in children before and after the period of hepatitis vaccine, and to find the most effective way of protection .

A random selection of children who are below the age of 10 years was done after taking the consent of the parents. Blood samples were taken and tested for HBs Ag using the ELISA method , 247 children were included in the study during the year of 1997 . The same numbers of children were screened during the year of 2004 for the same age group who received the three doses of vaccine via the national vaccination program during the first year of their life.

A complete evaluation for the patients who were found to be HBs-positive , included liver function test , prothrombin time, partial thromboplastin time, HBs-Ab ,HBe-Ag and Ab, HBc-Ab, HAV-Ab , HCV-Ab. Family screening was done for all the family members.

During the year of 1997 a total number of 247 children were screened; 106 (43%) were females and 141 (57%) were males; a total of 8 patients were found to be HBs Ag-positive.

The same number of patients was screened for HBs Ag, for the group of children who received INGERIX vaccine via the national vaccination program. It consisted of three doses. The first dose is given at the age of two months, and the second dose is given at three months and the third dose at the fifth or the six month. The age group ranged from the first year of life to ten years of age.

According to the percentage of HBV chronic carriers among the adults in the general population , the countries were classified into three categories as low endemicity (<2%) , intermediate endemicity (2%-5%), and high endemicity (>5%).(5)

Here in Jordan the prevalence of HBS Ag positive ranges from 2.6-10%.(6)

Hepatitis B virus is one of the world's most important causes of disease and death. More than one third of the world population have serologic evidence of past or present infection, with over ???? being chronic carriers of the virus. (7,8)

There are many modes of transmission, including vertical transmission and horizontal transmission.

Vertical transmission: the virus does not cross the placenta but is transmitted from the pregnant carrier through invasive procedures such as amniocenteses, and when the newborn comes into contact with the mothers infected blood, during delivery. The infant can be protected by vaccination.

The proportion of infected newborns depend on levels of infectivity; if the mother is HBS Ag positive and HBe Ag positive, 90% of infants will become infected without appropriate prophylaxis, but if the mother is only HBs positive the risk of transmission is about 20 %.

90% of infected infants will become HBV carriers and 25% will ultimately develop a good morbidity rate from hepatitis B related disease.(9)

Horizontal transmission occurs to the family, friends and close contacts. The mechanism is not fully understood, but the vehicle is a small amount of infected saliva or blood contacting an open wound which may be a small abrasion.(10)

Also hepatitis B is considered to be a sexually transmitted disease (STD). Blood from minor lesions, semen and vaginal secretions are considered to likely be positive. The number of sexual partners, the number of years of sexual activity and a history of other sexual transmitted diseases have an increased risk of HBV infection.(11)

Another way of horizontal transmission is via HBV-contaminated blood and blood products, contaminated surgical instruments and other hazards.

The large majority of HBs-Ag carriers have normal function tests (75-90%), 1-5% develop chronic active hepatitis and the remaining had chronic persistent hepatitis.(13)

About 20% of individuals with chronic active hepatitis B progress to cirrhosis. (14)

In patients with cirrhosis, the annual incidence of hepatocelluler carcinoma ranges from 2% to 7%.

So as we can see from our study before the era of vaccination Jordan (Tafelah and Zarqa) have an intermediate endemicity rate of chronic hepatitis B carrier status. This chronic asymptomatic carriage can be prevented or decreased by vaccination. The vaccine is highly immunogenic, the sero-protection rates are greater than 95% after a 3-dose vaccine course, and the protection lasts for at least 8-10 years, even though the presence of antibodies would continue to provide protection against HBV infection.(15)

The most important aspect is the protection of newborn babies by giving the vaccine and the immunoglobulin as soon as possible after birth, and this can be achieved only by detecting the carrier mother before delivery as our patient's mother was neither screened nor vaccinated for hepatitis B.

It is apparent that vaccination of children under one year of age would be the most effective way of decreasing the prevalence of Hepatitis in accordance with the Expanded Program on Immunization (EPI).

Also we recommend a routine screening for the pregnant women as a part of antenatal care, and vaccination for HBs-Ag negative mothers ,and immediate vaccination for newborns of carrier mothers as soon as possible after birth. (12)