**9. How HBV infection is prevented and controlled**

All travelers should be screened for HBV infection markers, so that they will not be at risk of acquiring the virus during stay [74]. Recently updated guidelines also recommend that pregnant women with chronic HBV be referred to a specialist and considered for HBV treatment to further reduce the chance of transmitting the virus [3]. In infants born to HBsAg-positive mothers, the risk of mother-to-child transmission is significantly greater if the mother is positive for HBeAg, has a high viral load, and/or is infected with HIV [33]. Such infants should be given both vaccine and HBIgG (0.5 ml) within 12 hours of delivery. The infants should be evaluated for HBsAg, anti-HBs, and anti-HBc at age 12 months. The presence of anti-HBs depicts vaccine-induced immunity, and detection of both anti-HBs and anti-HBc shows immunoprophylaxis-modified infection, whereas the presence of HBsAg indicates prophylaxis failure [15, 76, 77].

Individuals who have not received the HBV vaccination and are exposed to the virus (through needle stick injury, splashing, or sexual exposure to partners infected with the viral agent) should be vaccinated with HBIG (0.04–0.07 ml/kg) as soon as possible after exposure. Immunization for the newborn babies should start immediately with the initial shot given at a site that is not similar with that for HBIG; an accelerated four dose immunization schedule (0, 1, 2, and 12 months) is required in the maternal-fetal transmission scenario [8, 77]. HBV can also be prevented by avoiding contact with contaminated blood and blood products and unprotected sexual exposure. Using condoms has also been shown to reduce the chance of sexually transmitted infections [8].
