It seems that COVID-19 has overshadowed other global health issues. It is likely to remain so for sometime especially as the world grapples with the virus and efforts to curb the infection and its effects. So for many, this year’s World Hepatitis Day, July 28 passed rather quietly.
Worldwide, 290 million people living with viral hepatitis are unaware. There are 900,000 deaths per year caused by hepatitis B virus infection. Only 10% of people living with hepatitis B and 19% living with hepatitis C know their hepatitis status. 42% of children, globally, have access to the birth dose of the hepatitis B vaccine.
World Hepatitis Day is commemorated each year on July 28 to enhance awareness of viral hepatitis, an inflammation of the liver that causes a range of health problems, including liver cancer. There are five main strains of the hepatitis virus – A, B, C, D and E. Together, hepatitis B and C are the most common cause of deaths, with 1.3 million lives lost each year.
Amid the COVID-19 pandemic, viral hepatitis continues to claim thousands of lives every day. This year’s theme is “Hepatitis-free future”, with a strong focus on preventing Hepatitis B among mothers and newborns. WHO estimated that in 2015, 257 million people were living with chronic Hepatitis B virus (HBV) infection worldwide, and that 900,000 had died from HBV infection, mostly as a result of cirrhosis or hepatocellular carcinoma. Most HBV-associated deaths among adults are secondary to infections acquired at birth or in the first five years of life.
In May 2016, the World Health Assembly endorsed the Global health sector strategy on viral hepatitis which calls for the elimination of viral hepatitis as a public health threat by 2030 (defined as a 90% reduction in incidence of new infections and a 65% reduction in mortality).
Elimination of HBV infection as a public health threat requires a reduction in the prevalence of hepatitis B surface antigen (HBsAg) to below 0.1% in children 5 years of age. This can be achieved through universal immunization of newborns against hepatitis B and other interventions to prevent mother-to-child transmission of HBV. The WHO position papers on immunization recommend that all infants receive their first dose of hepatitis B vaccine as soon as possible after birth, preferably within 24 hours, and that the birth dose be followed by two or three doses of hepatitis B vaccine at least four weeks apart to complete the primary series. Immunization against hepatitis B starting at birth is the foundation of the prevention of perinatal and horizontal transmission of HBV.
On 28 July, WHO published new recommendations on the prevention of mother-to-child transmission of the virus. Among others, all infants should receive their first dose of hepatitis B vaccine as soon as possible after birth, preferably within 24 hour. Delivery of hepatitis B vaccine within 24 hours of birth should be a performance indicator for all immunization programmes, and reporting and monitoring systems should be strengthened to improve the quality of data on the birth dose. The birth dose should be followed by two or three doses to complete the primary series. All pregnant women should be tested for HIV, syphilis and hepatitis B surface antigen (HBsAg) at least once and as early as possible in the pregnancy.WHO recommends that pregnant women testing positive for HBV infection (HBsAg positive) with a high viral load (HBV DNA ≥ 5.3 log10 IU/mL or ≥ 200,000 IU/mL) receive tenofovir prophylaxis from the 28th week of pregnancy until at least birth, to prevent mother-to-child transmission of HBV. This is in addition to three-dose hepatitis B vaccination in all infants, including timely birth dose.WHO recommends that in settings in which antenatal viral load (HBV DNA) testing is not available, HBeAg testing can be used as an alternative to HBV DNA testing to determine eligibility for tenofovir prophylaxis to prevent mother-to-child transmission of HBV.Universal immunization of infants with hepatitis B vaccine, including a timely birth dose, is the foundation of programmes to prevent HBV infection at birth and in the first years of life. Countries that have not yet reached the 2020 goal of 1% HBsAg prevalence among children aged 5 years through vaccination need to focus their efforts on increasing their vaccination coverage, including timely birth dose.
The clinical trials that evaluated the efficacy and safety of tenofovir prophylaxis also included hepatitis B immune globulin (HBIG) as an additional preventive strategy in both trial arms. In a number of settings (mostly in high income countries) where it is available, HBIG is used inaddition to hepatitis B vaccination, including birth dose, to reduce the risk of mother-to-child transmission of HBV. However, HBIG is a blood product that has to be screened for infectious diseases. The costs are high, a cold chain is required and HBIG can be in short supply. In low and middle-income setting, it may only be available when purchased by individuals.
Testing of pregnant women needs to take place under circumstances that prevents stigma and discrimination and provides post-test counselling and education on measures to reduce the risk of transmitting HBV to the infant, encourage partner testing and ensure linkage to care of HBsAg positive women. Diagnostic tests used need to meet quality, safety and performance standards (with regard to analytical, diagnostic and clinical sensitivity and specificity).
The risk of vertical transmission is determined by the intensity of maternal HBV replication, with highly replicative infection characterized by a high HBV DNA viral load and hepatitis B e antigen (HBeAg) positivity. Up to 90% of infants born to HBeAg-positive mothers acquire the infection if untreated, compared to less than 10% of those born to HBeAg-negative mothers. It is important to give hepatitis B vaccine plus hepatitis B immune globulin (HBIG) prophylaxis shortly after birth. Maternal peripartum prophylaxis with antivirals can provide additional protection to that provided by a timely birth dose of hepatitis B vaccine. Very high maternal concentrations of HBV DNA, typically observed in HBeAg-positive women, are associated with an elevated risk of transmission (ranging from 20% in Asia to 32% in Africa), despite vaccine prophylaxis and HBIG. This compares to less than 1% transmission in Asia and Africa among HBeAg-negative women. Evidence suggests that the use of antivirals may suppress HBV DNA levels and reduce transmission of HBV to infants of HBsAg-positive women. Therefore, pregnant women with high HBV DNA levels may be considered for antiviral prophylaxis during pregnancy to prevent perinatal HBV infection. The use of antiviralprophylaxis in addition to infant immunization is consistent with approaches used to prevent mother-to-child transmission of HIV and syphilis. This provides opportunities for integrated triple or quadruple elimination of mother-to-child transmission of all pathogens. In addition, 6.1% of women with HIV infection have coinfection with HBV. As related earlier, COVID-19 appears to taken all our attention for now. HBV is considered a disease of significant public health importance.
DR. EDWARD O. AMPORFUL