Hepatitis B

Context: On September 3, Bangladesh, Bhutan, Nepal, and Thailand became the first four countries in the World Health Organization’s Southeast Asia region to have successfully controlled hepatitis B. The virus is said to be controlled when the disease prevalence is reduced to less than 1% among children less than five years of age.

Relevance: 
Mains: GS II, GS III

Hepatitis B: 

Hepatitis B is an infection of the liver. It can cause scarring of the organ, liver failure, and cancer. It can be fatal if it isn’t treated. It’s spread when people come in contact with the blood, open sores, or body fluids of someone who has the hepatitis B virus.

Hepatitis B is serious but an adult's body can fight the disease and the body is immune for the rest of the life (means the disease is not reoccurring). The disease is unlikely to go away if a child gets it. 

Symptoms: 

Most people do not experience any symptoms when newly infected. However, some people have acute illness with symptoms that last several weeks, including yellowing of the skin and eyes (jaundice), dark urine, extreme fatigue, nausea, vomiting, and abdominal pain. A small subset of persons with acute hepatitis can develop acute liver failure, which can lead to death. In some people, the hepatitis B virus can also cause a chronic liver infection that can later develop into cirrhosis (a scarring of the liver) or liver cancer.

What Causes Hepatitis B?

It’s caused by the hepatitis B virus.

Transmission:

• In highly endemic areas, hepatitis B is most commonly spread from mother to child at birth (perinatal transmission), or through horizontal transmission (exposure to infected blood), especially from an infected child to an uninfected child during the first 5 years of life. The development of chronic infection is very common in infants infected from their mothers or before the age of 5 years.
• Hepatitis B is also spread by needlestick injury, tattooing, piercing, and exposure to infected blood and body fluids, such as saliva and, menstrual, vaginal, and seminal fluids. Sexual transmission of hepatitis B may occur, particularly in unvaccinated men who have sex with men and heterosexual persons with multiple sex partners or contact with sex workers.
• Transmission of the virus may also occur through the reuse of needles and syringes either in health-care settings or among persons who inject drugs. In addition, the infection can occur during medical, surgical and dental procedures, through tattooing, or through the use of razors and similar objects that are contaminated with infected blood.
• The hepatitis B virus can survive outside the body for at least 7 days. During this time, the virus can still cause infection if it enters the body of a person who is not protected by the vaccine. The incubation period of the hepatitis B virus is 75 days on average but can vary from 30 to 180 days. The virus may be detected within 30 to 60 days after infection and can persist and develop into chronic hepatitis B.

HBV-HIV coinfection:

About 1% of persons living with HBV infection (2.7 million people) are also infected with HIV. Conversely, the global prevalence of HBV infection in HIV-infected persons is 7.4%. Since 2015, WHO has recommended treatment for everyone diagnosed with HIV infection, regardless of the stage of the disease. Tenofovir, which is included in the treatment combinations recommended as first-line therapy for HIV infection, is also active against HBV.

Diagnosis:

• It is not possible, on clinical grounds, to differentiate hepatitis B from hepatitis caused by other viral agents, hence, laboratory confirmation of the diagnosis is essential. A number of blood tests are available to diagnose and monitor people with hepatitis B. They can be used to distinguish acute and chronic infections.
• WHO recommends that all blood donations be tested for hepatitis B to ensure blood safety and avoid accidental transmission to people who receive blood products.
• Acute HBV infection is characterized by the presence of HBsAg and immunoglobulin M (IgM) antibody to the core antigen, HBcAg. During the initial phase of infection, patients are also seropositive for hepatitis B e antigen (HBeAg). HBeAg is usually a marker of high levels of replication of the virus. The presence of HBeAg indicates that the blood and body fluids of the infected individual are highly infectious.
• Chronic infection is characterized by the persistence of HBsAg for at least 6 months (with or without concurrent HBeAg). Persistence of HBsAg is the principal marker of risk for developing chronic liver disease and liver cancer (hepatocellular carcinoma) later in life.

Treatment:

• There is no specific treatment for acute hepatitis B. Therefore, care is aimed at maintaining comfort and adequate nutritional balance, including replacement of fluids lost from vomiting and diarrhea. Most important is the avoidance of unnecessary medications. Acetaminophen/Paracetamol and medication against vomiting should not be given.
• Chronic hepatitis B infection can be treated with medicines, including oral antiviral agents. Treatment can slow the progression of cirrhosis, reduce the incidence of liver cancer and improve long term survival. Only a proportion (estimates vary from 10% to 40% depending on setting and eligibility criteria) of people with chronic hepatitis B infection will require treatment.
• WHO recommends the use of oral treatments – tenofovir or entecavir- as the most potent drugs to suppress hepatitis B virus. 

Prevention:

The hepatitis B vaccine is the mainstay of hepatitis B prevention. WHO recommends that all infants receive the hepatitis B vaccine as soon as possible after birth, preferably within 24 hours. Routine infant immunization against hepatitis B has increased globally with an estimated coverage (third dose) of 84% in 2017. The low prevalence of chronic HBV infection in children under 5 years of age, estimated at 1.3% in 2015, can be attributed to the widespread use of hepatitis B vaccine. In most cases, 1 of the following 2 options is considered appropriate:

1. a 3-dose schedule of hepatitis B vaccine, with the first dose (monovalent) given at birth and the second and third doses (monovalent or combined vaccine) given at the same time as the first and third doses of diphtheria, pertussis (whooping cough), and tetanus – (DTP vaccine); or
2. a 4-dose schedule, where a monovalent birth dose is followed by 3 monovalent or combined vaccine doses, usually given with other routine infant vaccines.

The complete vaccine series induces protective antibody levels in more than 95% of infants, children and young adults. Protection lasts at least 20 years and is probably lifelong. Thus, the WHO does not recommend booster vaccinations for persons who have completed the 3 dose vaccination schedule.

All children and adolescents younger than 18 years and not previously vaccinated should receive the vaccine if they live in countries where there is low or intermediate endemicity. In those settings, it is possible that more people in high-risk groups may acquire the infection and they should also be vaccinated.

Hepatitis in India:

• Despite the introduction of the hepatitis B vaccine in the Universal Immunisation Programme in 2002 and scaling-up nationwide in 2011, about one million people in India become chronically infected with the virus every year.
• According to the Health Ministry, as of February 2019, an estimated 40 million people in India were infected. Hepatitis B infection at a young age turns chronic, causing over 1,00,000 premature deaths annually from liver cirrhosis or liver cancer.
• A study published in 2013 found lower coverage of the hepatitis B vaccine in eight of the 10 districts surveyed. But the coverage has witnessed an increase with the introduction of a pentavalent vaccine on a pilot basis in Kerala and Tamil Nadu in December 2011 and national roll-out in 2014-2015. According to the WHO, the coverage of hepatitis B's third dose had reached 86% in 2015.
• Hepatitis B birth dose, given in the first 24 hours, helps prevent vertical transmission from the mother to child. The compulsion to increase the birth dose to cut vertical transmission arises from two important reasons — about 70-90% newborns infected this way become chronic carriers of hepatitis B, and about 20-30% carriers in India are due to vertical transmission.
• But even seven years after the Health Ministry approved the birth dose in 2008, its coverage remained low — 45% in 2015 and 60% in 2016 — according to a 2019 Health Ministry report. What is indeed puzzling is that even in the case of institutional delivery, the birth dose vaccine coverage is low — 76.36% in 2017.
• Incidentally, institutional delivery accounts for about 80% of all deliveries in the country. The birth dose coverage when delivery takes place outside health-care institutions is not known. One of the reasons for the low coverage is the fear of wastage of vaccines when a 10-dose vial is used. Unfortunately, health-care workers are very often unaware of the WHO recommendation that allows hepatitis B open-vial policy.
• Opened vials of the hepatitis B vaccine can be kept for a maximum duration of 28 days for use in other children if the vaccine meets certain conditions. There is also a need to increase public awareness about the merits of the birth dose.