Hepatitis B, also known as Hep B or HBV, is a viral infection that targets and causes inflammation of the liver. The infection starts as an acute condition and progresses into a chronic infection that lasts for longer than six months. People who suffer from chronic hepatitis B are more likely to suffer from cirrhosis (scarring of liver tissues) and liver failure. Hepatitis B infection can be treated effectively by using direct-acting-antiviral (DAA) drugs. However, a few times viruses develop resistance to these drugs, which is termed hepatitis B drug resistance.
Symptoms of Hepatitis B infection
Most hepatitis B patients don't exhibit any symptoms. However, even without any symptoms, infected people can transmit the hepatitis B virus to others.
Short-term or acute symptoms include:
- Fever
- Diarrhea
- Stomach pain
- Fatigue
- Loss of appetite
- Dark urine
- Grey-colored faeces
- Jaundice
Chronic hepatitis B can develop in people whose immune systems are weak enough to fight off acute infections after six months of exposure. People who may develop a chronic hepatitis B infection include infants, young children, and those diagnosed with human immunodeficiency virus (HIV) infection. Chronic hepatitis B patients are more likely to develop liver diseases, liver failure, and liver cancer.
Transmission of Hepatitis B infection
Hepatitis B can spread when an infected person comes into contact with another person's blood, sperm, or vaginal fluid. The Hepatitis B virus is very infectious and can persist outside of the body for up to seven days.
Hepatitis B is transmitted by:
- Having unprotected vaginal, oral, and anal sex with a hepatitis B-infected person
- Using contaminated equipment (e.g., injections) to inject drugs, medical or dental procedures, tattoos, or body piercings
- Having multiple sexual partners
- Sharing a razor or toothbrush
- Accidental exposure from infected instruments
In countries such as Asia, Africa, South America, and the Caribbean, where the hepatitis-B infection is widespread, during childbirth mothers can also transmit the hepatitis-B infection to their newborn.
Diagnosis of hepatitis B infection
Healthcare providers will examine the infected person for any signs of liver damage, such as pale skin or abdominal pain. The hepatitis B virus or complications of infection can be determined by performing the below tests:
Hepatitis B blood tests: Blood tests help to identify the hepatitis B virus in an individual’s body and to diagnose whether the infection is acute or chronic. A panel of blood tests for hepatitis B includes:
- Hepatitis B surface antigen (HBsAg) test: This test detects the presence of Hepatitis B surface antigen. The test result is "positive" or "reactive," signifying that the patient has hepatitis B. It requires additional testing to determine whether the infection is acute or chronic.
- Hepatitis B surface antibody, or anti-HBs (HBsAb) test: This test detects the presence of HBsAb. The test result is "positive" or "reactive," signifying that the patient is immune to the hepatitis B virus. The hepatitis B vaccine or a full recovery from a past hepatitis B infection can both provide this protection.
- Hepatitis B core antibody or anti-HBc (HBcAb) test: This test detects the presence of anti-HBc, or HBcAb. The test result "positive" or "reactive" signifies a past or present hepatitis B infection.
Liver ultrasound: The level of liver damage can be determined by performing a specialized ultrasound known as transient elastography.
Liver biopsy: A small tissue sample of the liver is collected using a fine needle during a liver biopsy procedure to test for liver damage.
Treatment of hepatitis B infection
Based on the duration and severity of the infection, your healthcare provider may provide different treatment options:
Prophylactic treatment
If the healthcare provider believes that the infection is due to a recent exposure, then they might suggest prophylactic treatment. It is more effective in children. It includes:
- Hepatitis B vaccination: It is recommended if you are not yet vaccinated or more commonly, within 24 hours of virus exposure. It is necessary to get two more booster doses over a period of six months to become fully vaccinated. The hepatitis B vaccine is available for all age groups, from 0 to 60 years of age or older, with or without known risk factors for hepatitis B infection.
- Hepatitis B immune globulin (HBIG): It is a protein substance obtained from naturally produced hepatitis B antibodies. It is given to those who have been exposed to the infection recently.
- Acute treatment: There is no particular treatment for acute infection. Treatment depends on symptoms and includes rest, nutritious food, and IV fluids.
- Chronic treatment: People diagnosed with chronic hepatitis B require lifelong treatment. Depending on your condition and risk factors, treatment may include antiviral medications, immune modulator drugs, interferon injections, or a liver transplant. All these treatment modalities lower the risk of developing liver disease and stop the spread of hepatitis B infection.
Hepatitis B Drug Resistance
The overall prevalence and reinfection of hepatitis B have increased due to antiviral drug-resistance mutations and hepatitis B immune globulin mutations. Resistance is due to a lack of adherence to treatment and genetic causes. Hepatitis B drug resistance can be detected by genotyping and/or phenotyping. Hepatitis B drug resistance can be prevented by avoiding unnecessary medications, making careful choices like therapy, and conducting continuous surveillance of drug resistance.
Though hepatitis B infection in its initial stages doesn’t cause severe complications, it is necessary to begin treatment as early as possible. To prevent hepatitis flares and liver failure, it is important to undergo an early diagnosis of antiviral drug resistance and the immediate initiation of alternate viral therapy.