Hepatitis B is caused by hepatitis B virus (HBV). It’s a serious liver infection and can become chronic for some patients, lasting over six months.
Chronic hepatitis B infection is associated with increased risk of developing various liver diseases including:
- Liver failure
- Cirrhosis of liver
- Liver cancer
It’s a potential life threatening liver disease and is a major global health problem. It can result in chronic infection and the complications like cirrhosis and cancer can cause death too.
Adults tend to recover completely from hepatitis B infection, however children and infants are more likely to develop chronic infection. Vaccination can help in preventing hepatitis B, however there’s no definite medicine to cure once it occurs. Certain precautions are to be taken if one is infected from hepatitis B to prevent it from spreading to others.
Transmission of hepatitis B virus
The hepatitis B virus can survive for at least 7 days outside living body. During this time, if it comes in contact with a human body that’s not vaccinated earlier, it can cause the infection in it.
Average incubation period for this virus is 75 days, varying from 30 to 180 days. Hepatitis B virus can be detected one to two months after the infection. The infection can persist and develop into chronic in some patients.
In regions where hepatitis B is endemic, it spreads through perinatal transmission (from mother to child during birth) or through horizontal transmission (through exposure to blood of infected person). Those infants, who get infected from their mothers or before any other means during first 5 years of their life, have high chances of developing chronic infection.
Hepatitis B virus also spreads through:
- Mucosal or percutaneous exposure
- Through saliva
- Through menstrual fluid
- Through vaginal secretions
- Through seminal fluids
- Sexual transmission
o Especially in unvaccinated people
- Reuse of needles and syringes
o In health care setups
o Drug abusers
- During medical or surgical procedures
- Dental procedures
- Using any object contaminated with hepatitis B virus
Less than 5% adults who develop hepatitis B develop chronic disease.
Symptoms of hepatitis B
Acute phase of the infection might not be symptomatic in most people. However, some patients might have symptoms during the last few weeks of acute illness, including:
- Jaundice (yellowish discoloration of skin and eyes)
- Dark urine
- Extreme fatigue
Chronic hepatitis B infection can develop into liver cancer or cirrhosis of liver.
Diagnosing hepatitis B
Hepatitis B can’t be differentiated from other types of hepatitis on the basis of symptoms only. Laboratory investigations are required to confirm the diagnosis in suspected individuals. There are various blood tests available that can help in the diagnosis of hepatitis B.
Laboratory investigations done for the detection of hepatitis B infection focus on detecting HBsAg, the surface antigen of hepatitis B.
All donated blood has to be tested for hepatitis B as per WHO recommendation.
Laboratory investigations for the diagnosis of hepatitis B virus includes:
- Acute HBV infection
o Presence of HBsAg and IgM (immunoglobulin M) antibody to HBcAg (the core antigen)
o During initial stages, patients are seropositive for HBeAg (hepatitis B e antigen) too, which is a marker of high levels of virus replication and indicate that the body fluids and blood of the individual are highly contagious
- Chronic HBV infection
o When HBsAg has been present for at least 6 months
o Can be with or without HBeAg
o If HBsAg is present, it’s a marker of developing complications later in life, like:
§ Liver cancer (hepatocellular carcinmona)
§ Chronic liver disease
Prevention of Hepatitis B
Hepatitis B vaccine is the main way of preventing the infection from HBV and is recommended by WHO to be delivered to infants as soon as possible, with in 24 hours of birth preferably.
The birth dose is followed by 2 or 3 doses for the completion of primary series. Mostly any one of these two options is used:
- 3 doses schedule of hepatitis B vaccine
o First monovalent dose at birth
o Second and third (monovalent or combined) at the same time along with the doses for DPT (diphtheria, pertussis (whooping cough) and tetanus) vaccine
- 4 doses schedule of hepatitis B vaccine
o Monovalent at birth
o Three combined or monovalent vaccine doses, given with other infant routine vaccines usually
All children and adults under the age of 18 who haven’t been vaccinated earlier must be vaccinated, especially in the regions where the disease is endemic even if low to moderate. In regions with high endemicity, vaccination should also be done for people who:
- Require blood frequently
- Interns in prisons
- Drug injectors
- People with contact with hepatitis B patients at home or outside
- Having multiple sexual partners
- Traveller who didn’t complete vaccination series earlier, should be vaccinated before leaving to those areas
Treatment of Hepatits B
Care and symptomatic treatment is the main aim of hepatitis B treatment as there is no definitive cure to the disease.
- Maintaining comfort
- Replacing fluids, that are lost through diarrhea or vomiting
- Antiviral drugs to treat chronic hepatitis B
o Drugs recommended by WHO include:
o The drugs recommended by WHO are most potent ones and rarely lead to drug resistance
o They require minimum monitoring
o Usually one pill per day is the required dose
- Some patients might need injections for treatment
o They are more costly
o Need more careful monitoring due to significant adverse effects
Treatment of hepatitis B can help in slowing down the progression of the complications like cirrhosis and liver cancer, along with improving the long-term survival.
Consult your doctor if you’re experiencing any symptoms related to hepatitis B or if you have any queries.