::::::::::: Hepatitis B virus(HBV) infection:::::::::
-Hepatitis B is a viral infection that leads to inflammation of the liver. It is caused due to infection with the hepatitis B virus (HBV).
•Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.
•An estimated 240 million people are chronically infected with hepatitis B (defined as hepatitis B surface antigen positive for at least 6 months).
•More than 780 000 people die every year due to complications of hepatitis B, including cirrhosis and liver cancer.
It is transmitted through infected blood and other body fluids like seminal fluid, vaginal secretions, breast milk, tears, saliva,sweat and open sores.
This can happen through direct blood-to-blood contact, unprotected sex or illicit drug use. The other common mode of transmission is from hepatitis B infected mothers to the fetus prior to birth.
-People who may be at risk for developing hepatitis B:-
Healthcare workers
People who share personal items such as toothbrush, razor and nail clippers with an infected person.
Living in the same household with an infected person.
Indulging in sex with a carrier or chronically infected person.
People who have more than one sex partner.
People who work or are incarcerated in a prison.
Traveling to countries with a high incidence of hepatitis B.
People who get tattoos made or have their ear or body pierced.
Intravenous drug users who share needles and syringes are at extremely high risk.
CLINICAL MANIFESTATION:-
Many people with hepatitis B may not have symptoms and not know they are infected.
However, some people develop acute hepatitis B with the following symptoms-
Pain in the joints
Weakness and fatigue
Jaundice
Dark yellow colored urine
Clay colored stools
Fever
Generalized itching
Loss of appetite
Nausea and vomiting
Indigestion and abdominal pain
Tenderness and enlargement of the liver
These symptoms usually go away in a few weeks. However, some people never get rid of the hepatitis B virus; and this is known as chronic hepatitis B.
Over a period of time, people with chronic hepatitis B may develop symptoms of-
Liver cancer
Cirrhosis of the liver
Diagnosis:-
•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 contagious.
-Hepat itis B DNA polymerase = e-Antigen = Hepatitis B PCR for DNA
These 3 tests are essentially equal in meaning. They all indicate active viral replication.
•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.
In case of chronic hepatitis B the doctor advises the following tests to look for liver damage-
Serum albumin level
Liver function tests
Prothrombin time
Sometimes a liver biopsy may be needed for assessment of severity.
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 diarrhoea. Chronic hepatitis B infection can be treated with drugs, including oral antiviral agents. Treatment can slow the progression of cirrhosis, reduce incidence of liver cancer and improve long term survival.
WHO recommends the use of oral treatments - tenofovir or entecavir, because these are the most potent drugs to suppress hepatitis B virus. They rarely lead to drug resistance as compared with other drugs, are simple to take (1 pill a day), and have few side effects so require only limited monitoring.
However, in most people, the treatment does not cure hepatitis B infection, but only suppresses the replication of the virus. Therefore, most people who start hepatitis B treatment must continue it for life.
Treatment using interferon injections may be considered in some people in certain high-income settings, but its use is less feasible in low-resource settings due to high cost and significant adverse effects requiring careful monitoring.
Interferon: Interferon has the most adverse effects:
- Flulike symptoms
- Arthralgia
- Myalgia
- Fatigue
- Thrombocytopenia
- Depression
There is still limited access to diagnosis and treatment of hepatitis B in many resource-constrained settings, and many people are diagnosed only when they already have advanced liver disease. Liver cancer progresses rapidly, and since treatment options are limited, the outcome is in general poor. In low-income settings, most people with liver cancer die within months of diagnosis. In high-income countries, surgery and chemotherapy can prolong life for up to a few years. In high-income countries, liver transplantation is sometimes used in people with cirrhosis, with varying success
WHO recommends administration of the hepatitis B vaccine for the prevention of hepatitis B.
The hepatitis B vaccine is available for all age groups. It can be given in either three or four separate doses, as part of routine immunization schedules.
The vaccination schedule which is often used involves administering three intramuscular injections, the second and third administered 1 and 6 months after the first.
In cases where mother-to-infant spread of hepatitis B virus is a possibility, the first dose of the vaccine should be given within 24 hours after birth.
The protection obtained from the hepatitis B vaccine lasts at least 20 years and is possibly for lifetime.