Hepatitis B: How Do I Know I have Hepatitis B Infection?

What is Hepatitis B?

Hepatitis B is a potentially life-threatening infection that affect the liver and it is cause by the hepatitis B virus (HBV). It is a major global health problem. It can cause chronic infection and puts people at high risk of death from cirrhosis and liver cancer.

A safe and effective vaccine that offers a 98-100% protection against hepatitis B is available. Preventing hepatitis B infection averts the development of complications including the development of chronic disease and liver cancer.

Geographical distribution.

Hepatitis B prevalence is highest in the WHO Western Pacific Region and the WHO African Region, where 6.2% and 6.1% of the adult population is infected respectively. In the WHO Eastern Mediterranean Region, the WHO South-East Asia Region and the WHO European Region, an estimated 3.3%, 2.0% and 1.6% of the general population is infected, respectively. And in the WHO Region of the Americas, 0.7% of the population is infected.

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. 

Infection in adulthood leads to chronic hepatitis in less than 5% of cases, whereas infection in infancy and early childhood leads to chronic hepatitis in about 95% of cases. 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, 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.

What causes Hepatitis B?

Hepatitis B infection is caused by the hepatitis B virus (HBV). The virus is passed from person to person through blood, semen or other body fluids. It does not spread by sneezing or coughing.

Common ways that HBV can spread are:

Sexual contact. 

You may get hepatitis B if you have unprotected sex with someone who is infected. The virus can pass to you if the person's blood, saliva, semen or vaginal secretions enter your body.

Sharing of needles. 

HBV easily spreads through needles and syringes contaminated with infected blood. Sharing IV drug paraphernalia puts you at high risk of hepatitis B.

Accidental needle sticks. 

Hepatitis B is a concern for health care workers and anyone else who comes in contact with human blood.

Mother to child. 

Pregnant women infected with HBV can pass the virus to their babies during childbirth. However, the newborn can be vaccinated to avoid getting infected in almost all cases. Talk to your doctor about being tested for hepatitis B if you are pregnant or want to become pregnant.

Acute vs. chronic hepatitis B.

Hepatitis B infection may be either short-lived (acute) or long lasting (chronic).

Acute hepatitis B infection lasts less than six months. Your immune system likely can clear acute hepatitis B from your body, and you should recover completely within a few months. Most people who get hepatitis B as adults have an acute infection, but it can lead to chronic infection.

Chronic hepatitis B infection lasts six months or longer. It lingers because your immune system can't fight off the infection. Chronic hepatitis B infection may last a lifetime, possibly leading to serious illnesses such as cirrhosis and liver cancer.

The younger you are when you get hepatitis B particularly newborns or children younger than 5, the higher your risk of the infection becoming chronic. Chronic infection may go undetected for decades until a person becomes seriously ill from liver disease.

Risk factors of hepatitis B

Hepatitis B spreads through contact with blood, semen or other body fluids from an infected person. Your risk of hepatitis B infection increases if you:

Have unprotected sex with multiple sex partners or with someone who is infected with HBV

Share needles during IV drug use

Are a man who has sex with other men

Live with someone who has a chronic HBV infection

Are an infant born to an infected mother

Have a job that exposes you to human blood

Travel to regions with high infection rates of HBV, such as Asia, the Pacific Islands, Africa and Eastern Europe.

Symptoms of Hepatitis B

Short-term (acute) hepatitis B infection doesn’t always cause symptoms. For instance, it’s uncommon for children younger than 5 to have symptoms if they’re infected.

If you do have symptoms, they may include:

Jaundice (Your skin or the whites of the eyes turn yellow, and your pee turns brown or orange.)

Light-colored poop

Fever

Fatigue that persists for weeks or months

Stomach trouble like loss of appetite, nausea, and vomiting

Belly pain

Joint pain

Symptoms may not show up until 1 to 6 months after you catch the virus. You might not feel anything. About a third of the people who have this disease don’t. They find out only through a blood test.

Symptoms of long-term (chronic) hepatitis B infection don’t always show up, either. If they do, they may be like those of short-term (acute) infection.

The likelihood that infection becomes chronic depends on the age at which a person becomes infected. Children less than 6 years of age who become infected with the hepatitis B virus are the most likely to develop chronic infections.

In infants and children:

80–90% of infants infected during the first year of life develop chronic infections; and

30–50% of children infected before the age of 6 years develop chronic infections.

In adults:

less than 5% of otherwise healthy persons who are infected as adults will develop chronic infections; and

20–30% of adults who are chronically infected will develop cirrhosis and/or liver cancer.

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 disease. Tenofovir, which is included in the treatment combinations recommended as first-line therapy for HIV infection, is also active against HBV.

How to diagnose Hepatitis B?

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.

Laboratory diagnosis of hepatitis B infection focuses on the detection of the hepatitis B surface antigen HBsAg. 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.

Possible complications of Hepatitis B.

Having a chronic HBV infection can lead to serious complications, such as:

Scarring of the liver (cirrhosis). 

The inflammation associated with a hepatitis B infection can lead to extensive liver scarring (cirrhosis), which may impair the liver's ability to function.

Liver cancer. 

People with chronic hepatitis B infection have an increased risk of liver cancer.

Liver failure. 

Acute liver failure is a condition in which the vital functions of the liver shut down. When that occurs, a liver transplant is necessary to sustain life.

Other conditions. 

People with chronic hepatitis B may develop kidney disease or inflammation of blood vessels.

Treatment of Hepatitis B.

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. 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 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. They rarely lead to drug resistance compared with other drugs, are simple to take (1 pill a day), and have few side effects, so require only limited monitoring.

Entecavir is off-patent. In 2017, all low- and middle-income countries could legally procure generic entecavir, but the costs and availability varied widely. Tenofovir is no longer protected by a patent anywhere in the world. The median price of WHO-prequalified generic tenofovir on the international market fell from US$ 208 per year to US$ 32 per year in 2016.

In most people, however, 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.

There is still limited access to diagnosis and treatment of hepatitis B in many resource-constrained settings. In 2016, of the more than 250 million people living with HBV infection, 10.5% (27 million) were aware of their infection. Of those diagnosed, the global treatment coverage is 16.7% (4.5 million). Many people are diagnosed only when they already have advanced liver disease.

Among the long-term complications of HBV infections, cirrhosis and hepatocellular carcinoma cause a large disease burden. Liver cancer progresses rapidly, and since treatment options are limited, the outcome is generally 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. Liver transplantation is sometimes used in people with cirrhosis in high income countries, with varying success.

Preventions of Hepatitis B.

The hepatitis B vaccine is typically given as three or four injections over six months. You can't get hepatitis B from the vaccine.

The hepatitis B vaccine is recommended for:

Newborns

Children and adolescents not vaccinated at birth

Those who work or live in a center for people who are developmentally disabled

People who live with someone who has hepatitis B

Health care workers, emergency workers and other people who come into contact with blood

Anyone who has a sexually transmitted infection, including HIV

Men who have sex with men

People who have multiple sexual partners

Sexual partners of someone who has hepatitis B

People who inject illegal drugs or share needles and syringes

People with chronic liver disease

People with end-stage kidney disease

Travelers planning to go to an area of the world with a high hepatitis B infection rate

Take precautions to avoid HBV.

Other ways to reduce your risk of HBV include:

Know the HBV status of any sexual partner. Don't engage in unprotected sex unless you're absolutely certain your partner isn't infected with HBV or any other sexually transmitted infection.

Use a new latex or polyurethane condom every time you have sex if you don't know the health status of your partner. Remember that although condoms can reduce your risk of contracting HBV, they don't eliminate the risk.

Don't use illegal drugs. If you use illicit drugs, get help to stop. If you can't stop, use a sterile needle each time you inject illicit drugs. Never share needles.

Be cautious about body piercing and tattooing. If you get a piercing or tattoo, look for a reputable shop. Ask about how the equipment is cleaned. Make sure the employees use sterile needles. If you can't get answers, look for another shop.

Ask about the hepatitis B vaccine before you travel. If you are traveling to a region where hepatitis B is common, ask your doctor about the hepatitis B vaccine in advance. It's usually given in a series of three injections over a six-month period.

Sources: 

www.who.int

www.mayoclinic.org

www.webMD.com