Hepatitis B: Causes, Symptoms, Transmission, Treatment and Prevention
Hepatitis B is a liver infection caused by the hepatitis B virus (HBV). Viral hepatitis B remains a major health problem worldwide.
The hepatitis B virus can cause a chronic infection and puts people at high risk of death from cirrhosis and liver cancer. The virus can affect people of all ages. Once infected, some people are carriers of the virus for life.
Hepatitis B infection acquired in adulthood leads to chronic hepatitis in less than 5% of cases, while infection in childhood and early life leads to chronic hepatitis in about 95% of cases. This is the basis for strengthening and prioritizing the vaccination of infants and children.
Acute vs. chronic hepatitis B
Hepatitis B infection can be either short-term (acute) or long-term (chronic).
Acute hepatitis B infection lasts less than six months. The immune system can clear acute hepatitis B from the body, leading to a full recovery in just a few months. Most people who get hepatitis B as adults have an acute infection, but it can lead to a chronic infection.
Chronic hepatitis B infection lasts for six months or longer. It persists because the immune system cannot fight off the infection. It can last a lifetime, progressing to serious diseases such as cirrhosis and liver cancer.
Newborns or children younger than 5 years are more prone to the risk of the infection becoming chronic. It can go unnoticed for decades until it evolves into liver disease.
It is recognized that 10% of adults with acute hepatitis B and 90% of perinatally infected children will develop the chronic form of hepatitis B virus infection.
Mode of transmission
In areas with high endemicity, hepatitis B is most commonly transmitted 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 in the first 5 years of life.
Hepatitis B is also transmitted through needle sticks, tattoos, piercings, and exposure to infected blood and body fluids, such as saliva and menstrual, vaginal, and seminal fluids.
Transmission of the hepatitis virus can also occur through the reuse ofcontaminated needles and syringes or sharp objects, whether in healthcare settings, in the community, or among people who inject drugs.
Sexual transmission is more common among unvaccinated individuals and those who have multiple sexual partners.
The hepatitis B virus can survive outside the body for at least 7 days. During this time, the virus can still cause an infection if it enters the body of a person who is not protected by a vaccine.
Symptoms
The incubation period of the hepatitis B virus ranges from 30 to 180 days. The virus can be detected between 30 and 60 days after infection and can persist and progress to chronic hepatitis B, especially when transmitted in childhood.
Most people do not show any symptoms when they are freshly infected. However, some people have an acute illness with symptoms that last for several weeks, including yellowing of the skin and eyes (jaundice), dark urine, extreme fatigue, nausea, vomiting, and abdominal pain.
People with acute hepatitis can develop acute liver failure, which can lead to death. Among the long-term complications of HBV infections, a subgroup of people develops advanced liver disease, such as cirrhosis and hepatocellular carcinoma.
Diagnosis
For clinical reasons, it is not possible to distinguish between hepatitis B and hepatitis caused by other viral agents; therefore, laboratory confirmation of the diagnosis is essential.
Several blood tests (excluding routine blood tests) are available for diagnosing and monitoring people with hepatitis B. These can be used to distinguish acute from chronic infections.
To detect hepatitis B, the doctor will order the following tests:
- The HBsAg test for the hepatitis B surface antigen, which, if positive, will attest that the patient is a carrier and can transmit the virus to other people.
- The anti-HBs antibody test, which, in the case of a positive result, will attest that the patient has specific antibodies against the HBV virus in their body. This translates to either a previous infection or antibodies that appeared following vaccination. If this test is positive, it means that the person cannot be infected with the hepatitis B virus and cannot infect other people.
WHO recommends that all blood donations be tested for hepatitis B to avoid accidental transmission.
Treatment
There is no specific treatment for acute hepatitis B. Therefore, care is aimed at maintaining comfort and adequate nutritional balance, including replacing fluids lost from vomiting and diarrhea. Most importantly, unnecessary medications should be avoided. Paracetamol and anti-vomiting medications should be avoided.
The use of oral treatments to suppress the hepatitis B virus is recommended. Most people who begin treatment for hepatitis B must continue it for life. Treatment can slow the progression of cirrhosis, reduce the incidence of liver cancer, and increase the chances of survival.
Prevention
Currently, the most effective method of prevention is vaccination against the hepatitis B virus. The anti-hepatitis vaccine can ensure increased immunity against infection, and in some cases, it provides permanent immunity.
The dose of the hepatitis B vaccine varies depending on the manufacturer, the age of the vaccinated person, and the needs of the population groups at risk. The hepatitis B vaccine can be administered simultaneously with other vaccines, provided that the administration site is different.
The interval between the first and second dose is at least four weeks.
WHO recommends that all infants receive the hepatitis B vaccine as soon as possible after birth, preferably within 24 hours, followed by 2 or 3 doses of the hepatitis B vaccine at least 4 weeks apart to complete the vaccination series.
In addition to infant vaccination, WHO recommends the use of antiviral prophylaxis to prevent the transmission of hepatitis B from mother to child. Implementing blood safety strategies and safe sexual practices, including minimizing the number of partners and using barrier protection measures (condoms), also protects against transmission.
References
https://www.nfid.org/infectious-diseases/hepatitis/
https://www.who.int/news-room/fact-sheets/detail/hepatitis-b
https://www.mayoclinic.org/diseases-conditions/hepatitis-b/symptoms-causes/syc-20366802
https://www.healthline.com/health/hepatitis-b
https://www.hpsc.ie/a-z/otherlanguages/hpscfactsheetsinromanian/Hep%20B%20Chronic-6PP%20Romanian-D2.pdf
http://www.cnscbt.ro/index.php/metodologii/hepatite-virale-b-si-c/1041-metodologia-de-supraveghere-a-hepatitelor-virale-tip-b-si-c-actualizare-4-ian-2019-pentru-anul-2019/file
https://www.catena.ro/hepatita-b-transmitere-simptome-tratament-si-preventie
