Identification
The infection caused by Hepatitis B virus (HBV) is called Hepatitis B. The infection is acute, subsequently it may evolve towards healing or chronicling.
- Acute hepatitis B is characterized by the presence of viral replication markers and more or less noisy symptoms.
- Chronic hepatitis B can follow an acute hepatitis B and is characterized by the persistence of viral replication markers over 6 months. Chronic hepatitis B has three stages that evolve differently according to age and the patient’s immune status at infection and the HBV genotype that produces the infection. The stages are:
- of immune tolerance,
- of immune neutralization,
- HBsAg with or without symptoms.
The markers of the viral replication are: DNA/HBV and HBeAg. The risk of developing chronic hepatitis with HBV after acute hepatitis varies inversely in proportion to age: Chronic infection occurs in 90% of infants infected at birth; 20-50% of children infected from 1 to 5 years and 1-10% in infected adolescents and adults. An estimated rate of up to 25% of people with chronic hepatitis B will die prematurely due to cirrhosis or hepatic carcinoma (cancer). Worldwide, approximately 80% of hepatocellular cancer cases are caused by HBV.
In the adult
A small fraction of acute hepatitis B can be clinically recognized because only 30-50% of infected adults are symptomatic. In those with clinical manifestations the onset is insidious with:
- Jaundice
- Anorexia
- Vague abdominal discomfort
- Nausea
- Vomiting
- Arthralgia
- Rash (papular acrodermatitis of childhood),
- Fever, which may be absent or moderate.
In the pregnant women
- Hepatitis B is often asymptomatic and is discovered as a result of routine tests, for any other purpose.
- In infected pregnant women, the disease does not take more severe forms than in the general population.
- Some authors state that in pregnant patients with chronic hepatitis B, the infection has no repercussions on the fetus, and the pregnancy would not affect the evolution of the infection.
- If complications such as decompensated cirrhosis occur, fertility decreases as a result of hormonal disorders and may be a number of complications:
- Gestational hypertension,
- Premature birth,
- Fetal growth restriction,
- In some cases the fetus may die.
In the newborn mother infected with hepatitis B
- Chronic infection occurs in 90% of infants infected at birth,
- Newborns should be monitored very carefully.
- Clinical and biochemical symptoms may occur after long intervals (up to 20-30 years) and in evolution there may be cirrhosis and liver carcinoma.
Screening of pregnant women
The screening of the pregnant woman for the detection of hepatitis B is very important. It must be done as early as possible, from the first visit to the gynecologist.
- The initial tests consist in detecting Ag HBs and Ac anti-HBs.
- If the two results are negative it is necessary to vaccinate the pregnant women, especially in situations at high risk of transmitting the infection.
- If Ag HBs is positive there are 2 measurements of HBV DNA at that time and than in the 28 week, together with the dosage of HBeAg, Ac anti-HBe and TGO and TGP.
- If viral DNA exceeds the value of 200,000 IU/ml should be considered initiation of antiviral therapy in the weeks 28-32.
- If the viral load is less than 200,000 IU/ml it is not necessary to initiate anti-viral therapy (only in exceptional cases, e.g. premature birth).
- In all cases, the newborn will be vaccinated. Monitoring of post-partum patients (after birth) is important.
- If antiviral therapy has been initiated to pregnant, it may be stopped at 0-3 months after birth.
Screening in the case of newborn
- It is recommended to test infants for HBsAg and for Ac anti HBs at 9 and 15 months after birth, to monitor the effectiveness/inefficiency of prophylaxis by vaccination.
- Infants who are positive for Ac anti-HBs and negative for HBsAg are protected and do not require any further doses of the vaccine.
- Infants who do not present anti-HBs and have negative serology for HBsAg must be revaccinated.
Nota Bene. In this document, the laboratory diagnosis was not treated in the hepatitis B virus infection (HBV), but there were several elements related to pregnancy and newborn. For the complete diagnosis of this infection, those interested will be addressed to infectious physicians, epidemiology doctors or other physicians with competences in this area.
The infectious agent
Hepatitis B virus belongs to the Hepadnaviridae family. It’s a double stranded DNA virus, tire. The rate of chronic HBV infection in adults is about 5%, instead the newborn rate is much higher, around 90%. HBV is currently classified in 8 main genotypes, from A to H. The severity of the infection is different for each genotype.
About Corneliu Zaharia
