( See also Overview of Acute Viral Hepatitis Overview of Acute Viral Hepatitis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more in adults and Overview of Neonatal Infections Overview of Neonatal Infections Neonatal infection can be acquired In utero transplacentally or through ruptured membranes In the birth canal during delivery (intrapartum) From external sources after birth (postpartum) Common... read more .)
Of the recognized forms of primary viral hepatitis, only hepatitis B virus (HBV) is a cause of neonatal hepatitis. Neonatal infection with other viruses (eg, cytomegalovirus Congenital and Perinatal Cytomegalovirus Infection (CMV) Cytomegalovirus infection may be acquired prenatally or perinatally and is the most common congenital viral infection. Signs at birth, if present, are intrauterine growth restriction, prematurity... read more , herpes simplex virus Neonatal Herpes Simplex Virus (HSV) Infection Neonatal herpes simplex virus infection is usually transmitted during delivery. A typical sign is vesicular eruption, which may be accompanied by or progress to disseminated disease. Diagnosis... read more ) may cause liver inflammation along with other manifestations.
Etiology of Neonatal HBV Infection
HBV infection occurs during delivery from an infected mother. The risk of transmission is 70 to 90% from women seropositive for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg— see Serology Serology Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more ) at the time of delivery. Women without the e antigen or with anti-HBe transmit the infection only 5 to 20% of the time.
Mother–infant HBV transmission results primarily from maternofetal microtransfusions during labor or contact with infectious secretions in the birth canal. Transplacental transmission is identified in < 2% of infections. Postpartum transmission occurs rarely through exposure to infectious maternal blood, saliva, stool, urine, or breast milk. Up to 90% of infants infected perinatally will develop chronic infection, and perinatally acquired HBV infection may be an important viral reservoir in certain communities.
Symptoms and Signs of Neonatal HBV Infection
Most neonates with HBV infection are asymptomatic but develop chronic, subclinical infection characterized by persistent HBsAg antigenemia and variably elevated transaminase activity. Many neonates born to women with acute hepatitis B during pregnancy are of low birth weight, regardless of whether they are infected.
Infrequently, infected neonates develop acute, symptomatic hepatitis B, which is usually mild and self-limited. They develop jaundice, lethargy, failure to thrive, abdominal distention, and clay-colored stools. Occasionally, severe infection with hepatomegaly, ascites, and hyperbilirubinemia Neonatal Hyperbilirubinemia Jaundice is a yellow discoloration of the skin and eyes caused by hyperbilirubinemia (elevated serum bilirubin concentration). The serum bilirubin level required to cause jaundice varies with... read more (primarily conjugated bilirubin) occurs. Rarely, the disease is fulminant and even fatal. Fulminant disease occurs more often in neonates whose mothers are chronic carriers of hepatitis B.
Diagnosis of Neonatal HBV Infection
Diagnosis of neonatal HBV infection is by serologic testing Diagnosis Acute viral hepatitis is diffuse liver inflammation caused by specific hepatotropic viruses that have diverse modes of transmission and epidemiologies. A nonspecific viral prodrome is followed... read more , including measurement of HBsAg, HBeAg, antibody to hepatitis B e antigen (anti-HBe), and quantitation of HBV DNA in blood. Other initial tests include complete blood count (CBC) with platelets, alanine aminotransferase (ALT) and alpha-fetoprotein levels, and liver ultrasonography.
Family history of liver cancer or liver disease is noted because of the long-term risk of hepatocellular carcinoma. If testing suggests HBV infection, consultation with a pediatric hepatologist is recommended.
Prognosis for Neonatal HBV Infection
Long-term prognosis is not predictable, although chronic HBV infection early in life increases the risk of subsequent liver disease including chronic hepatitis, cirrhosis, end-stage liver disease, and hepatocellular carcinoma.
Treatment of Neonatal HBV Infection
Symptomatic care and adequate nutrition are needed. Neither corticosteroids nor hepatitis B immune globulin (HBIG) is helpful for acute infection. No therapy decreases the likelihood of developing chronic, subclinical hepatitis once infection is acquired.
All children with chronic HBV infection Hepatitis B, Chronic Hepatitis B is a common cause of chronic hepatitis. Patients may be asymptomatic or have nonspecific manifestations such as fatigue and malaise. Diagnosis is by serologic testing. Without treatment... read more should be immunized with hepatitis A vaccine Hepatitis A (HepA) Vaccine Both hepatitis A vaccines provide long-term protection against hepatitis A. For more information, see Hepatitis A Advisory Committee on Immunization Practices Vaccine Recommendations and Centers... read more . Children with chronic HBV infection may benefit from antiviral drugs (eg, interferon alfa, lamivudine, adefovir) but these should be used only in consultation with a pediatric hepatologist.
Prevention of Neonatal HBV Infection
Pregnant women should be tested for HBsAg during an early prenatal visit. Failing that, they should be tested when admitted for delivery. Some women who are HBsAg-positive are treated with lamivudine or telbivudine during the 3rd trimester, which may prevent perinatal transmission of HBV.
Neonates whose mothers are HBsAg-positive should be given 1 dose of HBIG 0.5 mL IM within 12 hours of birth. Recombinant HBV vaccine Hepatitis B (HepB) Vaccine The hepatitis B vaccine is 80 to 100% effective in preventing infection or clinical hepatitis B in people who complete the vaccine series. For more information, see Hepatitis B Advisory Committee... read more should be given IM in a series of 3 doses, as is recommended for all infants in the US. (NOTE: Doses vary among proprietary vaccines.) The first dose is given concurrently with HBIG but at a different site. The 2nd dose is given at 1 to 2 months, and the 3rd dose is given 6 to 18 months after the first. If the infant weighs < 2 kg, the first dose of vaccine may be less effective. Subsequent vaccine doses are given at age 30 days (or when discharged from the hospital), and then 2 other doses are given at 1 to 2 months and 6 months after the 30-day dose.
Neonates whose mothers have unknown HBsAg status at the time of delivery should also receive their first dose of vaccine within 12 hours of birth. For infants < 2 kg, the first dose is given concurrently with HBIG (0.5 mL IM) at a different site. For infants ≥ 2 kg and whose mothers can be tested for HBsAg and in whom follow up is ensured, HBIG (0.5 mL IM) can be delayed up to 7 days pending a positive maternal test for HBsAg. Testing for HBsAg and anti-HBs at 9 to 15 months is recommended for all infants born to HBsAg-positive mothers.
Neonates whose mothers are known HBsAg–negative should receive their first dose of vaccine within 24 hours of birth if they are medically stable and weigh ≥ 2 kg. For infants < 2 kg, administer 1 dose at age 1 month or before hospital discharge.
Separating a neonate from its HBsAg-positive mother is not recommended, and breastfeeding does not seem to increase the risk of postpartum HBV transmission, particularly if HBIG and HBV vaccine have been given. However, if a mother has cracked nipples, abscesses, or other breast pathology, breastfeeding could potentially transmit HBV.
Only hepatitis B virus (HBV) is a major cause of viral neonatal hepatitis; it is typically transmitted during delivery.
Most neonates are asymptomatic but develop chronic, subclinical HBsAg antigenemia and elevated transaminase levels.
Some infants develop mild hepatitis, and a few have fulminant liver disease.
Do serologic testing of infant and mother.
Neonates whose mothers are HBsAg-positive should be given 1 dose of HBIG 0.5 mL IM and HBV vaccine within 12 hours of birth.
HBV-infected children should be immunized with hepatitis A vaccine; anti-HBV drugs (eg, interferon alfa) may help but should be used only in consultation with a pediatric hepatologist.