Abstract
Question Many of my patients are from Southeast Asia, where hepatitis A virus (HAV) infection is quite common. What precautions can I suggest my pregnant patients take before traveling to these areas and what is the risk of contracting HAV during pregnancy?
Answer Hepatitis A virus is a water-borne pathogen transmitted by the fecal-oral route. To reduce the risk of contracting HAV while traveling to endemic areas, it is important to maintain hygienic practices such as hand washing with safe water, particularly before handling food, avoiding drinking water or using ice cubes of unknown purity, and avoiding eating unpeeled fruits and vegetables. An HAV vaccine is available and can be administered before traveling to endemic countries. Hepatitis A virus infection has a largely favourable expected outcome even during pregnancy. Infection occurring in the second or third trimester has been reported to be associated with preterm labour.
Hepatitis A virus (HAV) is a common cause of acute viral hepatitis across the globe and is preventable by a safe and effective vaccine. Hepatitis A virus is a single-stranded RNA virus that belongs to the Picornaviridae family.1 Hepatitis A virus infection is typically self-limited and rarely life-threatening, with an estimated mortality rate of 0.3% to 0.6%. The mortality rate increases to 1.8% in adults older than 50 years.2,3 It is highly endemic in South and Central Asia, sub-Saharan Africa, Latin America, North Africa, the Middle East, and Oceania.4 Approximately 1.5 million new cases are reported annually, although the true incidence is likely much higher, as milder cases are under-reported.5
Mode of transmission
Hepatitis A virus is transmitted via the fecal-oral route either by direct contact with an infected person or indirectly by ingestion of fecally contaminated food, especially raw and undercooked shellfish.6,7 The incubation period for HAV is 15 to 50 days, with a mean of 28 days.8 In a dried state, the virus can survive for at least 1 week in ambient conditions, and it can survive in fresh or salty water for up to 12 months.9,10 Hepatitis A virus infection is common in developing countries owing to poor hygiene and sanitation systems, resulting in contaminated food and water supplies, which typically leads to infection in early childhood and a mild form of the disease.11 Transmission of HAV from the mother to the fetus is uncommon, although there are numerous case reports of vertical transmission, with 2 cases associated with meconium peritonitis and perforation of the distal ileum requiring surgery.11–13 Nosocomial spread is also possible from pregnant women and neonates to other infants, adults, or health care workers.
Effects of hepatitis on pregnancy
Hepatitis A infection is the most common cause of acute viral hepatitis in the general population but it is infrequently reported among pregnant women. Hence, data on the incidence and outcome of HAV infection during pregnancy are scarce.14–16 Overall, HAV infection during pregnancy is not associated with serious outcomes.17 However, the available data show a causal relationship between HAV infection and preterm labour, especially if infection occurs in the second or third trimester.11 Hepatitis A virus infection has also been reported to be associated with other gestational complications such as increased premature uterine contractions, placental abruption, and premature rupture of membranes.11 The markers for a more aggressive course of the disease are fever and hypoalbuminemia. Overall, no mortality was reported among mothers and infants exposed to HAV infection, with full resolution of the infection.18 Most infants born to mothers with HAV infection were not affected and had normal antibody and transaminase levels. However, in the rare cases in which mother-to-child HAV infection occurs, it can be associated with fetal ascites, meconium peritonitis, neonatal icteric HAV infection, and distal ileum perforation.19
Breastfeeding
Although mothers infected with HAV have anti-HAV antibodies and HAV RNA in their breast milk, there is no evidence that breastfeeding transmits HAV to suckling infants. Therefore, breastfeeding should not be discouraged; the child should be protected through administration of immunoglobulin or the inactivated vaccine.20
Prevention
To reduce the risk of contracting HAV while traveling to endemic areas, it is important to maintain hygienic practices such as hand washing with safe water, particularly before handling food, avoiding drinking water or using ice cubes of unknown purity, and avoiding eating unpeeled fruits and vegetables. Before visiting HAV-endemic countries or underdeveloped countries with poor sanitation and hygienic standards, pregnant women and women of reproductive age need protection against HAV.4 The HAV vaccine is available both in a monovalent form and in combination with hepatitis B virus. Hepatitis A virus vaccine is prepared from the inactivated virus and is considered safe during pregnancy, but there should be a clear indication for administering the vaccine during pregnancy.21 About 70% of individuals develop protective levels of antibodies 2 weeks after the first dose of the vaccine.22 Hence, if the vaccine is administered immediately before travel, it can ensure adequate protection, as the incubation period for HAV is 15 to 50 days. Adequate levels of antibodies will likely persist for at least 10 to 29 years, if not for life, after receiving the second dose.23
Conclusion
Overall, infection with HAV is a result of poor hygiene and can be prevented through appropriate food handling and water sanitation. Hepatitis A virus infection is preventable with a vaccine and has a largely favourable expected outcome with regard to the mother and the fetus. However, infection in the second and third trimesters has been associated with preterm labour and other complications. Breastfeeding should not be discouraged in mothers with HAV infection. Infants should be protected by administration of either immunoglobulin or the inactivated HAV vaccine.
Notes
MOTHERISK
Motherisk questions are prepared by the Motherisk Team at the Hospital for Sick Children in Toronto, Ont. Dr Chaudhry is a clinical pharmacology and toxicology fellow in the Motherisk Program. Dr Koren is the founder of the Motherisk Program.
Do you have questions about the effects of drugs, chemicals, radiation, or infections in women who are pregnant or breastfeeding? We invite you to submit them to the Motherisk Program by fax at 416 813-7562; they will be addressed in future Motherisk Updates. Published Motherisk Updates are available on the Canadian Family Physician website (www.cfp.ca) and also on the Motherisk website (www.motherisk.org).
Footnotes
Competing interests
None declared
- Copyright© the College of Family Physicians of Canada
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