The ABCs of Hepatitis
Hepatitis is emerging in the news, and many recommendations circulate regarding this virus and its different alphabetical types. Vaccines have been developed that are now recommended for certain groups. Blanket screening for one strain is recommended by some for all baby boomers and older. Another type can be transmitted by food and yet another via sexual relations. It's hard to keep everything straight and digest the really vital information. This blog will offer a brief primer on the common hepatitis types A, B and C.
Hepatitis A (HAV)
Of the three main tyes of hepatitis, HAV carries the least potential for harm. Like the others, it can cause symptoms of nausea, vomiting, diarrhea, jaundice (yellow skin and eyes), fever, abdominal pain, dark urine, and weight loss.
With infection, presentation may vary greatly. While it is common for the infection to cause no symptoms whatsoever, it can also be debilitating. Symptoms do not typically last more than two months before subsiding.
HAV is contracted via the fecal to oral route. In other words, the virus is shed in stool. Contact with this stool either directly or through contamination of food is the main source of infection. In underdeveloped countries, human feces is a common source of fertilizer making infection commonplace in such areas. Outbreaks have occurred in the US due to imported food contaminated with the virus (strawberries or other such produce grown on the ground).
Persons who are at risk include those who travel to underdeveloped countries, daycare employees, those occupationally exposed to sewage, and men who have sex with men. For those at higher risk, vaccine should be considered. Recently, the vaccine has become routine for children at one year of age.
Treatment is not necessary as the virus is usually self-limited. A blood test can detect if HAV infection is present.
Hepatitis B (HBV)
Like Hepatitis A, Hepatitis B is a common infection. In China, for instance, it is endemic. About a third of the world's population has had or has HBV.
The symptoms of HBV are the same as the other types, but HBV differs in that the infection can be either acute (lasting weeks to months) or chronic (years to lifetime).
HBV is transmitted via bodily fluids. While the virus is present in saliva and tears, these secretions are not considered infectious. Transmission happens for the most part via exposure to blood or bodily fluids containing blood. The most common routes of transmission are via sex, blood transfusions, sharing needles in IV drug use, and occupational healthcare exposure.
In developed countries, one of the most prevalent forms of transmission is from mother to newborn during childbirth. Therefore, all pregnant women are tested for HBV, and babies are offered the vaccine immediately after birth.
Testing involves examining the blood for infection similar to the other types. Treatment is only necessary if chronic infection exists (less than 1%). Antiviral medications are used and must be taken for 6-12 months. Prevention in developed countries occurs with routine immunization.
Hepatitis C (HCV)
Hepatitis C has been in the news recently for its increasing prevalence in the baby boomer generation. In fact, the CDC is now calling for routine screening for adults born between 1945 and 1965.
Of the three types of Hepatitis, HCV has the most potential to become serious. 85% of infections become chronic and it's estimated that approximately 130-170 million individuals are infected with HCV worldwide.
Like HBV, HCV is transmitted via blood exposure. Documented sources include shared needles in IV drug use, blood transfusions (before routine testing of blood products occurred), and poorly sterilized surgical/tattoo equipment. Tattooing is associated with a 3-fold increase in risk for contracting HCV. It's not clearly understood if intercourse can transmit HCV, and while sharing razors or toothbrushes can theoretically spread infection, no documented cases have been reported.
With chronic infection, the liver can continue to deteriorate and eventually fail, a condition called cirrhosis. Antiviral medication can be used to treat chronic infection as with HBV. The course of treatment lasts about a year and the cure rate is ultimately around 50%. The last resort in treatment is a liver transplant (HCV is the leading cause of liver transplant these days). Adding to the insidious nature of this type of hepatitis, there is no vaccine available.
When I heard the recommendation for screening all baby boomers for HCV, I questioned the utility of the exercise. According to an infectious disease specialist with whom I work, screening can reduce the numbers of liver transplants needed and is a worthy endeavor. In addition, new therapy will be available in the next 1-2 years that has vastly improved cure rates. It's also not a bad idea to get screened if you have a tattoo.
Hepatitis A,B and C have some distinct similarities and differences. If you feel you are at risk for Hepatitis A or B and have not been vaccinated, I encourage you to do so. If you're part of the Baby Boom generation, consider getting tested for Hepatitis C.