Hepatitis A: Thriving in Unsanitary Conditions
Hepatitis A is transmitted by human consumption of fecal-contaminated drinking water or food. Like cholera, the risk of contracting hepatitis A depends on the hygiene and sanitary conditions in a given area. Developing countries are at high risk, although 180,000 people in the United States are infected each year by hepatitis A. About 100 people in the United States die from hepatitis A-related complications each year.
A high concentration of the virus is found in fecal matter, and the virus can survive on the hands or other surfaces for up to four hours at room temperature. Eating utensils are a frequent source of infection, as are contaminated shellfish. Hepatitis A can also be spread through intravenous drug use and sexual contact.
When traveling to an area known to have hepatitis, always emphasize personal hygiene. And don't forget the basics of food preparation and consumption: boil it, broil it, peel it, or forget it!
Symptoms and Treatment
A common characteristic of hepatitis is that the infected person may not have any symptoms. When symptoms do occur, usually within the first four weeks of infection, they may be flu-like, with fatigue, body ache, nausea, vomiting, pain, and tenderness in the liver area, dark urine, or light colored stools and fever.
Other indications are jaundice in adults, where the skin and eye color take on a yellow hue, and liver test results that indicate a higher level of activity of key enzymes than normal. There is no specific treatment for hepatitis A. Supportive care is recommended and is guided by symptoms, which often last from about four weeks to a few months. Symptoms may return in 20 percent of people who get the disease and continue on and off for up to 15 months. However, the infection will resolve by itself, with no serious after-effects. Once recovered, an individual is then immune to reinfection. Only about one percent of all hepatitis A infections cause a severe enough infection that damages the liver to an extent that a transplant is required.
Testing for Hepatitis A
There are currently two blood tests available to detect hepatitis A. Antibodies may be detected for up to six months following the onset of symptoms, but they tend to disappear after time.
Hepatitis A is the most common vaccine-preventable disease in international travelers. It is 1,000 times more common than cholera and 100 times more common than typhoid among international travelers.
There are two approved vaccines available in the United States for protection against hepatitis A. They provide long-term protection and are licensed for use in children two years of age and older. Two doses are needed, 6 to 12 months apart, to ensure long-term protection. International travelers should get the first dose at least four weeks prior to their departure.
Immunoglobulin (plasma containing different classes of antibodies made from people who are immune to the disease) is recommended for short-term protection, but it must be given within two weeks of exposure for maximum protection. People born and raised in developing countries where hepatitis A is endemic have usually been infected in childhood with a mild case, and are generally immune to the disease.
Hepatitis E: The Hepatitis A Copycat
Having access to clean drinking water, washing hands before eating, and proper disposal of sewage are still the best ways to decrease the incidence of this disease.
Hepatitis E disease has symptoms much like hepatitis A. It is an acute, short-duration disease spread widely in many tropical and underdeveloped countries, usually through contaminated drinking water. Hepatitis E affects young adults rather than children, and causes a high death rate, particularly in pregnant women. Major waterborne epidemics have occurred in Asia and North and East Africa, but there have been no known outbreaks in the United States besides some sporadic cases in Los Angeles in 1987.
Like hepatitis A, good sanitation and personal hygiene are the best preventive measures. The incubation period for hepatitis E varies from two to nine weeks, with the disease itself usually lasting about two weeks. Although infections are generally mild for young adults, the fatality rate in pregnant women approaches 20 percent. Protection from the disease in endemic areas lies mainly in prevention, as a vaccine for hepatitis E is in the experimental stage. Hepatitis E can be diagnosed based on symptoms and the elevated presence of liver enzymes.
Excerpted from The Complete Idiot's Guide to Dangerous Diseases and Epidemics © 2002 by David Perlin, Ph.D., and Ann Cohen. All rights reserved including the right of reproduction in whole or in part in any form. Used by arrangement with Alpha Books, a member of Penguin Group (USA) Inc.