Hepatitis E is also found in animal waste. Studies have shown that the virus can infect many kinds of animals.

STEVE EMBER: The WHO says many hepatitis E cases have been reported in Central and Southeast Asia, North and West Africa and Mexico. No vaccines or medicines are effective against hepatitis E. Most people recover, usually in several weeks or months. But the disease can cause liver damage. In some cases, hepatitis E can be deadly.

The virus is especially dangerous to pregnant women. Twenty percent of those living with hepatitis E die in the last three months of pregnancy.

BARBARA KLEIN: Scientists discovered yet another kind of hepatitis in the nineteen nineties. It has been named hepatitis G. The hepatitis G virus is totally different from any of the other hepatitis viruses.

Donald Poretz is an infectious disease specialist in Washington, DC. He says the hepatitis G virus is spread through blood and blood products. But he says the virus has not been found to cause any real disease.

STEVE EMBER: The World Hepatitis Alliance works to increase knowledge about the dangers of hepatitis. The group says people should know that the disease kills about one million five hundred thousand people each year. It also says one in twelve people worldwide is living with hepatitis B or hepatitis C. And, it says, most of those infected do not even know it.

Hepatitis cannot be cured. The only way to protect against infection is to receive vaccines against hepatitis A and B, and to avoid contact with the other viruses. And that may be difficult.