Unlike cold or flu viruses, the hepatitis C virus (HCV) does not spread easily. It is transmitted by direct contact with blood that carries the virus. Before screening donated blood for hepatitis C became mandatory in 1991, most transmission occurred through blood transfusions.
Now that the blood supply is tested for the hepatitis C virus, this kind of transmission is extremely rare: It occurs less than once in every two million units of blood transfused. In the past, the virus was also spread through transplanted organs from people infected with HCV. Today, that risk has all but been eliminated.
One of the main ways the virus continues to be transmitted is through the injection of illegal drugs -- this accounts for 60 percent of all new cases of hepatitis C, according to the Centers for Disease Control and Prevention (CDC). Drug users who share needles are at very high risk of being exposed. Sharing a needle just once is enough to be exposed to the virus, even if that exposure took place decades ago.
Fetuses vulnerable to virus
The hepatitis C virus can spread in other ways as well. Mothers infected with the virus can transmit it to their babies during childbirth. About four out of every 100 infants born to infected mothers contracts the illness. Mothers who have hepatitis C often worry about spreading the virus to infants through breast milk. However, experts say there is no evidence that the virus is transmitted through breastfeeding. Still, to be safe, mothers who've tested positive for the hepatitis C virus whose nipples are cracked or bleeding should not breastfeed until their nipples heal.
Laboratory workers and medical personnel also run the risk of being exposed to the virus through accidental sticks from needles or other "sharps." Fortunately, this is not a very effective way to transmit HCV -- fewer than two people in 100 exposed to a stick from a contaminated source will become infected, according to the CDC. However, plenty of people with the hepatitis C virus do not report any of these risk factors, and the mode of transmission remains a mystery.
And unlike the virus that causes AIDS, the hepatitis C virus does not spread easily through sexual contact. Research shows there is some risk of transmission through sexual intercourse, but it is minimal. Couples in a monogamous relationship do not need to take any additional precautions when one partner is diagnosed with the hepatitis C virus. People who have sex with multiple partners should always use a condom to prevent sexually transmitted diseases.
Knowing how hepatitis C virus doesn't spread is as important as knowing how it does spread. The virus is not transmitted by sneezing, coughing, or sharing eating utensils or drinking glasses. It's also not spread through food, water, or casual physical contact like hugging or kissing. The only risk to people in a household comes from sharing personal items that may transmit blood from one person to another. These include razors, toothbrushes, and manicuring items such as nail clippers.
Chronic Hepatitis C: Disease Management, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis.
Viral Hepatitis C, National Center for Infectious Diseases, Centers for Disease Control and Prevention. http://www.cdc.gov/ncidod/diseases/hepatitis/c/
Centers for Disease Control and Prevention. Frequently Asked Questions About Hepatitis C. http://www.cdc.gov/hepatitis/C/cFAQ.htm