In my preschool setting, I come into contact with a child who has hepatitis C. I know very little about the disease. Are there precautions I should take?

M.R.

I wonder how it became known that the preschool child was infected with the hepatitis C virus (HCV). It is not one of the infections that a parent is necessarily obligated to report to his school or day-care center. Be that as it may, hepatitis C is an infection of the liver. In most cases, the infection is not cleared from the body and remains in the patient forever. About 30 percent of patients will develop end-stage liver disease 20 to 30 years after they contract the infection.

This virus is spread by contact with infected body fluids, typically blood. The usual modes of transmission are blood transfusion (which is far less likely today than in the past), sharing of infected needles to shoot drugs, and, less commonly, sexual intercourse. Organ transplantation and the infection of health care workers after accidental exposure in the workplace are far less frequent modes of transmission.

There are no studies documenting the risk of HCV transmission in a preschool setting, but the risk should be extremely low -- even lower than a household setting. In the household, transmission can occur rarely, but it usually involves direct contact with infected blood, as would occur with the sharing of razors or after a bloody accident. In a preschool, it would be unusual to have direct contact with someone else's blood. Although biting can be an occasional problem with preschoolers, and a particular concern of parents, this would be a rare mode of transmission of HCV (or HIV for that matter). Transmission theoretically could happen if a bite broke the skin, but this possibility is vanishingly small.

What I recommend is that you exercise common sense. The chance of your catching hepatitis C from this child is very low. If the child does cut himself, you should ensure that the wound is promptly covered. If a bite occurs that breaks the skin, wash out the wound. You should not share toothbrushes, but I would think you would not want to do that anyway. I do not think that you need to take any more precautions -- or that there is any reason to create alarm in the other children or their parents. I am an extremely nervous father of a two-year-old, but it would not bother me at all if someone in my son's preschool had HCV.