Polio is caused by the poliovirus. It gains entry to the body by fecal-oral spread and can infect the intestinal tract. It can be excreted and may be spread through the feces. Polio attacks the nervous system and can cause paralysis in legs or other parts of the body. Polio is still common in other parts of the world where many people remain unvaccinated.

Because of widespread use of polio vaccine, the United States has not had a naturally occurring case of polio in over 10 years. However, the polio vaccine uses a weakened virus that can be spread from people who have received the vaccine to people who are not immune. Eight to 10 cases of polio are reported each year associated with the vaccine virus, and half of these cases are among persons who have contact with someone who has recently been vaccinated.

All children should be immunized against polio with doses of the oral polio vaccine at 2, 4, and 6 months and at 4 to 6 years of age. When children are vaccinated using live polio vaccine, they may shed live polio vaccine virus in their saliva or feces for several weeks after receiving the vaccine. Anyone who is in frequent contact with recently vaccinated children, especially changing diapers, should be certain they have been vaccinated against polio. Anyone who is not immune to polio or whose immune system is compromised for any reason, such as persons on chemotherapy for cancer, persons with HIV infection or AIDS, or pregnant women, should not have contact with the saliva or feces of a person who may be shedding polio vaccine virus. To avoid the risk of exposing immune deficient persons to live polio vaccine virus, persons with normal immune systems who share the same household may be immunized with an inactivated ("killed") polio vaccine. Persons with immune deficiency should avoid contact with diapered children who have been immunized for at least 1 month after the immunization. Following good hand washing technique after changing children's diapers is essential in preventing transmission of the vaccine virus after children have been immunized.

© January 1997