Poliomyelitis (polio) is a highly infectious viral disease that primarily affects children under five. The virus is transmitted by person-to-person spread mainly through the fecal-oral route or, less frequently, by contaminated water or food. The virus multiplies in the intestine, from where it can invade the nervous system and cause paralysis.
The best way to avoid infection is by vaccination. Adults traveling to areas where polio cases are still occurring should receive one dose of IPV if they have previously been immunized against polio. If they have not been vaccinated, they will need a complete vaccination series consisting of the three doses.
Additional steps to prevent the spread of polio include washing hands with soap and water after using the bathroom and changing diapers, and before preparing food and eating. If soap and water are not available, use an alcohol-based hand rub.
The inactivated polio vaccine (IPV) is the only polio vaccine that has been given in the United States since 2000. It is provided by a shot in the arm or leg, depending on their age. Oral polio vaccine (OPV) is used in other countries.
The CDC recommends that children get four doses of the polio vaccine. They should get one dose at each of the following ages:
Two months’ old
Four months’ old
6 through 18 months’ old
4 through 6 years’ old
Almost all children (99 out of 100) receiving the recommended doses of the polio vaccine will be protected from polio.
The first polio vaccine was available in the United States in 1955. Due to widespread polio vaccination, the United States has been polio-free since 1979. But poliovirus is still a threat in some countries.
Approximately 90% of people infected with poliovirus have mild or no symptoms. If symptoms do occur, they usually appear about seven to 10 days after exposure to the virus but can take as long as 35 days to show up.
Early symptoms of polio are similar to influenza (flu) and last about two to 10 days:
While most people fully recover from polio, the disease can cause severe problems. These problems can sometimes develop quickly (hours after infection) and include: