What you need to know about Polio
Recently, a patient developed severe muscle weakness, or paralysis, from polio in New York. Since the individual’s diagnosis, state public health officials have been testing wastewater for polio viruses, detecting it in two counties, as well as in New York City at levels suggesting hundreds of people have the virus in their stool.
What is polio?
Polio refers to three different viruses that cause the same disease, otherwise known as types one, two and three. Nowadays, most people do know much about polio viruses because of effective vaccines.
Polio viruses found in nature disappeared from North and South America in 1991, with the last natural case being found in Europe in 1998. Alternatively, cases reported throughout the 1990’s were due to the oral polio vaccine, a live virus, which could mutate. At that time, it led to between 12 and 15 diagnoses annually in children with weak immune systems. Due to these cases, the United States stopped using the oral polio vaccine in 2000 and only continues to use the injectable polio vaccine, which is not a live virus. Sadly, polio continues to cause disease in a few African and Asian countries.
Polio is typically spread by the fecal-oral route when a person puts something in their mouth that is contaminated with poop. Young children are at especially high risk of infection as they often place objects into their mouths, as are families and those in classroom settings.
Most individuals do not have symptoms when infected. The following, which is based on information from the Centers for Disease Control (CDC), highlights symptoms found when an infection takes place:
- 75% have no symptoms.
- 25% have mild symptoms, including: fever, sore throat, fatigue, headache, nausea or stomach pain.
- 5% have central nervous system inflammation in the brain and/or spinal cord called meningitis or encephalitis. Patients have fevers, severe headaches and may have behavior changes.
- 0.05% to 0.5% of infected patients will develop paralysis because of muscle weakness. This may be permanent or improve over time. Polio can kill if the muscles that allow us to breath are paralyzed. If the paralysis improves over time, the muscles may again become weak decades later, which is called post-polio syndrome.
The best way to prevent polio is to receive routine vaccines. If people are not vaccinated, it is possible that polio will cause more paralysis in the United States. In addition, especially as there is no treatment for paralysis caused by polio, health officials greatly encourage hand washing with soap and water, or a waterless alcohol rub.
Children receive the polio vaccine as part of routine immunizations at two, four and six months, and, again, between ages four and six. It is unknown how long the vaccine protection will last so the CDC recommends a single lifetime booster for adults travelling to parts of the world with polio.