Polio is an infectious(contagious) viral disease that causes nerve injury in its most severe form, leading to stroke, difficulty breathing, and sometimes death.
In the United States, polio naturally occurred in 1979. Today, despite global efforts to eradicate polio, poliovirus continues to infect children and adults in parts of Asia and Africa.
The Centers for Disease Control and Prevention (CDC) advises you to take precautionary measures to protect yourself from polio if you travel to polio-prone areas.
Vaccinated adults and those planning to travel to a polio-affected area should receive a booster dose of the inactivated poliovirus vaccine (IPV). Immunity after a booster lasts a lifetime.
Although polio can cause stroke and death, most people infected with the virus do not become ill and are unaware that they are infected.
Some people who develop symptoms from the poliovirus develop a form of polio that does not lead to stroke (abortion polio). It usually causes the same mild, flu-like signs and symptoms as are common to other viral illnesses.
Symptoms, which can last up to 10 days, include:
- Sore throat
- Back pain or stiffness
- Neck pain or stiffness
- Muscle weakness or tenderness
- Pain or stiffness in the arms or legs
This most serious form of the disease is rare. Initial signs of paralytic polio, such as fever and headache, often mimic those of nonparalytic polio. Within a week, however, other signs and symptoms appear, including:
- Loss of reflexes
- Loose and floppy limbs (flaccid paralysis)
- Severe muscle aches or weakness
Post-polio syndrome is a cluster of disabling signs that affect some people years after having polio. Common symptoms include:
- Progressive muscle or joint weakness and pain
- Breathing or swallowing problems
- Decreased tolerance to cold temperatures
- Muscle wasting (atrophy)
- Sleep-related breathing disorders, such as sleep apnea
The poliovirus is spread through direct contact with an infected person or contaminated food and water in general. People who carry the poliovirus can spread the virus in their stools for several weeks. People who have the virus but no symptoms can transmit the virus to others.
Polio mainly affects children younger than 5. However, anyone who has not been vaccinated is at risk of developing the disease.
Paralytic polio can lead to temporary or permanent muscle paralysis, bone deformities, disability, and death.
When to see a doctor
Check with your doctor for polio vaccination recommendations before moving to a part of the world where polio still occurs naturally or where the oral polio vaccine (OPV) is used in Central and South America, Africa, and Asia.