Poliomyelitis is a viral disease that can affect nerves and lead to paralysis.

Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by direct person-to-person contact, by contact with infected mucus or phlegm from the nose or mouth, or by contact with infected feces.

The virus enters through the mouth and nose, multiplies in the throat and intestinal tract, and then is absorbed and spread through the blood and lymph system. The time from being infected with the virus to developing symptoms of disease (incubation) ranges from 5 - 35 days (average 7 - 14 days).

Risks include:

• Lack of immunization against polio and then exposure to polio
• Travel to an area that has experienced a polio outbreak

In areas where there is an outbreak, those most likely to get the disease include children, pregnant women, and the elderly. The disease is more common in the summer and fall.

Between 1840 and the 1950s, polio was a worldwide epidemic. Since the development of polio vaccines, the incidence of the disease has been greatly reduced. Polio has been wiped out in a number of countries. There have been very few cases of polio in the Western hemisphere since the late 1970s. Children in the United States are now routinely vaccinated against the disease.

Outbreaks still occur in the developed world, usually in groups of people who have not been vaccinated. Polio often occurs after someone travels to a region where the disease is common. Thanks to a massive global campaign over the past 20 years, polio exists only in a few countries in Africa and Asia.

There are three basic patterns of polio infection: subclinical infections, nonparalytic, and paralytic. Approximately 95% of infections are subclinical infections, which may not have symptoms.

SUBCLINICAL INFECTION

• General discomfort or uneasiness (malaise)
• Headache
• Red throat
• Slight fever
• Sore throat
• Vomiting

People with subclinical polio infection might not have symptoms, or their symptoms may last 72 hours or less.

Clinical poliomyelitis affects the central nervous system (brain and spinal cord), and is divided into nonparalytic and paralytic forms. It may occur after recovery from a subclinical infection.

NONPARALYTIC POLIOMYELITIS

• Back pain or backache
• Diarrhea
• Excessive tiredness, fatigue
• Headache
• Irritability
• Leg pain (calf muscles)
• Moderate fever
• Muscle stiffness
• Muscle tenderness and spasm in any area of the body
• Neck pain and stiffness
• Pain in front part of neck
• Pain or stiffness of the back, arms, legs, abdomen
• Skin rash or lesion with pain
• Vomiting

Symptoms usually last 1 - 2 weeks.

PARALYTIC POLIOMYELITIS

• Abnormal sensations (but not loss of sensation) in an area
• Bloated feeling in abdomen
• Breathing difficulty
• Constipation
• Difficulty beginning to urinate
• Drooling
• Fever 5 - 7 days before other symptoms
• Headache
• Irritability or poor temper control
• Muscle contractions or muscle spasms in the calf, neck, or back
• Muscle pain
• Muscle weakness, asymmetrical (only on one side or worse on one side)
  • Location depends on where the spinal cord is affected
  • Progresses to paralysis
  • Rapid onset
• Sensitivity to touch, mild touch may be painful
• Stiff neck and back
• Swallowing difficulty

The health care provider may find signs of meningeal irritation (similar to meningitis), such as stiff neck or back stiffness with difficulty bending the neck. The person also might have difficulty lifting the head or lifting the legs when lying flat on the back, and abnormal reflexes.

Tests include:

• Routine CSF examination
• Test for levels of antibodies to the polio virus
• Viral cultures of throat washings, stools, or cerebrospinal fluid (CSF)