Polio is an infectious disease caused by the poliovirus. The poliovirus predominantly attacks the central nervous system (brain and/or spinal cord). Paralysis occurs with 0.1% of all infections.
Polio is caused by ingesting infected foods. This is how the virus enters the mouth and pharyngeal cavity. From here it spreads to the intestines, where it multiplies and is finally excreted with the feces.
The incubation period (time from the infection to the onset of illness) is around 6 to 10 days. When the infection stops at this stage, it is referred to as asymptomatic or abortive polio. This is the case in around 4% to 8% of all infected individuals.
Non-specific symptoms, which may also occur with other viral infections, are seen in the early stages of the illness: nausea, headaches, fever and possibly diarrhea. In about 1% of all polio infections, the virus perforates the barrier of the intestinal tract and penetrates into the spinal cord and brain via the bloodstream. This can lead to a non-paralytic form of polio that manifests itself through pain in the head, neck and back. In about 0.1% of all infections, the nerve cells in the spinal cord and/or brain are attacked by the virus directly, which results in the paralytic form of polio.
The symptoms of polio and long-term consequences of polio (post-polio syndrome) include:
- A general lack of strength and endurance
- Extreme fatigue
- Difficulty breathing and swallowing
- Intolerance to cold
- Pain in the muscles and/or joints
- Increased muscle weakness/muscle pain
- Decrease in muscle mass (muscle atrophy)
- Increasing joint instability/joint deformities
- Muscle twitching
- Changes in gait pattern and/or an increased tendency to fall
Since no causative antiviral therapy exists, treatment is limited to addressing the symptoms. This includes bed rest with careful nursing, correct positioning, and physical therapy. In addition to physical therapy, follow-up treatment also includes fittings with orthopedic devices such as orthoses. The use of orthoses can result in improved mobility.