Synonyms
Poliomyelitis, Polio
Introduction
Polio (poliomyelitis, “polio”) is an infectious disease that belongs to the so-called childhood diseases. It is caused by polioviruses. When unvaccinated, these can cause paralysis by infecting muscle-controlling nerve cells of the spinal cord.
The clinical picture can be very different and can range from mild or asymptomatic symptoms to pronounced paralysis. The poliovirus is transmitted faecal-orally and is highly contagious. 90-95% of infections are completely asymptomatic.
Since the vaccine has been among the vaccinations recommended by the STIKO within the first year of life, polio epidemics have largely decreased. Only in developing countries do polio cases remain high. The incubation period is 1-2 weeks.
After infection with the virus, it multiplies massively. This occurs mainly in epithelia, the lymphatic tissue of the throat and in the intestine. When the virus passes through the blood–brain barrier of the central nervous system, it mainly infects the grey (“polio”) substance of the spinal cord.
This is where the motor anterior horn cells are located and then lead to the clinical manifestation of the infection. The poliovirus comes from the enterovirus family (intestinal viruses). It is highly contagious and is mainly found in the stool and bronchial secretions.
The infection is faecal-oral or via droplet infection. In areas where the poliovirus is still present due to insufficient vaccination rates (Afghanistan and Pakistan), it leads to outbreaks of epidemics due to its high contagiousness (infection rate). The only preventive measure against the poliovirus is a deadly vaccine.
The dead vaccine leads to immunity through active immunization. The symptoms of polio are divided into different stages.
- Minor illness: This manifests itself in unspecific symptoms such as fever, fatigue, sore throat, vomiting and diarrhea.
The symptoms usually persist for 3-5 days and in most cases the disease is over after that.
- Major illness (nonparalytic poliomyelitis): After a latency period of about 1 week, meningism symptoms occur in 5-10% of cases. These include fever around 39°C, neck stiffness, CSF pleocytosis and headaches.
- Paralytic Poliomyelitis: This form of the disease occurs in 1% of cases and often leads to a characteristic double peaked fever curve. This is usually accompanied by severe pain, flaccid paralysis and weakness.
In some cases, vegetative symptoms such as tachycardia, hypertension and sweating may also be present. Since the paralysis can also affect the diaphragm, patients become breathless. There is no loss of sensitivity with polio.
- Bulbar Poliomyelitis: This form of the disease is characterized by high fever, cerebral nerve paralysis and swallowing difficulties.
It also leads to central respiratory paralysis, which makes intubation and artificial respiration necessary.
- Postpoliomyelitis syndrome: This syndrome is very common. Typical are renewed pain and muscle atrophy 10-30 years after the primary infection. The symptoms can occur in the previously affected regions or in muscle regions that have not yet been affected.
