The Different Types Of Poliomyelitis

The different types of poliomyelitis (also called polio)  are infectious diseases that primarily affect people’s nervous systems. As international sources such as the World Health Organization say, poliovirus, which is a viral substance consisting of RNA and a protein shell, causes this disease.

According to several studies, experts have distinguished between three serotypes (different variants). Experts discovered the last case of serotype PV-1 in India in 1999. Experts thus consider it extinct. Yet serotypes PV-1 and PV-3 are still circulating among the population today. Both are highly contagious and cause crippling poliomyelitis.

About polio and its spread

The World Health Organization reported figures that allowed people to get an idea of ​​the global poliovirus situation. Some of them are as follows:

• In 1988, more than 350,000 cases were reported globally when the campaign to combat this disease began.
• Due to containment and vaccination, only 18 cases were reported worldwide in 2018 (a decrease of 99%).
• This disorder  primarily affects children under the age of five.

As you can see, polio is basically a disease that belongs to the past. Still, one has to be careful. Experts estimate that more than 200,000 new cases could occur in less than 10 years if the virus is not completely eradicated.

Types of poliomyelitis

Clinical studies emphasize that there are four primary types of polio. These are the following:

• Subclinical polio or asymptomatic polio. It covers about 90% of cases worldwide.
• Minor diseases that do not affect the central nervous system. Up to 9% of cases. It causes fever, malaise, nausea, vomiting, diarrhea and constipation.
• Non-paralyzing serous meningitis. 1 to 2% of cases.
• Paralyzing poliomyelitis. Less than 1% of cases.

Since the first two types are benign in their development, we will focus on non-paralyzing serous meningitis and paralyzing poliomyelitis. Below we will explain everything you need to know about both disorders.

Non-paralyzing serous meningitis

According to scientific research, serous meningitis is an infectious process that  affects the meninges of the central nervous system and causes it to swell. It causes the following symptoms:

• Fever.
• Headache and stiffness in the neck.
• General malaise.
• Pain in muscles.
• Loss of appetite and vomiting.

According to other bibliographic references, viral serous meningitis (such as that caused by poliovirus) has a good prognosis. It is not just poliovirus that is causing it. In fact, enterovirus, herpes virus and HIV can also cause it.

Despite the fact that this condition is benign, it  may require hospitalization and antibiotics. We say antibiotics, even if they are caused by viruses, because healthcare professionals begin treatment immediately in the most affected patients as a preventative measure against a much more dangerous bacterial meningitis.

Paralyzing poliomyelitis

This is the most severe manifestation of poliomyelitis. The sources we cited above estimate that one in 200 patients will suffer from irreversible paralysis,  of which 10% will die from musculoskeletal problems.

It is a simple task to detect this severe type as the symptoms are very aggressive. Bibliographic references report that five days after infection, processes such as intense malaise (pain in muscles) and limiting muscle cramps occur, ending in chronic weakening of the limbs.

The paralysis usually reaches its peak within a week after the infection.

The mortality rate in acute stages is 5 to 20%. Worst of all, there is no treatment once it occurs. Yet, paralysis typically improves over the years following the critical stages. It is due to a resetting process that the nerves that remain undamaged undergo.

Depending on the affected area, there are three types of crippling poliomyelitis, which are the following:

• Spinal.
• Bulbo-spinal.
• Bulbær.

50% of patients who survive this severe manifestation suffer from lifelong impairment, and 20 to 85% of patients with childhood poliomyelitis may develop post-polio syndrome. It causes progressive muscle wasting, which limits the functional abilities.

This you should keep in mind about the types of polio

As we have explained in this article, poliomyelitis is a disease that is under control in most areas of the world. In addition, 90% of cases are asymptomatic, which is why it is unlikely that a clinical picture is associated with poliovirus today.

On the other hand  , there is a very effective oral and intravenous polio vaccine  with an effectiveness of 99% after three doses. If global efforts to eradicate it continue, polio will soon be a thing of the past.