Poliomyelitis (Polio): Causes, Symptoms, Diagnosis, and Prevention

Overview

Poliomyelitis, commonly known as Polio, is a viral infection characterized by the sudden onset of flaccid paralysis. The poliovirus initially infects the gastrointestinal tract and then spreads to nearby lymph nodes. In rare cases, it reaches the central nervous system, leading to paralysis.
Polio is a highly contagious viral disease that enters the body through the mouth, multiplies in the intestines, and can invade the nervous system, causing complete paralysis within hours. It primarily affects children under the age of five.

Causes of Polio

Polio is caused by the poliovirus, which belongs to the enterovirus genus. There are three types of poliovirus — Type 1, Type 2, and Type 3 — and all types can cause paralysis.

At-Risk Groups

The disease primarily affects children under five years of age, especially those who are unvaccinated or living in areas with poor sanitation.

Modes of Transmission

Poliovirus spreads mainly through the fecal-oral route, meaning infection occurs when contaminated food or water is ingested.
It can also be transmitted through respiratory droplets or saliva from an infected person.

Incubation Period

The incubation period for poliovirus ranges from 3 to 35 days, and for paralytic cases, it typically falls between 7 to 14 days.

Signs and Symptoms

1. Abortive Poliomyelitis (Non-Paralytic Infection)

This mild form occurs in about 4–8% of infections and does not cause paralysis. Symptoms may include:

Fever lasting two to three days
Fatigue and muscle pain
Headache
These symptoms are often indistinguishable from those caused by other viral infections.

2. Non-Paralytic Polio

In this form, symptoms resemble those of the flu, such as:

Fever
Sore throat
Headache
Vomiting
Fatigue
Muscle stiffness or pain in the back, neck, arms, or legs
Mild meningitis

3. Paralytic Polio

This severe form occurs in less than 0.1% of cases. It usually develops in two stages — the first stage mimics non-paralytic polio, followed by:

Muscle pain
Flaccid paralysis (sudden muscle weakness)
Stiffness in the neck and back

Diagnosis

Doctors often suspect polio based on clinical symptoms, but a laboratory test is needed to confirm it.
The definitive diagnosis is made by isolating the virus from a stool sample, as recommended by the World Health Organization (WHO).

Treatment

There is no cure for poliomyelitis. Treatment focuses on managing symptoms, relieving pain, and preventing complications. Physical therapy may help maintain muscle strength and mobility.

Prevention

Since there is no specific treatment, vaccination is the only effective way to prevent polio. In Saudi Arabia, both the inactivated polio vaccine (IPV) and the oral polio vaccine (OPV) are used.

Vaccination Schedule

A. Primary Doses

First dose (IPV): at 2 months
Second dose (IPV): at 4 months
Third dose (IPV + OPV): at 6 months

B. Booster Doses

First booster (OPV): at 18 months
Second booster (OPV): at school entry age

C. Additional Doses

Additional doses may be given through mass immunization campaigns, depending on local disease prevalence and public health policies.

Key Takeaway

Polio remains one of the most serious viral diseases, capable of causing lifelong paralysis within hours. The most effective protection is timely vaccination and maintaining good hygiene practices to prevent virus transmission.

SEO Keywords:

Poliomyelitis, Polio disease, causes of polio, symptoms of poliomyelitis, paralytic polio, oral polio vaccine, inactivated polio vaccine, polio prevention, WHO polio vaccination schedule, children polio infection.