Poliomyelitis

Poliomyelitis is a highly infectious disease caused by a virus belonging to the Picornaviridae family. It finds a mention even in ancient Egyptian paintings and carvings. The clinical features are varied ranging from mild cases of respiratory illness, gastroenteritis, and malaise to severe forms of paralysis. These have been categorized into inapparent infection without symptoms, mild illness (abortive poliomyelitis), aseptic meningitis (nonparalytic poliomyelitis), and paralytic poliomyelitis. This disease has been associated with crippling deformities affecting thousands of lives throughout the world. Only due to the perseverance and determination of great scientists in 1900s, the genomic structure of the virus and its pathogenesis could be elucidated. Contribution of Salk and Sabin in the form of vaccines—oral polio vaccine (OPV) and the inactivated polio vaccine—heralded a scientific revolution. In 1994, the World Health Organization (WHO) Region of The Americas was certified polio free followed by the WHO Western Pacific Region in 2000 and the WHO European Region in June 2002 of the 3 types of wild poliovirus (types 1, 2, and 3). In 2013, only 3 countries remained polio endemic—Nigeria, Pakistan, and Afghanistan. Global eradication of polio is imperative else the threat of an outbreak will hover forever. Today, all the governments of the world in collaboration with WHO stand unified in their fight against poliomyelitis and the task when achieved will pave the way for eliminating other infections in future.

About 90% of people infected with poliovirus have no signs of the disease or just mild symptoms. If symptoms do occur, they usually appear about seven to 10 days after exposure to the virus. But symptoms can take as long as 35 days to show up.

Early symptoms of polio are like those of influenza (flu) and last about two to 10 days:

Fatigue.

Fever.

Headache.

Neck stiffness.

Pain in the arms and legs.

Vomiting.

While most people fully recover from polio, the disease can cause very serious problems. These problems can sometimes develop quickly (hours after infection) and include:

Numbness, a feeling of pins and needles or tingling in the legs or arms.

Paralysis in the legs, arms or torso.

Trouble breathing because of muscle paralysis in the lungs.

Death when the muscles you use to breathe become paralyzed.

A virus called poliovirus causes polio. The virus enters the body through the mouth or nose, getting into the digestive and respiratory (breathing) systems. It multiplies in the throat and intestines. From there, it can enter the bloodstream. It can also attack the nervous system, the nerve network that helps the brain communicate with the rest of the body.

There are three strains of poliovirus: types 1, 2 and 3. Types 2 and 3 have been eradicated (eliminated), but type 1 still affects people in a few countries.

In some parts of the world, a live poliovirus vaccine is still used. This oral live virus vaccine can very rarely cause polio. In the United States and many areas of the world, this live virus vaccine is no longer used and an inactivated vaccine that cannot cause polio is used instead.

Muscle trauma (provocation poliomyelitis)

Excessive exercise (provocation poliomyelitis)

Injections (provocation poliomyelitis)

Pregnancy.

B-cell immunodeficiency.

Tonsilectomy.

Progressive muscle or joint weakness and pain.

Fatigue.

Muscle wasting (atrophy)

Breathing or swallowing problems.

Sleep-related breathing disorders, such as sleep apnea.

Decreased tolerance of cold temperatures.

The best prevention against polio is a series of four vaccine shots in the arm or leg.

The inactivated polio vaccine used in the United States is very effective and safe, and cannot cause polio.

The recommended vaccination schedule for children is based on age:

First shot when 2 months old.

Second shot when 4 months old.

Third shot between 6 and 18 months old.

A “booster” shot when 4 to 6 years old, for an extra dose to secure protection.

If you didn’t get polio vaccines as a child, you should get three shots in adulthood:

First dose at any time.

Second dose a month or two later.

Final dose six to 12 months after the second.