Polio: Symptoms, Causes and Treatment

Polio is a highly contagious infectious disease that is caused by a virus. The polio virus attacks the nervous system, and can cause total paralysis in a matter of hours.

HISTORY

Polio was a devastating and usually fatal disease. At the height of the polio epidemic in 1952, 3,000 people of the 60,000 infected died in the US alone. Jonas Salk developed a vaccine that became available in 1955. This drastically reduced the death toll associated with polio. During the 1970's routine immunization with oral polio vaccine (CPV) was introduced worldwide. An advantage of CPV was that it offered contact immunization. An un-immunized person who came into contact with a recently immunized person might become immune too. A disadvantage was that in very rare cases, paralytic polio developed in immunized people or those they had contact with.

In an effort to eradicate the cases associated with CPV, a new form of the vaccine was created. Inactivated polio vaccination (IPV) has now become the standard vaccine against polio. IPV stimulates the immune system to fight off the polio virus if it comes into contact with it. IPV cannot cause polio.

Today, the disease has been eliminated from most of the world. Only a few countries in the world still have polio circulating. These countries are Afghanistan, Egypt, India, Niger, Nigeria, and Pakistan.

TYPES OF POLIO

• Mild upper respiratory infection;
• Diarrhea;
• Fever;
• Sore throat.

Paralytic polio is severe and debilitating; it occurs in less than 2% of cases. The virus causes muscle paralysis and can result in death. The virus leaves the intestinal tract and travels through the blood stream attacking the nervous system. Among those paralyzed 5-10% die because their breathing muscles become paralyzed.

HOW POLIO IS SPREAD

Polio enters the body primarily through the mouth and then it multiplies in the intestines. It is transmitted either through feces or direct human contact. People usually get polio from contaminated food or water.

SIGNS AND SYMPTOMS

The majority of people who contract the polio virus do not become sick and they are often not even aware that they are sick. These people are called carriers. They can still infect people even if they are not sick. In places with poor sanitation and hygiene, a single carrier can infect literally hundreds of people before paralytic polio first appears.

• Sore throat;
• Fever;
• Vomiting;
• Constipation or diarrhea.

Symptoms clear up in about a week.

• Fever;
• Headache;
• Vomiting;
• Diarrhea;
• Fatigue;
• Back and neck pain;
• Back and neck stiffness;
• Muscle spasms or tenderness;
• Joint pain.

• Begins with a fever;
• Headache;
• Neck and back stiffness;
• Constipation;
• Increased sensitivity to light;
• Loose, floppy limbs.

DURATION

Acute polio usually lasts about 2 weeks, but damage to the nerves can never be repaired.

DIAGNOSIS

Polio is often recognized through a physical exam. To confirm a diagnosis, a doctor will take a sample of the throat tissue, stool and cerebrospinal fluid.

COMPLICATIONS

Polio paralysis:

Once the virus is established in the intestines, it can enter the blood stream and invade the central nervous system. As the virus multiplies, it destroys nerve cells which activate muscles. Nerve cells cannot regenerate and the affected muscles no longer work. Leg muscles are most commonly affected, however, in the most severe cases of polio, the muscles in the chest and the neurons in the brain stem are affected. This reduces breathing ability and difficulty in speaking and swallowing. No treatment is available, but symptoms, like pain, can be treated.

Post Polio Syndrome (PPS):

PPS affects some people who have recovered from polio. It usually only appears 10-40 years after the initial illness.

• New muscle weakness in muscles that were not previously affected;
• Fatigue and exhaustion after minimal activity;
• Muscle and joint pain;
• Breathing and/or swallowing problems;
• Sleep-related breathing disorders;
• Intolerance of cold temperatures.

There are no prevention or treatment options available for PPS.

RISK FACTORS

• You are at risk if you have not been immunized against the poliovirus.
• People in areas with poor sanitation and sporadic or no immunization programs are at risk.
• If you travel to an area where polio is still rife you are at increased risk.
• Living with or caring for someone with polio increases your risk of contracting polio.
• People who have immune deficiencies don't have the ability to fight off polio.

PREVENTION

• Improved sanitation and public hygiene could reduce the spread of polio.
• The most effective prevention method is immunization:
  • Children should receive 4 doses of IPV between the ages of 2 months and 18 months;
  • A booster shot should be given when a child is 6 years.

Polio vaccination will protect most people for life and significantly reduce an individual's chance of contracting paralytic polio. There is no cure for polio, so it is very important that every person be immunized. Some people can contract polio even if they have been immunized, because they fail to respond to the vaccine. It is also recommended that you get a booster shot of IPV if you travel to a country where polio still occurs or the oral form of vaccination is used.

SIDE EFFECTS OF IPV

• The most common side effects include swelling and redness at the injection site.
• IPV can cause severe allergic reactions in some children.
• Signs and symptoms of an allergic reaction include:
  • High fever;
  • Breathing difficulty;
  • General weakness;
  • Wheezing;
  • Rapid heart rate;
  • Hives;
  • Dizziness;
  • Pale skin;
  • Swollen throat.

Seek medical attention if any of these symptoms appear following a shot.

WHEN TO PHONE YOUR DOCTOR

• Your child has not completed vaccinations.
• Your child has signs and symptoms of an allergic reaction.
• You had polio years ago and are experiencing unexplained weakness and fatigue.