Poliomyelitis (Polio) - Types, Causes, Symptoms and Prevention

Poliomyelitis or Polio or Infantile Paralysis

 

Poliomyelitis, also called polio or infantile paralysis. Polio is an acute viral infectious disease caused by the poliovirus (RNA viruses); three types  PV-1, PV-2, and PV-3. 

Mostly polio infection occurs due to type-l poliovirus.  Viruses colonize the gastrointestinal tract (GI), specifically in the oropharynx and  intestine.

Poliovirus is highly contagious and spreads through person to person contact. This viruses lives in an infected person’s throat and intestines.

Polio or poliomyelitis Infection mainly affects children under age of  5 years.

The word “myletis” means an inflammation in the “spinal cord”, which affect the insulating material covering nerve cell fibres, “myelin”.

“Polios”- grey

“Myelos” - spinal cord

Epidemiology Triad

Agent  - Causative agent of  Poliomyelitis is poliovirus (RNA viruses) The causative agent of poliomyelitis is poliovirus.  Poliovirus is a member of the subgroup enterovirus and picornaviridae family.

The virus found in the oropharyngeal secretions and in intestine of a patient infected with polio virus.

 

Host- Humans are the only natural hosts or reservoir of poliovirus. This virus usually attack the children below 5 years of age.

 Poliomyelitis is a disease of infancy and childhood. Most occurs between 6 months to 3 years.

 

Environment- Infection increases in dirty, overcrowded place, poor sanitation and can occur more in rainy season. Contaminated water, food, flies are environmental factor which can cause poliomyelitis.

 

Mode of Transmission

 

Portal of entry; faecal–oral route

 

1. Through faeces (fecal-oral route) contact - Contact with the feces (poop) of an infected person. Directly spread with fingers contaminated with the virus.

2.  Indirectly spreads by contaminated milk, water, food,  article etc.

3. Flies play an important role in spreading the disease

4.  Through droplets (saliva) infection- Direct contact with infected person cause spread of infection.

5. Oral-oral transmission by way of an infected person's saliva

6. Sneezing or coughing also spreads the virus

7. Spreads through person to person contact

 

Types  of Polio

 

Three types- 

1. Non- paralytic polio (NPP) - abortive polio

2. Paralytic polio

3. Post-polio syndrome

 

1. Non- paralytic polio

 

In non- paralytic polio, poliovirus neither entered the central nervous system (CNS) nor damaged neurons.

Non-paralytic polio symptoms are-

Fever, sore throat, Headache, vomiting, fatigue, backache, neck pain, stiffness, Pain/stiffness in the legs, muscle weakness or tenderness.

 

2. Paralytic polio

 

Symptomatic person develop paralytic polio, it characterized by severe back, neck, and muscle pain with muscle weakness, loss of reflexes, and paralysis.

Main symptoms are-

Loss of reflexes, severe muscle aches or weakness,

It lead to paralysis in the spinal cord (spinal polio) and brain stem (Bulbar polio)  

 

Spinal poliomyelitis is the most frequent and characterized by flaccid paralysis (muscles to shrink and become flabby) of muscles innervated by the motor neurons of the spinal cord.

Bulbar poliomyelitis results from the destruction of neurons of the brainstem and can be fatal, lead to respiratory or cardiac failure.

 

3. Post polio syndrome

 

Post polio syndrome (PPS) refers to disorder of the nerves and muscles in which a cluster of potentially disabling signs and symptoms that appear decades after they have had polio.

Symptoms of post-polio syndrome -

Progressive muscle and joint, pain in muscle and joints, Fatigue, Breathing problems, Swallowing problems, Muscle shrinkage, Decrease tolerance of cold temperature - Sensitivity to cold temperatures

 

Causes of Polio Infection

 

1. Caused by poliovirus

2. Colonizes in the gastrointestinal track in intestine

3. Spread through -

a. Feco- oral route 

b. Intake of contaminated food or water

 

 

Incubation period

 

The incubation period is 7 to 35 days

Non-paralytic poliomyelitis - The incubation period for non-paralytic poliomyelitis is 3-6 days.

Paralytic poliomyelitis - The incubation period of paralytic poliomyelitis usually is 7 to 21 days (onset of paralysis in paralytic poliomyelitis).

The cases of polio are infective 7-10 days before and after the onset of symptoms means a period of communicability is 7- 10 days before and after the onset of symptoms.

 

Life cycle of Polio Virus

 

1. Enter through the mouth

2. Adhere to Intestine if the virus finds a cell with the correct receptor in the intestine

3. Infection begins

4. The polio virus (RNA) enters the intestinal cell 

5. The viral RNA takes over the cell

6. Replicates (RNA) in intestinal cell

7. New RNA + new capsids (protein shell of a virus) = New polio viruss

 

8. Thousand of polio virus burst out of cell and enters the blood stream

 

 

Pathophysiology of  Poliomyelitis

 

Polio is caused by a virus called polio virus

 

1. Virus gets enter through the mouth

2. Then moves to gastrointestinal tract (GI) Track towards  intestine

3. Primary multiplication of the virus occurs at the site of pharynx and gastrointestinal tract

3. Virus invades local lymphoid tissue, enters the bloodstream

4. Reaches the spinal cord

5. Attacks the nerves cell of CNS

6. Destruction of motor neurons of brain stem

7. Result in polio paralysis; poliomyelitis

 

The virus is usually present in the throat and in the stool of individual before the onset of illness. One week after onset, less virus present in the throat, but virus continues to be excreted in the individual stool for several weeks.

 

Clinical Manifestation

 

1. Fever, Headache, Fatigue/Restlessness, Vomiting, Diarrhoea, Cough/cold, sore throat

2. Asymmetrical flaccid paralysis

3. Anorexia/Nausea/ Malaise

4. Abdominal pain

5. Stiffness of neck and back muscle

6. Difficulty in swallowing

7. Weak or diminished deep tendon reflexes before the onset of paralysis

 

Paralysis occur in-

 

1. Lower extremities (most common) - Asymmetric paralysis that most often involves the legs.

2. Face

3. Oesophagus

 

Warning sign of paralysis -

 

1. Muscular weakness

2. Stiffness and pain in the neck, back and lower part of body

 

 

Laboratory Test

 

1. (RT-PCR) test - Reverse transcriptase -polymerase chain reaction test

2. Cerebrospinal fluid (CSF) test

3. Blood test

4. Stool examination

5. Serology test

Highly infectious 7-10 days before and after onset of symptoms virus present in stool 3-6 weeks.

 

Prevention and Control

 

The poliovirus is found in the stool and throat of infected individual.

Polio virus remains in throat secretions, stools of infected person which can infect water, milk, food and other substance, article.

 

1. Immunization – Vaccine used for immunization is of two types-

a. Inactivated polio vaccine (IPV) – it is Salk vaccine, it contain all three types of polio which are inactivated by formalin. It is inactivated (killed) polio vaccine.  Administered by injection.

 

b. Oral polio vaccine (OPV) – Sabin (oral) vaccine and contain live virus oral polio vaccine induces humoral and intestinal immunity and highly effective in producing immunity to poliovirus. It is attenuated (weakened)  poliovirus vaccine. Administered by drop.

 

Vaccination is the best way of protection against polio infection and the only way to control  the spread of disease.

 

Vaccine            Dose                    Route            Age

Oral polio             2 drops doses          oral              at birth- 0 dose

Vaccine                                                                    6 week – 1st dose                            (OPV)                                                                      10 week – 2^nd dose,

                                                                                 14 week – 3^rd dose,

                                                                                 16-24 months- booster dose

 

Vaccine vial monitor (VVMs)   - Introduced on the oral polio vaccine (OPV), it is heat and temperature indicator, that provides information on the exposure of a given vaccine vial to heat and temperature. If gets darker, then vaccine must not be used.

                                                                                                

Note- Oral polio vaccine should be kept in 4°C,  if the vaccine is stabilised vaccine

For Non-stabilised vaccine, should kept at -20°C in deep freeze.

 

2. Passive immunization – human normal Ig is used as a passive immunization

 

 

Complications of Poliomyelitis

 

Polio  is a disease of digestive track and cause paralysis and deformity. Polio virus infection spreads from person to person and can infect a person’s spinal cord that causing paralysis.

1. Most severe complication of polio is paralysis.

2. Lead to problems with swallowing, breathing and bowel and bladder function

3. Paresthesia (feeling of pins and needles in the legs)

4. Meningitis (infection of the covering of the spinal cord and or brain)

5. Paralysis or weakness in the lower extremity and also in arms, legs, or both

 

 

Control of Polio

 

1. Early diagnosis and treatment of cases

2. Surveillance

3. Isolation

4. Environmental sanitation

5. Pulse polio campaign/ immunization

 

 

Pulse polio campaign/ immunization In India

 

It is immunization campaign.

Pulse Polio Immunization programme was launched in India in 1995, established by Government of India.

Aim- to eliminate poliomyelitis in India by monitoring polio cases, vaccinating under 5 year’s children against polio virus through large scale.

 

India managed to successfully eradicate polio with the global initiative of eradication of polio, India was officially declared polio-free by WHO.

 

 

Nursing Diagnosis

 

1. Imbalanced Nutrition-Less than body requirement related to anorexia, nausea, and vomiting

2. Ineffective airway clearance relate to muscle paralysis

3. Acute pain related to the infection that attack the nerve

4. Impaired physical mobility related to paralysis

 

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