Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by direct person-to-person contact, by contact with infected mucus or phlegm from the nose or mouth, or by contact with infected feces. The virus enters the mouth and multiplies in lymphoid tissues in the pharynx and intestine. Small numbers of virus enter the blood and go to other sites where the virus multiplies more extensively.

 

 

Poliomyelitis is a disease caused by infection with the poliovirus. The virus spreads by direct person-to-person contact, by contact with infected mucus or phlegm from the nose or mouth, or by contact with infected feces. The virus enters the mouth and multiplies in lymphoid tissues in the pharynx and intestine. Small numbers of virus enter the blood and go to other sites where the virus multiplies more extensively. Another round of viremia i.e. virus in the bloodstream leads to invasion of the central nervous system (CNS), the spinal cord and brain, the key sites struck by the virus. Acute poliomyelitis is a disease of the anterior horn motor neurons of the spinal cord and brain stem caused by poliovirus. Flaccid asymmetric weakness and muscle atrophy are the hallmarks of its clinical manifestations, due to loss of motor neurons and denervation of their associated skeletal muscles.

Causes

Poliovirus may infect a person who is not vaccinated against the disease. There are 3 types of polioviruses. All three can cause paralysis, but type 1 cause’s paralysis most often followed by types 3 and 2. Most epidemics are caused by type 1. Types 3 and 2 cause cases of paralysis associated with vaccination.

Risk Factors

• Lack of immunization against polio and then exposure to polio
• Travel to an area that has experienced a polio outbreak
• Living with or caring for someone who may be shedding poliovirus
• Handling laboratory specimens that contain live poliovirus
• A compromised immune system, such as occurs with HIV infection
• Tonsillectomy makes an individual more susceptible for polio infection
  
• Extreme stress or strenuous physical activity after being exposed to poliovirus, both of which can depress the immune system

Symptoms of Poliomyelitis

Polio occurs in three forms and depending upon the form of polio the symptoms are –

Subclinical Infection

• General discomfort or uneasiness
• Headache
• Red throat
• Slight fever
• Sore throat
• Vomiting

Non paralytic Poliomyelitis

• Back pain or backache
• Diarrhea
• Excessive tiredness, fatigue
• Headache
• Irritability
• Leg pain especially in calf muscles
  
• Moderate fever
• Muscle stiffness
• Muscle tenderness and spasm in any area of the body
• Neck pain and stiffness
• Pain in front part of neck
• Pain or stiffness of the back, arms, legs, abdomen
• Skin rash or lesion with pain
• Vomiting

Paralytic Poliomyelitis

• Abnormal sensations in an area
• Bloated feeling in abdomen
• Breathing difficulty
• Constipation
• Difficulty beginning to urinate
• Drooling
• Fever 5 - 7 days before other symptoms
• Headache
• Irritability or poor temper control
• Muscle contractions or muscle spasms in the calf, neck, or back
• Muscle pain
• Muscle weakness, asymmetrical (only on one side or worse on one side)
• Location depends on where the spinal cord is affected
• Progresses to paralysis
• Rapid onset
• Sensitivity to touch; mild touch may be painful
• Stiff neck and back
• Swallowing difficulty

Complications

• Aspiration pneumonia
• Cor pulmonale
• High blood pressure
• Kidney stones
• Lack of movement
• Lung problems
• Myocarditis
• Paralytic ileus resulting in loss of intestinal functions
  
• Permanent muscle paralysis, disability, deformity
• Pulmonary edema
• Shock
• Urinary tract infections

Diagnosis of Poliomyelitis

Diagnosis can be made on symptoms like back stiffness, abnormal reflexes and difficulty in swallowing and breathing. Some investigations like Cerebro Spinal Fluid examination may show evidence of poliovirus.

Treatment

• The treatment is mostly symptomatic and can include –
• Antibiotics for infections
• Analgesics if there patient complains of pain
• Nutritious balanced diet
• If needed patient can be put on ventilators for artificial breathing.