Polio virus

---

---

There are three serotypes (1-3)

It was the most common causes of flaccid paralysis  2-3 decades ago.

Transmission

Transmission is through faecal-oral route

Incubation period

Incubation period-1 to 2 weeks.

Infectious period- 3 days before the onset of illness to 1 week after the onset.

 

---

Clinical presentations

---

 

Prodromal Phase

Acute onset of fever, malaise.

 

Aseptic meningitis

Vomiting, fever, headache and stiff neck.

May experience spastic type of paralysis and increased deep tendon reflex.

 

Paralytic phase

Flaccid paralysis

It only affects the motor neuron

(Muscle tone and tendon reflex are reduced)

 

Complications

Ø      Bulbar poliomyelitis

Ø      Deformity of the lower limb

Ø      Disability

 

---

 Investigation 

---

Tests

Stools, pharyngeal swab and CSF

Virus isolation- cell culture

Identification is done by acid labile testing and neutralisation test.

 

---

Management

---

 

Most isolates are vaccine strains. They do not cause problems in immunocompetent patients. Wild strains if isolated should be reported to the communicable disease control centres.

There is no specific treatment however immunocompromised patients with persistent wild or vaccine strains polio virus infection might benefit from therapy with human normal immunoglobulin or piloconaril (antiviral)

 Symptomatic therapy is essential to reduce disability and deformity of the bone.

 

---

Prevention

---

 

There is an effective vaccine.

Inactivated polio vaccine is advocated by many expertise although attenuated polio vaccine was used to eradicate the virus from a number of countries.

Safe and clean water supply and proper disposal of waste are the corner stone of controlling any water borne infection.

 

---

---