Introduction

Poliomyelitis is a highly infectious viral disease of the central nervous system. Poliomyelitis is also known as infantile paralysis because it most frequently causes paralysis in infants and young children.

Wild poliovirus transmission has ceased in all industrialized countries and much of the developing world. Until all countries have stopped wild poliovirus transmission, all areas remain at high risk of importations and even the re-establishment of endemic transmission.

Causative agent: Polivirus types 1, 2 and 3 (genus Enteroviruses).

Mode of transmission: The virus is spread predominantly by the faecal-oral route from person to person, although rare outbreaks caused by contaminated food or water have occurred. Poliovirus infection occurs in the GI tract with spread to the regional lymph nodes and in a minority of cases to the central nervous system.

Incubation period: Commonly 7 – 14 days for paralytic cases, reported range of 3 to possibly 35 days.

Sign & Symptoms

About 90% of cases show no symptoms, producing a lifelong immunity. Others however display a flu-like illness and then recover. While about 1 in every 1000 cases of the illness develops a paralytic illness affecting the nervous system. Flaccid paralysis occurs in less than 1% of poliovirus infection.

A minor illness recognized in 10% of infections with symptoms including fever, malaise, headache, nausea and vomiting.

If the disease progresses to major illness, severe muscle pain and stiffness of the neck and back with flaccid paralysis may occur. The paralysis is usually asymmetric, with fever present at the onset. The legs are affected more often than the arms.

Complication

Paralysis of the respiration and/or swallowing muscles can be life threatening. Permanent limb paralysis may occur.

Treatment

Specific treatment: None, attention during acute illness to complications of paralysis. Expert knowledge and equipment is required especially for patients in need of respiratory assistance.

Physical therapy is used to attain maximum function after paralytic poliomyelitis and can prevent many deformities that are late manifestations of the illness.

Prevention & Precautions

Vaccination

Type of vaccine: Live oral (OPV) or killed inactivated injectable (IPV)

Number of doses: Four of OPV, three of IPV

Schedule: OPV at 6, 10, and 14 weeks of age (plus a dose at birth in endemic countries)

IPV at 2, 4 and 12-18 months.

Contraindications: None

Before departure: 4 weeks

Recommended for: All travelers to developing countries where poliomyelitis is still transmitted

Special precautions: Immunocompromised travelers should receive IPV rather than OPV

General advices to prevent infection via faeco-oral route: –

• Wash hands and soap before eating, handling food and after using toilet.
• Boil any drinking water of unsure cleanliness or drink bottled water (checking seal is in place) or carbonated water.
• Foods that require little handling are safer. Peel all fruit. Avoid salads or uncooked vegetables.
• Ensure that seafood, fish and meat are thoroughly cooked and eaten hot whenever possible.
• Eat early if one is served a buffet.
• Avoid ready – to – eat food from roadside vendors