Poliomyelitis

Poliomyelitis

Often called polio or infantile paralysis, is an infectious disease caused by a virus.

This virus is a member of the enterovirus subgroup of the Picornaviridae family and has three serotypes: PV1, PV2 and PV3.

The tissue most commonly affected is the spinal cord which leads to the classic manifestations of paralysis.

Epidemiology

As a result of a massive, global vaccination campaign over the past 20 years, polio exists only in a few countries in Africa and Asia. In the Philippines, the last polio case was recorded in 1993, and in 2000 the Philippines was certified polio-free (UNICEF, 2005).

Transmission

Person-to-person spread of poliovirus via the fecal-oral route is the most important route of transmission, although the oral-oral route may account for some cases.

Risk Factors

©Age: Infants and elderly

©Living with an infected person

©Compromised immmune system

©Lack of immunization against polio

©Extreme stress or strenous activity

©Travel to an area that has experienced a polio outbreak

Pathogenesis

The mouth is the portal of entry of the virus and primary multiplication of the virus occurs at the site of implantation in the pharynx and gastrointestinal tract. The virus is usually present in the throat and in the stools before the onset of illness. One week after onset there is little virus in the throat, but virus continues to be excreted in the stools for several weeks. The virus invades local lymphoid tissue, enters the blood stream, and then may infect cells of the central nervous system. Replication of poliovirus in motor neurons of the anterior horn and brain stem results in cell destruction and causes the typical manifestations of poliomyelitis.

Paralytic polio is classified into three types...

© Spinal polio - the most common, and accounted for 79% of paralytic cases from 1969-1979. It is characterized by asymmetric paralysis that most often involves the legs.

©Bulbar polio - accounts for 2% of cases and leads to weakness of muscles innervated by cranial nerves.

©Bulbospinal polio - it accounts for 19% of cases and is a combination of bulbar and spinal paralysis.

Clinical Features

The incubation period for poliomyelitis is commonly 6 to 20 days with a range from 3 to 35 days. The response to poliovirus infection is highly variable and has been categorized based on the severity of clinical presentation.

PATHOGNOMONIC SIGN

flaccid paralysis, weakness or paralysis and reduced muscle tone.

• PATHOGNOMONIC SIGN• flaccid paralysis, weakness or paralysis and

reduced muscle tone.

ASSESSMENT

S E V E R I T Y O B J E C T I V E S U B J E C T I V E P R O B L E M i D E N T I F I E D

INAPPARENT INFECTION no manifestation no manifestation

ABORTIVE POLIOMYELITIS

• sore throat

• abdominal pain

• constipation or diarrhea

• nausea

• decreased appetite

• upper respiratory tract infection

• fever

• Pain

• Fluid Volume Deficit

• Imbalanced Nutrition: less than body requirement

• Fatigue

• HyperthermiaNONPARALYTIC POLIOMYELITIS

• stiffness of the neck, back, and/or legs

• Pain

• Hyperthermia

PARALYTIC POLIOMYELITIS

• severe muscle aches and spasms in the limbs or back

• flaccid paralysis

• loss of superficial reflexes

• diminished deep tendon reflexes

• weakened breathing

• flushed or blotchy skin

• Disturbed body image

• Risk for Injury

• Self-Care Deficit

• Impaired breathing pattern

DIAGNOSTIC STUDIES

© Virus Culture

The laboratory diagnosis of polio is confirmed by isolation of virus by cultures, from the stool or throat swab or cerebrospinal fluid (rare). In an infected person, the virus is most likely to be cultured in stool cultures.

Serologic test

Acute and convalescent serum sample may be tested for rise in antibody titer (antibodies to the poliovirus), but the report can be difficult to interpret as in many cases, the rise in titer may occur prior to paralysis.

Cerebrospinal fluid test

Infection with polio virus may cause an increased number of white blood cells and a mildly elevated protein level in cerebrospinal fluid

MANAGEMENT

Treatment of pain with analgesics (such as acetaminophen). Antibiotics for secondary infections (none for poliovirus). Fluid Therapy Bed rest (until fever is reduced) Adequate diet Minimal exertion and exercise Hot packs or heating pads (for muscle pain). Prolong rehabilitation may be necessary including braces,

splint or surgery.

Hospitalization (may be required for those individuals who develop paralytic poliomyelitis).

If the respiratory is involved, LONG-TERM VENTILATION is necessary.

Physiotherapy may be necessary. Place the child on firm mattress with support for feet,

change position frequently.Encourage oral intake of food and fluid. Catheterization of distended bladder may be

necessary.

MANAGEMENT

PREVENTION

• The best preventive measure for poliomyelitis is ensuring hygiene and encouraging good sanitation practices. But, polio prevention begins with polio vaccination. Polio vaccine has been developed against all 3 subtypes of the poliovirus and is very effective in producing protective antibodies that induces immunity against the poliovirus and provides protection from paralytic polio.

Two types of vaccine are available: an inactivated (killed) polio vaccine (IPV) and a live attenuated (weakened) oral polio

vaccine (OPV).

ADVANTAGES DISADVANTAGES

Inactivated Polio Vaccine It is inactivated, so it cannot replicate, and cannot be shed in the stool of a vaccinated person.It cannot cause vaccine associated paralysis, and is safe to use in immunodeficient persons or in household contacts of immunodeficient persons.

Requires injection More expensiveProduces less local gastrointestinal immunityRecipients could become infected with wild polio virus

Oral Polio Vaccine It is very easy to administer Less expensive Produces excellent intestinal immunity which helpsPrevent infection with wild virus

May cause vaccine-associated paralytic polio

GUIDE ON POLIOMYELITIS IMMUNIZATION (OPV)

Route Oral

Site Mouth

Number of Dose 3 doses

Age at First Dose 6 weeks after birth

Minimum Intervals between Doses

4 weeks

Dosage 2 drops

Storage Temperature -15 to -25 °C

EVALUATION

PROGNOSIS

• The outlook depends on the form of the disease (subclinical, or paralytic) and the body area affected. Most of the time, complete recovery is likely if the spinal cord and brain are not involved.

• Brain or spinal cord involvement is a medical emergency that may

result in paralysis or death (usually from respiratory problems). • Disability is more common than death. Infection that is located high in

the spinal cord or in the brain increases the risk of breathing problems