An acute viral infection,

The word Poliomyelitis comes from two Greek words:  polio, which means gray, and myelitis means inflammation of the spinal cord.

It is caused by poliovirus. Placed in the enterovirus family of viruses

that live in the Gastrointestinal system. Formed of a single strand of RNA enclosed

in a protein coat that protects it from environmental attack (inactivation).

Quite small by viral standards (22-32 nanometers).

There are three serotypes of polio virus---P1, P2, P3

P1 most typically causes outbreaks—is the most likely virus to cause paralysis.

P2 is the easiest to eradicate followed by P3.

The Virus is excreted in the stools for three to six weeks.

It is more stable than most viruses ,can stay alive for several weeks in contaminated food or water.

It is one of the most contagious viruses.

If one family member is infected, nearly all the rest of the family becomes infected.

The Poliovirus is transmitted from one person to another through,

contact with feces-contaminated water or food,

or directly through saliva and the droplets exhaled by an infected individual during the first two weeks following infection.

Portal of entry is the mouth.

Once the Poliovirus enters the body, it multiplies in the cells of the mucous membranes in the pharynx and intestines.

The virus invades the local lymphoid tissue

Enters the blood stream and infects the CNS.

The incubation period lasts from 07 - 21 days.

the first symptoms of the disease usually appear between seven and 14 days after infection.

The major illness of poliomyelitis usually develops suddenly,

• with fever, • stiff neck and back, • severe headache, and• muscle pain.

Major illness can progress to loss of tendon reflexes and asymmetrical weakness or paralysis.

The paralysis produced by poliomyelitis results from inflammation and destruction of motor neurons in the gray matter of the spinal cord and brain.

The type or degree of paralysis induced depends upon the location and extent of motor neuron destruction, and can range from minor to severe limb paralysis, to paralysis of the muscles that allow us to breathe.

There are three types of paralytic polio Spinal polio Bulbar polio Bulbospinal polio

Poliomyelitis is Generally Diagnosed Clinically by….

The concurrent presence of acute & high grade fever,

Asymmetrical flaccid paralysis, which develops in 2-4 days following the fever and muscle aches.

To detect poliovirus today, according to CDC and WHO guidelines, two stool samples should be collected from each patient, 24 - 48 hours apart within 14 days of the onset of paralysis, and they must arrive at the laboratory in "good condition."

This new sequencing methodology was immediately applied to poliovirus research. During the 1970s, the CDC began routinely performing genotypic testing ("molecular sequencing" or "oligo-nucleotide fingerprinting") on stool samples collected in suspected poliovirus outbreaks to determine whether the virus was present.

Treatment is symptomatic:

Non-narcotic pain killers,

Application of hot packs, and

Physical therapy.

The injectable vaccine (IPV), developed in 1954 by Jonas Salk – salk vaccine.

The oral vaccine (OPV), which is made using live, attenuated strains of the virus, was developed by several teams in the late 1950s, but it was Albert Sabin's vaccine that was adopted universally – sabin vaccine

Among children who are paralyzed by polio:

30% make a full recovery 30% are left with mild paralysis 30% have medium to severe paralysis 10% die.

The World Health Organization (WHO) defines polio eradication essentially as ‘zero incidence of wild poliovirus transmission anywhere in the world’.

Humans are thought to be poliovirus's only host,

Virus survival in the environment is limited.

Immunization with vaccines interrupts virus transmission

which is why the WHO launched an Eradication Program..

supports the Global Polio Eradication Initiative through partnerships with the World Health Organization (WHO), the US Centers for Disease Control and prevention (CDC)

Global Eradication of polio program was established in 1989.

Today only 5 countries --- Pakistan, Nigeria, India, Niger, Afghanistan are endemic to polio.

On 13 May, 1988, the General Assembly of the World Health Organization decided to launch a campaign to eradicate polio.

An extension of the Expanded Program on Immunization (EPI), which aimed to immunize as many children as possible against the primary vaccine-preventable diseases: measles, diphtheria, pertussis, tetanus, tuberculosis and polio.

Routine immunization of young children. National Immunization Days (NIDs)in

countries where the disease is endemic.

Surveillance of new cases of polio through reporting of all cases of Acute Flaccid Paralysis, the primary symptom of polio.

"Mop-up" campaigns to eliminate remaining reservoirs of disease where it continues to spread.

The goal of Global Eradication of wild polio virus is defined as no cases of clinically poliomyelitis, associated with a wild polio viruses and no polio virus found worldwide despite intensive effort to do so.

The primary strategies for achieving this goal are..

Administration of the polio vaccine in the manner most effective to interrupt transmission of wild polio virus---this includes

Attaining high routine immunization coverage with at least five doses of OPV

Conducting national immunization days Mopping-up” immunization when polio is

reduced to focal transmission.

Surveillance for acute flaccid paralysis, the signal condition for polio, is conducted in virtually all countries, and stool samples from suspected cases are delivered to an accredited laboratory for poliovirus testing.

Implementation of action oriented surveillance for all cases of polio. this includes case investigation and isolation of virus from stool specimens.

Milestones for future Target year

1. Establish comprehensive policy for future management.

2003

2. Eliminate wild poliovirus transmission.

2003

3. Certification of ‘eradication’ of wild viruses.

2006

4. Introduction of IPV in routine immunization.

2006

5. Complete withdrawal of OPV. 2009

6. Certification of ‘true eradication’ of polioviruses.

2012

7. Discontinue polio immunization. 2015

The goal of polio eradication has humanitarian and economic benefits.

The humanitarian goal is to ensure that no child will ever get polio paralysis by eliminating the infectious agents from humans altogether.

The ‘victory point’ is when polio vaccination can be stopped without risk of re-emergence of polio.