Polio
DEFINITION:
A
viral infection that can lead to permanent paralysis.
SYMPTOMS:
Most
people infected have no symptoms. Others have fever, headache,
sore throat, nausea, vomiting, constipation, abdominal pain,
cough, runny nose, stiff neck, muscle weakness, or paralysis.
CAUSES:
A viral illness.
CONTAGION:
This
virus is contagious through respiratory droplets (coughing
or sneezing) or fecal/oral transmission (poor hand washing
or changing a diaper and getting this into the mouth). Humans
are the only host for this virus.
DIAGNOSIS:
The diagnosis is made by the clinical symptoms of the illness.
A blood test can confirm the diagnosis.
TREATMENT:
Since this is a virus there is no cure. Treatment is supportive
including physical therapy, treating any secondary infections
such as pneumonia, and helping with the complications of being
immobile.
OUTCOME:
Almost 95% of people who contract polio will have no symptoms.
The remaining 5% may have a transient illness or transient
paralysis. About one out of one thousand people will go on
to the paralytic type that is life-long.
DISCUSSION:
Polio used to be a devastating illness. Prior to the vaccine,
people feared polio. It was an illness of the late summer,
early fall and people would worry about this the whole time.
Epidemics occurred and people feared for their children. In
1954, Dr. Jonas Salk gave the first vaccine. It was called
the IPV, inactivated polio vaccine. After vaccination the
incidence of paralytic polio decreased from 20,000 cases per
year to 2500 in 1960. A second vaccine, called OPV (oral polio
vaccine) made by Dr. Albert Sabin was created in 1961. The
oral polio vaccine was more effective and this became the
vaccine of choice. It conferred immunity to the oral route
of transmission better than IPV. The immunity from OPV also
lasts longer. From 1963 to 2000 the oral polio vaccine was
the vaccine of choice. However, the OPV is a live-virus vaccine
and about 7 children a year actually contracted the illness
through the vaccine. When all of the risks and benefits of
IPV versus OPV were considered, the overall incidence of polio
from OPV turned out to be much less than if IPV were used.
This changed in 2000. The vaccine has been so effective that
there have been no cases of natural polio in the United States
of America since 1979 and in the Western Hemisphere since
1991. The illness still does exist in other parts of the world,
however, so the vaccine cannot be stopped yet. But it is now
safer to use the IPV, as there is no chance of getting the
illness from this vaccine since it is not a live virus vaccine.
Eventually polio will be eradicated and the vaccine will become
history just like the smallpox vaccine. For now, the vaccine
schedule is inactivated polio vaccine (IPV) at two months,
four months, six-to-eighteen months, and four years of age.
ONE
DOCTOR'S OPINION:
There
was always a fear with the oral polio vaccine that a child
would catch the very illness that you're trying to prevent.
There was also a fear that by going to the less effective
IPV vaccine, we would cause polio to make a comeback. Now
that polio is so rare it's okay to use a less effective but
safer vaccine, since the chances of being exposed to this
illness are minimal. Hopefully we will be able to eliminate
polio from the face of the earth through vaccination and eventually
have one less injection to give our children.
