Polio Causes, Effects and Precautions
Polio Causes, Effects and
Precautions
Polio Overview
The word polio is an abbreviation
for poliomyelitis, which is a life-threatening infectious disease caused by the
poliovirus. It is easily transmitted from one person to another and the most
severe symptom of this infection is complete or partial paralysis.
Polio has been around since
ancient times, but with the help of the right vaccine and vaccination, most of
the world is now polio-free. Mass vaccination has helped create herd immunity
among people and even now, while cases still occur in low-income countries,
their numbers are not very high. A global effort was taken in 1988 to eradicate
the virus and the following regions are now completely polio-free:
Western Pacific
Africa
Americas
Europe
Southeast Asia
Only two countries, Pakistan and
Afghanistan, have reported recent cases of poliomyelitis. The lockdown has
reduced the spread of polio cases in Afghanistan and only 4 cases were reported
in 2021. A total of 22 cases were reported in Pakistan in 2020, all of which
were from Khyber Pakhtunkhwa, with no further cases reported in 2021.
Balochistan reported one case of polio in 2021. It would be fair to say that
with the help of the government’s mass vaccination programs, Pakistan is on the
path to becoming polio-free.
Types of Polio
There are three types of poliovirus
and despite each being structurally similar, they need to be included in
vaccine formulations for their eradication. To date, only type 1 of the virus
remains. Types 2 and 3 have been completely eradicated from the world. The
world was declared free of type 2 poliovirus in September 2015, after being
free of type 2 poliovirus for almost 5 years, as the last recorded case was in
India in 1999. In October 2019, the world was declared free of type 3 virus,
the last reported case was in November 2012.
On the other hand, type 1 is
still present in Pakistan and Afghanistan, and both countries are carrying out
large-scale vaccination programs to eradicate it.
Signs and symptoms of polio
Some poliomyelitis cases have no visible symptoms and therefore may go
unnoticed. In severe cases, it can be fatal. The virus can infect people in
different ways and does not always cause paralytic polio, also known as
abortive/partial polio. This type of polio often causes flu-like symptoms,
including:
Sore throat
Fever
Vomiting
Headache
Fatigue
Back pain
Neck pain
Joint stiffness or pain
Muscle weakness
Numbness/tingling
Severe cases of polio are rare, but the initial symptoms are similar to
those of non-paralytic polio. They include loss of automatic reflexes, muscle
twitching or weakness, irregular breathing, flaccid paralysis, and sometimes
death.
Post-polio syndrome:
Some effects remain in the body even after recovery
from polio. This is called post-polio syndrome. PPS primarily affects the
nerves and muscles in patients. These symptoms appear 30-40 years after polio
and include severe joint pain and weakness, muscle weakness, muscle wasting,
swallowing problems, sleep apnea/stopping breathing during sleep, and decreased
tolerance to cold temperatures.
Causes of Polio
Polio is easily spread through infected feces. Poor hygiene, such as
incomplete hand washing or consumption of contaminated food, are major factors
in its transmission, but the virus can also be spread through sneezing,
coughing, or any action that causes droplets of saliva to become airborne.
The virus enters the body through the mouth or nose. The virus multiplies
in the throat, travels to the digestive and respiratory systems. It also
multiplies in the intestines and from the intestines enters the bloodstream and
spreads easily to different parts of the body.
The virus also travels to the nervous system and causes effects that
disrupt the brain's communication with the rest of the body. The motor neurons
in the spinal cord are the parts of the body most affected in polio cases.
Diagnosis of Polio
In many cases, the symptoms of polio are easily recognizable, but several
tests are recommended to confirm the diagnosis. These tests include:
Physical examination:
A complete physical examination may include muscle testing, especially of
the spinal cord, to determine the effect of the virus on breathing. Muscle
stiffness and muscle response to movement of your neck or limbs are also
checked.
Virus isolation and identification:
This is the most important part of diagnosing poliovirus. The virus is
obtained from stool or buccal swab/mouth samples. Although isolation from blood
or CSF is difficult, it is still performed in some cases. An average of 2 stool
samples are collected from the patient, at least one day apart. These samples
are usually collected within 14 days of the onset of symptoms.
Cerebrospinal fluid examination:
Cerebrospinal fluid is present in the brain and spinal cord. This test is
done with the help of a lumbar puncture, in which a thin long needle is used
between the spinal cord. The fluid obtained is then tested for blood cells,
especially for the number of leukocytes and also for protein. However, the
examination of CSF is not so conclusive, as these conditions can also be caused
by other types of infections.
Oligonucleotide mapping:
Also called fingerprinting, this process involves looking at the genetic
sequence of an isolated virus to determine whether the virus is from a vaccine
or a wild-type virus.
Blood test:
This is the most common type of test. The test detects the presence of
antibodies against the poliovirus.
Polio treatment
Polio treatment is symptomatic, meaning it treats the symptoms to help the
body fight the virus, rather than treating the virus itself. There is no direct
cure.
Proper care is essential to help your body recover quickly and prevent the
disease from getting worse. The following are steps recommended by healthcare
practitioners for a proper recovery from polio:
Complete rest
Isolation to prevent further spread
In case of paralysis, passive movements are used to avoid any physical
deterioration
Use of positive pressure ventilator to help with breathing
Painkillers
Antibiotics in case of urinary tract infection
Antispasmodics to reduce muscle stiffness
Pulmonary rehabilitation
Assisted mobility with wheelchair or cane
A well-balanced diet
Complications of Polio
In addition to paralysis and muscle weakness, polio can cause a lot of
damage to the human body. Some of the complications that polio patients often
face are as follows:
Pharyngeal paralysis
Myocarditis
Hypertension
Post-polio syndrome
Gastrointestinal bleeding
Heart failure
Joint pain
Myalgia/muscle pain
Atrophy/muscle wasting
Fatigue
Risk factors for polio
Only a small percentage of the total infected population develops
paralysis. However, there are several risk factors that have emerged after
years of research. The following are common factors in people who have suffered
from paralytic poliomyelitis:
Tonsil removal
Not being vaccinated against poliovirus
Children
Polio
Being infected during pregnancy
Immune-compromised individuals
Use of IM injections
Excessive exercise
Caring for or coming into contact with a polio patient
Polio Precautions
Prevention is better than cure. Especially when it comes to polio, several
vaccines have been developed over the years. Two types of vaccines are
available:
Inactivated poliovirus vaccine (IPV):
Developed by Dr. Jonas Salk in 1955, this vaccine is also known as the Salk
vaccine. The vaccine contains inactivated or killed forms of all three
poliovirus types. Since it is not a live vaccine, there is no risk of paralytic
poliomyelitis from the vaccine. With sufficient evidence to support this claim,
IPV induces a good response with adequate antibody formation and minimal side
effects. The vaccine is administered intramuscularly or intradermally.
Oral Polio Virus Vaccine (OPV):
Made with all three types of live attenuated virus, this type of vaccine is
used to stimulate our body’s immune response to the attack of wild poliovirus.
OPV is used most in developing countries, especially countries like Pakistan,
which is struggling with vaccine acceptance due to the issue of polio.
Vaccination is crucial for Pakistan to become polio-free. The major drawback of
the OPV vaccine is that it can trigger infection in some people and can even
cause paralytic infection in at least 1 in 2.5 million. Since side effects are
very rare, on average, it is recommended to get about 4 doses of the vaccine
during childhood. They can be given one dose at 2 months of age, the second at
4 months of age, the third at any time between 6 and 18 months of age, while
the final dose can be given when the child is 4-6 years old for full immunity.
The advantage of this type of vaccine is that it does not require a healthcare
professional or a syringe. This makes it much easier to carry out mass
vaccinations, which in the case of Pakistan is often done door-to-door.
Latest research on polio
In the current pandemic, which has seen a huge amount of research, several
researchers from Kirov Medical University monitored the effects of bivalent OPV
on COVID-19. The study concluded that people who were vaccinated had fewer
cases of COVID than those who were not vaccinated with a placebo.
The UK has recently reported its first suspected polio outbreak in 40 years. Despite no actual outbreak, scientists have identified the strain of poliovirus by closely examining London’s sewage. However, the overall risk is low as most of the UK population is fully vaccinated against the virus.
Key points
Polio is a very old disease that has paralyzed countless people. It has
been eradicated from many parts of the world, but the disease is still found in
Pakistan and Afghanistan.
There are three types of polio virus strains. Fortunately, type 2 and type
3 have been declared eradicated from the world, but Pakistan and Afghanistan
are still suffering from type 1 infection.
In most cases, polio is transmitted through poor hygiene and methods,
including contact with feces, incomplete hand washing, and contact with saliva
from droplets and utensils.
There are several traditional methods of diagnosing the disease, the best
of which is stool sample culture/stool test.
There is no cure for polio. The only treatment is to provide symptomatic relief.
Although not all types of polio can paralyze you, you can suffer from
post-polio complications, which occur decades after polio and cause muscle
weakness, joint pain, muscle wasting/atrophy, etc.
There are two types of vaccines available, called IPV. This is given by a
healthcare practitioner through a sterile needle, the traditional way, and OPV,
which can be given orally, and this is the type that is commonly given in
Pakistan.
Please note that poliomyelitis is a notifiable disease and must be reported immediately to the relevant healthcare authorities.
