What happens to an organism when polio attacks?
When poliovirus infects an organism, it primarily targets the nervous system, particularly the motor neurons within the spinal cord and brainstem. The infection can manifest in a range of severity, from asymptomatic or mild symptoms to severe paralytic poliomyelitis. Here's what happens to an organism when polio attacks:
Entry and Replication:
The poliovirus typically enters the body through the mouth, via contaminated food, water, or close contact with an infected person. After gaining entry, the virus replicates rapidly in the throat and gastrointestinal tract.
Invasion of Nervous System:
From the initial site of infection, the virus may spread to the central nervous system through the bloodstream. While many infections are asymptomatic, some may progress and affect the nervous system.
Damage to Motor Neurons:
Poliovirus specifically targets motor neurons, which are nerve cells responsible for controlling muscle movement. Infection and replication within these neurons cause inflammation and damage, leading to muscle weakness or paralysis.
Paralytic Poliomyelitis:
The most severe form of polio is paralytic poliomyelitis, where damage to motor neurons results in significant muscle weakness or complete paralysis. Paralysis can affect various muscle groups, including the limbs, respiratory muscles, and muscles involved in swallowing and speech.
Asymptomatic Infections:
It's important to note that many poliovirus infections are asymptomatic, meaning the individual doesn't experience any noticeable symptoms. Asymptomatic individuals can still spread the virus to others without realizing they are infected.
Immune Response:
During a poliovirus infection, the body's immune system mounts a response to fight the virus. This involves the production of antibodies and immune cells to neutralize and eliminate the virus. In some cases, the immune response itself can contribute to tissue damage and inflammation.
Long-Term Consequences:
In individuals who develop paralytic poliomyelitis, paralysis can be permanent and lead to lifelong functional impairments. However, with proper care and rehabilitation, many people with polio can achieve a good quality of life.
Preventing polio through vaccination is crucial as there is no cure for the infection. Vaccination effectively stimulates the immune system to produce antibodies that protect against future poliovirus infections and prevent the development of severe complications.