Hitting children under 5 the hardest, the worst form of the virus causes nerve damage that can lead to paralysis, difficulty breathing and death. During epidemics in the 20th century, the virus often struck in the hot summer months, sweeping through cities and towns every year or so.
Poliomyelitis was one of the most feared diseases in the world until Dr. Jonas Salk invented the polio vaccine and tested its safety in 1954.
What causes poliomyelitis?
However, a wild type of polio virus is still circulating in Pakistan and Afghanistan and can be picked up by travelers and carried around the world. “It only takes one traveler with polio to bring the disease to the United States,” the CDC said.
Transmission can also occur when there are not enough vaccinated children in an area. This usually happens with the oral polio vaccine, created by Dr. Albert Sabin and first used in 1961. The formulation of this vaccine contains a mixture of each of the three types of live attenuated poliovirus strains, according to the GPEI.
“The weakened strains are released by vaccinated children into the environment via their digestive system and can pass from one unvaccinated individual to another, a process exacerbated by poor sanitation systems and the absence of safe drinking water” , said the GPEI.
Once the strain has infected an unvaccinated person, it begins to circulate and can be carried around the world.
“This suggests that the virus may originate from a location outside of the United States where OPV is administered, as (reversed) strains cannot emerge from inactivated vaccines,” the statement said.
Poliomyelitis is highly contagious
Most people come into contact with polio by picking up a small piece of infected poop and then touching their mouth. Exposure to the virus also occurs when children oral toys or other objects contaminated with feces.
In unsanitary conditions, the virus can also spread through contaminated food and water.
Polio symptoms start like the flu
Like Covid-19, many polio cases are asymptomatic. In fact, people have no symptoms in about 95% of all polio cases, the CDC said.
When symptoms appear, they can take three forms. Flu-like symptoms such as headache, sore throat, nausea, diarrhea, fever, and fatigue are hallmarks of abortive polio.
If these symptoms include additional neurological symptoms, such as sensitivity to light or a stiff neck, the person may have nonparalytic poliomyelitis.
The most dangerous version of polio can cause paralysis within “hours”, the WHO has said. The illness begins with flu-like symptoms, then progresses to muscle pain or spasms and loss of reflexes. Paralysis on one side or the other may follow.
Poliomyelitis treatment
There is no cure for poliomyelitis, only treatment to relieve symptoms.
“Heat and physiotherapy (are) used to stimulate the muscles and antispasmodic drugs are given to relax the muscles,” the GPEI said. “While it may improve mobility, it cannot reverse the permanent paralysis from polio.”
Vaccination is the only prevention.