Key points about Polio
- Poliomyelitis is a viral infection transmitted via the fecal-oral route.
- The majority of infections are asymptomatic. Neurological forms are rare but can lead to irreversible paralysis.
- There is no specific curative treatment.
- Vaccination is the cornerstone of prevention and global eradication.
What is polio?
Poliomyelitis is a viral infectious disease due to polio virus, an enterovirus of which there are three serotypes. Transmission occurs mainly through orofecal routeInfection occurs through the ingestion of contaminated water or food, and more rarely through contact with oropharyngeal secretions. After infection, the virus multiplies in the pharynx and intestines. In rare cases, it crosses the blood-brain barrier and infects the motor neurons of the spinal cord and brainstemleading to flaccid paralysis that is sometimes irreversible.
Polio worldwide
Thanks to vaccination campaigns, polio has been virtually eradicated in the world. However, some wild polioviruses continue to circulate in a very small number of countries, including Afghanistan and Pakistan where it remains endemic. Outbreaks due to vaccine-derived polioviruses can occur in regions where vaccination coverage is insufficient. Monitoring of acute flaccid paralysis Maintaining high vaccination rates remains essential to prevent the re-emergence of the disease. Polio thus remains a global public health emergency as long as eradication is not complete.
Symptoms of Polio
In more than 90% of cases, the infection is asymptomatic or manifests as a mild form with moderate fever, headaches, fatigue, muscle pain, or digestive problems. In about 1 in 200 infections, the virus causes a neurological impairment, most often in the form of acute, asymmetrical, rapidly developing flaccid paralysis, primarily affecting the lower limbs. Bulbar forms can cause swallowing difficulties and respiratory failure potentially fatal.
Diagnosis of Poliomyelitis
The diagnosis should be discussed before any acute flaccid paralysis, particularly in an unvaccinated or incompletely vaccinated individual. Confirmation is based on the poliovirus detection by RT-PCR or viral culture, primarily from repeated stool samples. Cerebrospinal fluid generally shows a moderate lymphocytic meningitis with normal or slightly elevated cerebrospinal fluid protein levels.
Treatment of Polio
There is no specific antiviral treatment poliomyelitis. Treatment is symptomatic, based on supportive treatment, prevention of respiratory and orthopedic complications, and a early and prolonged functional rehabilitationMotor impairments can be permanent and cause disability.
Prevention
Prevention is based primarily on the polio vaccinationwhich is very effective. Available vaccines include an injectable inactivated vaccine and a live attenuated oral vaccine, used in certain public health settings. Maintaining a high vaccination coverageEpidemiological surveillance and vaccination of travelers to at-risk areas are essential to achieving and maintaining global eradication.
FAQ
Poliomyelitis is primarily transmitted via the fecal-oral route, through the ingestion of water or food contaminated with the poliovirus. Less frequently, transmission can occur through contact with oropharyngeal secretions. Inadequate hygiene facilitates transmission.
In most cases, the infection is asymptomatic or causes mild symptoms such as mild fever, fatigue, headaches, muscle aches, or digestive problems. In rare cases, neurological involvement occurs.
Approximately 1 in 200 infections progresses to a neurological form with acute flaccid paralysis, often asymmetrical and of rapid onset, primarily affecting the lower limbs. Bulbar forms can lead to swallowing difficulties and potentially fatal respiratory failure.
The diagnosis should be considered in any case of acute flaccid paralysis, particularly in an unvaccinated or insufficiently vaccinated individual. Confirmation relies on the detection of poliovirus by RT-PCR or viral culture, primarily from stool samples.
There is no specific curative treatment. Management is symptomatic and relies on supportive care and rehabilitation. Prevention is based on vaccination, which is the cornerstone of global eradication efforts, combined with close epidemiological surveillance.
