Enterovirus

Enteroviruses are part of the Picornavirus family and, as their names suggest, are very small viruses with a size of around 30nm and a genome of around 8kb. It is an RNA virus with a capsid of icosahedral symmetry¹ without an envelope with a single stranded RNA. There are many different serotypes among picornaviruses grouped into 2 types: the enterovirus² genus and the rhinovirus³ genus. Among the enteroviruses, a distinction is made between coxsackieviruses, echoviruses, polioviruses and enteroviruses in the strict sense.

Contaminated water

The transmission of enteroviruses is mainly faecal-oral via contaminated water. The various enteroviruses cause epidemics that are often seasonal in summer. In terms of symptoms, the excretion of the virus in the stool may be asymptomatic. But there are also various clinical presentations: febrile state without an infectious focus, meningitis⁴ (called aseptic), poliomyelitis⁵.

Public swimming pools and summer meningitis

Note that acute meningitis in summer is most often viral and mainly caused by enteroviruses. The disease then progresses spontaneously benign and is treated with febrifuges⁶ and / or painkillers (paracetamol, for example). The importance of a diagnosis in this situation is to quickly prove it to be viral meningitis and rule out bacterial meningitis which requires immediate empiric antibiotic treatment. This early diagnosis of enterovirus meningitis is based on rapid PCR tests.

Polio

Poliomyelitis is a particular enterovirus that will replicate especially in the lymphoid tissue of the oropharynx and the intestine, due to the distribution of the poliovirus receptor to the lymphoid cells of the intestine and also to neurons of the central nervous system. The clinical manifestation of polio is highly variable with nearly 90% of infections asymptomatic. In symptomatic patients the disease often presents with a nonspecific febrile state and possibly with viral meningitis. Paralytic polio, which can lead to paralysis of the respiratory muscles and require intubation and ventilation in intensive care, is fortunately rare, occurring in about 0.5% of infections.

Success of the vaccines

Poliovirus was largely eradicated from the world in 1988 over a period of 30 years thanks to vaccination efforts. More than 2 endemic countries are documented today (Afghanistan and Pakistan).