Full Program »

Acute Flaccid Myelitis Caused By Non-Polio Enteroviruses and Reemergence of Poliovirus In The World: Diagnostic Challenges, Management Modalities, Preventive Measures, and Future Investigations

Administrator: Olcay Ünver

Clinical, neuroimaging and epidemiological features of AFM: Toward a consensus criteria for diagnosis and management.
Carlos Pardo-Villamizar

AFM is an acute neurological disorder characterized by acute onset of flaccid paralysis which may affect upper and/or lower limbs. AFM mimics the clinical profile of poliomyelitis presenting with flaccid weakness and acute myelitis. The magnetic resonance imaging shows characteristic lesions in the anterior gray matter of the spinal cord which is frequently longitudinally extensive. The cerebrospinal fluid shows pleocytosis during the acute phase. AFM has been associated to infections by enteroviruses, particularly enterovirus D-68, a virus which appears to have a pattern of seasonality around the world.  At the present, there is not an established treatment for AFM although development of neutralizing antibodies against enteroviruses appears to be a promising treatment. The pattern of seasonality of AFM was disrupted during the COVID-19 pandemics but circulation of enteroviruses increased recently in 2022 and it is expected to increase in future years after the lifting of public health measures introduced during the pandemic. The subsequent re-appearance of cases of AFM due to increase re-circulation of enteroviruses and re-emergence of vaccine-derived polioviruses which have the potential of producing outbreaks of poliomyelitis in some areas of the world requires full attention by health care providers including pediatric neurologists and public health organizations.We plan to discuss the current consensus for the diagnosis and management of AFM.

 

Challenges to the recognition, diagnosis, and surveillance of AFM and enteroviruses in Europe
Jelte Helfferich

In Europe, cases of AFM have been described since 2014, mostly in association with enterovirus D68 (EV-D68). The number of cases, and hence the health impact, is however largely unknown as there is no clinical surveillance system. AFP surveillance, instituted for the detection of poliomyelitis, is ineffective in many European countries and has often been replaced by enterovirus surveillance. Through coordinative efforts of the European non-polio enterovirus network (ENPEN) different outbreaks of EV-D68 have been captured. Only limited cases of AFM have been identified, as an associated virus is often not found in AFM. Therefore, the European AFM network, embedded in ENPEN and collaborating with the international AFM working group was initiated. This emerging network aims to create a registry of new AFM cases in Europe, to gain more insight in the epidemiology of AFM and its relation to enteroviruses in Europe. The success of this registry depends on recognition and correct diagnoses by clinicians. 
The diagnosis of AFM may be challenging, for example because of subtle MRI abnormalities or a misleading distribution of weakness. Also, other causes of AFP, such as Guillain-Barré syndrome and inflammatory myelopathies, may mimic AFM, especially at onset of disease. We plan to describe clinical and diagnostic clues for the diagnosis of AFM and discuss the challenges in surveillance of AFM in Europe and worldwide.

 

The previous and current situation of AFM and poliomyelitis in Turkey, differential diagnosis of AFM with case presentations.
Olcay Ünver

Acute flaccid weakness is a common presentation to pediatric emergency departments with a list of broad differential diagnoses. With the eradication of poliomyelitis, the most common cause of acute weakness in the pediatric age group is Guillain Barré syndrome (GBS). Although acute flaccid weakness, attributed to poliovirus infection, is not a new entity, the term acute flaccid myelitis, first introduced by Centers for Disease Control in 2015, refers to acute flaccid paralysis associated with longitudinally extensive myelitis on MRI associated with non-poliovirus enteroviruses. Outbreaks of AFM have been observedince 2012 and several case series are reported worldwide, including the US, many European countries as well as Argentina, Japan, and Australia/New Zealand. In late summer and early fall of 2016 and 2018, there was an outbreak of AFM in Turkey. Other myelopathies including acute transverse myelitis (ATM), neuromyelitis optica (NMO), acute disseminating encephalomyelitis (ADEM), and spinal stroke are also in the differential diagnoses list. Acute flaccid weakness is a life-threatening pediatric emergency because of the possible bulbar involvement and associated pulmonary problems. Most recently, re-emergence of vaccine-associated cases of poliomyelitis and poliomyelitis in unvaccinated immigrants during Syrian war has raised alarm and the need of awareness about poliomyelitis as cause of acute flaccid weakness. Cases will be discussed in detail with video presentations.

 

Enterovirus circulation and evolution in Eastern United States.
Heba H. Mostafa

Enteroviruses are ubiquitous environmental pathogens that have the potential to cause severe disease. Besides paralytic poliomyelitis caused by poliovirus, other serotypes including EV-A71 and EV-D68 have been associated with neurological pathology. A plethora of serotypes and high mutation rates characterize these viruses, and evidently evolution drives neuro-virulence (e.g., the poliovirus vaccine and EV-A71 hybrid strains derived paralysis). With the emerging public concern about the recent outbreaks of EV-D68 and their correlation with hundreds of cases of paralysis, it is essential to develop an efficient surveillance system that identifies both the environmentally and clinically circulating enteroviruses, examines their genomic polymorphisms, and correlates that with disease presentations. The Johns Hopkins Diagnostic Virology Laboratory implemented a whole genome sequencing based surveillance for enteroviruses and developed a pipeline that integrates laboratory positivity rates and associated clinical presentations and disease outcomes with genomic data. In this session, we will discuss trends of the circulation of and infections with enteroviruses in cohorts from the Eastern United States with a focus on the genomic evolution of EV-D68.