Circulation and Molecular Epidemiology of Enteroviruses in Paralyzed, Immunodeficient and Healthy Individuals in Tunisia, a Country with a Polio-Free Status for Decades.

Anissa Chouikha,Essia Ben Farhat,Henda Triki,Zina Meddeb,Dorra Rezig,Nadia Driss,Ichrak Abdelkhalek,Mahrez Yahyaoui,Ahlem Ben Yahia,Henda Touzi

doi:10.3390/v13030380

Anissa Chouikha, Essia Ben Farhat + Show 8 more

Open Access

https://doi.org/10.3390/v13030380

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Abstract

This report is an overview of enterovirus (EV) detection in Tunisian polio-suspected paralytic cases (acute flaccid paralysis (AFP) cases), healthy contacts and patients with primary immunodeficiencies (PID) during an 11-year period. A total of 2735 clinical samples were analyzed for EV isolation and type identification, according to the recommended protocols of the World Health Organization. Three poliovirus (PV) serotypes and 28 different nonpolio enteroviruses (NPEVs) were detected. The NPEV detection rate was 4.3%, 2.8% and 12.4% in AFP cases, healthy contacts and PID patients, respectively. The predominant species was EV-B, and the circulation of viruses from species EV-A was noted since 2011. All PVs detected were of Sabin origin. The PV detection rate was higher in PID patients compared to AFP cases and contacts (6.8%, 1.5% and 1.3% respectively). PV2 was not detected since 2015. Using nucleotide sequencing of the entire VP1 region, 61 strains were characterized as Sabin-like. Among them, six strains of types 1 and 3 PV were identified as pre-vaccine-derived polioviruses (VDPVs). Five type 2 PV, four strains belonging to type 1 PV and two strains belonging to type 3 PV, were classified as iVDPVs. The data presented provide a comprehensive picture of EVs circulating in Tunisia over an 11-year period, reveal changes in their epidemiology as compared to previous studies and highlight the need to set up a warning system to avoid unnoticed PVs.

Highlights

The genus Enterovirus belongs to the Picornaviridae family of small nonenveloped viruses with icosahedral symmetry and a single-stranded positive-sense RNA genome of approximately 7500 nucleotides [1]
This paper reports the results of EV detection in Tunisian polio-suspected paralytic cases, healthy contacts and primary immunodeficiencies (PID) patients during an 11-year period starting from 2007
The nonpolio enteroviruses (NPEVs) detection rate was higher in patients with PIDs: 12.4% (76 positive out of 614 specimens) vs. 4.3% (56 positive out of 1296 specimens) and 2.8% (23 positive out of specimens) in acute flaccid paralysis (AFP) cases and contacts, respectively

Summary

Introduction

The genus Enterovirus belongs to the Picornaviridae family of small nonenveloped viruses with icosahedral symmetry and a single-stranded positive-sense RNA genome of approximately 7500 nucleotides [1]. This genus is divided into 15 species, 7 of which contain human pathogenic viruses, namely the species Enterovirus A-D, including polioviruses, echoviruses and coxsackieviruses as well as Rhinovirus A-C [2]. EVs have been associated with a wide range of illnesses, including aseptic meningitidis, myocarditis, newborn sepsis, conjunctivitis, hepatitis and severe flaccid paralysis [3]. PVs are the leading cause of acute flaccid paralysis (AFP) in infants and young children. Since 1988, wild PVs have been targeted by a global eradication program based on the mass vaccination of the human population and attentive surveillance of circulating

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