Retrospective Characterization of a Vaccine-Derived Poliovirus Type 1 Isolate from Sewage in Greece

Abstract

Retrospective molecular and phenotypic characterization of a vaccine-derived poliovirus (VDPV) type 1 isolate (7/b/97) isolated from sewage in Athens, Greece, in 1997 is reported. VP1 sequencing of this isolate revealed 1.87% divergence from the VP1 region of reference strain Sabin 1, while further genomic characterization of isolate 7/b/97 revealed a recombination event in the nonstructural part of the genome between a vaccine strain and a nonvaccine strain probably belonging to Enterovirus species C. Amino acid substitutions commonly found in previous studies were identified in the capsid coding region of the isolate, while most of the attenuation and temperature sensitivity determinants were reverted. The ultimate source of isolate 7/b/97 is unknown. The recovery of such a highly divergent derivative of a vaccine strain emphasizes the need for urgent implementation of environmental surveillance as a supportive procedure in the polio surveillance system even in countries with high rates of OPV coverage in order to prevent cases or even outbreaks of poliomyelitis that otherwise would be inevitable.

Polio Eradication in Bangladesh: Evaluation of AFP Surveillance Indicators, 2011-2015

“…Researches suggest that Environmental Poliovirus Surveillance (ENV) should be in place during the period between interruption of wild poliovirus (WPV) transmission & certification of eradication and should be continued into the post eradication phase and OPV cessation period to monitor emergence of Vaccine Derived Poliovirus (VDPV) re-emergence of WPV or disappearance of all OPV-related strains [26]. There is also evidence that ENV along with routine AFP case based surveillance is more effective to detect introduction and circulation of Wild Poliovirus (WPV) and Vaccine Derived Poliovirus (VDPV) [27][28][29][30][31]. Environmental surveillance also has a role in new WHO strategy for intensified effort to complete poliomyelitis eradication [32] and can be useful to monitor the efficacy of immunisation initiatives when necessary [26].…”

Role of environmental poliovirus surveillance in global polio eradication and beyond

“…Highly diverged neurovirulent VDPVs have been isolated by ENV from many geographical locations such as Egypt, Greece, Haiti, India, South Africa and Switzerland [33,[42][43][44][45][46]. Two independent epidemiological sources of type 2 VDPV have been identified in central Israel.…”

Sporadic Isolation of Sabin-Like Polioviruses and High-Level Detection of Non-Polio Enteroviruses during Sewage Surveillance in Seven Italian Cities, after Several Years of Inactivated Poliovirus Vaccination

“…In addition to virological investigation of AFP patients, several countries also survey the circulation of wild or Sabin-derived polioviruses by analysis of surface waters and sewage samples (13,14,15). As poliovirus is shed from infected subjects both with and without paralysis, environmental poliovirus surveillance is thought to allow sampling the entire population (13,14,16,17,18,19).…”