Environmental Surveillance for Poliovirus and Other Enteroviruses: Long-Term Experience in Moscow, Russian Federation, 2004–2017

Polio and enterovirus surveillance may include a number of approaches, including incidence-based observation, a sentinel physician system, environmental monitoring and acute flaccid paralysis (AFP) surveillance. The relative value of these methods is widely debated. Here we summarized the results of 14 years of environmental surveillance at four sewage treatment plants of various capacities in Moscow, Russia. A total of 5450 samples were screened, yielding 1089 (20.0%) positive samples. There were 1168 viruses isolated including types 1−3 polioviruses (43%) and 29 different types of non-polio enteroviruses (51%). Despite using the same methodology, a significant variation in detection rates was observed between the treatment plants and within the same facility over time. The number of poliovirus isolates obtained from sewage was roughly 60 times higher than from AFP surveillance over the same time frame. All except one poliovirus isolate were Sabin-like polioviruses. The one isolate was vaccine-derived poliovirus type 2 with 17.6% difference from the corresponding Sabin strain, suggesting long-term circulation outside the scope of the surveillance. For some non-polio enterovirus types (e.g., Echovirus 6) there was a good correlation between detection in sewage and incidence of clinical cases in a given year, while other types (e.g., Echovirus 30) could cause large outbreaks and be almost absent in sewage samples. Therefore, sewage monitoring can be an important part of enterovirus surveillance, but cannot substitute other approaches

Vaccine-associated paralytic poliomyelitis in a child: fast transformation from Sabin-like virus to vaccine-derived poliovirus triggered an epidemiological response in two countries of the European region

Objectives: The detection of a vaccine-derived poliovirus (VDPV) requires an epidemiological assessment and response. Using repeated stool sampling from a child who is immunocompetent and was vaccinated against poliomyelitis with acute flaccid paralysis, a case of an extremely rapid evolution of Sabin-like poliovirus (PV) type 3 was traced in the child's body. Methods: The case was independently identified in two countries—Tajikistan and Russia. Stool samples for the study were also independently collected in two countries on different days from the onset of paralysis. Virological, serological, and molecular methods; full genome Sanger; and high-throughput sequencing were performed to characterize isolates. Results: PV isolates from samples collected on days 2, 3, and 14 contained eight, seven, and seven mutations in the VP1-coding region, respectively, and were classified as Sabin-like PV type 3. The isolates from samples collected on days 15 and 18 had 11 mutations and were classified as vaccine-derived PVs, which required an epidemiological response in the two countries. Conclusion: The results indicate the need to continue acute flaccid paralysis surveillance, maintain high vaccination coverage, and develop and introduce new effective, genetically stable PV vaccines