The integration of the molecular methods in the diagnosis algorithm for the poliovirus detection in the sewage water: comparing concentration and detection methods. A Pilot Study

Abstract

Introduction: Two cases of circulating vaccine-derived poliovirus type 1(cVDPV1), from southwestern Ukraine, bordering Romania, were confirmed in 2015 and the environmental enterovirus surveillance was enhanced in our country. The molecular detection of human enteroviruses as a screening test followed by isolation on cell culture lines or sequencing could be proposed as a new diagnosis algorithm.

Material and methods: The sensitivity of two molecular methods for the detection of enterovirus strains in 10 mL of sewage water (15 samples) was studied with Film Array ME panel BioFire (Biomerieux, France) and Xpert EV assay (Cepheid, USA). These are standardized methods for the detection of microorganisms in the cerebrospinal fluid (CSF).

Results: Of the 15 samples, six enterovirus strains were detected using Film Array ME, four enterovirus strains were detected using Xpert EV assay, while only two nonpolio enterovirus strains were isolated on RD cell line, using the standard WHO algorithm. However, only one of the strains detected by the standard WHO algorithm was detected by one of the molecular methods.

Conclusions: The molecular methods for enterovirus detection are more sensitive than the virus isolation on cell culture lines, but in one case the virus isolated on RD cell line was not detected by the molecular methods. The results could be influenced by the small number of the samples investigated, by the volume and the concentration method used for samples tested, and by the limits of detection (LoD) of the enterovirus species in the samples, depending on the method used.

Keywords: Film Array ME; Xpert EV assay; multiplex PCR; poliovirus; sewage water.