Rotavirus genotypes in sewage treatment plants and in children hospitalized with acute diarrhea in Italy 2010 - 2011

Although the molecular surveillance network RotaNet-Italy provides useful nation-wide data on rotaviruses causing severe acute gastroenteritis in children in Italy, scarce information is available on rotavirus circulation in the general Italian population, including adults with mild or asymptomatic infection. This study investigated the genotypes of rotavirus present in urban wastewaters, and compared them with viral strains from clinical pediatric cases. During 2010 and 2011, 285 sewage samples from 4 Italian cities were tested by RT-PCRs specific for rotavirus VP7 and VP4 genes. Rotavirus was detected in 172 (60.4%) samples, 26 of which contained multiple rotavirus G (VP7 gene) genotypes, for a total of 198 G types. Thirty-two samples also contained multiple P (VP4 gene) genotypes, yielding 204 P types in 172 samples. Genotype G1 accounted for 65.6% of rotaviruses typed, followed by G2 (20.2%), G9 (7.6%), G4 (4.6%), G6 (1.0%), G3 (0.5%), and G26 (0.5%). VP4 genotype P[8] accounted for 75.0% of strains, P[4] for 23.0%, and the uncommon P[6], P[9], P[14], and P[19] for 2.0% of strains altogether. These rotavirus genotypes were also found in pediatric patients hospitalized in the same areas and years but in different proportions. Specifically, genotypes G2, G9, and P[4] were more prevalent in sewage samples than among patients, which suggests either a larger circulation of these latter strains through the general population not requiring medical care or their higher survival in wastewaters. A high nucleotide identity in the G1, G2, and G6 VP7 sequences was observed between strains from the environment and patients

Helicobacter pylori infection and acid secretion.

Sewage surveillance in seven Italian cities between 2005 and 2008, after the introduction of inactivated poliovirus vaccination (IPV) in 2002, showed rare polioviruses, none that were wild-type or circulating vaccine-derived poliovirus (cVDPV), and many other enteroviruses among 1,392 samples analyzed. Two of five polioviruses (PV) detected were Sabin-like PV2 and three PV3, based on enzyme-linked immunosorbent assay (ELISA) and PCR results. Neurovirulence-related mutations were found in the 5\u2032 noncoding region (5'NCR) of all strains and, for a PV2, also in VP1 region 143 (Ile > Thr). Intertypic recombination in the 3D region was detected in a second PV2 (Sabin 2/Sabin 1) and a PV3 (Sabin 3/Sabin 2). The low mutation rate in VP1 for all PVs suggests limited interhuman virus passages, consistent with efficient polio immunization in Italy. Nonetheless, these findings highlight the risk of wild or Sabin poliovirus reintroduction from abroad. Non-polio enteroviruses (NPEVs) were detected, 448 of which were coxsackievirus B (CVB) and 294 of which were echoviruses (Echo). Fifty-six NPEVs failing serological typing were characterized by sequencing the VP1 region (nucleotides [nt] 2628 to 2976). A total of 448 CVB and 294 Echo strains were identified; among those strains, CVB2, CVB5, and Echo 11 predominated. Environmental CVB5 and CVB2 strains from this study showed high sequence identity with GenBank global strains. The high similarity between environmental NPEVs and clinical strains from the same areas of Italy and the same periods indicates that environmental strains reflect the viruses circulating in the population and highlights the potential risk of inefficient wastewater treatments. This study confirmed that sewage surveillance can be more sensitive than acute flaccid paralysis (AFP) surveillance in monitoring silent poliovirus circulation in the population as well as the suitability of molecular approaches to enterovirus typing

Sporadic isolation of Sabin-like polioviruses and high detection of non-polio enteroviruses during sewage surveillance in seven Italian cities, after several years of inactivated polio vaccination

Sewage surveillance in seven Italian cities between 2005-2008, after IPV introduction in 2002, showed rare polioviruses, none wild-type or cVDPV, and many other enteroviruses among 1,392 samples analyzed. Two of five polioviruses (PV) detected were Sabin-like PV2 and three PV3, based on ELISA and PCR. Neurovirulence-related mutations were found in the 5'NCR of all strains, and for a PV2 also in the VP1 region 143 (Ile>Thr). Intertypic recombination in the 3D region was detected in a second PV2 (Sabin2/Sabin1) and a PV3 (Sabin3/Sabin2). The low mutation rate in VP1 for all PVs suggests limited inter-human virus passages, consistent with efficient polio immunization in Italy. Nonetheless, these findings highlight the risk of wild or Sabin polio reintroduction from abroad. Non-polio-enteroviruses (NPEVs) were detected, of which 448 were Coxsackievirus B (CVB) and 294 Echoviruses (Echo). Fifty-six NPEVs failing serological typing were characterized by sequencing the VP1 region (nt 2628-2976). Four-hundred forty-eight CVB and two-hundred ninety-four Echo strains were identified, among which CVB2, CVB5 and Echo11 predominated. Environmental CVB5 and CVB2 strains from this study showed high sequence identity with GenBank global strains. The high similarity between environmental NPEVs and clinical strains from the same areas of Italy and periods indicates that environmental strains reflect the viruses circulating in the population and highlights the potential risk of inefficient wastewater treatments. This study confirms that sewage surveillance can be more sensitive than AFP surveillance in monitoring silent poliovirus circulation in the population, and the suitability of molecular approaches to enterovirus typing

Circolazione ambientale dei poliovirus e altri enterovirus : un potenziale rischio per la salute pubblica

Gli studi hanno dimostrato assenza di poliovirus selvaggi nell'ambiente ma circolazione di virus vaccinali poco mutati. La presenza di enterovirus non polio nell'ambiente indica una diffusione ubiquitaria di tali virus ed una vasta circolazione nella popolazione