Rotavirus Genotypes in Sewage Treatment Plants and in Children Hospitalized with Acute Diarrhea in Italy in 2010 and 2011

Abstract

Although the molecular surveillance network RotaNet-Italy provides useful nationwide 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. We investigated the genotypes of rotaviruses present in urban wastewaters and compared them with those of viral strains from clinical pediatric cases. During 2010 and 2011, 285 sewage samples from 4 Italian cities were tested by reverse transcription-PCRs (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. Thirtytwo 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 genotypes 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, genotype P[4] accounted for 23.0% of strains, and the uncommon genotypes P[6], P[9], P[14], and P[19] accounted 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 samples from patients, which suggests either a larger circulation of the latter strains through the general population not requiring medical care or their greater survival in wastewaters. A high level of nucleotide identity in the G1, G2, and G6 VP7 sequences was observed between strains from the environment and those from patients.

High Prevalence of Rotavirus A in Raw Sewage Samples from Northeast Spain

“…These results corroborate a previous study [33], which showed the circulation of the genotypes G2, G3, G9, P [4], P [8] and P [9] in Barcelona; more specifically, at the Sant Adrià de Besòs WWTP. A study conducted between 2010 and 2011 [26] also showed RVA circulation in urban wastewater samples from different Italian cities. Corroborating our present data, those authors detected a large variety of G and P genotypes, such as G1, G2, G3, G4, G6, G9, G26, P [4], P [6], P [8], P [9], P [14] and P [19], as well as combined genotypes: G1+G2-P [4]+P [8].…”

“…The presence of RVA in a large portion of samples indicates the high circulation of this virus in Catalonia. Both high-and low-income countries have indicated the presence of RVA in WWTP samples, thus demonstrating the great dispersion of this virus in the environment worldwide [25][26][27]. All samples were found positive for the bacteriophage MS2 (our internal control), with recovery efficiency ranging from 9.8% to 88.2%.…”

The impact of anthropogenic pressure on the virological quality of water from the Tiber River, Italy

“…Recently, Ruggeri et al . () detected RV in 60·4% of sewage samples from four Italian cities. The evidence thus underscores the importance of monitoring water sources in order to assess the potential public health risks of waterborne RV.…”

“…A few studies have investigated the presence of RV in Grassi et al (2010) showed widespread RV contamination of raw sewage, treated sewage and surface water. Recently, Ruggeri et al (2015) detected RV in 60Á4% of sewage samples from four Italian cities. The evidence thus underscores the importance of monitoring water sources in order to assess the potential public health risks of waterborne RV.…”

Biological HRPs in wastewater

“…Moreover, 285 sewage samples from four Italian cities were tested for rotavirus VP7 and VP4 genes, which revealed that rotavirus was detected in 172 (60.4%) samples and 26 samples contained multiple rotavirus G genotypes (Ruggeri et al, 2015). In China, 46 sewage samples were monthly collected for the detection of rotavirus, and 93.5% of samples were found to be positive (Zhou et al, 2016).…”