Monitoring of rotavirus in treated wastewater in Tehran with a monthly interval, in 2017-2018.

Rotaviruses are among the major causes of viral acute gastroenteritis in newborns and children younger than 5 years worldwide. The ability of rotaviruses to remain infectious in harsh environments as well as in the wastewater treatment process makes them one of the most prevalent enteric viruses. The current study aimed to determine the presence of rotavirus genomes and to analyze them phylogenetically in secondary treated wastewater (TW) samples. In total, 13 TW samples were collected from September 2017 to August 2018. Viral concentration was carried out using the absorption-elution method, and after RNA extraction and cDNA synthesis, real-time and conventional polymerase chain reaction (PCR) were performed. A phylogenetic tree was drawn using Maximum Likelihood and Tamura 3-parameter using MEGA v.6 software. Rotavirus genomes were detected in 7/13 (53.8%) and 3/13 (23.07%) samples using reverse transcription (RT)-PCR and conventional PCR, respectively. Accordingly, phylogenetic analysis revealed G4P[8], G9P[4], and G9P[8] genotypes among the samples. The presence of rotavirus in secondary TW samples discharged into surface water emphasizes the importance of monitoring and assessing viral contamination in the water sources used for agricultural and recreational purposes.