en عمومى General مقاله مروری Review Article <div style="text-align: justify;">Introduction: Conventional wastewater treatment processes significantly reduce but do not completely remove viral genetic material. This narrative review (2000&ndash;2025) synthesizes evidence on the presence and persistence of viral genomes, particularly RNA from coronaviruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in sewage and sludge, distinguishing these detectable genetic signals from infectious viruses.<br> Methods: A literature search was conducted in PubMed, Scopus, Web of Science, Science Direct, and Google Scholar. Keywords included &ldquo;virus,&rdquo; &ldquo;coronavirus,&rdquo; &ldquo;SARS-CoV-2,&rdquo; &ldquo;sewage,&rdquo; &ldquo;sludge,&rdquo; &ldquo;concentration,&rdquo; &ldquo;detection,&rdquo; and &ldquo;quantification.&rdquo; After screening 1,350 records, 152 studies meeting the inclusion criteria (peer-reviewed studies on human viruses in municipal sewage/sludge, published between 2000 and 2025) were included.<br> Results: SARS-CoV-2 RNA was detected in raw sewage at concentrations up to 10⁶ copies/L during the 2020 peak, declining to 10&sup3;&ndash;10⁴ copies/L by 2025. In sludge, SARS-CoV-2 RNA persisted at 10&sup3;&ndash;10⁵ copies/g dry weight after anaerobic digestion, with only a 1&ndash;2 log₁₀ reduction. Viral genomes of other pathogens (adenoviruses [AdVs], noroviruses [NoVs], hepatitis E virus [HEV], and rotaviruses [RoVs]) were also frequently identified. Notably, the reviewed studies reported the detection of viral RNA, not the isolation of infectious virions.<br> Conclusion: Viral genomes, especially coronavirus RNA, are not fully eliminated during wastewater and sludge treatment and can persist in the environment. This persistence underscores the utility of wastewater-based epidemiology for surveillance. However, the detection of RNA does not<br> indicate the presence of an infection risk, as standard treatment processes effectively inactivate viable viruses.</div> Wastewater, Sewage, SARS-CoV-2, Coronavirus, Wastewater-based 1 15 http://ehemj.com/browse.php?a_code=A-10-1-475&slc_lang=en&sid=1 Mohammad Ali Zazouli zazouli49@yahoo.com 0000-0003-2314-3859 Yes Department of Environmental Health Engineering, Faculty of Health, Health Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran Samaneh Dehghan sdehghan2010@gmail.com 0000-0002-8215-9853 No Correspondence to: Department of Environmental Health Engineering, Faculty of Health, Mazandaran University of Medical Sciences, Sari, Iran