Molecular Typing of Enteroviruses, Adenoviruses, and Hepatitis A Viruses in Untreated and Treated Sewage of a Biological Treatment Plant in Greece

Abstract

The effluents of a sewage treatment plant may contain infectious human viruses representing a major public health issue. In the present study, an 8 months survey was conducted in order to evaluate the presence of enteroviruses (EV), adenoviruses (AdV), and hepatitis A viruses (HAV) in untreated and treated sewage samples collected from a primary treatment municipal wastewater plant, located in the northeastern Greece. Reverse transcriptase-polymerase chain reaction (RT-PCR) and nested polymerase chain reaction techniques have been applied for viral nucleic acid detection. Positive samples were confirmed by sequencing, and comparative phylogenetic analysis was performed on the isolated viral strains. EVs, AdVs, and HAV have been detected in 40% (10/25), 40% (10/25), 4% (1/25) of the samples collected from the plant's inlet, and in 12% (3/25), 44% (11/25), 0% (0/25) of the samples collected from the plant's outlet. Adenovirus types 3 (Ad3), 10 (Ad10) and 41 (Ad41), and hepatitis A virus type H2 have been recognized, while for enteroviruses Coxsackie type A2 and Echovirus types 27 and 30 have been recorded. The results suggest that treated sewage may still contain human viruses and thereby represent a potential health hazard. Moreover, their possible reuse in agriculture or elsewhere must be considered with concern. Furthermore, this study shows the usefulness of molecular methods for virus detection, typing and virological quality analysis of sewage treatment plants.

Assessment of enteric viruses in a sewage treatment plant located in Porto Alegre, southern Brazil

“…The HAdV and EV rates in treated sewage samples were higher than those found by Kokkinos et al (2010) in Greece, but lower than those found by La Rosa et al (2010a) in Italy, who detected HAdV in 96% of influent samples and in 76% of effluent samples, and EV in 96% and 84% in influents and effluents, respectively.…”

“…A similar study conducted by Kokkinos et al (2010) evaluated the presence of EV, HAdV and hepatitis A virus (HAV) in influent and effluents samples from a primary treatment wastewater plant in Greece, in a period of 8 months. Both EV and HAdV were detected in 40% (10/25) of raw sewage, which were simultaneously present in 15% of the samples.…”

“…Many studies have found that, despite the treatment applied, enteric viruses may persist in high levels in wastewaters (He and Jiang, 2005;Villar et al, 2007;Carducci et al, 2008;Fong et al, 2010;Kokkinos et al, 2010;La Rosa et al, 2010a, b;Prado et al, 2011), proposing the use of a viral indicator of treated sewage contamination.…”

Comparison of Two Virus Concentration Methods for Enteric Viruses Detection in Moroccan Wastewater and Treated Effluent

“…According to public health data, those types can colonize the gastrointestinal tracts and cause a wide variety of illnesses, inducing variable epidemiological features and some water-related diseases (3) . EV, HAV, HEV, HAdV, HuNoV, RV and HAstV have been detected in raw wastewater and treated effluent in different studies (4)(5)(6)(7)(8)(9) .…”

“…Because relatively few viral particles are present in wastewater samples, it is necessary to concentrate the viruses in a large volume of water, commonly from 13 to 21 ml (14,15) . Hence, many virus concentration methods have been developed: the two-phase separation (16) , methods using an electronegative filter (17) , polyethylene glycol (PEG) precipitation (18,19) , the ultracentrifugation (4) and methods using an electropositive filter (20) . Furthermore, two virus concentration methods from wastewater are advised by the WHO for environmental poliovirus surveillance (21) .…”