Hepatitis E virus genotype 3 strains and a plethora of other viruses detected in raw and still in tap water
Journal article, 2020

© 2019 The Authors In this study, next generation sequencing was used to explore the virome in 20L up to 10,000L water from different purification steps at two Swedish drinking water treatment plants (DWTPs), and in tap water. One DWTP used ultrafiltration (UF) with 20 nm pores, the other UV light treatment after conventional treatment of the water. Viruses belonging to 26 different families were detected in raw water, in which 6–9 times more sequence reads were found for phages than for known environmental, plant or vertebrate viruses. The total number of viral reads was reduced more than 4-log10 after UF and 3-log10 over UV treatment. However, for some viruses the reduction was 3.5-log10 after UF, as for hepatitis E virus (HEV), which was also detected in tap water, with sequences similar to those in raw water and after treatment. This indicates that HEV had passed through the treatment and entered into the supply network. However, the viability of the viruses is unknown. In tap water 10–130 International Units of HEV RNA/mL were identified, which is a comparable low amount of virus. The risk of getting infected through consumption of tap water is probably negligible, but needs to be investigated. The HEV strains in the waters belonged to subtypes HEV3a and HEV3c/i, which is associated with unknown source of infection in humans infected in Sweden. None of these subtypes are common among pigs or wild boar, the major reservoirs for HEV, indicating that water may play a role in transmitting this virus. The results indicate that monitoring small fecal/oral transmitted viruses in DWTPs may be considered, especially during community outbreaks, to prevent potential transmission by tap water.

Virome in water

Microviridae

Drinking water

Phage

HEV3 in water

Gokushovirus

Author

Hao Wang

University of Gothenburg

Inger Kjellberg

City of Gothenburg

Per Sikora

University of Gothenburg

SciLife Labs

Henrik Rydberg

City of Gothenburg

Magnus Lindh

University of Gothenburg

Sahlgrenska University Hospital

Olof Bergstedt

Chalmers, Architecture and Civil Engineering, Water Environment Technology

City of Gothenburg

Helene Norder

Sahlgrenska University Hospital

University of Gothenburg

Water Research

0043-1354 (ISSN)

Vol. 168 115141

Subject Categories

Water Engineering

Oceanography, Hydrology, Water Resources

Environmental Sciences

DOI

10.1016/j.watres.2019.115141

More information

Latest update

12/4/2019