Human enteric viruses–potential indicators for enhanced monitoring of recreational water quality

Abstract

Recreational waters contaminated with human fecal pollution are a public health concern, and ensuring the safety of recreational waters for public use is a priority of both the Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC). Current recreational water standards rely on fecal indicator bacteria (FIB) levels as indicators of human disease risk. However present evidence indicates that levels of FIB do not always correspond to the presence of other potentially harmful organisms, such as viruses. Thus, enteric viruses are currently tested as water quality indicators, but have yet to be successfully implemented in routine monitoring of water quality. This study utilized enteric viruses as possible alternative indicators of water quality to examine 18 different fresh and offshore recreational waters on O'ahu, Hawai'i, by using newly established laboratory techniques including highly optimized PCR, real time PCR, and viral infectivity assays. All sample sites were detected positive for human enteric viruses by PCR including enterovirus, norovirus genogroups I and II, and male specific FRNA coliphage. A six time-point seasonal study of enteric virus presence indicated significant variation in virus detection between the rainy and dry seasons. Quantitative PCR detected the presence of norovirus genogroup II at levels at which disease risk may occur, and there was no correlation found between enteric virus presence and FIB counts. Under the present laboratory conditions, no infectious viruses were detected from the samples PCR-positive for enteric viruses. These data emphasize both the need for additional indicators for improved monitoring of water quality, and the feasibility of using enteric viruses as these indicators.

Surveillance of human enteric viruses in coastal waters using concentration with methacrylate monolithic supports prior to detection by RT-qPCR

“…One of the main limitations of coliform bacteria, as indicators of faecal pollution, is their poor correlation with the presence of non-bacterial pathogens, in particular with the presence of human viruses ( Cook, 2013 ; Eslamian, 2016 ; Payment and Locas, 2011 ; Petterson et al, 2001 ). Viruses persist in marine environments for long periods ( Suttle, 2005 ), which can lead to higher risk of human exposure ( Updyke et al, 2015 ). Not surprisingly, human viruses are believed to cause the majority of waterborne diseases worldwide Griffin et al, 2001 , Griffin et al, 2003 .…”

“…A group of viruses that have significant impact on public health are enteric viruses ( Griffin et al, 2003 ; Updyke et al, 2015 ). These pathogens are associated with a variety of human diseases, from ocular and respiratory infections to gastroenteritis, hepatitis, myocarditis and aseptic meningitis ( Gerba et al, 1996 ).…”

Increase in outbreaks of gastroenteritis linked to bathing water in Finland in summer 2014

“…Therefore, new candidates, such as Clostridium perfringens , coliphages, Bacteroides and human enteric viruses as well as new genomic approaches, e.g. metagenomics, have been proposed for water quality assessment [41-43]. However, during the summer, the higher temperature of bathing water and the increased amount of ultraviolet light have a negative impact on microbe survival.…”

‘Don’t put your head under water’: enteric viruses in Brazilian recreational waters

“…In other countries such as the United States (Ohio), EV was detected in 17% of the samples [35]. In Hawaii, it was detected in all the samples evaluated [11].…”

“…The monitoring of water quality is evaluated through parameters such as temperature, salinity, chlorophyl, turbidity, pH and dissolved oxygen, but currently there is no international regulation to evaluate the presence of viruses in recreational waters [8], [9]. The evaluation of the quality of recreational waters depends on bacteriologic markers such as Escherichia coli and Enterococcus, mainly because of low-complexity and inexpensive detection methods [10], [11]. However, the lack of correlation between the presence of faecal coliforms and enteric viruses is well established in the literature; in addition, enteric viruses are more stable in the environment than faecal coliforms and may be used as markers of faecal contamination of water [12], [13].…”