Quantitative Detection of Human Adenoviruses in Wastewater and Combined Sewer Overflows Influencing a Michigan River

Abstract

Enteric viruses are important pathogens found in contaminated surface waters and have previously been detected in waters of the Great Lakes. Human adenoviruses were monitored because of their high prevalence and persistence in aquatic environments. In this study, we quantified adenoviruses in wastewater, surface water, and combined sewer overflows (CSOs) by real-time PCR. Between August 2005 and August 2006, adenovirus concentrations in raw sewage, primary-treated effluent, secondary-treated effluent, and chlorinated effluent from a wastewater treatment plant in Michigan were examined. CSO samples (n ‫؍‬ 6) were collected from a CSO retention basin in Grand Rapids, MI. Adenoviruses were detected in 100% of wastewater and CSO discharge samples. Average adenovirus DNA concentrations in sewage and CSOs were 1.15 ؋ 10 6 viruses/liter and 5.35 ؋ 10 5 viruses/liter, respectively. Adenovirus removal was <2 log 10 (99%) at the wastewater treatment plant. Adenovirus type 41 (60% of clones), type 12 (29%), type 40 (3%), type 2 (3%), and type 3 (3%) were isolated from raw sewage and primary effluents (n ‫؍‬ 28). Six of 20 surface water samples from recreational parks at the lower Grand River showed virus concentrations above the real-time PCR detection limit (average, 7.8 ؋ 10 3 viruses/liter). This research demonstrates that wastewater effluents and wastewater-impacted surface waters in the lower Grand River in Michigan contain high levels of viruses and may not be suitable for full-body recreational activities. High concentrations of adenovirus in these waters may be due to inefficient removal during wastewater treatment and to the high persistence of these viruses in the environment.

Assessment of the prevalence of enteric viruses in the final effluents of two peri-urban wastewater treatment plants

“…Results of this study, however, showed that it was not only a question of which viruses were able to resist treatment processes Adv41 has replaced Adv40 as the predominant serotype isolated from gastroenteritis patients worldwide [23,52]. This study confirms these reports as Adv40 was not detected.…”

Comparison of Concentration Methods for Quantitative Detection of Sewage-Associated Viral Markers in Environmental Waters

“…However, we found no evidence of inhibition in samples processed by method A. This was supported by the Sketa22 PCR assay undertaken here, which indicated the absence of PCR inhibitors in samples processed by method A but indicated inhibition in river water samples processed by methods B and C. Method A was able to effectively concentrate and quantify more HAdVs and HPyVs in both tap and river water samples, which was not the case for methods B and C. The mean recovery efficiencies of 32% (HAdVs) and 78% (HPyVs) of method A in the present study can be considered highly sensitive for simultaneous detection/quantification of these two viral markers in environmental waters compared to other methods (32,33,43).…”

“…Katayama et al (27) reported up to 33 to 90% recovery rate of polioviruses from purified water and seawater. In contrast, low recoveries of noroviruses (0.8%) in seawater and HAdVs (0.92 to 1.03%) in river water have been reported (32,33).…”

Validation of Internal Controls for Extraction and Amplification of Nucleic Acids from Enteric Viruses in Water Samples

“…In this study, Ad5 and MNV were used as internal controls to evaluate the inhibitory effects of samples on DNA extraction of EAdVs and RNA extraction of GII NoVs, respectively. Because both Ad5 and MNV do not seem to be abundant in aquatic environments (11), the presence of indigenous Ad5 and MNV may be negligible, and the detected DNA and cDNA very possibly belong to the control viruses. Such effects on viral nucleic acid extraction have been reported using internal controls (8,10).…”

“…Microfiltration (MF) membrane-based methods using acid rinse procedures followed by alkaline elution were developed to avoid the use of beef extract (16,21). However, RT-PCR inhibition has been reported to be observed even under these conditions (11,15), probably because of coconcentration of humic acid, which precipitates in the presence of cations (6) or acid conditions and becomes soluble at alkaline pH (23). Moreover, a silica membrane-based nucleic acid extraction/ purification method, which is a commonly used method for molecular detection of viruses in aquatic environments (3,15,41), cannot always effectively remove humic acid from samples (3,34).…”