Disinfection of Human Enteric Viruses in Water by Copper: Silver and Reduced Levels of Chlorine

1993 ◽  
Vol 27 (3-4) ◽  
pp. 351-355 ◽  
Author(s):  
Albert Bosch ◽  
José M. Díez ◽  
F. Xavier Abad
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Silver Ions ◽  
Water Systems ◽  
Free Chlorine ◽  
Viral Pathogens ◽  
Human Rotavirus ◽  
Low Levels ◽  
Total Elimination

Electrolytically generated copper: silver ions were evaluated in combination with low levels of chlorine for their ability to reduce the infectivity of hepatitis A virus, human rotavirus, adenovirus and poliovirus seeded in well and tap water. Overall, hepatitis A virus and rotavirus showed less than 2.6 log10 titre reduction for concentrations of 1 mg/l of free chlorine. For free chlorine concentrations of 0.5 mg/l or lower, with or without copper: silver ions, both of these viral strains suffered little inactivation. Poliovirus showed more than 4 log10 titre reduction in the presence of copper: silver combined with 0.5 mg/l of free chlorine, or 1 mg/l of free chlorine alone. Copper: silver ions (700:70 µg/l) reduced the infectivity of poliovirus. Although adenovirus was more efficiently inactivated than rotavirus or hepatitis A virus, it persisted longer than poliovirus under the same treatments, and its infectivity was never completely removed. The addition of copper: silver ions to reduce the levels of free chlorine do not ensure the total elimination of viral pathogens from water systems.

Inactivation of Hepatitis A Virus, Other Enteric Viruses and Indicator Organisms in Water by Chlorination

1985 ◽  
Vol 17 (4-5) ◽  
pp. 657-664 ◽  
Author(s):  
W O. K. Grabow ◽  
P. Coubrough ◽  
C. Hilner ◽  
B. W. Bateman
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Free Chlorine ◽  
Coliform Bacteria ◽  
Plate Count ◽  
Mycobacterium Fortuitum ◽  
Indicator Organisms ◽  
Probable Number ◽  
Chlorine Residuals

Hepatitis A virus (HAV) and various indicator organisms were mixed together in autoclaved biofilter effluent and broth-enriched tap water, and the survival kinetics of individual organisms after the addition of chlorine were compared. Chlorine was present in the reaction mixtures predominantly in the form of combined residuals. HAV was enumerated by a most probable number dilution assay using PLC/PRF/5 liver cells for propagation of the virus and radioimmunoassay for its detection. In both reaction mixtures HAV survived longer than Escherichia coli, Streptococcus faecalisi, poliovirus type 2, coxsackievirus B5 and reovirus type 3, while it was less resistant than coliphage MS2, coliphage VI (except in tap water), the simian SA-11 rotavirus and Mycobacterium fortuitum. The survival data indicate that viruses (including coliphages) tend to be relatively more resistant to combined chlorine residuals than bacteria, while bacteria tend to be relatively more resistant to free chlorine residuals than viruses. Coliform bacteria may thus be fairly reliable indicators of the virological safety of waters disinfected by free chlorine residuals, but not of waters disinfected by combined chlorine residuals, as in the case of the chlorination of wastewater or the chloramination of drinking-water supplies. The relatively high resistance to combined chlorine residuals of HAV and SA-11 virus (which is closely related to human rotavirus) emphasizes the shortcomings of methods available for virological water analysis because they do not detect HAV and rotavirus. The results support views that the virological safety of all chlorinated waters can be reliably monitored by means of practical indicator systems consisting of appropriate combinations of determinands such as the standard plate count, coliform bacteria, coliphages, acid-fast bacteria and faecal streptococci.

Hepatitis a Virus Concentration from Experimentally Contaminated Distilled, Tap, Waste and Seawater

1989 ◽  
Vol 21 (3) ◽  
pp. 255-258 ◽  
Author(s):  
Evangélos Biziagos ◽  
Jacques Passagot ◽  
Jean-Marc Crance ◽  
Robert Deloince
Keyword(s):  
Cell Culture ◽  
Polyethylene Glycol ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Virus Concentration ◽  
Beef Extract ◽  
Polyethylene Glycol 6000

The concentration of cell-culture-adapted hepatitis A virus (HAV) from experimentally contaminated distilled, drinking, waste and seawater was performed by using a filter adsorption-elu-tion method in the following conditions: HAV seeded in water was adsorbed at pH 4.0 to two nitrocellulose membranes (1.2 and 0.45 µm porosity for distilled and tap water or 8.0 and 3.0 µm porosity for waste and seawater), then eluted by 3% beef-extract at pH 8.5 and further concentrated by polyethylene glycol 6000 precipitation. Thus, HAV in 5 to 50 liters of seeded waters was concentrated approximately 1,700 to 17,000 fold with greater than 70% recovery of the initial virus added to the samples.

Disinfection of bacteria in water systems by using electrolytically generated copper:silver and reduced levels of free chlorine

1990 ◽  
Vol 36 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Moyasar T. Yahya ◽  
Lee K. Landeen ◽  
Maria C. Messina ◽  
Susan M. Kutz ◽  
Richard Schulze ◽  
...  
Keyword(s):  
Drinking Water ◽  
Key Words ◽  
Tap Water ◽  
Total Coliform ◽  
Water Systems ◽  
Free Chlorine ◽  
Drinking Water Standards ◽  
Indoor And Outdoor

As an alternative disinfectant to chlorination, electrolytically generated copper:silver (400 and 40 μg/L copper and silver, respectively) with and without free chlorine (0.3 mg/L) was evaluated over a period of 4 weeks in indoor and outdoor water systems (100 L tap water with natural body flora and urine). Numbers of total coliform, pseudomonas, and staphylococci were all less than drinking water standards in systems treated with copper:silver and free chlorine and systems treated with free chlorine alone (1.0 mg/L). No significant differences (p ≤ 0.05) in bacterial numbers were observed between systems with copper:silver and free chlorine and those with free chlorine alone. Overall, free-chlorine treatments (0.3 or 1.0 mg/L) showed significantly lower heterotrophic plate numbers than those without free chlorine. When challenged with a natural Staphylococcus sp. isolate, water with copper:silver and free chlorine had a 2.4 log10 reduction in bacterial numbers within 2 min, while free chlorine alone or copper:silver alone showed 1.5 and 0.03 log10 reductions, respectively. Addition of copper:silver to water systems may allow the concentration of free chlorine to be reduced while still providing comparable sanitary quality of the water. Key words: disinfection, water, copper, silver, chlorine.

Inactivation of coliphage MS-2 and poliovirus by copper, silver, and chlorine

1992 ◽  
Vol 38 (5) ◽  
pp. 430-435 ◽  
Author(s):  
Moyasar T. Yahya ◽  
Timothy M. Straub ◽  
Charles P. Gerba
Keyword(s):  
Key Words ◽  
Enteric Viruses ◽  
Silver Ions ◽  
Water Systems ◽  
Free Chlorine ◽  
Inactivation Rate ◽  
Swimming Pools ◽  
Poliovirus Type ◽  
Test Systems

The efficacy of electrolytically generated copper and silver ions (400 and 40 μg/L, respectively) was evaluated separately and in combination with free chlorine (0.2 and 0.3 mg/L) for the inactivation of coliphage MS-2 and poliovirus type 1 in water at pH 7.3. The inactivation rate was calculated as log10 reduction/min: k = −(log10Ct/C0)/t. The inactivation of both viruses was at least 100 times slower in water containing 400 and 40 μg/L copper and silver, respectively (k = 0.023 and 0.0006 for MS-2 and poliovirus, respectively), compared with water containing 0.3 mg/L free chlorine (k = 4.88 and 0.036). Significant increases in the inactivation rates of both viruses were observed in test systems containing 400 and 40 μg/L copper and silver, respectively, with 0.3 mg/L free chlorine when compared with the water systems containing either metals or free chlorine alone. Poliovirus was approximately 10 times more resistant to the disinfectants than coliphage MS-2. This observation suggests either a synergistic or an additive effect between the metals and chlorine for inactivation of enteric viruses. Use of copper and silver ions in water systems currently used in swimming pools and spas may provide an alternative to high levels of chlorination. Key words: enteric viruses, poliovirus, coliphage MS-2, bacteriophage, disinfection, inactivation, copper, silver, chlorine.

scholarly journals Hepatitis A outbreak in British Columbia, Canada: the roles of established surveillance, consumer loyalty cards and collaboration, February to May 2012

2014 ◽  
Vol 19 (18) ◽  
Author(s):  
H M Swinkels ◽  
M Kuo ◽  
G Embree ◽  
Collective Fraser Health Environmental Health Investigation Team ◽  
A Andonov ◽  
...  
Keyword(s):  
British Columbia ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Early Recognition ◽  
Genotype 1A ◽  
Trace Back ◽  
Product Identification ◽  
Low Levels ◽  
Pomegranate Seeds ◽  
Loyalty Card

Non-travel-related hepatitis A is rare in Canada. We describe a hepatitis A outbreak investigation in British Columbia in February to May 2012 in which exposure history was collected from nine confirmed non-travel-related cases. Suspected foods were tested for hepatitis A virus (HAV): a frozen fruit blend was identified as a common exposure for six of the nine cases using supermarket loyalty cards. Consumption of the product was confirmed in each case. Genetic analysis confirmed HAV genotype 1B in the six exposed cases. Of the three non-exposed cases, the virus could not be genotyped for two of them; the virus from the other case was found to be genotype 1A and this case was therefore not considered part of the outbreak. HAV was detected by PCR from pomegranate seeds, a component of the identified frozen fruit blend. Historically low levels of HAV infection in British Columbia triggered early recognition of the outbreak. Loyalty card histories facilitated product identification and a trace-back investigation implicated imported pomegranate seeds.

Concentration of Hepatitis a Virus in Environmental Samples

1991 ◽  
Vol 24 (2) ◽  
pp. 229-234 ◽  
Author(s):  
A. Bosch ◽  
R. Gajardo ◽  
F. X. Abad ◽  
J. M. Diez ◽  
J. Jofre
Keyword(s):  
Environmental Samples ◽  
Hepatitis A ◽  
Glass Powder ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Plaque Assay ◽  
Wild Type ◽  
Filter Aid ◽  
Treatment Concentration ◽  
Positively Charged

The cytopathogenic pHM-175 strain of hepatitis A virus was used to develop different procedures for the concentration of HAV in tap water, fresh water, seawater and raw sewage, HAV was quantified by a plaque assay in the FRhK-4 cell line. Water samples were concentrated by a modification of the adsorption to and elution from glass powder (GPAE) method, by adsorption to and elution from filter aid, and by ammonium sulfate flocculation (ASF). The GPAE method consistently yielded greater HAV recoveries than filtration through filter aid, or ASF. HAV was concentrated by GPAE from 20-litre samples with satisfactory efficiencies in all kinds of water: 100% for tap water, 80% for freshwater, 75% for seawater and 61% for sewage. Concentration efficiencies for filter aid and ASF were always lower than 25% and 40%, respectively, in any kind of water. The charge of glass powder was modified by polyethylenimine treatment. Concentration efficiencies of HAV in 20 1 samples through adsorption to and elution from positively charged glass powder (PGPAE) were 100% for tap water, 94% for seawater, and 61% for freshwater and sewage. The presence of wild-type HAV in sewage samples could be monitored by molecular hybridization with cDNA probes after GPAE concentration.

Development of a PCR-based method for the detection of enteroviruses and hepatitis a virus in molluscan shellfish and its application to polluted field samples1

1995 ◽  
Vol 31 (5-6) ◽  
pp. 457-464 ◽  
Author(s):  
David N. Lees ◽  
Kathleen Henshilwood ◽  
Sarah Butcher
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Pcr Amplification ◽  
Field Site ◽  
Rt Pcr ◽  
Pcr Inhibition ◽  
Field Samples ◽  
Polymerase Chain ◽  
Low Levels ◽  
Bivalve Shellfish

The use of the polymerase chain reaction (PCR) for detection of low levels of enteric viruses in bivalve shellfish is hindered by the presence of potent amplification inhibitors. A procedure previously developed for removing the majority of these amplification inhibitors is applied to the detection of enteroviruses and hepatitis A virus in naturally polluted field samples. Quantification of PCR inhibition showed that PCR sample tolerance ranged from 2 to 4.7g shellfish for highly polluted samples. These results indicate the need for adequate controls for PCR inhibition, particularly for negative samples. Reverse transcription (RT)-PCR results were compared with conventional enterovirus isolation for a range of naturally contaminated shellfish. All enterovirus isolation positive samples were also positive by enterovirus RT-PCR. At one field site shellfish were positive by enterovirus RT-PCR but negative for virus isolation. All shellfish tested were negative for hepatitis A by RT-PCR. The procedure for removal of PCR amplification inhibitors should be equally applicable to the detection of Norwalk and related Small Round Structured Viruses (SRSVs) in shellfish.

Microbiological Evaluation of Copper : Silver Disinfection Units for Use in Swimming Pools

1989 ◽  
Vol 21 (3) ◽  
pp. 267-270 ◽  
Author(s):  
Lee K. Landeen ◽  
Moyasar T. Yahya ◽  
Susan M. Kutz ◽  
Charles P. Gerba
Keyword(s):  
Pathogenic Bacteria ◽  
Silver Ions ◽  
Free Chlorine ◽  
Swimming Pools ◽  
Log10 Reduction ◽  
Bactericidal Effects ◽  
Pure Cultures ◽  
Bactericidal Activities ◽  
Low Levels ◽  
Hot Tubs

The bactericidal effects of electrolytically generated copper:silver ions on pathogenic bacteria of concern in swimming pools, hot tubs and cooling towers were evaluated in disinfection experiments. Copper:silver ion concentrations generated in well water were 400:40 µg/L, respectively. Pure cultures of Legionellapneumophila, Staphylococcusaureus, Pseudomonasaeruginosa, Escherichiacoli, and Streptococcusfaecalis, were individually tested in water containing copper:silver ions alone, copper:silver ions with free chlorine, and free chlorine alone. Greater numbers of organisms were killed after exposure to copper: silver ions with 0.2 mg/L free chlorine than in either the copper:silver ions or free chlorine alone. L. pneumophlla showed greater than a 5 log10 reduction in numbers after 7 minutes exposure to copper:silver ions with 0.2 mg/L free chlorine. In comparison, less than a 2 log10 decrease was obtained after exposure to free chlorine alone. E.coli numbers decreased over 4 log10 after 1 minute exposure to copper:silver ions with 0.2 mg/L free chlorine and less than a 3 log10 decrease after exposure to free chlorine alone. The majority of the other organisms tested showed the same effect. Electrolytically generated copper:silver ions with low levels of free chlorine appear to have greater bactericidal activities than either disinfectant alone.

Differential accumulation and depuration of human enteric viruses by mussels

1995 ◽  
Vol 31 (5-6) ◽  
pp. 447-451 ◽  
Author(s):  
A. Bosch ◽  
R. M. Pintó ◽  
F. X. Abad
Keyword(s):  
Tissue Distribution ◽  
Digestive Tract ◽  
Continuous Flow ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Time Intervals ◽  
Virus Elimination ◽  
Human Rotavirus ◽  
The Common ◽  
Human Enteric Viruses

The tissue distribution of adenovirus 40 (ADV) and human rotavirus, serotype 3 (HRV) was determined after feeding the common mussel (Mytilus spp.) with high levels of clay-associated virus. At different time intervals, individual tissues were carefully dissected and assayed for infectivity. Viruses were detected in contaminated mussels after 1-hour contact, and maximum levels were observed after 6 hours. Most infectious viruses were located in the gills and in the digestive tract. Decreasing virus numbers were found in the mantle lobes. Mussels contaminated with poliovirus 1 (PV), hepatitis A virus, strain HM-175 (HAV), ADV, HRV, and bacteriophages of Bacteroides fragilis (B40-8) were depurated in 50-1 tanks with a continuous flow of ozonated marine water. After 96 hours, HAV and HRV suffered less than 2 Log10 titre reduction (LTR), while ADV showed a 2.7 LTR. PV showed a 3 LTR after 48 hours and became undetectable thereafter. Bacteriophage B40-8 suffered less than 2 LTR after 96 hours, suggesting that it could be an appropriate indicator of the efficiency of virus elimination during shellfish depuration.

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