112
T.G. Metcalf, C. Wallis and J.L. Melnick
despite the presence of heavy deposition of marine sediments on the filtering surfaces.
DISCUSSION
In this report we have described an apparatus which makes practical the detection of
viruses in large volumes of water. The transmission of certain viral diseases by the water
route is well known (Berg, 1967; Melnick, 1971), but consistent and quantitative
demonstration of viruses in natural waters has been delayed by the lack of adequate
methods for concentrating viruses from large samples of water.
Water recycling and reclamation is receiving increasing attention. However, virtually no
attention has been directed towards the possible presence of viruses in such recycled
water. Viruses would not be expected to be present at all times but only intermittently.
SUMMARY AND CONCLUSIONS
The concept of sampling large volumes of seawater for viruses by a flow-through
system using textile filters was shown to be feasible by the results of the study. Virus
concentrating equipment capable of sampling seawater at rates approaching 300 gallons
per hour was shown to function efficiently in field trials conducted in salt water. The
ability of filters prepared from synthetic materials to remove marine sedimentary material
without significant retention of virus makes it possible to expose viruses in clarified
seawater to the action of virus adsorbing filters. Collection of virus upon such filters was
shown to proceed without suffering significant loss of virus because of interference of
adsorption by membrane-coating components. Laboratory trials conducted with artificial
seawater demonstrated the ability of the virus concentration methods used to recover
virtually all virus contained in the samples tested. The results obtained in field trials
confirmed the promise of the virus concentration methods developed in the laboratory
and provide a new tool for detection of viruses in marine water.
ACKNOWLEDGEMENTS
The authors thank Dr. Richard Allison and Texas A&M University for boat facilities
used in conducting field studies in the Houston ship channel. The cooperation of the
Commercial Filter Division, Carborundum Company (Lebanon, Indiana) for providing
Fulflo filters and cartridge holders used is acknowledged with gratitude. The authors
appreciate the engineering assistance of Charles Stagg during the course of laboratory and
field studies. The technical assistance of Mrs. Anne Shirley in the laboratory is
acknowledged with gratitude.
REFERENCES
1 WALLIS, C , HOMMA, A., and MELNICK, J.L., "Development of an Apparatus for Concentration
of Viruses from Large Volumes of Water", J. Amer. Water Works Assoc, in press (1972 a).
2 WALLIS, C , HOMMA, A., and MELNICK, J.L., "A Portable Concentrator for Use in the Field",
International Virology II (Proceedings of the 2nd International Congress for Virology), p. 324
(1972b).
3 WALLIS, C , and MELNICK, J.L., "Concentration of Enteroviruses on Membrane Filters",
J.Virol. 1:472-477(1967).
T.G. Metcalf, C. Wallis and J.L. Melnick
despite the presence of heavy deposition of marine sediments on the filtering surfaces.
DISCUSSION
In this report we have described an apparatus which makes practical the detection of
viruses in large volumes of water. The transmission of certain viral diseases by the water
route is well known (Berg, 1967; Melnick, 1971), but consistent and quantitative
demonstration of viruses in natural waters has been delayed by the lack of adequate
methods for concentrating viruses from large samples of water.
Water recycling and reclamation is receiving increasing attention. However, virtually no
attention has been directed towards the possible presence of viruses in such recycled
water. Viruses would not be expected to be present at all times but only intermittently.
SUMMARY AND CONCLUSIONS
The concept of sampling large volumes of seawater for viruses by a flow-through
system using textile filters was shown to be feasible by the results of the study. Virus
concentrating equipment capable of sampling seawater at rates approaching 300 gallons
per hour was shown to function efficiently in field trials conducted in salt water. The
ability of filters prepared from synthetic materials to remove marine sedimentary material
without significant retention of virus makes it possible to expose viruses in clarified
seawater to the action of virus adsorbing filters. Collection of virus upon such filters was
shown to proceed without suffering significant loss of virus because of interference of
adsorption by membrane-coating components. Laboratory trials conducted with artificial
seawater demonstrated the ability of the virus concentration methods used to recover
virtually all virus contained in the samples tested. The results obtained in field trials
confirmed the promise of the virus concentration methods developed in the laboratory
and provide a new tool for detection of viruses in marine water.
ACKNOWLEDGEMENTS
The authors thank Dr. Richard Allison and Texas A&M University for boat facilities
used in conducting field studies in the Houston ship channel. The cooperation of the
Commercial Filter Division, Carborundum Company (Lebanon, Indiana) for providing
Fulflo filters and cartridge holders used is acknowledged with gratitude. The authors
appreciate the engineering assistance of Charles Stagg during the course of laboratory and
field studies. The technical assistance of Mrs. Anne Shirley in the laboratory is
acknowledged with gratitude.
REFERENCES
1 WALLIS, C , HOMMA, A., and MELNICK, J.L., "Development of an Apparatus for Concentration
of Viruses from Large Volumes of Water", J. Amer. Water Works Assoc, in press (1972 a).
2 WALLIS, C , HOMMA, A., and MELNICK, J.L., "A Portable Concentrator for Use in the Field",
International Virology II (Proceedings of the 2nd International Congress for Virology), p. 324
(1972b).
3 WALLIS, C , and MELNICK, J.L., "Concentration of Enteroviruses on Membrane Filters",
J.Virol. 1:472-477(1967).