title: Removal of parasitic protozoa from water using a mobile water filtration apparatus intended for field use by military or emergency personnel.
abstract: Approximately 3,200 L of water were inoculated with Cryptosporidium oocysts and Giardia cysts. The contaminated water was filtered through a Berkefeld Filter, type TWA 3, as used by the Norwegian army. Nine 10-L samples of filtered water and four 10-L control samples of unfiltered water were analyzed for Cryptosporidium oocysts and Giardia cysts. On average, 1,920 Giardia cysts and 2,735 Cryptosporidium oocysts per 10 L were detected in the unfiltered water. Between 0 and 2 Giardia cysts and between 2 and 47 Cryptosporidium oocysts were detected in the filtered 10-L samples. Percentage removal of parasites was between 99.8 and > 99.95% for Giardia (2.98 to > 3.28 log removal) and between 98.3 and 99.9% (1.76-3.14 log removal) for Cryptosporidium. The Berkefeld filter TWA 3 complies with published recommendations for municipal water supply for removal of Giardia but does not always comply with such regulations for Cryptosporidium.
authors.affiliation: Section of Parasitology, Department of Pharmacology, Microbiology and Food Hygiene, The Norwegian School of Veterinary Science, P.O. Box 8146 Dep., 0033 Oslo, Norway.
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Robertson
authors.forename: Bjørn K
authors.initials: BK
authors.lastname: Gjerde
authors.forename: Morten
authors.initials: M
authors.lastname: Opsahl
mesh_terms: D003457:Cryptosporidiosis / Q000517:prevention & control*; D005374:Filtration / Q000379:methods*; D005873:Giardiasis / Q000517:prevention & control*; D006801:Humans; D008889:Military Personnel; D009664:Norway; D018635:Rescue Work; D014867:Water / Q000032:analysis / Q000469:parasitology; D018508:Water Purification / Q000379:methods*
chemical_list: D014867:Water