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Schistosomes in the southwest United States and their potential for causing cercarial dermatitis or ‘swimmer's itch’

  • S.V. Brant (a1) and E.S. Loker (a1)

Cercarial dermatitis or swimmer's itch results when cercariae of schistosomes penetrate human skin and initiate inflammatory responses. The parasites typically die in the skin but in some cases may persist and infect other organs. Cercarial dermatitis is caused by a complex and poorly known assemblage of schistosome species, and can occur in any location where people come in contact with water bodies harbouring schistosome-infected snails. In North America, most cases are reported from the upper Midwest. In south-western USA, this phenomenon has not been well studied, and it is not known which schistosome species are present, or if cercarial dermatitis occurs with any regularity. As part of our ongoing studies of schistosome diversity, using morphological traits and sequence data to differentiate species, we have thus far identified eight schistosome genetic lineages from snails from New Mexico and Colorado. We have investigated two cercarial dermatitis outbreaks, one occurring in Stubblefield Lake in northern New Mexico, and one in Prospect Lake in the heart of Colorado Springs, Colorado. The New Mexico outbreak involved either one or two different avian schistosome species, both transmitted by physid snails. The Colorado outbreak was due to Trichobilharzia brantae, a species transmitted by geese and the snail Gyraulus parvus. These outbreaks are in contrast to those in northern states where schistosomes infecting snails of the family Lymnaeidae are more often responsible for outbreaks. Our survey suggests that dermatitis-causing schistosomes are not rare in the southwest, and that there are plenty of opportunities for dermatitis outbreaks to occur in this region.

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Bayssade-Dufour, C., Martins, C. & Vuong, P.N. (2001) Histopathologie pulmonaire d'un modèle mammifière et dermatite cercarienne humaine. Médecine et Maladies Infectieuses 31, 713722.
Blankespoor, H.D. & Reimink, R.L. (1991) The control of swimmer's itch in Michigan: Past, present and future. Michigan Academician 24, 723.
Brackett, S. (1940) Two new species of schistosome cercariae from Wisconsin. Journal of Parasitology 26, 195200.
Brackett, S. (1942) Five new species of avian schistosomes from Wisconsin and Michigan with the life cycle of Gigantobilharzia gyrauli (Brackett, 1940). Journal of Parasitology 28, 2542.
Brant, S.V. (2007) The occurrence of the avian schistosome Allobilharzia visceralis Kolarova, Rudolfova, Hampl, Skirnisson, 2006 (Schistosomatidae) in the tundra swan, Cygnus columbianus, (Anatidae) from North America. Folia Parasitologica 54, 99104.
Brant, S.V. & Loker, E.S. (2009) Systematics of the avian schistosome genus Trichobilharzia (Trematoda: Schistosomatidae) in North America. Journal of Parasitology in press.
Brant, S.V., Morgan, J.A.T., Mkoji, G.M., Snyder, S.D., Rajapakse, R.P.V.J. & Loker, E.S. (2006) An approach to revealing blood fluke life cycles, taxonomy, and diversity: provision of key reference data including DNA sequence from single life cycle stages. Journal of Parasitology 92, 7788.
Burch, J.B. (1989) North American freshwater snails. 365 pp. Hamburg, Malacological Publications.
Coady, N.R., Muzzall, P.M., Burton, T.M., Snider, R.J., Saxton, J., Sergeant, M. & Sommers, A. (2006) Ubiquitous variability in the prevalence of Trichobilharzia stagnicolae (Schistosomatidae) infecting Stagnicola emarginata in three northern Michigan lakes. Journal of Parasitology 92, 1015.
Cawston, F.G. (1917) The cercariae of Natal. Journal of Parasitology 3, 131135.
Cort, W.W. (1928) Schistosome dermatitis in the United States (Michigan). Journal of the American Medical Association 90, 10271029.
Cort, W.W. (1950) Studies on schistosome dermatitis XI. Status of knowledge after more than twenty years. American Journal of Hygiene 52, 251307.
Faust, E.C. (1926) Further observations on South African larval trematodes. Parasitology 18, 101127.
Farr, M.M. & Blankemeyer, V.G. (1956) Trichobilharzia brantae n. sp. (Trematoda: Schistosomatidae) from the Canada goose (Branta canadensis L.). Journal of Parasitology 42, 320325.
Horak, P. & Kolarova, L. (2000) Survival of bird schistosomes in mammalian lungs. International Journal for Parasitology 30, 6568.
Horak, P., Dvořák, J., Kolářová, L. & Trefil, L. (1999) Trichobilharzia regenti, a pathogen of the avian and mammalian central nervous system. Parasitology 119, 577581.
Hunter, G.W. (1960) Studies on schistosomiasis. XIII. Schistosome dermatitis in Colorado. Journal of Parasitology 46, 231233.
Jarcho, S. & van Burkalow, A. (1952) A geographical study of ‘Swimmer's Itch’ in the United States and Canada. Geographical Review 42, 212226.
Kagan, I.G. (1953) Experimental infections of rhesus monkeys with Schistosomatium douthitti (Cort, 1914). Journal of Infectious Disease 93, 200206.
Khalifa, R. (1972) Studies on Schistosomatidae Looss, 1899 (Trematoda) of aquatic birds of Poland. I. On the life cycle of Bilharziella polonica Kowalewski, 1895, with a discussion of the subfamily Bilharziellinae Price, 1929. Acta Parasitologica Polonica 20, 343365.
Khalifa, R. (1976) Studies on Schistosomatidae Looss, 1899 (Trematoda) of aquatic birds of Poland. III. Notes on the morphology and life cycle of Dendritobilharzia pulverulenta (Brauwn, 1901). Acta Parasitologica Polonica 24, 19.
Kolářová, L., Horák, P. & Sitko, J. (1997) Cercarial dermatitis in focus: schistosomes in the Czech Republic. Helminthologica 34, 127139.
Kouřilová, P., Syr˚ček, M. & Kolářová, L. (2004) The severity of mouse pathologies caused by the bird schistosome Trichobilharzia regenti in relation to host immune status. Parasitology Research 93, 816.
Laman, T.G., Daniell, D.L. & Blankespoor, H.D. (1984) The role of Gyraulus parvus as an intermediate host for avian schistosomes. Proceedings of the Helminthological Society of Washington 51, 267269.
Leighton, B.J., Zervos, S. & Webster, J.M. (2000) Ecological factors in schistosome transmission, and an environmentally benign method for controlling snails in a recreational lake with a record of schistosome dermatitis. Parasitology International 49, 917.
Levesque, B., Giovenazzo, P., Guerrier, P., Laverdiere, D. & Prud'Homme, H. (2002) Investigation of an outbreak of cercarial dermatitis. Epidemiology and Infections 129, 379386.
Lindblade, K.A. (1998) The epidemiology of cercarial dermatitis and its association with limnological characteristics of a northern Michigan Lake. Journal of Parasitology 84, 1923.
Macfarlane, D.G. & Macy, R.W. (1946) Cercaria oregonensis, n. sp., a dermatitis-producing schistosome cercaria from the Pacific Northwest. Journal of Parasitology 32, 281285.
McMullen, D.B. & Beaver, P.C. (1945) Studies on schistosome dermatitis IX. The life cycle of three dermatitis producing schistosomes from birds and a discussion of the subfamily Bilharziellinae (Trematoda: Schistosomatidae). American Journal of Hygiene 42, 128154.
McMullen, D.B. & Brackett, S. (1948) Studies on schistosome dermatitis. X. Distribution and epidemiology in Michigan. American Journal of Hygiene 47, 259270.
Nassi, H. (1987) Sur quatre furcocercaires emises par Biomphalaria glabrata en Guadeloupe. Annales Parasitologie Humaine et Comparee 62, 1735.
Olivier, L. (1953) Observations on the migration of avian schistosomes in mammals previously unexposed to cercariae. Journal of Parasitology 39, 237243.
Oyoo, A.O., Donnell, D. & Prendergast, T.J. Jr (1977) Epidemic of ‘swimmer's itch’ traced to cercarial trematodes. Missouri Medicine 74, 218219.
Penner, L.R. (1941) The possibilities of systemic infection with dermatitis producing schistosomes. Science 93, 327328.
Post, D.M., Taylor, J.P., Kitchell, J.F., Olson, M.H., Schindler, D.E. & Herwig, B.R. (1998) The role of migratory waterfowl as nutrient vectors in a managed wetland. Conservation Biology 12, 910920.
Rind, S. (1991) Three ocellate schistosome cercariae (Trematodea: Schistosomatidae) in Gyraulus corinna, with reference to Cercaria longicauda MacFarlane, 1944 in Lymnaea tomentosa. New Zealand Journal of Zoology 18, 5362.
Talbot, S.B. (1936) Studies on schistosome dermatitis. II. Morphological and life history studies on three dermatitis-producing schistosome cercariae, C. elvae Miller, 1923, C. stagnicolae n. sp., and C. physellae n. sp. American Journal of Hygiene 23, 372384.
Tanabe, H. (1951) Cercaria segmintinae Tanable 1948, a homonym of Cercaria sturniae. Journal of Parasitology 37, 321.
Taylor, D.W. (2003) Introduction to Physidae (Gastropoda: Hygrophila); biogeography, classification, morphology. Revista de Biologia Tropical 51, 1287.
Truett, G.E., Heeger, P., Mynatt, R.L., Truett, A.A., Walker, J.A. & Warman, M.L. (2000) Preparation of PCR-quality mouse genomic DNA with hot sodium hydroxide and Tris (HotShot). Biotechniques 29, 5254.
Unckless, R.L. & Makarewicz, J.C. (2007) The impact of nutrient loading from Canada Geese (Branta canadensis) on water quality, a mesocosm approach. Hydrobiologia 586, 393401.
Verbrugge, L.M., Rainey, J.J., Reimink, R.L. & Blankespoor, H.D. (2004a) Swimmer's itch: incidence and risk factors. American Journal of Public Health 94, 738741.
Verbrugge, L.M., Rainey, J.J., Reimink, R.L. & Blankespoor, H.D. (2004b) Prospective study of swimmer's itch incidence and severity. Journal of Parasitology 90, 697704.
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