Schistosome Dermatitis at Basswood Lake, Minnesota

During the summer of 1965 cases of schistosome dermatitis were reported at the Associated Colleges of the Midwest Wilderness Field, Station on Basswood Lake, Minnesota. Collection and isolation of gastropods from the lake revealed an extremely high incidence of Trichobilharzia ocellata infections in Lymnaea stagnalis. A flock of semi-domestic mallard ducks first introduced al the lake in 1963 are believed to be the principal definitive hosts contributing to the epidemiology of the parasite in the area

Studies on Schistosome Dermatitis (\u27Swimmer\u27s Itch ) in Minnesota

A preliminary study was conducted to determine the causative agents of schistosome dermatitis ( swimmer\u27s itch ) in Minnesota and to determine the incidence schistosome infection in vector snails. A total of 1180 snails were collected from ten different localities, eight of which were sites of known schistosome activity . The incidence of schistosome infection in snails from individual areas was always less than 10 percent. Cercariae of Trichobilharzia ocellata from Lymnaea stagnalis were the most frequently-found schistosomes in our study

Effect of Feedlots on Water Quality

The effect of feedlot runoff on water quality was examined. Samples were collected from river feedlots and offshore from lake feedlots and compared with samples from appropriate control sites. Bacterial contamination, as measured by the total coliform test over two successive summers, exhibited significant variation between feedlot and control sites. Coliform levels at lake sites adjacent to feedlots were double the levels at control sites; while in river systems average coliform levels downstream from feedlots were approximately 17 times the upstream controls

Egy ritka zoonosis: a Schistosoma turkestanicum vérmétely által okozott cercaria dermatitis Magyarországon | A rare zoonosis in Hungary: cercarial dermatitis caused by Schistosoma turkestanicum blood-fluke

Absztrakt Az állatokban sok mételyfaj él, amelyek lárvája a gazda bőrén keresztül fertőzi azt. Ezek közül az ember szempontjából a legfontosabbak az emlősök vérmételyei, mert belőlük kerülnek ki az embert fertőzni képes vérmételyek is. Több fajuk a trópusi országok lakóinak rettegett schistosomosisát okozza, míg más fajok behatolnak ugyan az ember bőrébe, de adulttá nem válnak a testében. A mérsékelt égövben főleg az utóbbi, bőrgyulladás formájában jelentkező infekció fordul elő. A mételylárvák eredete legtöbbször nem tisztázható, ezért általában sem orvosok, sem állatorvosok nem foglalkoznak a fertőzés forrásával. Szarvasokban élő mételyfajról bizonyítottuk be, hogy a régen „vízi rühösség”-nek nevezett bőrbántalmat csigákból kirajzó cercariák okozzák. A Duna egyik árterén endemikus Schistosoma turkestanicum okozta dermatitis ritkán kerül orvos szeme elé, pedig informális közlések alapján úgy tűnik, hogy rendszeresen előforduló tünet a métely élőhelyén lévő vizekben halászó vagy fürdőző embereken. Ráutaló kórelőzmény esetén indokolt a humán vérmétely-fertőzöttséghez hasonló szerológiai reakciót adó cercaria dermatitis eredetét kivizsgáltatni. Orv. Hetil., 2016, 157(40), 1579–1586. | Abstract Several trematodes that parasitize vertebrate animals utilize swimming aquatic larvae to infect the host percutaneously. The most important ones among these parasites are the blood-flukes of birds and mammals comprising species that are also zoonotic. Within this latter group are species that cause the bilharziasis or schistosomiasis of inhabitants of the tropical countries, and other trematode species that are able to penetrate human skin, but do not develop to an adult form of the worm in the body. In temperate climates this latter type of infection occurs mainly in the form of an unpleasant inflammation of the skin and is often called “swimmer’s itch”. In most of these cases, the origin of the larvae remains unexplored, the source of the infection is neglected by the medical or veterinarian practitioners. Herein we report for the first time in Hungary that the cause of such dermatitis was the cercariae of Schistosoma turkestanicum, which infected red deer (Cervus elaphus) in this country. The local name of this pristine disease is “water mange” and it occurs only in one of the floodplains of the Danube. On the basis of informal communication this symptom seems to be rather regular among people who do fishing or have a bath in the habitat of the blood-fluke. In the case of adequate anamnesis it is worth examining the origin of the cercarial dermatitis which may give cross-reactions with human schistosomiasis during serological tests. Orv. Hetil., 2016, 157(40), 1579–1586

Cytokine and eicosanoid regulation by Schistosoma mansoniduring LSE penetration

Cercarial penetration, in low to moderate numbers, does not cause a normal skin inflammatory response; therefore, the authors sought to determine whether cercariae can down-regulate keratinocyte activation and thus the secretion of pro-inflammatory cytokines and eicosanoids. Human living skin equivalent (LSE, Organogenesis) consisting of dermal, epidermal and stratum corneum-like layers was used as the skin substrate. The surface of the LSE membrane was exposed to 100 ng IFNγ or ~850 cercariae for 18 h. Incubation media and tissue was then assayed for IL-1α, IL-6, IL-8, TNFα, 5-HETE, 12-HETE, PGF2, LTB4, and LTC4 via RIA and Western Blots. TNFα was not detected. Secreted IL-1α levels were (mean ± S.E.M. (n)): Control, 1.03 ng ± 0.15 (11); IFNγ 1.90 ng ± 0.48 (5); cercariae, 1.79 ng ± 0.22 (22). In spite of this increase, cercariae down-regulated IL-8 (cercariae 11.13 ± 1.70 ng vs. IFNγ = 16.47 ± 0.29 ng, p = 0.04) and LTB4 (cercariae = 98.86 ± 19.65 pg/0.1 ml vs. IFNγ = 193.42 ± 44.21 pg/0.1 ml p = 0.02). No changes were seen in IL-6, 12-HETE, 5-HETE, and PGE2 levels. It is concluded that cercarial penetration causes a release of IL-1α consistent with skin trauma; however, schistosomulae may regulate the production of chemotactic (neutrophils, macrophages, T-cells, etc.) and activation factors such as IL-8 and LTB4