scholarly journals Transient definitive host presence is sufficient to sustain avian schistosome populations

2021 ◽  
Author(s):  
Sydney P Rudko ◽  
Brooke A McPhail ◽  
Ronald L Reimink ◽  
Kelsey Froelich ◽  
Alyssa Turnbull ◽  
...  
Keyword(s):  
Definitive Host ◽  
Snail Host ◽  
Effective Control ◽  
Lake Ecosystem ◽  
Infection Prevalence ◽  
Control Effort ◽  
Swimmer’S Itch ◽  
The Common ◽  
Common Merganser ◽  
Swimmer's Itch

To control swimmer's itch in northern Michigan inland lakes, one species of bird, the common merganser (Mergus merganser), has been relocated from several lakes since 2015. Relocation efforts are driven by a desire to reduce the prevalence of the swimmer's itch-causing parasite Trichobilharzia stagnicolae. The intention of this state-sponsored control effort was to interrupt the life cycle of T. stagnicolae and reduce parasite egg contribution into the environment from summer resident mergansers such that infections of the intermediate snail host Stagnicola emarginata declined. Reduced snail infection prevalence was expected to greatly reduce abundance of the swimmer's itch-causing cercarial stage of the parasite in water. With no official program in place to assess the success of this relocation effort, we sought to study the effectiveness and impact of the removal of a single definitive host from a location with high definitive host and parasite diversity. This was assessed through a comprehensive, lake-wide monitoring study measuring longitudinal changes in the abundance of three species of avian schistosome cercariae in four inland Michigan lakes. Environmental measurements were also taken at these lakes to understand how they can affect swimmer's itch incidence. Results from this study demonstrate that the diversity of avian schistosomes at the study lakes would likely make targeting of a single species of swimmer's itch-causing parasite meaningless from a swimmer's itch control perspective. Our data also suggest that removal of the common merganser is not an effective control strategy for the T. stagnicolae parasite, likely due to parasite contributions of migratory birds in the fall and spring. This suggests that only minimal contact time between the definitive host and the lake ecosystem is required to contribute sufficient parasite numbers to maintain a thriving population of parasite species with a high host-specificity.

scholarly journals The chemotactic swimming behavior of bird schistosome miracidia in the presence of compatible and incompatible snail hosts

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9487
Author(s):  
Anna Marszewska ◽  
Anna Cichy ◽  
Jana Bulantová ◽  
Petr Horák ◽  
Elżbieta Żbikowska
Keyword(s):  
Tap Water ◽  
Parasite Prevalence ◽  
Snail Host ◽  
Swimming Behavior ◽  
Snail Species ◽  
Host Snail ◽  
Bird Schistosome ◽  
Swimmer’S Itch ◽  
Secretory Products ◽  
Swimmer's Itch

No effective method has yet been developed to prevent the threat posed by the emerging disease—cercarial dermatitis (swimmer’s itch), caused by infective cercariae of bird schistosomes (Digenea: Schistosomatidae). In our previous studies, the New Zealand mud snail—Potamopyrgus antipodarum (Gray, 1853; Gastropoda, Tateidae)—was used as a barrier between the miracidia of Trichobilharzia regenti and the target snails Radix balthica. Since the presence of non-indigenous snails reduced the parasite prevalence under laboratory conditions, we posed three new research questions: (1) Do bird schistosomes show totally perfect efficacy for chemotactic swimming behavior? (2) Do the larvae respond to substances emitted by incompatible snail species? (3) Do the excretory-secretory products of incompatible snail species interfere with the search for a compatible snail host? The experiments were carried out in choice-chambers for the miracidia of T. regenti and T. szidati. The arms of the chambers, depending on the variant, were filled with water conditioned by P. antipodarum, water conditioned by lymnaeid hosts, and dechlorinated tap water. Miracidia of both bird schistosome species chose more frequently the water conditioned by snails—including the water conditioned by the incompatible lymnaeid host and the alien species, P. antipodarum. However, species-specific differences were noticed in the behavior of miracidia. T. regenti remained more often inside the base arm rather than in the arm filled with water conditioned by P. antipodarum or the control arm. T. szidati, however, usually left the base arm and moved to the arm filled with water conditioned by P. antipodarum. In conclusion, the non-host snail excretory-secretory products may interfere with the snail host-finding behavior of bird schistosome miracidia and therefore they may reduce the risk of swimmer’s itch.

A review on swimmer's itch and the occurrence of bird schistosomes in Iceland

2009 ◽  
Vol 83 (2) ◽  
pp. 165-171 ◽  
Author(s):  
K. Skírnisson ◽  
J.A. Aldhoun ◽  
L. Kolářová
Keyword(s):  
Bird Species ◽  
Infection Prevalence ◽  
Anser Anser ◽  
Morphological Examination ◽  
Unknown Species ◽  
Geothermal Activity ◽  
Swimmer’S Itch ◽  
Radix Peregra ◽  
Water Birds ◽  
Swimmer's Itch

AbstractIn the past decade, swimmer's itch (SI) has repeatedly occurred in people who have been wading or bathing in ponds or lakes in Iceland where water birds and snails are abundant. Some of the affected sites were warmed by geothermal activity, and others were not. A search for the causative agent of SI, ocellate furcocercariae that have been found in Iceland only in Radix peregra snails, revealed an average infection prevalence of 1.4% (n = 12,432). Locally, infection rates commonly exceeded 6%, the highest value observed being 24.5%. A search for adult schistosomes in visceral organs and the nasal cavities of 110 water birds belonging to the orders Gaviiformes, Podicipediformes and Anseriformes revealed eggs, miracidia or adult stages of at least seven previously identifiable schistosome species in four anseriform bird species. A previously unknown species of schistosome, Allobilharzia visceralis, was detected in whooper swans (Cygnus cygnus), and classified in a new genus. In mallards (Anas platyrhynchos) a nasal Trichobilharzia sp. and the visceral schistosome T. franki were identified. In red-breasted merganser (Mergus serrator), distinct egg types belonging to two species of the genus Trichobilharzia have been found. In grey-lag goose (Anser anser) two different egg types were also found – a large Trichobilharzia sp. and small eggs of a Dendritobilharzia sp. Additionally, unidentified cercariae, probably belonging to a previously undescribed genus were detected in R. peregra in Oslandsstjörn. Taken together, the data obtained by morphological examination of eggs and recent DNA sequencing results, indicate that at least eight species of bird schistosomes occur in Iceland.

Ultrastructural analysis of “Sensory” surface nerve endings and “putative” neurotransmitter sites in Schistosoma mansoni Miracidia

1989 ◽  
Vol 47 ◽  
pp. 962-963
Author(s):  
Betty Ruth Jones ◽  
Steve Chi-Tang Pan
Keyword(s):  
Nervous System ◽  
Life Cycle ◽  
Schistosoma Mansoni ◽  
Snail Host ◽  
Complex Life Cycle ◽  
Rational Approach ◽  
Effective Control ◽  
The Social ◽  
Social And Economic Development ◽  
Basic Biology

INTRODUCTION: Schistosomiasis has been described as “one of the most devastating diseases of mankind, second only to malaria in its deleterious effects on the social and economic development of populations in many warm areas of the world.” The disease is worldwide and is probably spreading faster and becoming more intense than the overall research efforts designed to provide the basis for countering it. Moreover, there are indications that the development of water resources and the demands for increasing cultivation and food in developing countries may prevent adequate control of the disease and thus the number of infections are increasing.Our knowledge of the basic biology of the parasites causing the disease is far from adequate. Such knowledge is essential if we are to develop a rational approach to the effective control of human schistosomiasis. The miracidium is the first infective stage in the complex life cycle of schistosomes. The future of the entire life cycle depends on the capacity and ability of this organism to locate and enter a suitable snail host for further development, Little is known about the nervous system of the miracidium of Schistosoma mansoni and of other trematodes. Studies indicate that miracidia contain a well developed and complex nervous system that may aid the larvae in locating and entering a susceptible snail host (Wilson, 1970; Brooker, 1972; Chernin, 1974; Pan, 1980; Mehlhorn, 1988; and Jones, 1987-1988).

scholarly journals A mathematical model for the control of swimmer's itch

2020 ◽  
Vol 33 (4) ◽  
Author(s):  
J. P. Peirce ◽  
J. J. Pellett ◽  
G. J. Sandland
Keyword(s):  
Mathematical Model ◽  
Swimmer’S Itch ◽  
Swimmer's Itch

Deep Sea Mining Partnerships with Developing States: Favourable Collaborations or Opportunistic Endeavours?

2021 ◽  
pp. 1-19
Author(s):  
Klaas Willaert ◽  
Pradeep A Singh
Keyword(s):  
Deep Sea ◽  
Recent Trend ◽  
The State ◽  
Effective Control ◽  
Forum Shopping ◽  
Mining Activities ◽  
Mining Companies ◽  
Common Heritage Of Mankind ◽  
Realistic Possibility ◽  
The Common

Abstract In order to engage in deep sea mining activities on the international seabed (otherwise known as ‘the Area’), non-State actors must be sponsored by a State, which bears the responsibility to ensure that the sponsored entity complies with the applicable rules. Not only the State of nationality, but also the State which exercises ‘effective control’ might be required to serve as a sponsoring State, depending on the circumstances. However, it is not completely clear how ‘effective control’ should be interpreted. Forum shopping seems a realistic possibility, and the recent trend of partnerships between private deep sea mining companies and developing States can produce similar effects. These collaborations might be beneficial to both parties, but given the privileges awarded to developing States, it should be scrutinised as to whether such partnerships undermine the principle of the common heritage of mankind and the objective to realise benefits for mankind as a whole.

scholarly journals Agents of swimmer’s itch—dangerous minority in the Digenea invasion of Lymnaeidae in water bodies and the first report of Trichobilharzia regenti in Poland

2018 ◽  
Vol 117 (12) ◽  
pp. 3695-3704 ◽  
Author(s):  
Anna Marszewska ◽  
Tomasz Strzała ◽  
Anna Cichy ◽  
Grażyna B. Dąbrowska ◽  
Elżbieta Żbikowska
Keyword(s):  
Water Bodies ◽  
First Report ◽  
Swimmer’S Itch ◽  
Swimmer's Itch ◽  
Trichobilharzia Regenti

More About the Photodistribution Viral Exanthems

PEDIATRICS ◽  
1978 ◽  
Vol 61 (4) ◽  
pp. 670-671
Author(s):  
Matti Uhari
Keyword(s):  
Swimmer’S Itch ◽  
Swimmer's Itch

Dr. Cupoli reported photodistribution of viral exanthems (Pediatrics 59:484, March 1977) just as Gilchrest and Baden had done earlier.1 Their conclusions are obviously right, but I would like to remind the reader of another disease, swimmer's itch, which may occur like the exanthems Cupoli reported.2 The lesions in Figure 1 of Cupoli's report resemble very much real swimmer's itch (accompanying Figure). It is caused by a worm, cercaria ocellata, and is acquired by swimming in infected water.3

Swimmer’s Itch

2016 ◽  
pp. 2587-2593
Author(s):  
Christian Selbach ◽  
Bernd Sures
Keyword(s):  
Swimmer’S Itch ◽  
Swimmer's Itch

limited data for the greater Townsville area (Kay et al.1996). Based on the prevalence of key vector species and their abundance and that of the viruses recovered, it was concluded that Big Bay, originally recommended as a prime site for recreational development by the Department of Local Government in 1985, actually presented lower risk than any other locality. Antill Creek also proved relatively safe in terms of mosquito-borne infections, whereas Toonpan during the wet season was a place to be avoided. Both Ross River and the environs of Townsville offered intermediate risk, the latter due to large numbers of saltmarsh mosquitoes breeding in intertidal wetlands. 9.5 Snails and swimmer’s itch Schistosome dermatitis, known as swimmer’s itch, is a common global problem for users of recreational swimming areas in water resource developments. The rash is caused by free living larvae called cercariae (Figure 9.4) of parasitic flukes which burrow into exposed parts of the body. Normally the life-cycle involves water birds such as ducks and pulmonate snails, so infection of humans is accidental. A large number of cercariae may penetrate the skin where they die but cause a localized allergic reaction in sensitized persons. In northern Australia, swimmer’s itch (Trichobilharzia) has been traditionally associated with Austropeplea (= Lymnaea) lessoni (= vinosa) although two planorbid snails, Amerianna carinata and Gyraulus stabilis, have also been identified as intermediate hosts in Lake Moondarra near Mt Isa, Queensland. Our recent data implicates Gyraulus gilberti at the Ross River dam. Snails are also commonly infected with other trematode cercariae, mainly echinostomes, strigeids/diplostomids and clinostomids.

1998 ◽  
pp. 148-148
Keyword(s):  
Lower Risk ◽  
The Body ◽  
Northern Australia ◽  
Intermediate Hosts ◽  
Wet Season ◽  
Large Numbers ◽  
Swimmer’S Itch ◽  
Intertidal Wetlands ◽  
Water Birds ◽  
Swimmer's Itch
Sign in / Sign up

Export Citation Format

Share Document