A Preliminary Study on the Bionomics of Oncomelania Snails, Intermediate Hosts of Schistosoma Japonicum, in Kiangsu and Chekiang Provinces, China 1

1950 ◽  
Vol s1-30 (3) ◽  
pp. 397-410
Author(s):  
H. F. Hsü
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Preliminary Study

Ultrastructure of Cercarial Tails

1974 ◽  
Vol 32 ◽  
pp. 180-181
Author(s):  
Richard S. Demaree ◽  
Donald M. Wootton
Keyword(s):  
Schistosoma Japonicum ◽  
Intermediate Hosts ◽  
Suitable Host ◽  
Ultrastructural Studies ◽  
Tail Structure

Cercariae (juvenile trematodes with tails) emerge from mollusk intermediate hosts and swim toward definitive hosts or encystment objects. The locomotor power is furnished by the tail. Upon reaching a suitable host or encystment object, the tail is cast off and the cercariae penetrate and/or encyst. Ultrastructural studies of cercariae are sparse. There is even lessUltrastructural studies of cercariae are sparse. There is even less information about the tail structure; and body-to-tail morphology has been documented only for Acanthatrium oregonense and Schistosoma japonicum.

scholarly journals Preliminary study of coronavirus disease 2019 on pets in pandemic in Denpasar, Bali, Indonesia

2021 ◽  
pp. 2979-2983
Author(s):  
Hamong Suharsono ◽  
Ali Ghufron Mukti ◽  
Ketut Suryana ◽  
I. Wayan Masa Tenaya ◽  
Dilasdita Kartika Pradana ◽  
...  
Keyword(s):  
Close Contact ◽  
Genetic Material ◽  
Rna Isolation ◽  
World Health ◽  
Intermediate Hosts ◽  
Rt Pcr ◽  
Pcr Products ◽  
Preliminary Study ◽  
Health Organization ◽  
Respiratory Droplets

Background and Aim: Coronavirus disease 2019 (COVID-19) is an acute infectious respiratory disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and has spread rapidly globally, resulting in a pandemic. In humans, the main routes of transmission are respiratory droplets and close contact with infected individuals or through contact with an object infected with the virus, followed by touching mouth, nose, or eyes. It is assumed that SARS-CoV-2 was originated in wild animals and was then transmitted to humans. Although some wildlife and domestic animals can be naturally or experimentally infected with the virus, the intermediate hosts that transmitted it to humans are still unknown. Understanding the dynamics of SARS-CoV-2 associated with possible zoonotic transmission of intermediate hosts is considered critical. Reportedly, cats or dogs living with COVID-19-positive humans tested positive for the disease, suggesting that the virus was transmitted to the animals from humans. Information regarding the epidemiological investigation and comprehensive studies is limited. Therefore, it is still unclear how high is the correlation of infection in humans and pet animals, especially those living together. The aim of this study was to investigate the possibility of SARS-CoV-2 infection in the pets of patients with COVID-19 who were hospitalized at the Wangaya hospital, Denpasar, Bali, Indonesia. Materials and Methods: A total of seven clinically asymptomatic pets (six dogs of different races and sexes and a cat [age, 360-2920 days]) were included in this study. These animals belonged to patients with confirmed SARS-CoV-2 infection from August to November 2020. Nasal swab and nasopharyngeal samples were collected from the pets individually under anesthetic condition and were collected 6-12 days after confirmed SARS-CoV-2 infection in owners and hospitalization at the Wangaya Hospital. The swab samples were then processed for RNA isolation and tested using reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2, in accordance with the World Health Organization manual 2020. Results: RT-PCR results for all seven RNA samples, prepared from the swab samples, were negative. For the samples, all PCR products were below the threshold limit, suggesting no genetic material belonging to the samples tested. Conclusion: This was the first preliminary study of COVID-19 on pets in pandemic using RT-PCR. The study tested a very limited quantity of samples, and all of them were negative. However, the way in which the samples were prepared was considered appropriate. Therefore, in further studies, testing of more samples of pets of more individuals with confirmed SARS-CoV-2 infection is required.

A preliminary study on biological control of the snail intermediate hosts of schistosomiasis in U.A.R. by Helisoma duryi snails

Hydrobiologia ◽  
1970 ◽  
Vol 35 (2) ◽  
pp. 196-202 ◽  
Author(s):  
N. Ayad ◽  
A. H. Mousa ◽  
M. M. Ishak ◽  
F. Yousif ◽  
S. Zaghloul
Keyword(s):  
Biological Control ◽  
Intermediate Hosts ◽  
Helisoma Duryi ◽  
Preliminary Study

scholarly journals Co-Occurrence of Domestic Dogs and Gastropod Molluscs in Public Dog-Walking Spaces and Implications for Infection with Angiostrongylus vasorum: A Preliminary Study

Animals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2577 ◽  
Author(s):  
Bryony A. Tolhurst ◽  
Andrew D. J. Overall ◽  
Peter J. King ◽  
Eric R. Morgan ◽  
Rowenna J. Baker
Keyword(s):  
Domestic Dogs ◽  
Intermediate Hosts ◽  
Gastropod Mollusc ◽  
Point Counts ◽  
Dog Walking ◽  
Preliminary Study ◽  
Spatio Temporal ◽  
Natural Grassland ◽  
Temporal Overlap

Angiostrongylusvasorum is a helminth parasite of domestic dogs that is increasing in range and prevalence. Its lifecycle requires terrestrial gastropod mollusc (“gastropod”) intermediate hosts, but research is lacking regarding contact risk in situ. We studied co-occurrence between dogs and gastropods in dog-walking spaces in an A. vasorum hotspot in southern England, United Kingdom, with the aim of quantifying environmental and spatio-temporal overlap. We surveyed 390 quadrats and 180 point-counts along 3 km transects at seven sites, yielding 1672 gastropod and 763 dog observations. Common gastropods comprised Arion, Cornu, Monacha, Deroceras, Tandonia, Cochlicella, and Trochulus species. Habitat was the most important factor structuring both gastropod and dog presence and abundance. Likelihood ratio comparisons from conditional probability trees revealed that dogs were 15× more likely to be present on hardstanding surfaces than other habitats but were also present on natural and amenity grassland. Presence of gastropod species associated with high A. vasorum prevalence was 65.12× more likely in woodland/scrub and 62.17× more likely in amenity grassland than other habitats. For gastropods overall, high abundance was 5.82× more likely in woodland/scrub and natural grassland. The findings suggest co-occurrence is highest in amenity and natural grassland, but infection risk is greatest in amenity grassland and woodland/scrub.

scholarly journals Gene Transcription Profile in Mice Vaccinated with Ultraviolet-attenuated Cercariae of Schistosoma japonicum Reveals Molecules Contributing to Elevated IFN-γ Levels

2005 ◽  
Vol 37 (4) ◽  
pp. 254-264 ◽  
Author(s):  
Xiang Zhu ◽  
Zhao-Song Zhang ◽  
Min-Jun Ji ◽  
Hai-Wei Wu ◽  
Yong Wang ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Schistosoma Japonicum ◽  
Protective Immunity ◽  
Early Stage ◽  
Post Vaccination ◽  
Ifn Γ ◽  
Preliminary Study ◽  
Gene Transcription Profile ◽  
Th1 And Th2 Responses ◽  
Draining Lymph Nodes

AbstractVaccination with ultraviolet-attenuated cercariae of Schistosoma japonicum induced protective immunity against challenge infection in experimental animal models. Our preliminary study on the transcription levels of IFN-γ and IL-4 in splenic CD4+ T cells revealed that attenuated cercariae elicited predominantly a Th1 response in mice at the early stage, whereas normal cercariae stimulated primarily Independent responses. Further analysis on the gene profile of the skin-draining lymph nodes demonstrated that the levels of IFN-γ were significantly higher in vaccinated mice than those in infected mice at day 4, 7 and 14 post-vaccination or post-infection. However, for IL-12 and IL-4, the potent inducers of Th1 and Th2 responses, respectively, as well as IL-10, there were no differences over the course of the experiment between the infected and vaccinated mice. To explore the underlying factors that may potentially contribute to elevated IFN-γ in vaccinated mice, the mRNA profiles of the skin-draining lymph nodes at day 4 post-exposure were compared using oligonucleotide microarrays. Within the 847 probe sets with increased signal values, we focused on chemokines, cytokines and relevant receptors, which were validated by semi-quantitative RT-PCR. A comprehensive understanding of the immune mechanisms of attenuated cercariae-induced protection may contribute to developing efficient vaccination strategies against S. japonicum, especially during the early stage of infection.

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