116 research outputs found
Harnessing molecular tools for the control of zoonotic soil-transmitted helminths
No full text© 2024 Patsy Alejandra Zendejas HerediaSoil-transmitted helminths (STHs) are a group of parasitic worms infecting over 1.5 billion people worldwide. These parasites cause some of the most significant Neglected Tropical Diseases and include the hookworms, whipworms, roundworms, and threadworms. STHs cause substantial morbidity in infected people that lead to severe health and socioeconomic consequences, particularly among children and women of reproductive age. Generally, these infections begin in childhood, and without proper control, infections persist into adulthood and promote intergenerational poverty. In 2020, the World Health Organization (WHO) introduced a new target aimed at eliminating the morbidity associated with STHs by 2030. However, the limited data available on zoonotic parasites, along with scant information on the applicability of molecular tools for their diagnosis, may potentially hamper the success of intervention strategies.
This thesis consists of a literature review, six chapters describing original research and a general discussion. The literature review provides an account of the role of STHs as significant causes of morbidity in humans and animals globally, and of the possible factors that drive the persistence of these parasites in endemic regions, despite years of control efforts. In addition, inaccurate diagnostic tools and mass deworming restricted to at-risk populations may contribute to making the WHO 2030 aims unachievable. Moreover, animals, particularly dogs, have been identified as potential reservoirs of zoonotic STHs, thus posing an additional threat to global control efforts. To this end, the objective of the present thesis was to conduct a robust comparison between microscopic and molecular tools to assess their diagnostic performance, providing evidence on the utility of real time qPCR in STH control surveys. Molecular tools were employed to gain insights into the epidemiology of zoonotic intestinal helminths in dogs across Cambodia and to describe the occurrence of the zoonotic hookworm Ancylostoma ceylanicum in unexpected regions of the Asia-Pacific and the Americas. Finally, I applied molecular tools to detect and genetically characterise STHs circulating in community dogs and in school-age children subjected to bi-annual mass drug administration. An integrated coprocopic and molecular approach was applied to assess the prevalence and distribution of zoonotic parasites infecting dogs in Cambodia (Chapter 2). The findings highlighted the need to transition from conventional microscopy techniques to more sensitive molecular tools to accurately identify zoonotic parasites in dogs. Notably, the high prevalence of zoonotic hookworms and Strongyloides stercoralis highlighted the need for inclusion of animals of all ages in control strategies.
Building on the results of Chapter 2, molecular tools were used to extend the investigation in selected areas of the Pacific and the Americas lacking molecular data on zoonotic STHs. The nation of Kiribati is one of the world’s poorest nations where STHs and diarrhoea remains leading infectious diseases. Despite the KIRIBATI–WHO Cooperation Strategy 2018–2022, no information was available on the presence and diversity of zoonotic STHs in free-roaming animals. The results (Chapter 3) demonstrated that dogs play a major role in contaminating the environment with zoonotic STHs, potentially serving as reservoirs for infections to humans. Given the effectiveness of molecular tools in detecting zoonotic parasites in dogs, I sought to apply qPCR in other regions lacking molecular data. The Americas were identified as a key area of interest due to historical A. ceylanicum presence, insufficient molecular data, and confirmed infections in travellers returning from Latin America. This study revealed a notable prevalence of zoonotic STHs in free-roaming dogs in Grenada, West Indies, in the Caribbean and the first molecular evidence confirming A. ceylanicum occurrence in dogs in the continent. Additionally, we utilised qPCR and DNA sequencing to screen coyote scats in Costa Rica, identifying A. ceylanicum in wildlife in the Americas for the first time.
In Chapter 5, a thorough comparison between conventional microscopy techniques and qPCR was conducted. Diagnostic performance, including egg recovery rates and limits of detection, was evaluated for human STHs and linear regression formulas were developed to estimate eggs per gram (EPG) from Ct values for N. americanus, Trichuris, and Ascaris spp., demonstrating superiority of qPCR in accurately estimating egg numbers and in detecting < 5 EPG in faecal samples. These results showed the utility of qPCR for quantitative estimation of infection levels, differentiation of hookworm species for One Health measures, and evaluation of intervention programs in low infection settings. Additionally, Chapter 6 evaluated how sample storage conditions affect egg development and influence infection intensity estimates based on Ct values particularly in the context of large-scale STH surveys in endemic countries. This study highlighted a substantial difference between qPCR estimates of embryonated and non-embryonated seeded eggs experiments.
Finally, in Chapter 7, the developed formulas and molecular techniques were employed to assess the success of bi-annual mass drug administration (MDA) in school-age children. Further, zoonotic transmission of STHs between children and their cohabiting dogs was investigated. Results underscored the complexity of controlling these infections in endemic areas where zoonotic species are abundant, emphasising the need to re-evaluate surveillance and control strategies to achieve WHO 2030 targets.
In conclusion, the findings of this doctoral thesis underscore the importance of employing refined diagnostic tools to achieve the WHO's 2030 targets for controlling morbidity attributed to STHs. Additionally, a comprehensive One Health approach that acknowledges the role of animal reservoirs in maintaining these infections in humans will be fundamental to effectively control STH at the regional and global levels
Emerg Infect Dis
No full textAncylostoma ceylanicum is the second most common hookworm infecting humans in the Asia-Pacific region. Recent reports suggest presence of the parasite in the Americas. We report A. ceylanicum infections in coyotes from the Guanacaste Conservation Area, Costa Rica. Our findings call for active surveillance in humans and animals
Emerg Infect Dis
No full textSoil-transmitted helminths are highly prevalent in the Asia-Pacific region. We report a 96.5% prevalence of zoonotic soil-transmitted helminths in dogs in Kiribati. We advocate for urgent implementation of treatment and prevention programs for these zoonotic pathogens, in line with the Kiribati-World Health Organization Cooperation Strategy 2018-2022
Counting the Patsy Edwards Benefit Show proceeds
No full textThis 1951 photograph shows three bank executives counting the proceeds donated from the Patsy Edwards Benefit Show. Patsy Edwards was the ballad champion in 1949 and 1951 in the Mountain Youth Jamboree. Her father was accidentally killed while Ms. Edwards was performing for the Dance Masters of America in Washington, D.C. with other Mountain Youth Jamboree contestants. The Jamboree champions gave a benenfit program to assist her and her family. Founder and director of the Mountain Youth Jamboree, Hubert H. Hayes (1901-1964) auditioned and directed youth to perform in folk dance, music, and folk and ballad singing. The jamboree was held in the Asheville City Auditorium (now known as Thomas Wolfe Auditorium) from 1948 to 1973, and Hayes’ wife, Leona Trantham Hayes (1913-1989) continued to direct the program after his death in 1964. Hubert Hayes was an author, playwright, and alumni of Duke University
American-sponsored overseas schools : a dissertation integration
No full textTypescript (photocopy).This inquiry integrates the dissertation literature on American-sponsored overseas schools from 1861 to 1982. Integration poses two design problems: (a) how to turn the many pieces of dissertation literature into an integrated representation of the research on American-sponsored overseas schools, and (b) given these integrated findings, how to create an agenda for future research that extends the knowledge base on American-sponsored overseas schools. The solution takes the form of a general dissertation integration model which consists of five discrete phases: Phase One (selection of integration topic and dissertation sample), Phase Two (specification of theoretical framework), Phase Three (identification and application of data coding structures), Phase Four (elaboration of empirical data), and Phase Five (integration of findings and development of research agenda). Findings of the study are organized around the four integration dimensions of Phase Two. These are: (1) Research Issues--which emphasizes the nine research issues specified for the integration topic on ASOS. Ranked from most to least frequently addressed, issues are school personnel, school setting, student body, school programs, interinstitutional relationships, school administration, institutional foundations, school governance, and school clientele. (2) Research Strategy--which addresses the eight research strategies specified for the integration model. Survey research (76%) is the predominant strategy employed. Other strategies used are case study (19%), historical study (8%), and experimental research (6%). (3) Quality--which rates dissertations as marginal, adequate, good or excellent. For the 89 dissertations on ASOS, the quality is judged to be adequate. (4) Demographic Characteristics--which provides information about the dissertation author, the institution, and the dissertation. The findings indicate that the average dissertation analyzed in this inquiry is written by a male with previous overseas experience, who completed a Ph.D. in educational administration at a public university in the early 1970s. The average dissertation is approximately 200 pages in length, uses other than APA style, relies on the questionnaire as its data source, and is analyzed using simple descriptive statistics. In Phase Five, two propositional inventories are constructed, one containing 61 statements and 25 trends for the substantive findings on the nine research issues and the second yielding 52 statements and 12 trends for the research strategy and quality of research dimensions. Finally, a research agenda is specified to guide future inquiries
Emerg Infect Dis
No full textAncylostoma ceylanicum hookworms are recognized agents of human infection in the Asia-Pacific region. We investigated prevalence of zoonotic hookworm infections in dogs in Grenada in 2021; 40.8% were infected by hookworms, including Ancylostoma ceylanicum. Surveillance of this parasite in dogs and humans is needed in tropical/subtropical countries in the Americas
My Nursery Tale Book
No full textThis is my earliest version of this book. I have two other copies printed in 1970 and 1972. All three of these stem from the 1961 copyright. Earlier copyrights were in 1949 and 1954. This copy differs from the 1970 printing by using the blue page facing the title-page as a paste-down inside front cover. The same is true in the back of the book. Thus two nice illustrations are not included, as they are on the first page facing the blank inside cover and the corresponding last page facing the blank inside back cover: Pierre Bear reading a book (excerpted from the front cover's picture and the first picture in "Pierre Bear") and Duck sleeping in bed. As I wrote on the 1970 version, TMCM told by Patsy Scarry has a quaint flapper city mouse in its water colors. The picture of the cat discovering the two mice may be the best. This story adds a vacuum cleaner! The picture on the back cover has a dog never mentioned in the story! FC by the same author adds an elephant and a tiger to its cast of characters. Overall, I continue to believe that there is little special here for the lover of new and different understandings of fables. Inscribed in 1966.This is a hardbound book (hard cover)1964 printingPatsy Scarry et a
A study of the personality differences between altruistic and non-altruistic adolescents
No full textThe purpose of the present study was to investigate the personality differences between altruistic and nonaltruistic adolescents. A secondary purpose was to compare the two measures employed in assessing altruism, and to determine whether or not altruistic behavior differed as a function of sex and socio-economic groups. One hundred eighty junior high school students were subjects for the experiment. Each subject was administered an author adapted version of the Mf 3 Scale from the MMPI (Minnesota Multaphasic Personality Inventory), made a voluntary monetary contribution to the March of Dimes, and was then administered the Junior Senior High School Personality Questionnaire. A small but significant correlation was found between the adapted Mf 3 Scale and the March of Dimes donation, and significant personality variables were found to differentiate altruistic from non-altruistic adolescents. No differences were found in altruistic behavior as a function of sex and socio-economic status. Recommendations were made for further research, and research findings were discussed with their implications for education, counseling, and the identification of potentially helpful people.Thesis (D. Ed.
Zoonotic Ancylostoma ceylanicum Infection in Coyotes from Guanacaste Conservation Area, Costa Rica, 2021
No full textAncylostoma ceylanicum is the second most common hookworm infecting humans in the Asia-Pacific region. Recent reports suggest presence of the parasite in the Americas. We report A. ceylanicum infections in coyotes from the Guanacaste Conservation Area, Costa Rica. Our findings call for active surveillance in humans and animals
Patsy Nailed the Horse-Shoe
No full textA man hangs a horse shoe upside down and has bad luck.https://egrove.olemiss.edu/kgbsides_uk/2510/thumbnail.jp
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