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Puchner KP, Bottazzi ME, Periago V, Grobusch M, Maizels R, McCarthy J, Lee B, Gaspari E, Diemert D, Hotez P. Vaccine value profile for Hookworm. Vaccine 2023:S0264-410X(23)00540-6. [PMID: 37863671 DOI: 10.1016/j.vaccine.2023.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 04/24/2023] [Accepted: 05/03/2023] [Indexed: 10/22/2023]
Abstract
Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and remains one of the leading causes of mild to severe anemia in Low and Middle Income Countries (LMICs), particularly in pregnancy and children under 5. Despite repeated large scale Preventive Chemotherapy (PC) interventions since more than 3 decades, there is broad consensus among scholars that elimination targets set in the newly launched NTD roadmap will require additional tools and interventions. Development of a vaccine could constitute a promising expansion of the existing arsenal against hookworm. Therefore, we have evaluated the biological and implementation feasibility of the vaccine development as well as the added value of such a novel tool. Based on pipeline landscaping and the current knowledge on key biological aspects of the pathogen and its interactions with the host, we found biological feasibility of development of a hookworm vaccine to be moderate. Also, our analysis on manufacturing and regulatory issues as well as potential uptake yielded moderate implementation feasibility. Modelling studies suggest a that introduction of a vaccine in parallel with ongoing integrated interventions (PC, WASH, shoe campaigns), could substantially reduce burden of disease in a cost - saving mode. Finally a set of actions are recommended that might impact positively the likelihood of timely development and introduction of a hookworm vaccine.
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Affiliation(s)
| | - Maria Elena Bottazzi
- National School of Tropical Medicine, Baylor College of Medicine, Baylor, TX, USA
| | | | - Martin Grobusch
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, Location AMC, Amsterdam Infection & Immunity, Amsterdam Public Health, University of Amsterdam, Amsterdam, The Netherlands
| | - Rick Maizels
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - James McCarthy
- The Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Bruce Lee
- Public Health Informatics, Computational, and Operations Research, Graduate School of Public Health and Health Policy, City University of New York, New York, NY, USA
| | - Erika Gaspari
- European & Developing Countries Clinical Trials Partnership (EDCTP), The Hague, The Netherlands
| | - David Diemert
- Department of Microbiology, Immunology & Tropical Medicine, George Washington University Medical Center, Washington, DC, USA
| | - Peter Hotez
- National School of Tropical Medicine, Baylor College of Medicine, Baylor, TX, USA
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Zacharia F, Silvestri V, Mushi V, Ogweno G, Makene T, Mhamilawa LE. Burden and factors associated with ongoing transmission of soil-transmitted helminths infections among the adult population: A community-based cross-sectional survey in Muleba district, Tanzania. PLoS One 2023; 18:e0288936. [PMID: 37494358 PMCID: PMC10370771 DOI: 10.1371/journal.pone.0288936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 07/06/2023] [Indexed: 07/28/2023] Open
Abstract
BACKGROUND In Tanzania, school-based Mass Drug Administration (MDA) campaigns have been the main strategy for the prevention and control of Soil Transmitted Helminths (STH) infection. Adults are not part of the program and could remain as the reservoir of infection, favoring continuity in transmission. Water, Sanitation, and Hygiene (WaSH) issues and slow progress in community awareness promotion campaigns contribute to the persistence of STH as public health issue among target populations notwithstanding the achievements of the control interventions. OBJECTIVE This study aimed to determine the current prevalence and the risk factors associated with ongoing transmission of STH infection among adults in Muleba District, Tanzania. METHODOLOGY A household-based quantitative cross-sectional study was carried out among 552 adults in Muleba district. Through a quantitative interviewer-administered questionnaire, information was registered related to socio-demographic characteristics, level of knowledge on the disease, and WaSH factors. The prevalence of STH and estimation of its intensity were assessed by analyzing stool samples through formol-ether concentration and the Kato-Katz technique. Descriptive statistics was used to summarise data; logistic regression to determine the association between STH infection and socio-demographic and WaSH factors. A p-value < 0.05 was considered statistically significant. RESULTS A total of 552 adults were included in the study; 50.7% (280/552) were female. The median age was of 30 years, ranging from 18 to 73 years. A prevalence of 9.1% (50/552) for STH infection was reported; the prevalence of Hookworm Spp., Ascaris lumbricoides, and Trichuris trichiura was 7.43%, 0.91%, and 0.72%, respectively. The factors significantly associated with STH infection were farming (aOR = 3.34, 95% CI: 1.45-7.70), the habit of not wearing shoes in general (aOR = 5.11, 95% CI: 1.55-16.87), and during garden activities (aOR = 4.89, 95% CI: 1.47-16.28). CONCLUSIONS AND RECOMMENDATIONS We observed an aggregated prevalence of STH infections (Ancylostoma duodenale, Trichuris trichiura, and Ascaris lumbricoides) of 9.1% among the adult population, indicating a decreasing prevalence but ongoing transmission. Integrated management is needed to address practices contributing to ongoing transmission.
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Affiliation(s)
- Franco Zacharia
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Valeria Silvestri
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Vivian Mushi
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
- Department of Zoology and Wildlife Conservation, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - George Ogweno
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Twilumba Makene
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Lwidiko E Mhamilawa
- Department of Parasitology and Medical Entomology, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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Sumboh JG, Agyenkwa-Mawuli K, Schwinger E, Donkor IO, Akorli JEB, Dwomoh D, Ashong Y, Osabutey D, Ababio FO, Koram KA, Humphries D, Cappello M, Kwofie SK, Wilson MD. Investigating Environmental Determinants of Soil-Transmitted Helminths Transmission using GPS Tracking and Metagenomics Technologies. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.07.17.23292808. [PMID: 37503260 PMCID: PMC10371187 DOI: 10.1101/2023.07.17.23292808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Background The Global Health community aims to eliminate soil-transmitted helminth (STH) infections by 2030. Current preventive methods such as Mass Drug Administration, WASH practices, and health education needs to be complimented to halt transmission. We tracked the movement of hookworm-infected and non-infected persons and investigated soil factors in the places they frequented within an endemic community to further understand the role of human movement and sources of infections. Methods 59 positive and negative participants wore GPS tracking devices for 10 consecutive days and their movement data captured in real time. The data was overlaid on the community map to determine where each group differentially spent most of their time. Soil samples were collected from these identified sites and other communal places. Physical and chemical properties were determined for each sample using standard methods and helminth eggs cultured into larvae using the Baermann technique. Bivariate and multivariate analyses were used to determine associations between larvae counts and soil factors. Helminth species were identified with metagenomic sequencing and their distributions mapped to sampling sites in the community. Results The study found that there was no significant difference in the average larvae counts in soil between sites assessed by infected and non-infected participants (P=0.59). However, soil factors, such as pH, carbon and sandy-loamy texture were associated with high larvae counts (P<0.001) while nitrogen and clay content were associated with low counts(P<0.001). The dominant helminth species identified were Panagrolaimus superbus (an anhydrobiotic helminth), Parastrongyloides trichosuri (a parasite of small mammals), Trichuris trichuria (whipworm), and Ancylostoma caninum (dog hookworm). Notably, no Necator americanus was identified in any soil sample. Conclusion This study provides important insights into the association between soil factors and soil-transmitted helminths. These findings contribute to our understanding of STH epidemiology and support evidence-based decision-making for elimination strategies.
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Affiliation(s)
- Jeffrey Gabriel Sumboh
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Kwasi Agyenkwa-Mawuli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Eyram Schwinger
- Department of Mathematics, University of Ghana. Legon, Accra, Ghana
| | - Irene Owusu Donkor
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Jewelna E. B. Akorli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Duah Dwomoh
- Department of Biostatistics, School of Public Health, University of Ghana. Legon, Accra, Ghana
| | - Yvonne Ashong
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Dickson Osabutey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Felix Owusu Ababio
- Soil Research Institute, Council for Scientific and Industrial Research, Accra, Ghana
| | - Kwadwo Ansah Koram
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
| | - Debbie Humphries
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, United States of America
| | - Michael Cappello
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, United States of America
| | - Samuel K. Kwofie
- School of Biomedical Engineering, Faculty of Engineering, University of Ghana. Legon, Accra, Ghana
| | - Michael D. Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana. Legon, Accra, Ghana
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Appiah-Twum F, Akorli J, Okyere L, Sagoe K, Osabutey D, Cappello M, Wilson MD. The effect of single dose albendazole (400 mg) treatment on the human gut microbiome of hookworm-infected Ghanaian individuals. Sci Rep 2023; 13:11302. [PMID: 37438457 PMCID: PMC10338455 DOI: 10.1038/s41598-023-38376-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 07/07/2023] [Indexed: 07/14/2023] Open
Abstract
Microbes play a key role in human gut homeostasis, metabolic, immunologic and physiopathology of the body. A longitudinal study conducted during 2018-2021 in the Kintampo North Municipality in Ghana demonstrated low hookworm infection cure rates following treatment with a single dose of 400 mg albendazole in some communities. To investigate associations between hookworm infection and the gut microbiome, we examined stool samples from consented participants who were either cured or remained infected after treatment. At each time point, stool was collected prior to and 10-14 days after albendazole treatment. We used 16S rRNA amplicon sequencing of DNA extracted from stool samples to investigate the composition and diversity of the gut microbiota and to identify potential microbial biomarkers associated with treatment outcomes. Hookworm infection was associated with increased species richness (p = 0.0093). Among treated individuals, there was also a significant variation in microbiota composition at 10-14 days following single-dose albendazole treatment. Individuals cured of hookworm infection after treatment showed a significant reduction in microbiota composition when compared to their pre-treatment state (ANOSIM; p = 0.02), whilst individuals who failed to clear the infection showed no change in microbiota composition (ANOSIM; p = 0.35). Uninfected individuals and those who were successfully treated were similar in their microbial composition and structure. We also found that the abundance of Clostridia spp. was increased in infected individuals pre- or post-treatment. Predictive functional profiling revealed the enrichment of two pyruvate ferredoxin oxidoreductase subunit pathways in individuals who remained infected after treatment (p < 0.05), alluding to an upturn of strictly anaerobic commensal bacteria such as Clostridia spp. This study suggests a relationship between human gut microbiome dysbiosis and albendazole therapy outcomes of hookworm infection. Future studies will further characterize specific biomarkers identified within this study to establish their potential for assessment of pharmacological responses to anthelminthic therapies, as well as explore the possibility of using probiotic supplementation as an adjunct treatment to increase albendazole effectiveness against hookworm.
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Affiliation(s)
- Francis Appiah-Twum
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana
| | - Jewelna Akorli
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana
| | - Lydia Okyere
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana
- Department of Pathobiology, University of Illinois, Urbana-Champaign, 2522 Vet Med Basic Sciences Bldg., 2001 South Lincoln Avenue, Urbana, IL, 61802, USA
| | - Kate Sagoe
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana
- Pan African University Institute for Basic Sciences, Technology, and Innovation (PAUSTI), P. O. Box 62000 00200, Nairobi, Kenya
| | - Dickson Osabutey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana
| | - Michael Cappello
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, 60 College St, New Haven, CT, 06520, USA
| | - Michael D Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, PO Box LG 581, Legon, Accra, Ghana.
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Li H, Gazzola D, Hu Y, Aroian RV. An efficient method for viable cryopreservation and recovery of hookworms and other gastrointestinal nematodes in the laboratory. Int J Parasitol 2023; 53:451-458. [PMID: 37201563 PMCID: PMC10330584 DOI: 10.1016/j.ijpara.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/11/2023] [Accepted: 05/03/2023] [Indexed: 05/20/2023]
Abstract
Hookworms (genera Ancylostoma and Necator) are amongst the most prevalent and important parasites of humans globally. These intestinal parasites ingest blood, resulting in anemia, growth stunting, malnutrition, and adverse pregnancy outcomes. They are also critical parasites of dogs and other animals. In addition, hookworms and hookworm products are being explored for their use in treatment of autoimmune and inflammatory diseases. There is thus a significant and growing interest in these mammalian host-obligate parasites. Laboratory research is hampered by the lack of good means of cryopreservation and recovery of parasites. Here, we describe a robust method for long-term (≥3 year) cryopreservation and recovery of both Ancylostoma and Necator hookworms that is also applicable to two other intestinal parasites that passage through the infective L3 stage, Strongyloides ratti and Heligmosomoides polygyrus bakeri. The key is a revised recovery method, in which cryopreserved L1s are thawed and raised to the infective L3 stage using activated charcoal mixed with uninfected feces from a permissive host. This technique will greatly facilitate research on and availability of gastrointestinal parasitic nematodes with great importance to global health, companion animal health, and autoimmune/inflammatory disease therapies.
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Affiliation(s)
- Hanchen Li
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - David Gazzola
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Yan Hu
- Department of Biology, Worcester State University, Worcester, MA, USA
| | - Raffi V Aroian
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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Lamptey ANL, Larbi IA, Donkor IOO, Sumboh JG, Ashong Y, Osabutey D, Cappello M, Adu-Gyasi D, Konadu DG, Asante KP, Koram KA, Wilson MD. Regular deworming and seasonality are potential challenges but also offer opportunities for hookworm elimination. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.09.23287064. [PMID: 36993166 PMCID: PMC10055453 DOI: 10.1101/2023.03.09.23287064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The global health community has targeted the elimination of neglected tropical diseases (NTDs) including soil-transmitted helminthiasis by 2030. The elimination strategy has not changed from that of control using regular mass drug administration (MDA) with albendazole, WASH and education. Already doubts have been expressed about this achievement, principally because drugs do not interrupt transmission. We report here the findings of a cohort study aimed to identify host modifiable and environmental factors associated with hookworm infection and reinfection in rural communities in Kintampo North Municipality, Ghana. Faecal samples of 564 consented participants were screened for intestinal parasites at baseline, 9 months and 24 months using the Kato-Katz method. At each time point, positive cases were treated with a single dose of albendazole (400 mg) and their samples were again screened 10-14 days post-treatment to record treatment failures. The hookworm prevalence at the three-time points was 16.7%, 9.22% and 5.3% respectively, whilst treatment failure rates were 17.25%, 29.03% and 40.9% respectively. The intensities of hookworm infection (in eggs per gram) at the time points were 138.3, 40.5 and 135, which showed a likely association with wet and dry seasons. We posit that the very low intensity of hookworm infections in humans during the dry season offers a window of opportunity for any intervention that could drastically reduce the community worm burden before the rainy season.
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Affiliation(s)
- Amanda NL Lamptey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Irene A Larbi
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Irene Ofei Owusu Donkor
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Jeffrey G Sumboh
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Yvonne Ashong
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Dickson Osabutey
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Michael Cappello
- Epidemiology of Microbial Diseases Department, Yale School of Public Health and Department of Pediatrics, Yale University School of Medicine, 333 Cedar St, New Haven, CT 06510, USA
| | - Dennis Adu-Gyasi
- Kintampo Health Research Centre, Ghana Health Service, Hospital Road, Kintampo, Ghana
| | - Dennis Gyasi Konadu
- Kintampo Health Research Centre, Ghana Health Service, Hospital Road, Kintampo, Ghana
| | - Kwaku Poku Asante
- Kintampo Health Research Centre, Ghana Health Service, Hospital Road, Kintampo, Ghana
| | - Kwadwo A Koram
- Department of Epidemiology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
| | - Michael D Wilson
- Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana
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Li B, Chen S, Cui X, Dai M, Meng W, Wu Q, Sheng H. Chronic Hemorrhagic Anemia Caused by Hookworm Infection: A Case Report. Acta Parasitol 2023; 68:288-292. [PMID: 36539676 DOI: 10.1007/s11686-022-00653-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 12/06/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE Hookworm infection is one of the causes of long-term chronic hemorrhagic anemia in patients. This article reports a case of chronic severe anemia caused by hookworm infection. METHODS The capsule endoscopy showed that there were a large number of hookworms in the small intestine of a patient. At the same time, using the technique of saturated brine floatation and the automatic stool analyzer, hookworm eggs were detected. RESULTS The patient's anemia was caused by hookworm infection and was significantly improved after anti-hookworm treatment. CONCLUSION Hookworm infection cannot be ignored in the differential diagnosis of patients with chronic anemia. Capsule endoscopy combined with stool detection haves an important clinical value for the diagnosis of hookworm disease.
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Affiliation(s)
- Baisheng Li
- Department of Clinical Laboratory, Tongren Hospital Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China.
| | - Shihong Chen
- Department of Clinical Laboratory, Tongren Hospital Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China
| | - Xiangming Cui
- Department of Clinical Laboratory, Tongren Hospital Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China
| | - Ming Dai
- Department of Clinical Laboratory, Tongren Hospital Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China
| | - Wenying Meng
- Department of Gastroenterology, Tongren Hospital Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiong Wu
- Department of Gastroenterology, Tongren Hospital Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huiming Sheng
- Department of Clinical Laboratory, Tongren Hospital Shanghai Jiao Tong University School of Medicine, 1111 XianXia Road, Shanghai, 200336, China.
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Wong MTJ, Anuar NS, Noordin R, Tye GJ. Soil-transmitted helminthic vaccines: Where are we now? Acta Trop 2023; 239:106796. [PMID: 36586174 DOI: 10.1016/j.actatropica.2022.106796] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/11/2022] [Accepted: 12/13/2022] [Indexed: 12/30/2022]
Abstract
It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human soil-transmitted helminthic diseases, despite their high prevalence globally, particularly in developing countries and rural areas with tropical climates and poor sanitation. The development of vaccines against helminths is riddled with obstacles. Helminths have a complex life cycle, multiple stages within the same host with stage-specific antigen expression, and the ability to regulate host immune reactions to evade the immune response. These elements contribute to the main challenge of helminthic vaccines: the identification of effective vaccine candidates. Therefore, this article reviews the current progress and potential future direction of soil-transmitted helminthic vaccines, particularly against Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercoralis, Necator americanus and Ancylostoma duodenale. The study design employed was a systematic review, using qualitative meta-summary synthesis. Preclinical studies and clinical trials on the development of protein subunit vaccines against the five soil-transmitted helminths were searched on PubMed and Scopus. Effectiveness was indicated by a reduction in worm burden or larval output, an increase in specific IgG levels, or an increase in cytokine production. Our findings show that only the hookworm vaccine against N. americanus is in the clinical trial phase, while the rest is still in exploratory research and pre-clinical development phase.
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Affiliation(s)
- Matthew Tze Jian Wong
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | - Nor Suhada Anuar
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | - Rahmah Noordin
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia
| | - Gee Jun Tye
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 11800 USM Pulau Pinang, Malaysia.
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Ekobol N, Boonjaraspinyo S, Artchayasawat A, Boonmars T. Monks: A Population at Risk for Liver Fluke and Skin-Penetrating Helminths. Trop Med Infect Dis 2023; 8:tropicalmed8030135. [PMID: 36977136 PMCID: PMC10059027 DOI: 10.3390/tropicalmed8030135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 02/06/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023] Open
Abstract
Monks cannot cook received raw meat dishes and should walk barefoot while working. This population lacks both a survey of parasitic infection and a proper prevention and control policy. Five hundred and fourteen monks from the Ubolratana, Ban Haet, and Ban Phai Districts of Kh on Kaen Province were enrolled in this study. A stool container and questionnaire were collected from each study participant. Stool samples were processed by formalin ethyl acetate concentration and agar plate culture techniques. We then analyzed the results and risk factors to demonstrate associations. The prevalence of overall parasites, liver flukes, and skin-penetrating helminths were 28.8%, 11.1%, and 19.3%, respectively. Raw fish dish offerings were associated with opisthorchiasis (ORcrude 3.32; 95% CI 1.53–7.20). The risk factors for skin-penetrating helminths were older age (ORcrude 5.02; 95% CI 2.2–11.17), being a long-term ordinate (ORcrude 3.28; 95% CI 1.15–9.34), smoking (ORcrude 2.03; 95% CI 1.23–3.36), and chronic kidney disease with other underlying disease (ORcrude 20.7; 95% CI 2.54–190.1). The protective factors for skin-penetrating helminths were secular education above primary education (ORcrude 0.41; 95% CI 0.25–0.65) and having received health education about parasitic infection (ORcrude 0.47; 95% CI 0.28–0.80). Wearing shoes at times other than alms work does not show a protective effect against skin-penetrating helminths (ORcrude 0.86; 95% CI 0.51–1.46). These findings support the recommendation for a strict Rule of Discipline regarding raw meat ingestion and allowing shoes to be worn for protection against skin-penetrating helminths in high-risk situations.
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Affiliation(s)
- Nuttapon Ekobol
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Sirintip Boonjaraspinyo
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand
- Department of Community Medicine, Family Medicine and Occupational Medicine, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Atchara Artchayasawat
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Thidarut Boonmars
- Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand
- Cholangiocarcinoma Research Institute, Khon Kaen University, Khon Kaen 40002, Thailand
- Correspondence: ; Tel.: +66-43-363-434
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10
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Li H, Gazzola D, Hu Y, Aroian RV. An efficient method for viable cryopreservation of hookworms and other gastrointestinal nematodes in the laboratory. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526637. [PMID: 36778351 PMCID: PMC9915591 DOI: 10.1101/2023.02.01.526637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hookworms (genera Ancylostoma and Necator ) are amongst of the most prevalent and important parasites of humans globally. These intestinal parasites ingest blood, resulting in anemia, growth stunting, malnutrition, and adverse pregnancy outcomes. They are also critical parasites of dogs and other animals. In addition, hookworms and hookworm products are being explored for their use in treatment of autoimmune and inflammatory diseases. There is thus a significant and growing interest in these mammalian host-obligate parasites. Laboratory research is hampered by the lack of good means of cryopreservation. Here, we describe a robust method for long-term (≥3 year) cryoprotection and recovery of both Ancylostoma and Necator hookworms that is also applicable to two other intestinal parasites that passages through the infective third larval stage, Strongyloides ratti and H eligmosomoides polygyrus bakeri . The key is the use cryo-preserved first-staged larvae raised to the infective third larval stage using activated charcoal mixed with uninfected feces from a permissive host. This technique will greatly facilitate research on and availability of gastrointestinal parasitic nematodes with great importance to global health, companion animal health, and autoimmune/inflammatory disease therapies.
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Ellwanger JH, Ziliotto M, Kulmann-Leal B, Chies JAB. Iron deficiency and soil-transmitted helminth infection: classic and neglected connections. Parasitol Res 2022; 121:3381-3392. [PMID: 36258094 DOI: 10.1007/s00436-022-07697-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/14/2022] [Indexed: 10/24/2022]
Abstract
Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.
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Affiliation(s)
- Joel Henrique Ellwanger
- Laboratory of Immunobiology and Immunogenetics (Prédio 43323, Laboratório 212), Department of Genetics, Postgraduate Program in Genetics and Molecular Biology (PPGBM), Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Campus do Vale, Rio Grande do Sul, Porto Alegre, Brazil.
| | - Marina Ziliotto
- Laboratory of Immunobiology and Immunogenetics (Prédio 43323, Laboratório 212), Department of Genetics, Postgraduate Program in Genetics and Molecular Biology (PPGBM), Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Campus do Vale, Rio Grande do Sul, Porto Alegre, Brazil
| | - Bruna Kulmann-Leal
- Laboratory of Immunobiology and Immunogenetics (Prédio 43323, Laboratório 212), Department of Genetics, Postgraduate Program in Genetics and Molecular Biology (PPGBM), Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Campus do Vale, Rio Grande do Sul, Porto Alegre, Brazil
| | - José Artur Bogo Chies
- Laboratory of Immunobiology and Immunogenetics (Prédio 43323, Laboratório 212), Department of Genetics, Postgraduate Program in Genetics and Molecular Biology (PPGBM), Instituto de Biociências, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, Campus do Vale, Rio Grande do Sul, Porto Alegre, Brazil
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Grolimund CM, Bärenbold O, Utzinger J, Keiser J, Vounatsou P. Modeling the effect of different drugs and treatment regimen for hookworm on cure and egg reduction rates taking into account diagnostic error. PLoS Negl Trop Dis 2022; 16:e0010810. [PMID: 36194622 PMCID: PMC9595538 DOI: 10.1371/journal.pntd.0010810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/25/2022] [Accepted: 09/12/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Hookworm infections, caused by Ancylostoma duodenale and Necator americanus, are of considerable public health importance. The World Health Organization recommends preventive chemotherapy as the key strategy for morbidity control. Meta-analyses have been conducted to estimate treatment efficacy of available drugs and drug combinations. However, in most studies, the relation between the diagnostic error and infection intensity have not been considered, resulting in an overestimation of cure rates (CRs). METHODOLOGY A Bayesian model was developed to compare the 'true' CR and egg reduction rate of different treatment regimens for hookworm infections taking into account the error of the recommended Kato-Katz thick smear diagnostic technique. It was fitted to the observed egg count data which was linked to the distribution of worms, considered the day-to-day variation of hookworm egg excretion and estimated the infection intensity-dependent sensitivity. The CR was obtained by defining the prevalence of infection at follow-up as the probability of having at least one fertilized female worm. The model was applied to individual-level egg count data available from 17 treatments and six clinical trials. PRINCIPAL FINDINGS Taking the diagnostic error into account resulted in considerably lower CRs than previously reported. Overall, of all treatments analyzed, mebendazole administered in six dosages of 100 mg each was the most efficacious treatment with a CR of 88% (95% Bayesian credible interval: 79-95%). Furthermore, diagnostic sensitivity varied with the infection intensity and sampling effort. For an infection intensity of 50 eggs per gram of stool, the sensitivity is close to 60%; for two Kato-Katz thick smears it increased to approximately 76%. CONCLUSIONS/SIGNIFICANCE Our model-based estimates provide the true efficacy of different treatment regimens against hookworm infection taking into account the diagnostic error of the Kato-Katz method. Estimates of the diagnostic sensitivity for different number of stool samples and thick smears are obtained. To accurately assess efficacy in clinical trials with the Kato-Katz method, at least two stool samples on consecutive days should be collected.
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Affiliation(s)
- Carla M. Grolimund
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Oliver Bärenbold
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- Swiss Tropical and Public Health Institute, Allschwil, Switzerland
- University of Basel, Basel, Switzerland
- * E-mail:
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da Silva Medeiros C, de Almeida LR, Rabelo ÉML, Furtado LFV. Phenotypic characterization and multiple resistance analysis in an experimentally selected albendazole-resistant hookworm isolate. Exp Parasitol 2022; 242:108393. [PMID: 36179854 DOI: 10.1016/j.exppara.2022.108393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022]
Abstract
For some nematodes, alterations that leads to a resistance genotype may be accompanied by other modifications, causing changes in the biology of the parasite, although the exact mechanisms of this relationship are still not very clear. These alterations can have deleterious effects on their survival or even potentiate their pathogenicity. In this study a phenotypic characterization was carried out to compare two Ancylostoma ceylanicum isolates, a wild type one, kept in the laboratory and an albendazole selected resistant isolate (AceyBZR2). Differences in some analyzed parameters, between the two strains, were registered, as patency period, number and size of the recovered worms, including differences in the body structures. The AceyBZR2 isolate showed to be less adapted to the host, leading to a smaller number of recovered worms. However, no difference on the female egg content was observed between the two isolates. Concerning blood evaluation, no differences were found between the wild type and AceyBZR2 isolates, related to hemoglobin and hematocrit levels. However, animals in the group infected with the wild type isolate had lower serum iron concentrations than animals in the AceyBZR2 group. The possibility that the AceyBZR2 isolate might be resistant to other drugs was evaluated and it was demonstrated that it does not present cross-resistance to ivermectin and nitazoxanide. However, when animals infected with the AceyBZR2 were treated with another drug from the benzimidazoles group (mebendazole), the cross-resistance effect was observed. Morphometric analyses were performed comparing female and male adult worms from the two isolates. The results presented here allow a better understanding of the parasite-host relationship and may constitute a useful basis for establishing future control strategies for soil-transmitted helminths.
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Affiliation(s)
- Celi da Silva Medeiros
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Avenida Presidente Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Lara Ribeiro de Almeida
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Avenida Presidente Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Élida Mara Leite Rabelo
- Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Parasitologia, Avenida Presidente Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil
| | - Luis Fernando Viana Furtado
- Universidade Federal de Minas Gerais, Faculdade de Farmácia, Departamento de Análises Clínicas e Toxicológicas, Avenida Presidente Antônio Carlos, 6627, Pampulha, CEP 31270-901, Belo Horizonte, Minas Gerais, Brazil.
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Efficient and Scalable Process to Produce Novel and Highly Bioactive Purified Cytosolic Crystals from Bacillus thuringiensis. Microbiol Spectr 2022; 10:e0235622. [PMID: 35946940 PMCID: PMC9430767 DOI: 10.1128/spectrum.02356-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a Gram-positive soil bacterium that is widely and safely applied in the environment as an insecticide for combatting insect pests that damage crops or are disease vectors. Dominant active ingredients made by Bt are insect-killing crystal (Cry) proteins released as crystalline inclusions upon bacterial sporulation. Some Bt Cry proteins, e.g., Cry5B (formally Cry5Ba1), target nematodes (roundworms) and show exceptional promise as anthelmintics (cures for parasitic nematode diseases). We have recently described inactivated bacteria with cytosolic crystal(s) (IBaCC) in which bioactive Bt Cry crystals (containing Cry5B) are fully contained within the cytosol of dead bacterial ghosts. Here, we demonstrate that these IBaCC-trapped Cry5B crystals can be liberated and purified away from cellular constituents, yielding purified cytosolic crystals (PCC). Cry5B PCC contains ~95% Cry5B protein out of the total protein content. Cry5B PCC is highly bioactive against parasitic nematode larvae and adults in vitro. Cry5B PCC is also highly active in vivo against experimental human hookworm and Ascaris infections in rodents. The process was scaled up to the 100-liter scale to produce PCC for a pilot study to treat two foals infected with the ascarid Parascaris spp. Single-dose Cry5B PCC brought the fecal egg counts of both foals to zero. These studies describe the process for the scalable production of purified Bt crystals and define a new and attractive pharmaceutical ingredient form of Bt Cry proteins. IMPORTANCEBacillus thuringiensis crystal proteins are widely and safely used as insecticides. Recent studies have shown they also can cure gastrointestinal parasitic worm (nematode) infections when ingested. However, reproducible, scalable, and practical techniques for purifying these proteins have been lacking. Here, we address this severe limitation and present scalable and practical methods for large-scale purification of potently bioactive B. thuringiensis crystals and crystal proteins. The resultant product, called purified cytosolic crystals (PCC), is highly compatible with ingestible drug delivery and formulation. Furthermore, there are growing applications in agriculture and insect control where access to large quantities of purified crystal proteins is desirable and where these methods will find great utility.
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Abstract
Intestinal nematode infections caused by soil-transmitted helminths (STH), such as the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and the hookworms Ancylostoma duodenale, and Necator americanus, infect more than 1 billion people throughout the world. School-aged children tend to harbor the greatest numbers of intestinal worms, and as a result, experience more adverse health consequences, such as poor growth, anemia, and cognitive decline. Clinicians should maintain a high degree of suspicion in endemic areas when patients present with surgical abdomens, particularly children. Current antihelminthic drugs are moderately effective, but reinfection is possible. Global efforts are needed to eradicate STH infections.
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Affiliation(s)
- Angela F Veesenmeyer
- Department of Child Health, University of Arizona College of Medicine-Phoenix, Pediatric Infectious Disease, Valleywise Health Medical Center, 2601 East Roosevelt Street, Phoenix, AZ 85008, USA.
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Oliveira FBD, Correia TPD, Neves LBD, Teixeira PEF, Moreira JDC, Souza LSD, Neves RH, Almeida FBD, Bóia MN, Silva RRE, Silva JRME. Spurious infection by Calodium hepaticum (Bancroft, 1983) Moravec, 1982 and intestinal parasites in forest reserve dwellers in Western Brazilian Amazon. Rev Inst Med Trop Sao Paulo 2022; 64:e2. [PMID: 35137896 PMCID: PMC8815845 DOI: 10.1590/s1678-9946202264002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/22/2021] [Indexed: 11/22/2022] Open
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Xu FF, Niu YF, Chen WQ, Liu SS, Li JR, Jiang P, Wang ZQ, Cui J, Zhang X. Hookworm infection in central China: morphological and molecular diagnosis. Parasit Vectors 2021; 14:537. [PMID: 34649597 PMCID: PMC8518228 DOI: 10.1186/s13071-021-05035-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Necator americanus is one of the major etiological agents of human ancylostomiasis. Historically, the epidemiology of ancylostomiasis in Henan Province of central China and the molecular characteristics of N. americanus have been poorly understood. METHODS In this study, we report a case of ancylostomiasis in Zhengzhou city of Henan Province. We also review the epidemiology of ancylostomiasis in Henan Province from 1949 to 2020. In addition, the complete mitochondrial (mt) genome of one clinical isolate is fully characterized using Illumina sequencing. All available mt genomes of hookworms in GenBank were included to reconstruct the phylogeny using both maximum likelihood (ML) and Bayesian inference (BI) methods. RESULTS A total of three worms were collected from the patient. These worms were identified as N. americanus based on morphological characteristics as well as confirmed by genotyping with the barcoding gene cox1. Although ancylostomiasis cases have dropped substantially in recent years, hookworm infection is still a public health problem in underdeveloped areas and remote rural areas in Henan Province. The mt genome features of the N. americanus contained 12 protein-coding genes (PCGs), 22 transfer RNA genes, two ribosomal RNA genes, and a major non-coding region. The nad1 gene showed high sequence variability among isolates, which is worth considering for future genetic studies of N. americanus. Phylogenetic analyses support the monophyly of hookworm isolates from different hosts and distinct geographical locations. CONCLUSIONS The mt genome of N. americanus presented here will serve as a useful data set for studying population genetics and phylogenetic relationships of hookworms. Positive measures for preventing and controlling ancylostomiasis are required by both health services and individuals in Henan Province.
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Affiliation(s)
- Fang Fang Xu
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Yu Fei Niu
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Wen Qing Chen
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Sha Sha Liu
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Jing Ru Li
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Peng Jiang
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Zhong Quan Wang
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Jing Cui
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Xi Zhang
- Department of Parasitology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450001, China.
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Patel C, Coulibaly JT, Hofmann D, N'Gbesso Y, Hattendorf J, Keiser J. Efficacy and Safety of Albendazole in Hookworm-infected Preschool-aged Children, School-aged Children, and Adults in Côte d'Ivoire: A Phase 2 Randomized, Controlled Dose-finding Trial. Clin Infect Dis 2021; 73:e494-e502. [PMID: 32668456 PMCID: PMC8282316 DOI: 10.1093/cid/ciaa989] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 11/30/2022] Open
Abstract
Background Infections with hookworms affect about half a billion people worldwide. Recommended therapy includes 400 mg of albendazole, which is moderately efficacious. Higher doses have been rarely assessed. Methods A randomized, controlled dose-finding trial was conducted in Côte d’Ivoire with the aim of recruiting 120 preschool-aged children (PSAC), 200 school-aged children (SAC), and 200 adults. Eligible PSAC were randomized 1:1:1 to 200 mg, 400 mg, or 600 mg of albendazole; the other age groups were randomized 1:1:1:1:1 to placebo or 200 mg, 400 mg, 600 mg, or 800 mg. The primary outcome was cure rates (CRs) assessed 14–21 days post-treatment by quadruplicate Kato-Katz thick smears. Hyperbolic Emax models were used to determine dose-response. Results 38 PSAC, 133 SAC, and 196 adults were enrolled. In adults, predicted CRs increased with ascending doses of albendazole, with a CR of 74.9% (95% confidence interval [CI], 55.6%–87.7%) in the 800-mg arm. Observed CRs increased with ascending doses of albendazole reaching a maximum of 94.1% (95% CI, 80.3%–99.3%). In SAC, the predicted dose-response curve increased marginally, with CRs ranging from 64.0% in the 200-mg arm to 76.0% in the 800-mg arm. Sample size in PSAC was considered too small to derive meaningful conclusions. 10.7% and 5.1% of participants reported any adverse event at 3 hours and 24 hours post-treatment, respectively. Conclusions A single 800-mg albendazole dose provides higher efficacy against hookworm and is well tolerated in adults and should be considered for community-based strategies targeting adults. For PSAC and SAC, current recommendations suffice. Clinical Trials Registration NCT03527745.
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Affiliation(s)
- Chandni Patel
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel Switzerland
| | - Jean T Coulibaly
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel Switzerland.,Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire.,Centre Suisse de Recherches Scientifiques en Côte d'Ivoire, Abidjan, Côte d'Ivoire
| | - Daniela Hofmann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel Switzerland
| | - Yves N'Gbesso
- Centre de Santé Urbain d'Azaguié, Department de Agboville, Côte d'Ivoire
| | - Jan Hattendorf
- University of Basel, Basel Switzerland.,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel Switzerland
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Zawawi A, Else KJ. Soil-Transmitted Helminth Vaccines: Are We Getting Closer? Front Immunol 2020; 11:576748. [PMID: 33133094 PMCID: PMC7565266 DOI: 10.3389/fimmu.2020.576748] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/02/2020] [Indexed: 01/07/2023] Open
Abstract
Parasitic helminths infect over one-fourth of the human population resulting in significant morbidity, and in some cases, death in endemic countries. Despite mass drug administration (MDA) to school-aged children and other control measures, helminth infections are spreading into new areas. Thus, there is a strong rationale for developing anthelminthic vaccines as cost-effective, long-term immunological control strategies, which, unlike MDA, are not haunted by the threat of emerging drug-resistant helminths nor limited by reinfection risk. Advances in vaccinology, immunology, and immunomics include the development of new tools that improve the safety, immunogenicity, and efficacy of vaccines; and some of these tools have been used in the development of helminth vaccines. The development of anthelminthic vaccines is fraught with difficulty. Multiple lifecycle stages exist each presenting stage-specific antigens. Further, helminth parasites are notorious for their ability to dampen down and regulate host immunity. One of the first significant challenges in developing any vaccine is identifying suitable candidate protective antigens. This review explores our current knowledge in lead antigen identification and reports on recent pre-clinical and clinical trials in the context of the soil-transmitted helminths Trichuris, the hookworms and Ascaris. Ultimately, a multivalent anthelminthic vaccine could become an essential tool for achieving the medium-to long-term goal of controlling, or even eliminating helminth infections.
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Affiliation(s)
- Ayat Zawawi
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia,*Correspondence: Ayat Zawawi
| | - Kathryn J. Else
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine, and Health, School of Biological Sciences, Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester, United Kingdom,Kathryn J. Else
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Bartlett S, Skwarczynski M, Xie X, Toth I, Loukas A, Eichenberger RM. Development of natural and unnatural amino acid delivery systems against hookworm infection. PRECISION NANOMEDICINE 2020. [DOI: 10.33218/prnano3(1).191210.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Peptide-based vaccines consist of short antigen fragments derived from a specific pathogen. Alone, these peptide fragments are poorly or non-immunogenic; however, when incorporated into a proper delivery system, they can trigger strong immune responses. To eliminate the need for toxic and often ineffective oral adjuvants, we designed single molecule-based self-adjuvating vaccines against hookworms using natural and unnatural hydrophobic amino acids. Two vaccine conjugates were synthesized, consisting of B-cell epitope p3, derived from the hookworm Na-APR-1 protein; universal T-helper peptide P25; and either double copies of unnatural lipoamino acid (2-amino-D,L-eicosanoic acid), or ten copies of the natural amino acid leucine. After challenge with the model hookworm, Nippostrongylus brasiliensis, mice orally immunized with the conjugates, but without adjuvant, generated antibody responses against the hookworm epitope, resulting in significantly reduced worm and egg burdens compared to control mice. We have demonstrated that vaccine nanoparticles composed exclusively of natural amino acids can be effective even when administered orally.
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Affiliation(s)
| | | | - Xin Xie
- The University of Queensland,, St Lucia, Australia
| | - Istvan Toth
- The University of Queensland,, St Lucia, Australia
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Bakshi SS, Prabu BSM. A Hooked Worm! Am J Med Sci 2020; 359:249. [PMID: 31902519 DOI: 10.1016/j.amjms.2019.11.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/27/2019] [Accepted: 11/27/2019] [Indexed: 11/27/2022]
Affiliation(s)
- Satvinder Singh Bakshi
- Department of ENT and Head & Neck Surgery, All India Institute of Medical Sciences, Mangalagiri, Mangalagiri, India.
| | - B Sajeeth Manikanda Prabu
- Department of Medical Gastroenterology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth, Pondicherry, India
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