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Hon KL, Leung AKC. An update on the current and emerging pharmacotherapy for the treatment of human ascariasis. Expert Opin Pharmacother 2024. [PMID: 38372051 DOI: 10.1080/14656566.2024.2319686] [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: 07/29/2023] [Accepted: 02/13/2024] [Indexed: 02/20/2024]
Abstract
INTRODUCTION Globally, Ascaris lumbricoides is the commonest helminthic infection that affects people in underdeveloped countries and returning immigrants in industrialized nations. This article aims to provide latest updates on the epidemiology, clinical manifestations, and pharmacotherapy of ascariasis. AREAS COVERED A PubMed search was conducted using Clinical Queries and the key terms 'human ascariasis' OR 'Ascaris lumbricoides.' Ascaris lumbricoides is highly endemic in tropical and subtropic regions and among returning immigrants in industrialized nations. Predisposing factors include poor sanitation and poverty. The prevalence is greatest in young children. Most infected patients are asymptomatic. Patients with A. lumbricoides infection should be treated with anti-helminthic drugs to prevent complications from migration of the worm. Mebendazole and albendazole are indicated for children and nonpregnant women. Pregnant individuals should be treated with pyrantel pamoate. EXPERT OPINION Cure rates with anthelmintic treatment are high. No emerging pharmacotherapy can replace these existing drugs of good efficacy, safety profile and low cost for public health. It is opinioned that advances in the management of ascariasis include diagnostic accuracy at affordable costs, Emodepside is highly effective in single doses against ascarids in mammals and in human trials. The drug could be registered for human use in multiple neglected tropical diseases.
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Affiliation(s)
- Kam Lun Hon
- Department of Paediatrics, The Chinese University of Hong Kong, and Department of Paediatrics and Adolescent Medicine, Hong Kong Children's Hospital, Hong Kong, China
| | - Alexander K C Leung
- Department of Pediatrics, The University of Calgary and the Alberta Children's Hospital, Calgary, Alberta, Canada
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Intestinal Helminth Infections in Ghanaian Children from the Ashanti Region between 2007 and 2008—A Retrospective Cross-Sectional Real-Time PCR-Based Assessment. Trop Med Infect Dis 2022; 7:tropicalmed7110374. [DOI: 10.3390/tropicalmed7110374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 10/18/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022] Open
Abstract
In spite of ongoing eradication programs, helminth infections are still a medical issue in Ghana. For follow-up assessments on the decline of regional helminth infections, historic baseline prevalence values obtained with standardized diagnostic procedures can be helpful. In this retrospective cross-sectional study, real-time PCR targeting the nematodes Ancylostoma spp. (ITS2), Ascaris lumbricoides (ITS1), Enterobius vermicularis (ITS1), Necator americanus (ITS2), Strongyloides stercoralis (18S rRNA) and Trichuris trichiura (18S rRNA), the trematodes Schistosoma spp. (ITS2) as well as the cestodes Hymenolepis nana (ITS1), Taenia saginata (ITS1) and Taenia solium (ITS1) was applied with 2046 DNA eluates from stool samples of Ghanaian children from the Ashanti region collected between 2007 and 2008 in order to retrospectively define prevalence values. The overall prevalence was low with 3.8% (n = 77) and only 0.1% (n = 2) double infections with helminths were recorded. The three most frequently detected enteric helminth species comprised 2% S. stercoralis (n = 41), 0.8% H. nana (n = 16), and 0.7% N. americanus (n = 14), while only sporadic infection events were recorded for other helminth species comprising 0.1% E. vermicularis (n = 2), 0.1% Schistosoma spp. (n = 2), 0.1% T. saginata (n = 1) and 0.1% T. trichiura (n = 1). A. lumbricoides, Ancylostoma spp. and T. solium were not detected at all. In conclusion, the retrospective assessment suggests a low prevalence of enteric helminth infections in Ghanaian children from the Ashanti Region within the assessment period between 2007 and 2008.
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Al-Murisi WMS, Al-Mekhlafi AM, Mahdy MAK, Al-Haidari SA, Annuzaili DA, Thabit AAQ. Schistosoma mansoni and soil-transmitted helminths among schoolchildren in An-Nadirah District, Ibb Governorate, Yemen after a decade of preventive chemotherapy. PLoS One 2022; 17:e0273503. [PMID: 36006980 PMCID: PMC9409567 DOI: 10.1371/journal.pone.0273503] [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: 01/18/2022] [Accepted: 08/09/2022] [Indexed: 11/19/2022] Open
Abstract
The Ministry of Public Health in Yemen continues the implementation of school and community–based preventive chemotherapy with praziquantel and albendazole for the control and elimination of schistosomiasis and soil-transmitted helminths (STH). The latest remapping to update the distribution of schistosomiasis and STH was conducted seven years ago. This study aimed to estimate the prevalence, intensity and associated risk factors of Schistosoma mansoni and STH among schoolchildren in An-Nadirah District, Ibb Governorate, Yemen. A cross-sectional study was carried out among schoolchildren aged 6–15 years in four selected schools. Biological, demographic, socioeconomic and environmental data were collected using a pre-tested questionnaire. S. mansoni and STH eggs were detected and counted by the microscopic examination of Kato-Katz fecal smears. Out of 417 schoolchildren, 17.0% were infected with at least one intestinal helminth. Prevalence of S. mansoni and STH were 6.5% and 9.1%, respectively. The most prevalent parasite among STH was Ascaris lumbricoides (8.4%). Unemployed fathers (Adjusted Odds Ratio (AOR) = 3.2; 95% Confidence interval (CI): 1.23, 8.52; P = 0.018), eating exposed food (AOR: 2.9; 95%CI = 1.24, 6.89; P = 0.014), not washing hands before eating and after defecation (AOR: 4.8; 95%CI = 1.77, 12.81; P = 0.002), and schools located close to water stream (AOR: 22.1; 95%CI = 5.12, 95.46; P <0.001) were independent risk factors of ascariasis. Swimming in ponds/stream (AOR: 3.9; 95%CI = 1.63, 9.55; P = 0.002), and schools close to the stream (AOR: 24.7; 95%CI = 3.05, 200.07; P = 0.003) were independent risk factors of intestinal schistosomiasis. The present study does not indicate a reduction in the prevalence of intestinal schistosomiasis in this rural area since the latest remapping conducted in 2014, although ascariasis was reduced by half. The prevalence of the two parasites was highly focal in areas close to the valley, suggesting a significant role of the stream in sustaining and accelerating the parasitic infection. Children practicing swimming and having poor hygienic practices were at high exposure to S. mansoni and A. lumbricoides, respectively. Water, Sanitation and Hygiene intervention, school–based health education, and snail control, in addition to mass drug administration, will help in the interruption of transmission of schistosomiasis and STH.
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Affiliation(s)
| | | | - Mohammed A. K. Mahdy
- Department of Parasitology, Faculty of Medicine, Sana’a University, Sana’a, Yemen
- Tropical Disease Research Center, Faculty of Medicine, University of Science and Technology, Sana’a, Yemen
- * E-mail:
| | - Sami Ahmed Al-Haidari
- Diseases Control & Surveillance, Ministry of Public Health and Population, Sana’a, Yemen
| | - Dhekra A. Annuzaili
- Primary Health Care Department, Ministry of Public Health and Population, Aden, Yemen
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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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Hayon J, Weatherhead J, Hotez PJ, Bottazzi ME, Zhan B. Advances in vaccine development for human trichuriasis. Parasitology 2021; 148:1-12. [PMID: 33757603 DOI: 10.1017/s0031182021000500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Trichuriasis known as whipworm infection caused by Trichuris trichiura, is a highly prevalent soil-transmitted helminthiasis in low- and middle-income countries located in tropical and subtropical areas and affecting approximately 360 million people. Children typically harbour the largest burden of T. trichiura and they are usually co-infected with other soil-transmitted helminth (STH), including Ascaris lumbricoides and hookworm. The consequences of trichuriasis, such as malnutrition and physical and cognitive growth restriction, lead to a massive health burden in endemic regions. Despite the implementation of mass drug administration of anthelminthic treatment to school-age children, T. trichiura infection remains challenging to control due to the low efficacy of current drugs as well as high rates of post-treatment re-infection. Thus, the development of a vaccine that would induce protective immunity and reduce infection rate or community faecal egg output is essential. Hurdles for human whipworm vaccine development include the lack of suitable vaccine antigen targets and animal models for human T. trichiura infection. Instead, rodent whipworm T. muris infected mouse models serve as a major surrogate for testing immunogenicity and efficacy of vaccine candidates. In this review, we summarize recent advances in animal models for T. trichiura antigen discovery and testing of vaccine candidates, while providing an overall view of the current status of T. trichiura vaccine development.
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Affiliation(s)
- Jesica Hayon
- Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA
| | - Jill Weatherhead
- Department of Medicine, Section of Infectious Diseases, Baylor College of Medicine, Houston, TX, USA
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Peter J Hotez
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX77030, USA
| | - Maria Elena Bottazzi
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX77030, USA
| | - Bin Zhan
- Department of Pediatrics, Section of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, USA
- Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX77030, USA
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Leung AK, Leung AA, Wong AH, Hon KL. Human Ascariasis: An Updated Review. ACTA ACUST UNITED AC 2021; 14:133-145. [DOI: 10.2174/1872213x14666200705235757] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/25/2020] [Accepted: 06/11/2020] [Indexed: 11/22/2022]
Abstract
Background:
Ascaris lumbricoides is the most common helminthic infection. More than
1.2 billion people have ascariasis worldwide.
Objective:
This article aimed to provide an update on the evaluation, diagnosis, and treatment of ascariasis.
Methods:
A PubMed search was conducted in February 2020 in Clinical Queries using the key
terms “ascariasis” OR “Ascaris lumbricoides”. The search strategy included meta-analyses, randomized
controlled trials, clinical trials, observational studies, and reviews published within the
past 10 years. The search was restricted to English literature. The information retrieved from the
above search was used in the compilation of the present article. Patents were searched using the
key term “ascariasis” OR “Ascaris lumbricoides” in www.freepatentsonline.com.
Results:
Ascaris lumbricoides is transmitted through the ingestion of embryonated eggs from fecal-
contaminated material. Ascariasis has high endemicity in tropical and subtropical areas. Predisposing
factors include poverty, poor sanitation, inadequate sewage disposal, and poor personal hygiene.
The prevalence is greatest in children younger than 5 years of age. The majority of patients
with intestinal ascariasis are asymptomatic. For those with symptoms, anorexia, nausea, bloating,
abdominal discomfort, recurrent abdominal pain, abdominal distension, and intermittent diarrhea
are not uncommon. Other clinical manifestations vary widely, depending on the underlying complications.
Complications include Löeffler syndrome, intestinal obstruction, biliary colic, recurrent
pyogenic cholangitis, cholecystitis, acalculous cholecystitis, obstructive jaundice, cholelithiasis,
pancreatitis, and malnutrition. The diagnosis is best established by microscopic examination of fecal
smears or following concentration techniques for the characteristic ova. Patients with A. lumbricoides
infection warrant anthelminthic treatment, even if they are asymptomatic, to prevent complications
from migration of the parasite. Albendazole and mebendazole are the drugs of choice for
children and nonpregnant individuals with ascariasis. Pregnant women with ascariasis should be
treated with pyrantel pamoate. Recent patents related to the management of ascariasis are also discussed.
Conclusion:
The average cure rate with anthelminthic treatment is over 95%. Unfortunately, most
treated patients in endemic areas become re-infected within months. Health education, personal hygiene,
improved sanitary conditions, proper disposal of human excreta, and discontinuing the use
of human fecal matter as a fertilizer are effective long-term preventive measures. Targeting deworming
treatment and mass anthelminthic treatment should be considered in regions where A. lumbricoides
is prevalent.
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Affiliation(s)
- Alexander K.C. Leung
- Department of Pediatrics, The University of Calgary, Alberta Children’s Hospital, Calgary, Alberta, Canada
| | - Amy A.M. Leung
- Department of Family Medicine, The University of Alberta, Edmonton, Alberta, Canada
| | - Alex H.C. Wong
- Department of Family Medicine, The University of Calgary, Calgary, Alberta, Canada
| | - Kam L. Hon
- Department of Paediatrics, The Chinese University of Hong Kong, and Department of Paediatrics and Adolescent Medicine, Hong Kong Children’s Hospital, Shatin, Hong Kong
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Faniyi AA, Wijanarko KJ, Tollitt J, Worthington JJ. Helminth Sensing at the Intestinal Epithelial Barrier-A Taste of Things to Come. Front Immunol 2020; 11:1489. [PMID: 32849506 PMCID: PMC7409516 DOI: 10.3389/fimmu.2020.01489] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 06/08/2020] [Indexed: 11/13/2022] Open
Abstract
Human intestinal helminth infection affects more than 1 billion people often in the world's most deprived communities. These parasites are one of the most prevalent neglected tropical diseases worldwide bringing huge morbidities to the host population. Effective treatments and vaccines for helminths are currently limited, and therefore, it is essential to understand the molecular sensors that the intestinal epithelium utilizes in detecting helminths and how the responding factors produced act as modulators of immunity. Defining the cellular and molecular mechanisms that enable helminth detection and expulsion will be critical in identifying potential therapeutic targets to alleviate disease. However, despite decades of research, we have only recently been able to identify the tuft cell as a key helminth sensor at the epithelial barrier. In this review, we will highlight the key intestinal epithelial chemosensory roles associated with the detection of intestinal helminths, summarizing the recent advances in tuft cell initiation of protective type 2 immunity. We will discuss other potential sensory roles of epithelial subsets and introduce enteroendocrine cells as potential key sensors of the microbial alterations that a helminth infection produces, which, given their direct communication to the nervous system via the recently described neuropod, have the potential to transfer the epithelial immune interface systemically.
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Affiliation(s)
- Aduragbemi A Faniyi
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Institute of Inflammation and Ageing, University of Birmingham, Birmingham, United Kingdom
| | - Kevin J Wijanarko
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Department of Biomedical Sciences, City University of Hong Kong, Kowloon, Hong Kong
| | - James Tollitt
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - John J Worthington
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
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Are intestinal parasites associated with obesity in Mexican children and adolescents? Parasitol Int 2019; 71:126-131. [PMID: 30951870 DOI: 10.1016/j.parint.2019.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 04/01/2019] [Accepted: 04/02/2019] [Indexed: 11/24/2022]
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Steel N, Faniyi AA, Rahman S, Swietlik S, Czajkowska BI, Chan BT, Hardgrave A, Steel A, Sparwasser TD, Assas MB, Grencis RK, Travis MA, Worthington JJ. TGFβ-activation by dendritic cells drives Th17 induction and intestinal contractility and augments the expulsion of the parasite Trichinella spiralis in mice. PLoS Pathog 2019; 15:e1007657. [PMID: 30998782 PMCID: PMC6472816 DOI: 10.1371/journal.ppat.1007657] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 02/25/2019] [Indexed: 12/17/2022] Open
Abstract
Helminths are highly prevalent metazoan parasites that infect over a billion of the world's population. Hosts have evolved numerous mechanisms to drive the expulsion of these parasites via Th2-driven immunity, but these responses must be tightly controlled to prevent equally devastating immunopathology. However, mechanisms that regulate this balance are still unclear. Here we show that the vigorous Th2 immune response driven by the small intestinal helminth Trichinella spiralis, is associated with increased TGFβ signalling responses in CD4+ T-cells. Mechanistically, enhanced TGFβ signalling in CD4+ T-cells is dependent on dendritic cell-mediated TGFβ activation which requires expression of the integrin αvβ8. Importantly, mice lacking integrin αvβ8 on DCs had a delayed ability to expel a T. spiralis infection, indicating an important functional role for integrin αvβ8-mediated TGFβ activation in promoting parasite expulsion. In addition to maintaining regulatory T-cell responses, the CD4+ T-cell signalling of this pleiotropic cytokine induces a Th17 response which is crucial in promoting the intestinal muscle hypercontractility that drives worm expulsion. Collectively, these results provide novel insights into intestinal helminth expulsion beyond that of classical Th2 driven immunity, and highlight the importance of IL-17 in intestinal contraction which may aid therapeutics to numerous diseases of the intestine.
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Affiliation(s)
- Nicola Steel
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Aduragbemi A. Faniyi
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Sayema Rahman
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Stefanie Swietlik
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Beata I. Czajkowska
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Bethany T. Chan
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Alexander Hardgrave
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
| | - Anthony Steel
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Tim D. Sparwasser
- Institute of Infection Immunology, TWINCORE, Center for Experimental and Clinical Infection Research, Hannover, Germany
| | - Mushref B. Assas
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Faculty of Applied Medical Sciences, King AbdulAziz University, Jeddah, Saudi Arabia
| | - Richard K. Grencis
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom
| | - Mark A. Travis
- The Lydia Becker Institute of Immunology and Inflammation, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, Manchester, United Kingdom
- Manchester Collaborative Centre for Inflammation Research, University of Manchester, Manchester, United Kingdom
| | - John J. Worthington
- Biomedical and Life Sciences, Faculty of Health and Medicine, University of Lancaster, Lancaster, United Kingdom
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Jenkins T, Brindley P, Gasser R, Cantacessi C. Helminth Microbiomes – A Hidden Treasure Trove? Trends Parasitol 2019; 35:13-22. [DOI: 10.1016/j.pt.2018.10.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 10/27/2018] [Accepted: 10/31/2018] [Indexed: 12/14/2022]
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Abstract
The soil-transmitted helminths (STHs), Ascaris lumbricoides, hookworm and Trichuris trichiura are common in areas with warm and moist climates with little access to adequate water, sanitation, and hygiene affecting the poorest populations. The current control strategy of the World Health Organization is preventive chemotherapy (PC), i.e., the administration of the two benzimidazoles (albendazole and mebendazole) using single, oral doses to at risk populations without prior diagnosis. The recent success of PC is threatened by anthelmintic drug resistance and the low efficacy of the drugs against hookworm (mebendazole) and T. trichiura (albendazole and mebendazole). Only a handful of alternative drugs with anthelmintic properties are available, however, none of the drugs show high efficacy against all three STHs. The combination of two drugs with different activity profiles presents an attractive alternative, which could prevent the development of drug resistance and increase the efficacy compared to monotherapy. In this review, we summarize the efficacy of current and alternative anthelmintics, coadministrations and triple drug therapies assessed by means of network meta-analysis including only randomized controlled trials. Our results highlight that coadministrations have improved efficacy over monotherapy and the necessity of adapting current STH control strategies for the successful continuation of PC programs.
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Mebendazole and radiation in combination increase survival through anticancer mechanisms in an intracranial rodent model of malignant meningioma. J Neurooncol 2018; 140:529-538. [PMID: 30414098 DOI: 10.1007/s11060-018-03009-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/20/2018] [Indexed: 12/16/2022]
Abstract
PURPOSE Meningiomas are a frequent tumor of the central nervous system. Although mostly benign, approximately 5% present as atypical or malignant tumors. Treatments for atypical meningiomas include gross total resection and radiotherapy, but about 33% of patients have recurrent tumors, sometimes as a higher grade. Recently, the brain penetrant anthelmintic drug, mebendazole, has shown promise as an anticancer agent in rodent models of glioblastoma and medulloblastoma. METHODS The half maximal inhibitory concentration (IC50) effect on colony formation, cell proliferation, and caspase-3/7 markers of apoptosis of mebendazole with and without radiation was measured in vitro. Mice intracranially implanted with KT21MG1 human meningioma were administered mebendazole alone or in combination with radiation. Survival benefit was evaluated, while tumors were investigated by immunohistochemical staining for apoptosis, cell proliferation, and vascular density. RESULTS In vitro experiments on meningioma cell lines showed the IC50 for mebendazole in the range of 0.26-0.42 µM. Mebendazole alone induced cytotoxicity, however the combination had a greater reduction in colony formation and resulted in higher levels of cleaved caspase-3. The in vivo study showed both, mebendazole alone and the combination, to have a survival benefit with an increase in apoptosis, and decreases in tumor cell and vascular proliferation. CONCLUSION These preclinical findings indicate that mebendazole alone or in combination with radiation can be considered for the treatment of malignant meningioma. The mechanism of action for this combination may include an increase in apoptosis, a reduction in proliferation and angiogenesis, or a combination of these effects.
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Tyagi R, Maddirala AR, Elfawal M, Fischer C, Bulman CA, Rosa BA, Gao X, Chugani R, Zhou M, Helander J, Brindley PJ, Tseng CC, Greig IR, Sakanari J, Wildman SA, Aroian R, Janetka JW, Mitreva M. Small Molecule Inhibitors of Metabolic Enzymes Repurposed as a New Class of Anthelmintics. ACS Infect Dis 2018; 4:1130-1145. [PMID: 29718656 PMCID: PMC6283408 DOI: 10.1021/acsinfecdis.8b00090] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The enormous prevalence of infections caused by parasitic nematodes worldwide, coupled to the rapid emergence of their resistance to commonly used anthelmintic drugs, presents an urgent need for the discovery of new drugs. Herein, we have identified several classes of small molecules with broad spectrum activity against these pathogens. Previously, we reported the identification of carnitine palmitoyltransferases (CPTs) as a representative class of enzymes as potential targets for metabolic chokepoint intervention that was elucidated from a combination of chemogenomic screening and experimental testing in nematodes. Expanding on these previous findings, we have discovered that several chemical classes of known small molecule inhibitors of mammalian CPTs have potent activity as anthelmintics. Cross-clade efficacy against a broad spectrum of adult parasitic nematodes was demonstrated for multiple compounds from different series. Several analogs of these initial hit compounds were designed and synthesized. The compounds we report represent a good starting point for further lead identification and optimization for development of new anthelmintic drugs with broad spectrum activity and a novel mechanism of action.
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Affiliation(s)
- Rahul Tyagi
- McDonnell Genome Institute, Washington University School of Medicine, 4444 Forest Park Ave, St. Louis, Missouri 63108, USA
| | - Amarendar Reddy Maddirala
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, Missouri 63110, USA
| | - Mostafa Elfawal
- University of Massachusetts Medical School, Suite 219 Biotech 2, 373 Plantation St., Worcester, Massachusetts 01605, USA
| | - Chelsea Fischer
- Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St, San Francisco, California 94158, USA
| | - Christina A. Bulman
- Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St, San Francisco, California 94158, USA
| | - Bruce A. Rosa
- McDonnell Genome Institute, Washington University School of Medicine, 4444 Forest Park Ave, St. Louis, Missouri 63108, USA
| | - Xin Gao
- McDonnell Genome Institute, Washington University School of Medicine, 4444 Forest Park Ave, St. Louis, Missouri 63108, USA
| | - Ryan Chugani
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, Missouri 63110, USA
| | - Mingzhou Zhou
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, Missouri 63110, USA
| | - Jon Helander
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, Missouri 63110, USA
| | - Paul J. Brindley
- Department of Microbiology, Immunology & Tropical Medicine, and Research Center for Neglected Diseases of Poverty, School of Medicine and Health Sciences, George Washington University, Ross Hall, Room 521, 2300 Eye Street, NW, Washington, DC 20037, USA
| | - Chih-Chung Tseng
- Kosterlitz Centre for Therapeutics, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, U.K
| | - Iain R. Greig
- Kosterlitz Centre for Therapeutics, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, U.K
| | - Judy Sakanari
- Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St, San Francisco, California 94158, USA
| | - Scott A. Wildman
- UW Carbone Cancer Center, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave., Madison, Wisconsin 53792, USA
| | - Raffi Aroian
- University of Massachusetts Medical School, Suite 219 Biotech 2, 373 Plantation St., Worcester, Massachusetts 01605, USA
| | - James W. Janetka
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, 660 S. Euclid Ave., Box 8231, St. Louis, Missouri 63110, USA
| | - Makedonka Mitreva
- McDonnell Genome Institute, Washington University School of Medicine, 4444 Forest Park Ave, St. Louis, Missouri 63108, USA
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 4523 Clayton Ave., CB 8051, St. Louis MO, 63110, USA
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Garcia-Espinoza J, Vásquez-Ciriaco S, Doña-Jaimes R, Aragon-Soto R, Velazco-Budar C, López-Martínez E. Parasitosis in the bile duct, report of 3 cases and literature review. REVISTA MÉDICA DEL HOSPITAL GENERAL DE MÉXICO 2018. [DOI: 10.1016/j.hgmx.2016.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Forrer A, Khieu V, Schär F, Vounatsou P, Chammartin F, Marti H, Muth S, Odermatt P. Strongyloides stercoralis and hookworm co-infection: spatial distribution and determinants in Preah Vihear Province, Cambodia. Parasit Vectors 2018; 11:33. [PMID: 29329561 PMCID: PMC5767026 DOI: 10.1186/s13071-017-2604-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 12/25/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Strongyloides stercoralis and hookworm are two soil-transmitted helminths (STH) that are highly prevalent in Cambodia. Strongyloides stercoralis causes long-lasting infections and significant morbidity but is largely neglected, while hookworm causes the highest public health burden among STH. The two parasites have the same infection route, i.e. skin penetration. The extent of co-distribution, which could result in potential high co-morbidities, is unknown in highly endemic settings like Cambodia. The aim of this study was to predict the spatial distribution of S. stercoralis-hookworm co-infection risk and to investigate determinants of co-infection in Preah Vihear Province, North Cambodia. METHODS A cross-sectional survey was conducted in 2010 in 60 villages of Preah Vihear Province. Diagnosis was performed on two stool samples, using combined Baermann technique and Koga agar culture plate for S. stercoralis and Kato-Katz technique for hookworm. Bayesian multinomial geostatistical models were used to assess demographic, socioeconomic, and behavioural determinants of S. stercoralis-hookworm co-infection and to predict co-infection risk at non-surveyed locations. RESULTS Of the 2576 participants included in the study, 48.6% and 49.0% were infected with S. stercoralis and hookworm, respectively; 43.8% of the cases were co-infections. Females, preschool aged children, adults aged 19-49 years, and participants who reported regularly defecating in toilets, systematically boiling drinking water and having been treated with anthelmintic drugs had lower odds of co-infection. While S. stercoralis infection risk did not appear to be spatially structured, hookworm mono-infection and co-infection exhibited spatial correlation at about 20 km. Co-infection risk was positively associated with longer walking distances to a health centre and exhibited a small clustering tendency. The association was only partly explained by climatic variables, suggesting a role for underlying factors, such as living conditions and remoteness. CONCLUSIONS Both parasites were ubiquitous in the province, with co-infections accounting for almost half of all cases. The high prevalence of S. stercoralis calls for control measures. Despite several years of school-based de-worming programmes, hookworm infection levels remain high. Mebendazole efficacy, as well as coverage of and compliance to STH control programmes should be investigated.
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Affiliation(s)
- Armelle Forrer
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Virak Khieu
- grid.415732.6National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Fabian Schär
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Penelope Vounatsou
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Frédérique Chammartin
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Hanspeter Marti
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
| | - Sinuon Muth
- grid.415732.6National Centre for Parasitology, Entomology and Malaria Control, Ministry of Health, Phnom Penh, Cambodia
| | - Peter Odermatt
- 0000 0004 0587 0574grid.416786.aSwiss Tropical and Public Health Institute, Basel, Switzerland
- 0000 0004 1937 0642grid.6612.3University of Basel, Basel, Switzerland
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A method for single pair mating in an obligate parasitic nematode. Int J Parasitol 2017; 48:159-165. [PMID: 29111440 DOI: 10.1016/j.ijpara.2017.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 08/18/2017] [Accepted: 08/21/2017] [Indexed: 11/23/2022]
Abstract
Parasitic nematode species have extremely high levels of genetic diversity, presenting a number of experimental challenges for genomic and genetic work. Consequently, there is a need to develop inbred laboratory strains with reduced levels of polymorphism. The most efficient approach to inbred line development is single pair mating, but this is challenging for obligate parasites where the adult sexual reproductive stages are inside the host, and thus difficult to experimentally manipulate. This paper describes a successful approach to single pair mating of a parasitic nematode, Haemonchus contortus. The method allows for polyandrous mating behaviour and involves the surgical transplantation of a single adult male worm with multiple immature adult females directly into the sheep abomasum. We used a panel of microsatellite markers to monitor and validate the single pair mating crosses and to ensure that the genotypes of progeny and subsequent filial generations were consistent with those expected from a mating between a single female parent of known genotype and a single male parent of unknown genotype. We have established two inbred lines that both show a significant overall reduction in genetic diversity based on microsatellite genotyping and genome-wide single nucleotide polymorphism. There was an approximately 50% reduction in heterozygous SNP sites across the genome in the MHco3.N1 line compared with the MoHco3(ISE) parental strain. The MHco3.N1 inbred line has subsequently been used to provide DNA template for whole genome sequencing of H. contortus. This work provides proof of concept and methodologies for forward genetic analysis of obligate parasitic nematodes.
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Rashwan N, Diawara A, Scott ME, Prichard RK. Isothermal diagnostic assays for the detection of soil-transmitted helminths based on the SmartAmp2 method. Parasit Vectors 2017; 10:496. [PMID: 29047387 PMCID: PMC5648480 DOI: 10.1186/s13071-017-2420-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 10/03/2017] [Indexed: 12/27/2022] Open
Abstract
Background Diagnosis of soil-transmitted helminths (STHs) has traditionally relied on stool microscopy, which has a number of critical deficiencies. Molecular diagnostics are powerful tools to identify closely related species, but the requirement for costly equipment makes their implementation difficult in low-resource or field settings. Rapid, sensitive and cost-effective diagnostic tools are crucial for accurate estimation of STH infection intensity in MDA programmes in which the goal is to reduce morbidity following repeated rounds of chemotherapy. Results In this study, colourimetric isothermal assays were developed using SmartAmp2 primer sets and reagents in loop-mediated amplification (LAMP) assays. Species-specific primer sets, designed on a specific target sequence in the β-tubulin gene, were used to identify Necator americanus, Trichuris trichiura and Ascaris lumbricoides. After initial optimization on control plasmids and genomic DNA from adult worms, assays were evaluated on field samples. Assays showed high sensitivity and demonstrated high tolerance to inhibitors in spiked faecal samples. Rapid and sensitive colourimetric assays were successfully developed to identify the STHs in field samples using hydroxy napthol blue (HNB) dye. Conclusions Rapid and simple colourimetric diagnostic assays, using the SmartAmp2 method, were developed, with the potential to be applied in the field for detection of STH infections and the estimation of response to treatment. However, further validation on large numbers of field samples is needed. Electronic supplementary material The online version of this article (10.1186/s13071-017-2420-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nour Rashwan
- Institute of Parasitology and Centre for Host-Parasite Interactions, Macdonald College, McGill University, Ste Anne de Bellevue, QC, Canada.,Department of Medical Parasitology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Aïssatou Diawara
- Biology Program, Division of Science and Mathematics, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Marilyn E Scott
- Institute of Parasitology and Centre for Host-Parasite Interactions, Macdonald College, McGill University, Ste Anne de Bellevue, QC, Canada
| | - Roger K Prichard
- Institute of Parasitology and Centre for Host-Parasite Interactions, Macdonald College, McGill University, Ste Anne de Bellevue, QC, Canada.
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Rudko SP, Ruecker NJ, Ashbolt NJ, Neumann NF, Hanington PC. Enterobius vermicularis as a Novel Surrogate for the Presence of Helminth Ova in Tertiary Wastewater Treatment Plants. Appl Environ Microbiol 2017; 83:e00547-17. [PMID: 28341675 PMCID: PMC5440721 DOI: 10.1128/aem.00547-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 03/18/2017] [Indexed: 01/07/2023] Open
Abstract
Significant effort has gone into assessing the fate and removal of viruses, bacteria, and protozoan parasites during wastewater treatment to provide data addressing potential health risks associated with reuse options. Comparatively less is known about the fate of parasitic worm species ova in these complex systems. It is largely assumed that these helminths settle, are removed with the sludge, and consequently represent a relatively low risk for wastewater reuse applications. However, helminths are a highly diverse group of organisms that display a wide range of physical properties that complicate the application of a single treatment for helminth reduction during wastewater treatment. Moreover, their diverse biological and physical properties make some ova highly resistant to both disinfection (i.e., with chlorine or UV treatment) and physical removal (settling) through the wastewater treatment train, indicating that there may be reason to broaden the scope of our investigations into whether parasitic worm eggs can be identified in treated wastewater. The ubiquitous human parasitic nematode Enterobius vermicularis (pinworm) produces small, buoyant ova. Utilizing a novel diagnostic quantitative PCR (qPCR), this study monitored E. vermicularis presence at two full-scale wastewater treatment plants over the course of 8 months and demonstrated incomplete physical removal of E. vermicularis ova through tertiary treatment, with removal efficiencies approximating only 0.5 and 1.6 log10 at the two wastewater treatment plants based on qPCR. These findings demonstrate the need for more-diverse surrogates of helminthic ova to fully assess treatment performance with respect to reclaimed wastewaters.IMPORTANCE Helminths, despite being a diverse and environmentally resistant class of pathogens, are often underestimated and ignored when treatment performance at modern wastewater treatment plants is considered. A one-size-fits-all surrogate for removal of helminth ova may be inappropriate to adequately assess risk and ensure public safety when treated and partially treated wastewaters are encountered. This study argues for the use of human pinworm as a conservative indicator of the presence of helminth ova due to its small size, buoyancy, prevalence in humans, and environmental resistance.
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Affiliation(s)
- Sydney P Rudko
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | | | - Nicholas J Ashbolt
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Environmental Microbiology Program, Alberta Provincial Laboratory for Public Health, Edmonton, Alberta, Canada
| | - Norman F Neumann
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
- Environmental Microbiology Program, Alberta Provincial Laboratory for Public Health, Edmonton, Alberta, Canada
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Morawski BM, Yunus M, Kerukadho E, Turyasingura G, Barbra L, Ojok AM, DiNardo AR, Sowinski S, Boulware DR, Mejia R. Hookworm infection is associated with decreased CD4+ T cell counts in HIV-infected adult Ugandans. PLoS Negl Trop Dis 2017; 11:e0005634. [PMID: 28542260 PMCID: PMC5462474 DOI: 10.1371/journal.pntd.0005634] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 06/07/2017] [Accepted: 05/10/2017] [Indexed: 01/02/2023] Open
Abstract
Most studies evaluating epidemiologic relationships between helminths and HIV have been conducted in the pre-ART era, and evidence of the impact of helminth infections on HIV disease progression remains conflicting. Less is known about helminth infection and clinical outcomes in HIV-infected adults receiving antiretroviral therapy (ART). We sampled HIV-infected adults for eight gastrointestinal parasites and correlated parasitic infection with demographic predictors, and clinical and immunologic outcomes. Contrasting with previous studies, we measured parasitic infection with a quantitative, highly sensitive and specific polymerase chain reaction (PCR) method. This cohort study enrolled HIV-infected Ugandans from August-September 2013 in Mbale, Uganda and collected stool and blood samples at enrollment. Real-time PCR quantified stool: Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, Cryptosporidium spp., Entamoeba histolytica, and Giardia intestinalis infection. Generalized linear models assessed relationships between parasitic infection and clinical or demographic data. 35% of participants (71/202) tested positive for ≥1 helminth, mainly N. americanus (55/199, 28%), and 4.5% (9/202) were infected with ≥2 stool parasites. Participants with hookworm infection had lower average CD4+ cell counts (-94 cells/mcL, 95%CI: -141, -48 cells/mcL; p<0.001) after adjustment for sex, CD4+ nadir at clinic entry, and time on ART. The high prevalence of parasitic infection and correlation with decreased CD4+ concentrations highlight the need to re-examine the effects of invasive helminth co-infection in rural, HIV-infected populations in the era of widely available ART. Elucidating the relationship between hookworm infection and immune recovery could provide opportunities for health optimization, e.g. integrated deworming, in these vulnerable populations.
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Affiliation(s)
- Bozena M. Morawski
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, United States of America
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States of America
| | - Miya Yunus
- The AIDS Support Organization, Kampala, Uganda
| | | | | | | | | | - Andrew R. DiNardo
- Division of Global and Immigrant Health, Department of Pediatrics, Baylor College of Medicine, Houston, TX, United States of America
| | - Stefanie Sowinski
- Infectious Diseases Institute, Makerere University, Kampala, Uganda
- The Gladstone Institute of Virology and Immunology, University of California, San Francisco, San Francisco, CA, United States of America
| | - David R. Boulware
- Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, MN, United States of America
- Division of Infectious Diseases and International Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN, United States of America
| | - Rojelio Mejia
- Section of Tropical Medicine, Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States of America
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Rapid Genotyping of β-tubulin Polymorphisms in Trichuris trichiura and Ascaris lumbricoides. PLoS Negl Trop Dis 2017; 11:e0005205. [PMID: 28081124 PMCID: PMC5230752 DOI: 10.1371/journal.pntd.0005205] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/22/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The benzimidazole (BZ) anthelmintics, albendazole (ABZ) and mebendazole (MBZ) are the most common drugs used for treatment of soil-transmitted helminths (STHs). Their intensive use increases the possibility that BZ resistance may develop. In veterinary nematodes, BZ resistance is caused by a single nucleotide polymorphism (SNP) in the β-tubulin isotype 1 gene at codon position 200, 167 or 198, and these SNPs have also been correlated with poor response of human Trichuris trichiura to BZ treatment. It is important to be able to investigate the presence of resistance-associated SNPs in STHs before resistance becomes clinically established. METHODS The objective of this study was to develop new genotyping assays to screen for the presence of β-tubulin SNPs in T. trichiura and Ascaris lumbricoides. Rapid, simple and accurate genotyping assays were developed based on the SmartAmp2 method. Primer sets were optimized and selected to distinguish the SNP-variant genotypes. After initial optimization on control plasmids, the feasibility of the assay was assessed in field samples from Haiti and Panama. Finally, spiked fecal samples were assessed to determine the tolerance of Aac polymerase to fecal inhibitors. FINDINGS Rapid SNP genotyping assays were developed to target β-tubulin polymorphisms in T. trichiura and A. lumbricoides. The assays showed high sensitivity and specificity in field samples and also demonstrated high tolerance to PCR inhibitors in fecal samples. CONCLUSION These assays proved to be robust and efficient with the potential to be used as field tools for monitoring SNPs that could be associated with BZ resistance. However, further work is needed to validate the assays on large numbers of field samples before and after treatment.
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Mapping Soil Transmitted Helminths and Schistosomiasis under Uncertainty: A Systematic Review and Critical Appraisal of Evidence. PLoS Negl Trop Dis 2016; 10:e0005208. [PMID: 28005901 PMCID: PMC5179027 DOI: 10.1371/journal.pntd.0005208] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/23/2016] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Spatial modelling of STH and schistosomiasis epidemiology is now commonplace. Spatial epidemiological studies help inform decisions regarding the number of people at risk as well as the geographic areas that need to be targeted with mass drug administration; however, limited attention has been given to propagated uncertainties, their interpretation, and consequences for the mapped values. Using currently published literature on the spatial epidemiology of helminth infections we identified: (1) the main uncertainty sources, their definition and quantification and (2) how uncertainty is informative for STH programme managers and scientists working in this domain. METHODOLOGY/PRINCIPAL FINDINGS We performed a systematic literature search using the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) protocol. We searched Web of Knowledge and PubMed using a combination of uncertainty, geographic and disease terms. A total of 73 papers fulfilled the inclusion criteria for the systematic review. Only 9% of the studies did not address any element of uncertainty, while 91% of studies quantified uncertainty in the predicted morbidity indicators and 23% of studies mapped it. In addition, 57% of the studies quantified uncertainty in the regression coefficients but only 7% incorporated it in the regression response variable (morbidity indicator). Fifty percent of the studies discussed uncertainty in the covariates but did not quantify it. Uncertainty was mostly defined as precision, and quantified using credible intervals by means of Bayesian approaches. CONCLUSION/SIGNIFICANCE None of the studies considered adequately all sources of uncertainties. We highlighted the need for uncertainty in the morbidity indicator and predictor variable to be incorporated into the modelling framework. Study design and spatial support require further attention and uncertainty associated with Earth observation data should be quantified. Finally, more attention should be given to mapping and interpreting uncertainty, since they are relevant to inform decisions regarding the number of people at risk as well as the geographic areas that need to be targeted with mass drug administration.
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Hotez PJ, Beaumier CM, Gillespie PM, Strych U, Hayward T, Bottazzi ME. Advancing a vaccine to prevent hookworm disease and anemia. Vaccine 2016; 34:3001-3005. [DOI: 10.1016/j.vaccine.2016.03.078] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 03/11/2016] [Indexed: 01/30/2023]
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Hotez PJ, Strych U, Lustigman S, Bottazzi ME. Human anthelminthic vaccines: Rationale and challenges. Vaccine 2016; 34:3549-55. [DOI: 10.1016/j.vaccine.2016.03.112] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/23/2016] [Accepted: 03/31/2016] [Indexed: 12/29/2022]
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Araujo ES, de Jesus Pereira CA, de Moura Pereira AT, Moreira JMP, de Rezende MC, Rodrigues JL, Teixeira MM, Negrão-Corrêa D. The role of IL-33/ST2, IL-4, and eosinophils on the airway hyperresponsiveness induced by Strongyloides venezuelensis in BALB/c mice. Parasitol Res 2016; 115:3107-17. [PMID: 27102638 DOI: 10.1007/s00436-016-5066-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 04/13/2016] [Indexed: 10/21/2022]
Abstract
Strongyloidiasis is a neglected chronic nematode infection, in which the control of autoinfection rate and severity of disease is dependent on type 2 immune responses. Strongyloides also causes Th2 responses in the lung of infected animals and changes in airway function, including airway hyperresponsiveness (AHR). Mechanisms of AHR during Strongyloides venezuelensis infection are not entirely known, and we investigate here the role of IL-4, eosinophils, and IL-33/ST2. AHR was evaluated in infected mice by determining changes in lung function after increasing doses of methacholine. Balb/C, but no C57Bl/6, mice developed AHR, tissue eosinophilia, and increased local IL-4 and IL-5 production. Functional changes peaked at day 4 and 7, after the larva had left the lungs. AHR was clearly dependent on IL-4 but not on eosinophils, as evaluated by experiments in IL-4 and Gata-1-deficient mice. Experiments in ST2-deficient mice showed that this pathway was not needed for induction of AHR but was necessary for the maintenance of AHR and for Th2 responses in the lung. These studies clearly show a crucial role for IL-4 in the induction of AHR following S. venezuelensis infection and for IL-33/ST2 in maintaining AHR and lung Th2 responses.
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Affiliation(s)
- Emilia Souza Araujo
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | - Cintia Aparecida de Jesus Pereira
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | - Ana Terezinha de Moura Pereira
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | - João Marcelo Peixoto Moreira
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | - Michelle Carvalho de Rezende
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | - Jailza Lima Rodrigues
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901
| | | | - Deborah Negrão-Corrêa
- Departamento de Parasitologia Bloco Q3-sala 242, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Campus Pampulha, Belo Horizonte, MG, Brazil, 31270-901.
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Abstract
• On the basis of research evidence, worm infections are important global child health conditions causing chronic disability that lasts from childhood into adulthood (Table 1). (2)(3) Evidence Quality: B • On the basis of research evidence, the major worm infections found in developing countries include ascariasis, trichuriasis, hookworm infection, and schistosomiasis; toxocariasis, enterobiasis, and cysticercosis are also found in poor regions of North America and Europe. (4)(9)(13) Evidence Quality: B • On the basis of expert consensus, children and adolescents are often vulnerable to acquiring large numbers of worms, ie, high-intensity infections (Fig 1)(21)(22)(23) Evidence Quality: D • On the basis of expert consensus and research evidence, moderate and heavy worm burdens cause increased morbidity because of growth and intellectual stunting in children and adolescents. Many of these effects may result from helminth-induced malnutrition. (21)(22)(23) Evidence Quality: C • On the basis of expert consensus and research evidence, worm infections are also commonly associated with eosinophilia. (48) (49) Evidence Quality: B • On the basis of research evidence as well as consensus, helminthes can cause inflammation in the lung (asthma), gastrointestinal tract (enteritis and colitis), liver (hepatitis and fibrosis), and urogenital tract. (7)(21)(22)(23)(27)(28)(40)(41)(43) Evidence Quality: B • On the basis of research evidence, microscopy techniques for diagnosis of worm infections in children often exhibit suboptimal sensitivities and specificities, necessitating new or improved diagnostic modalities such as polymerase chain reaction. (54)(55) Evidence Quality: A • On the basis of research evidence and expert consensus, mass drug administration (“preventive chemotherapy”) has becomea standard practice for ministries of health in low- and middle-income countries to control intestinal helminth infections and schistosomiasis. (67)(68) Evidence Quality: B.
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Affiliation(s)
- Jill E Weatherhead
- Department of Pediatrics (Sections of Infectious Diseases and Tropical Medicine), National School of Tropical Medicine, Baylor College of Medicine, Houston, TX. Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX
| | - Peter J Hotez
- Department of Pediatrics (Sections of Infectious Diseases and Tropical Medicine), National School of Tropical Medicine, Baylor College of Medicine, Houston, TX. Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Houston, TX
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Affiliation(s)
- Jill E. Weatherhead
- Department of Pediatrics (Sections of Infectious Diseases and Tropical Medicine), National School of Tropical Medicine, Baylor College of Medicine, Houston, TX
- Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development, Houston, TX
| | - Peter J. Hotez
- Department of Pediatrics (Sections of Infectious Diseases and Tropical Medicine), National School of Tropical Medicine, Baylor College of Medicine, Houston, TX
- Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development, Houston, TX
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Šlapeta J, Dowd SE, Alanazi AD, Westman ME, Brown GK. Differences in the faecal microbiome of non-diarrhoeic clinically healthy dogs and cats associated with Giardia duodenalis infection: impact of hookworms and coccidia. Int J Parasitol 2015; 45:585-94. [DOI: 10.1016/j.ijpara.2015.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/07/2015] [Accepted: 04/09/2015] [Indexed: 02/07/2023]
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Mehta P, Furuta GT. Eosinophils in Gastrointestinal Disorders: Eosinophilic Gastrointestinal Diseases, Celiac Disease, Inflammatory Bowel Diseases, and Parasitic Infections. Immunol Allergy Clin North Am 2015. [PMID: 26209893 DOI: 10.1016/j.iac.2015.04.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The gastrointestinal (GI) tract provides an intriguing organ for considering the eosinophil's role in health and disease. The normal GI tract, except for the esophagus, is populated by eosinophils that are present throughout the mucosa, raising the possibility that eosinophils participate in innate mechanisms of defense. However, data from clinical studies associates increased numbers of eosinophils with inflammatory GI diseases, prompting concerns that eosinophils may have a deleterious effect on the gut. We present clinical features of 4 disease processes that have been associated with eosinophilia and suggest areas requiring investigation as to their clinical significance and scientific relevance.
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Affiliation(s)
- Pooja Mehta
- Department of Pediatrics, Gastrointestinal Eosinophilic Diseases Program, Section of Pediatric Gastroenterology, Hepatology, and Nutrition, Digestive Health Institute, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Ave B290, Aurora, CO 80045, USA
| | - Glenn T Furuta
- Department of Pediatrics, Gastrointestinal Eosinophilic Diseases Program, Section of Pediatric Gastroenterology, Hepatology, and Nutrition, Digestive Health Institute, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Ave B290, Aurora, CO 80045, USA.
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Abstract
Approximately 440 million people globally are afflicted by hookworm disease, one of the 17 WHO-recognized neglected tropical diseases (NTDs). The iron-deficiency anaemia attributed to this disease contributes to at least 3.2 million disability-adjusted life years (DALYs) according to the Global Burden of Disease Study 2010. The current WHO-recommended control strategies rely primarily on mass drug administration or preventive chemotherapy. However, evidence is starting to accumulate confirming that preventive chemotherapy alone will not be sufficient to reduce the reinfection rates of hookworm, especially in areas of heavy transmission. The global health and research community is currently building a consensus stressing the need for the advancement of research and innovation to bridge the gaps and identify new public health interventions for diseases such as hookworm and other NTDs. This paper presents the strategies used by the Sabin Vaccine Institute Product Development Partnership (Sabin PDP) in their ongoing endeavour for the development of a human hookworm vaccine. Recent updates and the current prospects for success of an effective human hookworm vaccine, as a new technology to be linked to or combined with drug interventions, are presented.
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Buckingham SD, Partridge FA, Sattelle DB. Automated, high-throughput, motility analysis in Caenorhabditis elegans and parasitic nematodes: Applications in the search for new anthelmintics. Int J Parasitol Drugs Drug Resist 2014; 4:226-32. [PMID: 25516833 PMCID: PMC4266775 DOI: 10.1016/j.ijpddr.2014.10.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The scale of the damage worldwide to human health, animal health and agricultural crops resulting from parasitic nematodes, together with the paucity of treatments and the threat of developing resistance to the limited set of widely-deployed chemical tools, underlines the urgent need to develop novel drugs and chemicals to control nematode parasites. Robust chemical screens which can be automated are a key part of that discovery process. Hitherto, the successful automation of nematode behaviours has been a bottleneck in the chemical discovery process. As the measurement of nematode motility can provide a direct scalar readout of the activity of the neuromuscular system and an indirect measure of the health of the animal, this omission is acute. Motility offers a useful assay for high-throughput, phenotypic drug/chemical screening and several recent developments have helped realise, at least in part, the potential of nematode-based drug screening. Here we review the challenges encountered in automating nematode motility and some important developments in the application of machine vision, statistical imaging and tracking approaches which enable the automated characterisation of nematode movement. Such developments facilitate automated screening for new drugs and chemicals aimed at controlling human and animal nematode parasites (anthelmintics) and plant nematode parasites (nematicides).
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Affiliation(s)
| | | | - David B. Sattelle
- Wolfson Institute for Biomedical Research, Division of Medicine, University College London, Cruciform Building, Gower Street, London WC1E 6BT, United Kingdom
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Production and analysis of immunomodulatory excretory-secretory products from the mouse gastrointestinal nematode Heligmosomoides polygyrus bakeri. Nat Protoc 2014; 9:2740-54. [PMID: 25375989 DOI: 10.1038/nprot.2014.184] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Heligmosomoides polygyrus bakeri (Hpb) infection in mice is a convenient model for studying the pathophysiology and immunology of gastrointestinal (GI) helminth infection. Hpb infection suppresses immune responses to bystander antigens and unrelated pathogens, and it slows the progression and modifies the outcome of immune-mediated diseases. Hpb-derived excretory-secretory (ES) products potently modulate CD4(+) helper T cell (TH) responses by inducing regulatory T cells, tolerogenic dendritic cells (DCs) and immunoregulatory cytokines. This observation has spiked interest in identifying the immunomodulatory molecules, especially proteins, in ES products from Hpb and other GI nematodes for development as novel therapies to treat individuals with immune-mediated diseases, such as inflammatory bowel diseases (IBDs). In this protocol, we describe how to (i) maintain Hpb in the laboratory for experimental infections, (ii) collect adult worms from infected mice to generate ES products and (iii) evaluate the modulatory effects of ES products on toll-like receptor (TLR) ligand-induced maturation of CD11c(+) DCs. The three major sections of the PROCEDURE can be used independently, and they require ∼6, 10 and 27 h, respectively. Although other methods use a modified Baermann apparatus to collect Hpb adult worms, we describe a method that involves dissection of adult worms from intestinal tissue. The protocol will be useful to investigators studying the host-parasite interface and identifying and analyzing helminth-derived molecules with therapeutic potential.
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Barros N, Montes M. Infection and Hyperinfection with Strongyloides stercoralis: Clinical Presentation, Etiology of Disease, and Treatment Options. CURRENT TROPICAL MEDICINE REPORTS 2014. [DOI: 10.1007/s40475-014-0030-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Webster JP, Molyneux DH, Hotez PJ, Fenwick A. The contribution of mass drug administration to global health: past, present and future. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130434. [PMID: 24821920 DOI: 10.1098/rstb.2013.0434] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mass drug administration (MDA) is a means of delivering safe and inexpensive essential medicines based on the principles of preventive chemotherapy, where populations or sub-populations are offered treatment without individual diagnosis. High-coverage MDA in endemic areas aims to prevent and alleviate symptoms and morbidity on the one hand and can reduce transmission on the other, together improving global health. MDA is the recommended strategy of the World Health Organisation to control or eliminate several neglected tropical diseases (NTDs). More than 700 million people now receive these essential NTD medicines annually. The combined cost of integrated NTD MDA has been calculated to be in the order of $0.50 per person per year. Activities have recently been expanded due, in part, to the proposed attempt to eliminate certain NTDs in the coming two decades. More than 1.9 billion people need to receive MDA annually across several years if these targets are to be met. Such extensive coverage will require additional avenues of financial support, expanded monitoring and evaluation focusing on impact and drug efficacy, as well as new diagnostic tools and social science strategies to encourage adherence. MDA is a means to help reduce the burden of disease, and hence poverty, among the poorest sector of populations. It has already made significant improvements to global health and productivity and has the potential for further successes, particularly where incorporated into sanitation and education programmes. However logistical, financial and biological challenges remain.
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Affiliation(s)
- Joanne P Webster
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College Faculty of Medicine, , St Mary's Campus, London W2 1PG, UK
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Zhan B, Beaumier CM, Briggs N, Jones KM, Keegan BP, Bottazzi ME, Hotez PJ. Advancing a multivalent 'Pan-anthelmintic' vaccine against soil-transmitted nematode infections. Expert Rev Vaccines 2014; 13:321-31. [PMID: 24392641 PMCID: PMC3934375 DOI: 10.1586/14760584.2014.872035] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Ascaris lumbricoides The Sabin Vaccine Institute Product Development Partnership is developing a Pan-anthelmintic vaccine that simultaneously targets the major soil-transmitted nematode infections, in other words, ascariasis, trichuriasis and hookworm infection. The approach builds off the current bivalent Human Hookworm Vaccine now in clinical development and would ultimately add both a larval Ascaris lumbricoides antigen and an adult-stage Trichuris trichiura antigen from the parasite stichosome. Each selected antigen would partially reproduce the protective immunity afforded by UV-attenuated Ascaris eggs and Trichuris stichosome extracts, respectively. Final antigen selection will apply a ranking system that includes the evaluation of expression yields and solubility, feasibility of process development and the absence of circulating antigen-specific IgE among populations living in helminth-endemic regions. Here we describe a five year roadmap for the antigen discovery, feasibility and antigen selection, which will ultimately lead to the scale-up expression, process development, manufacture, good laboratory practices toxicology and preclinical evaluation, ultimately leading to Phase 1 clinical testing.
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Affiliation(s)
- Bin Zhan
- Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine , Houston, TX , USA
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