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Kepha S, Mazigo HD, Odiere MR, Mcharo C, Safari T, Gichuki PM, Omondi W, Wakesho F, Krolewiecki A, Pullan RL, Mwandawiro CS, Oswald WE, Halliday KE. Exploring factors associated with Trichuris trichiura infection in school children in a high-transmission setting in Kenya. IJID REGIONS 2024; 11:100352. [PMID: 38634069 PMCID: PMC11021359 DOI: 10.1016/j.ijregi.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 04/19/2024]
Abstract
Objectives Kenya has implemented a national school-based deworming program, which has led to substantial decline in the prevalence of soil-transmitted helminths (STHs), although some pockets of infections remain. To effectively design an STH control program that leads to significant reductions of Trichuris trichiura, there is a need to understand the drivers of persistent infection despite ongoing treatment programs. Methods This study was conducted between July and September 2019 at the south coast of Kenya, using a two-stage sampling design. First, a school-based cross-sectional survey was conducted in 2265 randomly selected school children from selected schools in areas known to be endemic for T. trichiura. After this, we conducted a nested case-control study wherein all children positive for T. trichiura (142) were matched to 148 negative controls based on age and village. A household survey was then conducted with all household members of cases and controls. In addition, a subsample of 116 children found to be infected with T. trichiura were followed up to assess the efficacy of albendazole at day 21 post-treatment. The predictors of presence of T. trichiura were investigated through multilevel logistic regression, considering clustering of infection. Results Overall, 34.4% of the children were infected with at least one STH species; T. trichiura was the most common (28.3%), 89.1% of those with T. trichiura had light-intensity infections. The prevalence of T. trichiura was significantly higher in male children and was positively associated with younger age and number of people infected with T. trichiura in a household. The parasitological cure rate and egg reduction rate of T. trichiura were 35% and 51%, respectively. Other STHs identified were hookworm (9.6%) and Ascaris lumbricoides (5.7%). Conclusions T. trichiura remains a significant public health challenge in the study area with albendazole treatment efficacy against the parasite, remaining lower than the World Health Organization-recommended thresholds. Because of the observed focal transmission of T. trichiura in the current area, control efforts tailored to local conditions and targeting lower implementation units should be used to achieve optimal results on transmission.
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Affiliation(s)
- Stella Kepha
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Humphrey D. Mazigo
- Department of Medical Parasitology and Entomology, School of Medicine, Catholic University of Health and Allied Sciences, Mwanza, United Republic of Tanzania
| | - Maurice R. Odiere
- Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya
| | - Carlos Mcharo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Th'uva Safari
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Paul M. Gichuki
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Wykcliff Omondi
- Division of Vector Borne and Neglected Tropical Diseases, Ministry of Health, Nairobi, Kenya
| | - Florence Wakesho
- Division of Vector Borne and Neglected Tropical Diseases, Ministry of Health, Nairobi, Kenya
| | - Alejandro Krolewiecki
- Universidad Nacional de Salta, Instituto de Investigaciones de Enfermedades Tropicales/CONICET, Oran, Salta, Argentina
| | - Rachel L. Pullan
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Charles S. Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - William E. Oswald
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Katherine E. Halliday
- Department of Disease Control, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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Belay S, Alemu G, Hailu T. Pattern and predictor of hookworm re-infection among schoolchildren in three districts of Amhara Region, northwest Ethiopia. PLoS One 2024; 19:e0303502. [PMID: 38805475 PMCID: PMC11132481 DOI: 10.1371/journal.pone.0303502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 04/25/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Despite integrated prevention and control measures, the prevalence of hookworm is still high in Ethiopia. The re-infection rates and predictors are poorly addressed. Therefore, this study aimed to determine the patterns of hookworm re-infection rates and predictors among schoolchildren in northwest Ethiopia. METHODS A prospective follow-up study was conducted among 86 schoolchildren from May to December 2022. Data on predictors was collected using a questionnaire. Stool samples were collected and processed via Kato-Katz, McMaster, and spontaneous tube sedimentation techniques. All hookworm-infected children were treated with albendazole and followed for six months. The re-infection rates of hookworm were checked in the 4th and 6th months. Data was entered into Epi-data version 3.1 and analysed using SPSS version 25. Descriptive statistics were used to compute the re-infection rate. The associations of predictors with hookworm re-infection rates were calculated by logistic regression. Variables with a p-value < 0.05 were considered statistically significant. RESULTS Of the 86, 81 schoolchildren completed the study. The prevalence of hookworm re-infection in the 4th and 6th months was 23.5% and 33.3%, respectively. Living with family members greater than five (p = .017), poor utilization of latrine (p = .008), infrequent shoe wear (p = .039), and participating in irrigation (p = .020) were the predictors significantly associated with hookworm re-infections. CONCLUSIONS The re-infection rate was high during the fourth and sixth months. Participating in irrigation, infrequent shoe wear, and poor latrine utilization were predictors of hookworm re-infection. Therefore, mass drug administration, regular shoe wearing, and health education should be advocated.
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Affiliation(s)
- Shegaw Belay
- Amhara National Regional State Health Bureau, Bahir Dar Health Science College, Bahir Dar, Ethiopia
| | - Getaneh Alemu
- Departments of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Tadesse Hailu
- Departments of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
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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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Edoa JR, Adégbitè BR, Honkpéhèdji YJ, Zinsou JF, Boussougou-Sambe ST, Woldearegai TG, Mordmüller B, Adegnika AA, Dejon-Agobé JC. Epidemiology of soil-transmitted helminth infections and the differential effect of treatment on the distribution of helminth species in rural areas of Gabon. Trop Med Health 2024; 52:3. [PMID: 38163912 PMCID: PMC10759385 DOI: 10.1186/s41182-023-00567-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/16/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infections are a public health concern in endemic areas. For efficient control, the epidemiology of the disease needs to be monitored. This report assesses the prevalence, incidence, post-treatment infection (PTI) rate, and risk factors for STH infections in two rural areas of Gabon. METHOD In this longitudinal and prospective study, participants aged six to 30 years from the vicinity of Lambaréné and selected households using a simple randomization process were included and followed in two consecutive periods of six and nine months. Stool samples were obtained at the beginning and the end of each follow-up phase (FUP). The Kato-Katz technique was used for the detection of STH eggs, while the Harada-Mori technique and coproculture were used for the detection of larvae in stool processed within a maximum of four hours of collection. Prevalence was determined at the three main time points of the study, incidence was assessed during the two study phases, and PTI was defined as an infection detected nine months post-treatment. RESULTS A total of 262 participants were included. The overall prevalence of STH infections was 42% (95%CI: 34-50) and 44% (95%CI: 37-51) at baseline for the six and nine month FUPs, respectively. Trichuris trichiura was the most prevalent species at each time point of assessment. The cumulative incidence of STH at the 6- and 9-month follow-ups was 18% (95%CI: 12-27) and 35% (95%CI: 27-43), respectively, while the incidence rates were 41 (95%CI: 28-55) and 56 (95%CI: 46-67) per 100 person-years, respectively. The PTI rates at the 9-month follow-up for T. trichiura, hookworm, and Ascaris lumbricoides were 58% (95%CI: 41-74), 31% (95%CI: 11-59) and 18% (95%CI: 5-40), respectively. The STH infection intensity was generally light. CONCLUSION The prevalence level of STH infection is moderate in the vicinity of Lambaréné, with T. trichiura being the most prevalent species. Our results reveal a rapid spread of the disease in the population mainly following intervention, particularly for trichuriasis, and therefore call for the full implementation of the World Health Organization's recommendations in the area. Trial registration clinicaltrials.gov Identifier NCT02769013. Registered 21 April 2016, https://clinicaltrials.gov/study/NCT02769013.
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Affiliation(s)
- Jean Ronald Edoa
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
| | - Bayodé Roméo Adégbitè
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam University Medical Centers, Location AMC, Amsterdam Public Health, Amsterdam Infection and Immunity, University of Amsterdam, Amsterdam, The Netherlands
- Fondation Pour la Recherche Scientifique, ISBA, P.O. Box 88, Cotonou, Bénin
| | - Yabo Josiane Honkpéhèdji
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Fondation Pour la Recherche Scientifique, ISBA, P.O. Box 88, Cotonou, Bénin
- Department of Parasitology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
| | - Jeannot Fréjus Zinsou
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Fondation Pour la Recherche Scientifique, ISBA, P.O. Box 88, Cotonou, Bénin
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
| | - Stravensky Térence Boussougou-Sambe
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
| | - Tamirat Gebru Woldearegai
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
- German Center for Infection Research, Tübingen, Germany
| | - Benjamin Mordmüller
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ayola Akim Adegnika
- Centre de Recherches Médicales de Lambaréné, P.O. Box 242, Lambaréné, Gabon
- Fondation Pour la Recherche Scientifique, ISBA, P.O. Box 88, Cotonou, Bénin
- Department of Parasitology, Leiden University Medical Center, 2333 ZA, Leiden, The Netherlands
- Institut für Tropenmedizin, Universitätsklinikum Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
- German Center for Infection Research, Tübingen, Germany
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Sulik M, Antoszczak M, Huczyński A, Steverding D. Antiparasitic activity of ivermectin: Four decades of research into a "wonder drug". Eur J Med Chem 2023; 261:115838. [PMID: 37793327 DOI: 10.1016/j.ejmech.2023.115838] [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: 08/22/2023] [Revised: 09/17/2023] [Accepted: 09/26/2023] [Indexed: 10/06/2023]
Abstract
Parasitic diseases still pose a serious threat to human and animal health, particularly for millions of people and their livelihoods in low-income countries. Therefore, research into the development of effective antiparasitic drugs remains a priority. Ivermectin, a sixteen-membered macrocyclic lactone, exhibits a broad spectrum of antiparasitic activities, which, combined with its low toxicity, has allowed the drug to be widely used in the treatment of parasitic diseases affecting humans and animals. In addition to its licensed use against river blindness and strongyloidiasis in humans, and against roundworm and arthropod infestations in animals, ivermectin is also used "off-label" to treat many other worm-related parasitic diseases, particularly in domestic animals. In addition, several experimental studies indicate that ivermectin displays also potent activity against viruses, bacteria, protozoans, trematodes, and insects. This review article summarizes the last 40 years of research on the antiparasitic effects of ivermectin, and the use of the drug in the treatment of parasitic diseases in humans and animals.
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Affiliation(s)
- Michał Sulik
- Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61‒614, Poznań, Poland
| | - Michał Antoszczak
- Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61‒614, Poznań, Poland
| | - Adam Huczyński
- Department of Medical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Uniwersytetu Poznańskiego 8, 61‒614, Poznań, Poland.
| | - Dietmar Steverding
- Bob Champion Research & Education Building, Norwich Medical School, University of East Anglia, Norwich, UK
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Ferguson AA, Inclan-Rico JM, Lu D, Bobardt SD, Hung L, Gouil Q, Baker L, Ritchie ME, Jex AR, Schwarz EM, Rossi HL, Nair MG, Dillman AR, Herbert DR. Hookworms dynamically respond to loss of Type 2 immune pressure. PLoS Pathog 2023; 19:e1011797. [PMID: 38079450 PMCID: PMC10735188 DOI: 10.1371/journal.ppat.1011797] [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: 05/03/2023] [Revised: 12/21/2023] [Accepted: 11/02/2023] [Indexed: 12/23/2023] Open
Abstract
The impact of the host immune environment on parasite transcription and fitness is currently unknown. It is widely held that hookworm infections have an immunomodulatory impact on the host, but whether the converse is true remains unclear. Immunity against adult-stage hookworms is largely mediated by Type 2 immune responses driven by the transcription factor Signal Transducer and Activator of Transcription 6 (STAT6). This study investigated whether serial passage of the rodent hookworm Nippostrongylus brasiliensis in STAT6-deficient mice (STAT6 KO) caused changes in parasites over time. After adaptation to STAT6 KO hosts, N. brasiliensis increased their reproductive output, feeding capacity, energy content, and body size. Using an improved N. brasiliensis genome, we found that these physiological changes corresponded with a dramatic shift in the transcriptional landscape, including increased expression of gene pathways associated with egg production, but a decrease in genes encoding neuropeptides, proteases, SCP/TAPS proteins, and transthyretin-like proteins; the latter three categories have been repeatedly observed in hookworm excreted/secreted proteins (ESPs) implicated in immunosuppression. Although transcriptional changes started to appear in the first generation of passage in STAT6 KO hosts for both immature and mature adult stages, downregulation of the genes putatively involved in immunosuppression was only observed after multiple generations in this immunodeficient environment. When STAT6 KO-adapted N. brasiliensis were reintroduced to a naive WT host after up to 26 generations, this progressive change in host-adaptation corresponded to increased production of inflammatory cytokines by the WT host. Surprisingly, however, this single exposure of STAT6 KO-adapted N. brasiliensis to WT hosts resulted in worms that were morphologically and transcriptionally indistinguishable from WT-adapted parasites. This work uncovers remarkable plasticity in the ability of hookworms to adapt to their hosts, which may present a general feature of parasitic nematodes.
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Affiliation(s)
- Annabel A. Ferguson
- University of Pennsylvania, School of Veterinary Medicine, Pathobiology Department, Philadelphia, Pennsylvania, United States of America
| | - Juan M. Inclan-Rico
- University of Pennsylvania, School of Veterinary Medicine, Pathobiology Department, Philadelphia, Pennsylvania, United States of America
| | - Dihong Lu
- University of California Riverside, Department of Nematology, Riverside, California, United States of America
| | - Sarah D. Bobardt
- University of California Riverside, School of Medicine, Department of Biomedical Sciences, Riverside, California, United States of America
| | - LiYin Hung
- University of Pennsylvania, School of Veterinary Medicine, Pathobiology Department, Philadelphia, Pennsylvania, United States of America
| | - Quentin Gouil
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- University of Melbourne, Department of Medical Biology, Parkville, Victoria, Australia
| | - Louise Baker
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- University of Melbourne, Department of Veterinary Biosciences, Parkville, Victoria, Australia
| | - Matthew E. Ritchie
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- University of Melbourne, Department of Medical Biology, Parkville, Victoria, Australia
| | - Aaron R. Jex
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- University of Melbourne, Department of Veterinary Biosciences, Parkville, Victoria, Australia
| | - Erich M. Schwarz
- University of Melbourne, Department of Veterinary Biosciences, Parkville, Victoria, Australia
- Cornell University, Department of Molecular Biology and Genetics, Ithaca, New York, United States of America
| | - Heather L. Rossi
- University of Pennsylvania, School of Veterinary Medicine, Pathobiology Department, Philadelphia, Pennsylvania, United States of America
| | - Meera G. Nair
- University of California Riverside, School of Medicine, Department of Biomedical Sciences, Riverside, California, United States of America
| | - Adler R. Dillman
- University of California Riverside, Department of Nematology, Riverside, California, United States of America
| | - De’Broski R. Herbert
- University of Pennsylvania, School of Veterinary Medicine, Pathobiology Department, Philadelphia, Pennsylvania, United States of America
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Hürlimann E, Hofmann D, Keiser J. Ivermectin and moxidectin against soil-transmitted helminth infections. Trends Parasitol 2023; 39:272-284. [PMID: 36804383 DOI: 10.1016/j.pt.2023.01.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/19/2023] [Accepted: 01/20/2023] [Indexed: 02/19/2023]
Abstract
Ivermectin and moxidectin, two macrocyclic lactones, are potent antiparasitic drugs currently registered and mainly used against filarial diseases; however, their potential value for improved soil-transmitted helminth (STH) control has been acknowledged. This review provides insights on recent studies evaluating the efficacy of ivermectin and moxidectin as single or coadministered therapy against human soil-transmitted helminthiases (including Strongyloides stercoralis infections) and on pharmacokinetic/pharmacodynamic parameters measured in treated populations. Furthermore, we discuss current gaps for research, highlight advantages - but also existing challenges - for uptake of ivermectin and/or moxidectin treatment schemes into routine STH control in endemic countries.
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Affiliation(s)
- Eveline Hürlimann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Daniela Hofmann
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Allschwil, Switzerland; University of Basel, Basel, Switzerland.
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Joshi P, Sangamwar AT. Insights into the Role of Compendial/Biorelevant Media on the Supersaturation Behaviour of Drug Combination (Drug-Drug Interaction) and Precipitation Inhibition by Polymers. AAPS PharmSciTech 2022; 23:300. [DOI: 10.1208/s12249-022-02448-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 10/27/2022] [Indexed: 11/16/2022] Open
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Papaiakovou M, Littlewood DTJ, Doyle SR, Gasser RB, Cantacessi C. Worms and bugs of the gut: the search for diagnostic signatures using barcoding, and metagenomics-metabolomics. Parasit Vectors 2022; 15:118. [PMID: 35365192 PMCID: PMC8973539 DOI: 10.1186/s13071-022-05225-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 02/25/2022] [Indexed: 02/07/2023] Open
Abstract
Gastrointestinal (GI) helminth infections cause significant morbidity in both humans and animals worldwide. Specific and sensitive diagnosis is central to the surveillance of such infections and to determine the effectiveness of treatment strategies used to control them. In this article, we: (i) assess the strengths and limitations of existing methods applied to the diagnosis of GI helminth infections of humans and livestock; (ii) examine high-throughput sequencing approaches, such as targeted molecular barcoding and shotgun sequencing, as tools to define the taxonomic composition of helminth infections; and (iii) discuss the current understanding of the interactions between helminths and microbiota in the host gut. Stool-based diagnostics are likely to serve as an important tool well into the future; improved diagnostics of helminths and their environment in the gut may assist the identification of biomarkers with the potential to define the health/disease status of individuals and populations, and to identify existing or emerging anthelmintic resistance.
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Affiliation(s)
- Marina Papaiakovou
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
- Department of Life Sciences, Natural History Museum, Cromwell Road, London, SW7 5BD UK
| | | | | | - Robin B. Gasser
- Melbourne Veterinary School, The University of Melbourne, Parkville, VIC 3010 Australia
| | - Cinzia Cantacessi
- Department of Veterinary Medicine, University of Cambridge, Cambridge, CB3 0ES UK
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Alatas FS, Pratiwi AA, Kurniawan A, Pudjiadi AH. Emerging Multiple Parasite Reinfection as Neglected Tropical Disease: A Case Series. JOURNAL OF CHILD SCIENCE 2022. [DOI: 10.1055/s-0042-1743196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
AbstractSoil-transmitted helminth infection is endemic in Indonesia, with cases of reinfection despite individualized therapy and a mass treatment program. Three cases of multiple helminth infections were described that might be associated with chronic bloody diarrhea and stunted growth. These case series alert pediatricians that untreated helminthic infections are part of the differential diagnosis in children with gastrointestinal bleeding. Environmental surveillance should be performed in high-risk areas to prevent reinfection and growth alteration. In endemic areas, bloody diarrhea warns for an early routine fecal analysis. Correct diagnosis, prompt treatment, and source control are crucial to prevent long-term complications.
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Affiliation(s)
- Fatima Safira Alatas
- Department of Child Health, Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Aldisa Ayu Pratiwi
- Department of Child Health, Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Agnes Kurniawan
- Department of Parasitology, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
| | - Antonius Hocky Pudjiadi
- Department of Child Health, Cipto Mangunkusumo Hospital, Faculty of Medicine, Universitas Indonesia, Jakarta, Indonesia
- Scientific Affair of Indonesian Pediatric Society Head Office, Jakarta, Indonesia
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Kim SY, Barnes MA, Sureshchandra S, Menicucci AR, Patel JJ, Messaoudi I, Nair MG. CX3CR1-Expressing Myeloid Cells Regulate Host-Helminth Interaction and Lung Inflammation. Adv Biol (Weinh) 2022; 6:e2101078. [PMID: 35119218 PMCID: PMC8934291 DOI: 10.1002/adbi.202101078] [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: 07/12/2021] [Revised: 12/31/2021] [Indexed: 11/06/2022]
Abstract
Many helminth life cycles, including hookworm, involve a mandatory lung phase, where myeloid and granulocyte subsets interact with the helminth and respond to infection-induced lung injury. To evaluate these innate subsets in Nippostrongylus brasiliensis infection, reporter mice for myeloid cells (CX3CR1GFP ) and granulocytes (PGRPdsRED ) are employed. Nippostrongylus infection induces lung infiltration of reporter cells, including CX3CR1+ myeloid cells and PGRP+ eosinophils. Strikingly, CX3CR1GFP/GFP mice, which are deficient in CX3CR1, are protected from Nippostrongylus infection with reduced weight loss, lung leukocyte infiltration, and worm burden compared to CX3CR1+/+ mice. This protective effect is specific for CX3CR1 as CCR2-deficient mice do not exhibit reduced worm burdens. Nippostrongylus co-culture with lung Ly6C+ monocytes or CD11c+ cells demonstrates that CX3CR1GFP/GFP monocytes secrete more pro-inflammatory cytokines and actively bind the parasites causing reduced motility. RNA sequencing of Ly6C+ or CD11c+ cells shows Nippostrongylus-induced gene expression changes, particularly in monocytes, associated with inflammation, chemotaxis, and extracellular matrix remodeling pathways. Analysis reveals cytotoxic and adhesion molecules as potential effectors against the parasite, such as Gzma and Gzmb, which are elevated in CX3CR1GFP/GFP monocytes. These studies validate a dual innate cell reporter for lung helminth infection and demonstrate that CX3CR1 impairs monocyte-helminth interaction.
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Affiliation(s)
| | | | | | - Andrea R. Menicucci
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, California 92697-3900, United States
| | - Jay J. Patel
- Division of Biomedical Sciences, School of Medicine, University of California Riverside, Riverside, California 92521, United States
| | - Ilhem Messaoudi
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California, Irvine, California 92697-3900, United States
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12
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Modelling the ability of mass drug administration to interrupt soil-transmitted helminth transmission: Community-based deworming in Kenya as a case study. PLoS Negl Trop Dis 2021; 15:e0009625. [PMID: 34339450 PMCID: PMC8360579 DOI: 10.1371/journal.pntd.0009625] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 08/12/2021] [Accepted: 07/05/2021] [Indexed: 12/05/2022] Open
Abstract
The World Health Organization has recommended the application of mass drug administration (MDA) in treating high prevalence neglected tropical diseases such as soil-transmitted helminths (STHs), schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. MDA—which is safe, effective and inexpensive—has been widely applied to eliminate or interrupt the transmission of STHs in particular and has been offered to people in endemic regions without requiring individual diagnosis. We propose two mathematical models to investigate the impact of MDA on the mean number of worms in both treated and untreated human subpopulations. By varying the efficay of drugs, initial conditions of the models, coverage and frequency of MDA (both annual and biannual), we examine the dynamic behaviour of both models and the possibility of interruption of transmission. Both models predict that the interruption of transmission is possible if the drug efficacy is sufficiently high, but STH infection remains endemic if the drug efficacy is sufficiently low. In between these two critical values, the two models produce different predictions. By applying an additional round of biannual and annual MDA, we find that interruption of transmission is likely to happen in both cases with lower drug efficacy. In order to interrupt the transmission of STH or eliminate the infection efficiently and effectively, it is crucial to identify the appropriate efficacy of drug, coverage, frequency, timing and number of rounds of MDA. We determine the best options for annual and biannual mass drug administration to control soil-transmitted helminths. An additional round of drugs can allow weaker drugs to be used. We apply the results to a community-based deworming project in Kenya.
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13
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Mationg MLS, Tallo VL, Williams GM, Gordon CA, Clements ACA, McManus DP, Gray DJ. The control of soil-transmitted helminthiases in the Philippines: the story continues. Infect Dis Poverty 2021; 10:85. [PMID: 34118990 PMCID: PMC8196932 DOI: 10.1186/s40249-021-00870-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 05/27/2021] [Indexed: 03/30/2023] Open
Abstract
Background Soil-transmitted helminth (STH) infections have long been an important public health concern in the Philippines. In this review, we describe the current status of STH infections there and highlight the control efforts undertaken to reduce STH burden. Main text A nationwide STH mass drug administration (MDA) programme was started in 2006 but the overall STH prevalence remains stubbornly high across the Philippines, ranging from 24.9% to 97.4%. The continued increase in the prevalence may have been due to the challenges related to MDA implementation which include the lack of people’s awareness about the importance of regular treatment, misconceptions about the MDA strategy, lack of confidence on the drugs used, fear of adverse events and general distrust of government programs. There are existing water, sanitation and hygiene (WASH) programmes implemented in communities [e.g., Community-Led Total Sanitation (CLTS) program and providing toilet bowls and provision of subsidy for latrine construction] and schools [e.g., WASH in School (WINS) program], but sustained implementation is required to achieve expected outcomes. Although WASH in general is being taught in schools, integration of STH as a disease and community problem in the current public elementary school curriculum is still inadequate. The Integrated Helminth Control Program (IHCP) currently implemented in the country, which is focused on improved sanitation and personal hygiene, health education and preventive chemotherapy, will require continuous appraisal. The sustainability of this programme still continues to be a challenge. Conclusions Despite the major efforts to control STH infections for almost two decades in the Philippines, persistently high STH prevalence has been reported across the country, which is likely due to suboptimal MDA coverage and limitations in WASH and health education programs. Sustainable delivery of integrated control approaches will continue to play a pivotal role in the control and elimination of STH in the Philippines. Graphic abstract ![]()
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Affiliation(s)
- Mary Lorraine S Mationg
- Department of Global Health, Research School of Population Health, The Australian National University, Building 62 Mills Rd, Acton ACT, Canberra, 2601, Australia. .,Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines.
| | - Veronica L Tallo
- Department of Epidemiology and Biostatistics, Research Institute for Tropical Medicine, Manila, Philippines
| | - Gail M Williams
- School of Public Health, University of Queensland, Brisbane, Australia
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | | | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Darren J Gray
- Department of Global Health, Research School of Population Health, The Australian National University, Building 62 Mills Rd, Acton ACT, Canberra, 2601, Australia
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14
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Keller L, Welsche S, Patel C, Sayasone S, Ali SM, Ame SM, Hattendorf J, Hürlimann E, Keiser J. Long-term outcomes of ivermectin-albendazole versus albendazole alone against soil-transmitted helminths: Results from randomized controlled trials in Lao PDR and Pemba Island, Tanzania. PLoS Negl Trop Dis 2021; 15:e0009561. [PMID: 34191812 PMCID: PMC8277064 DOI: 10.1371/journal.pntd.0009561] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/13/2021] [Accepted: 06/14/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Preventive chemotherapy is the cornerstone of soil-transmitted helminth (STH) control. Long-term outcomes and adequate treatment frequency of the recently recommended albendazole-ivermectin have not been studied to date. METHODOLOGY/PRINCIPAL FINDINGS Double-blind randomized controlled trials were conducted in Lao PDR, Pemba Island, Tanzania and Côte d'Ivoire between 2018 and 2020 to evaluate the efficacy and safety of ivermectin-albendazole versus albendazole-placebo in Trichuris trichiura-infected individuals aged 6 to 60. In the framework of this study, in Lao PDR 466 and 413 participants and on Pemba Island, 558 and 515 participants were followed-up six and 12 months post-treatment, respectively. From each participant at least one stool sample was processed for Kato-Katz diagnosis and cure rates (CRs), egg reduction rates (ERRs) and apparent reinfection rates were calculated. If found helminth-positive at six months, participants were re-treated according to their allocated treatment. Long-term outcomes against T. trichiura based on CRs and ERRs of ivermectin-albendazole compared to albendazole were significantly higher at six months in Lao PDR (CR, 65.8 vs 13.4%, difference; 52.4; 95% CI 45.0-60.0; ERRs, 99.0 vs 79.6, difference 19.4; 95% CI 14.4-24.4) and Pemba Island (CR, 17.8 vs 1.4%, difference; 16.4; 95% CI 11.6-21.0; ERRs, 84.9 vs 21.2, difference 63.8; 95% CI 50.6-76.9) and also at 12 months in Lao PDR (CR, 74.0 vs 23.4%, difference; 50.6; 95% CI 42.6-61.0; ERRs, 99.6 vs 91.3, difference 8.3; 95% CI 5.7-10.8) and Pemba Island (CR, 19.5 vs 3.4%, difference; 16.1; 95% CI 10.7-21.5; ERRs, 92.9 vs 53.6, difference 39.3; 95% CI 31.2-47.4) respectively. Apparent reinfection rates with T. trichiura were considerably higher on Pemba Island (100.0%, 95% CI, 29.2-100.0) than in Lao PDR (10.0%, 95% CI, 0.2-44.5) at 12 months post-treatment for participants treated with albendazole alone. CONCLUSIONS/SIGNIFICANCE The long-term outcomes against T. trichiura of ivermectin-albendazole are superior to albendazole in terms of CRs and ERRs and in reducing infection intensities. Our results will help to guide decisions on how to best use ivermectin-albendazole in the context of large-scale PC programs tailored to the local context to sustainably control STH infections. TRIAL REGISTRATION ClinicalTrials.gov registered with clinicaltrials.gov, reference: NCT03527732, date assigned: 17 May 2018.
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Affiliation(s)
- Ladina Keller
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sophie Welsche
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Chandni Patel
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Department of International Program for Health in the Tropics, Lao Tropical and Public Health Institute, Vientiane, Lao People’s Democratic Republic
| | - Said M. Ali
- Public Health Laboratory Ivo de Carneri, Chake Chake, Pemba, Zanzibar, Tanzania
| | - Shaali M. Ame
- Public Health Laboratory Ivo de Carneri, Chake Chake, Pemba, Zanzibar, Tanzania
| | - Jan Hattendorf
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Eveline Hürlimann
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Medical Parasitology and Infection Biology, Helminth Drug Development Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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15
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Partridge F, Bataille CJ, Forman R, Marriott AE, Forde-Thomas J, Häberli C, Dinsdale RL, O’Sullivan JD, Willis NJ, Wynne GM, Whiteland H, Archer J, Steven A, Keiser J, Turner JD, Hoffmann KF, Taylor MJ, Else KJ, Russell AJ, Sattelle DB. Structural Requirements for Dihydrobenzoxazepinone Anthelmintics: Actions against Medically Important and Model Parasites: Trichuris muris, Brugia malayi, Heligmosomoides polygyrus, and Schistosoma mansoni. ACS Infect Dis 2021; 7:1260-1274. [PMID: 33797218 PMCID: PMC8154432 DOI: 10.1021/acsinfecdis.1c00025] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Indexed: 02/07/2023]
Abstract
Nine hundred million people are infected with the soil-transmitted helminths Ascaris lumbricoides (roundworm), hookworm, and Trichuris trichiura (whipworm). However, low single-dose cure rates of the benzimidazole drugs, the mainstay of preventative chemotherapy for whipworm, together with parasite drug resistance, mean that current approaches may not be able to eliminate morbidity from trichuriasis. We are seeking to develop new anthelmintic drugs specifically with activity against whipworm as a priority and previously identified a hit series of dihydrobenzoxazepinone (DHB) compounds that block motility of ex vivo Trichuris muris. Here, we report a systematic investigation of the structure-activity relationship of the anthelmintic activity of DHB compounds. We synthesized 47 analogues, which allowed us to define features of the molecules essential for anthelmintic action as well as broadening the chemotype by identification of dihydrobenzoquinolinones (DBQs) with anthelmintic activity. We investigated the activity of these compounds against other parasitic nematodes, identifying DHB compounds with activity against Brugia malayi and Heligmosomoides polygyrus. We also demonstrated activity of DHB compounds against the trematode Schistosoma mansoni, a parasite that causes schistosomiasis. These results demonstrate the potential of DHB and DBQ compounds for further development as broad-spectrum anthelmintics.
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Affiliation(s)
- Frederick
A. Partridge
- Centre
for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London WC1E 6JF, United Kingdom
| | - Carole J.R. Bataille
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Ruth Forman
- Lydia
Becker Institute of Immunology and Inflammation, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Amy E. Marriott
- Centre
for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Josephine Forde-Thomas
- Institute
of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, Wales SY23 3DA, United Kingdom
| | - Cécile Häberli
- Department
of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel CH-4002, Switzerland
- University
of Basel, Petersplatz
1, Basel CH-4001, Switzerland
| | - Ria L. Dinsdale
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - James D.B. O’Sullivan
- Lydia
Becker Institute of Immunology and Inflammation, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
- Henry
Royce Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United
Kingdom
| | - Nicky J. Willis
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
- Alzheimer’s
Research UK UCL Drug Discovery Institute, University College London, Gower Street, London WC1E 6BT, United Kingdom
| | - Graham M. Wynne
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Helen Whiteland
- Institute
of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, Wales SY23 3DA, United Kingdom
| | - John Archer
- Centre
for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Andrew Steven
- Centre
for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Jennifer Keiser
- Department
of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Socinstrasse 57, Basel CH-4002, Switzerland
- University
of Basel, Petersplatz
1, Basel CH-4001, Switzerland
| | - Joseph D. Turner
- Centre
for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
- Centre
for Neglected Tropical Diseases, Liverpool
School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Karl F. Hoffmann
- Institute
of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University, Aberystwyth, Wales SY23 3DA, United Kingdom
| | - Mark J. Taylor
- Centre
for Drugs and Diagnostics, Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
- Centre
for Neglected Tropical Diseases, Liverpool
School of Tropical Medicine, Liverpool L3 5QA, United Kingdom
| | - Kathryn J. Else
- Lydia
Becker Institute of Immunology and Inflammation, Faculty of Biology,
Medicine and Health, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Angela J. Russell
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, United Kingdom
- Department
of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United
Kingdom
| | - David B. Sattelle
- Centre
for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London WC1E 6JF, United Kingdom
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16
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Abstract
The second World Neglected Tropical Diseases (NTDs) Day was celebrated on 30 January 2021. To mark the occasion, the World Health Organization (WHO) launched its roadmap for NTDs for the period 2021 to 2030, which is aimed at increasing prevention and control of these too-long neglected diseases. Described here is a global overview on past achievements, current challenges, and future prospects for the WHO NTDs roadmap 2021–2030.
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Affiliation(s)
- Adriano Casulli
- European Union Reference Laboratory for Parasites, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
- WHO Collaborating Centre for the Epidemiology, Detection and Control of Cystic and Alveolar Echinococcosis, Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
- * E-mail:
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17
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Matamoros G, Sánchez A, Gabrie JA, Juárez M, Ceballos L, Escalada A, Rodríguez C, Martí-Soler H, Rueda MM, Canales M, Lanusse C, Cajal P, Álvarez L, Cimino RO, Krolewiecki A. Efficacy and safety of albendazole and high-dose ivermectin co-administration in school-aged children infected with Trichuris trichiura in Honduras: A Randomized Controlled Trial. Clin Infect Dis 2021; 73:1203-1210. [PMID: 33906234 DOI: 10.1093/cid/ciab365] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The efficacy of currently available anthelminthics against Trichuris trichiura infections is significatively lower than for other soil-transmitted helminths (STH). The combination of ivermectin (IVM) and albendazole (ALB) has shown significant improvements in efficacy. METHODS Safety and efficacy randomized controlled clinical trial comparing 3 experimental regimens against ALB monotherapy for the treatment of T. trichiura infections in northern Honduras. Infected children were randomized to one of the following treatments: (Arm 1) single-dose ALB 400 mg; (Arm 2) single-dose ALB 400 mg/IVM 600 μg/kg; (Arm 3) ALB 400 mg for 3 consecutive days; or (Arm 4) ALB 400 mg/IVM 600 μg/kg for 3 consecutive days. Efficacy was measured through egg reduction rate (ERR) and cure rate (CR), both assessed 14-21 days after treatment using the Kato-Katz method. Safety was evaluated by analyzing the frequency and severity of adverse events. RESULTS A total of 176 children were randomized to one of the 4 treatment arms, 117 completed treatment and follow-up. The ERR for Arms 1 to 4 were: 47.7%, 96.7%, 72.1% and 100%, respectively; with p-values <0.001 between IVM groups and ALB only arms. The CRs were 4.2%, 88.6%, 33.3% and 100%, respectively. A total of 48 (85.4% mild) AEs were reported in 36 children. CONCLUSIONS The combined use of ALB and high-dose IVM is a highly effective and well tolerated treatment for the treatment of T. trichiura infections offering a significantly improved treatment for the control of this infection.
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Affiliation(s)
- Gabriela Matamoros
- Instituto de Investigaciones en Microbiología, Universidad Nacional Autónoma de Honduras.,Faculty of Applied Health Sciences, Brock University, Ontario. Canada
| | - Ana Sánchez
- Instituto de Investigaciones en Microbiología, Universidad Nacional Autónoma de Honduras.,Faculty of Applied Health Sciences, Brock University, Ontario. Canada
| | | | - Marisa Juárez
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Argentina
| | - Laura Ceballos
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - Andrés Escalada
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Argentina
| | - Carol Rodríguez
- Escuela de Microbiología, Universidad Nacional Autónoma de Honduras
| | | | | | - Maritza Canales
- Escuela de Microbiología, Universidad Nacional Autónoma de Honduras
| | - Carlos Lanusse
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - Pamela Cajal
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Argentina
| | - Luis Álvarez
- Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - Rubén O Cimino
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Argentina
| | - Alejandro Krolewiecki
- Instituto de Investigaciones de Enfermedades Tropicales (IIET-CONICET), Sede Regional Orán, Universidad Nacional de Salta, Argentina.,Laboratorio de Farmacología, Centro de Investigación Veterinaria de Tandil (CIVETAN), UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias, Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
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18
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Okoyo C, Medley G, Mwandawiro C, Onyango N. Modeling the Interruption of the Transmission of Soil-Transmitted Helminths Infections in Kenya: Modeling Deworming, Water, and Sanitation Impacts. Front Public Health 2021; 9:637866. [PMID: 33842421 PMCID: PMC8024473 DOI: 10.3389/fpubh.2021.637866] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/01/2021] [Indexed: 11/13/2022] Open
Abstract
Kenya, just like other countries with endemic soil-transmitted helminths (STH), has conducted regular mass drug administration (MDA) program for the last 5 years among school aged children as a way to reduce STH infections burden in the country. However, the point of interruption of transmission of these infections still remains unclear. In this study, we developed and analyzed an age structured mathematical model to predict the elimination period (i.e., time taken to interrupt STH transmission) of these infections in Kenya. The study utilized a deterministic age structured model of the STH population dynamics under a regular treatment program. The model was applied to three main age groups: pre-school age children (2-4 years), school age children (5-14 years), and adult populations (≥15 years) and compared the impact of two interventions on worm burden and elimination period. The model-simulated results were compared with the 5 year field data from the Kenyan deworming program for all the three types of STH (Ascaris lumbricoides, Trichuris trichiura, and hookworm). The model demonstrated that the reduction of worm burden and elimination period depended heavily on four parameter groups; drug efficacy, number of treatment rounds, MDA and water, sanitation and hygiene (WASH) coverage. The analysis showed that for STH infections to be eliminated using MDA alone in a short time period, 3-monthly MDA plan is desired. However, complementation of MDA with WASH at an optimal (95%) coverage level was most effective. These results are important to the Kenyan STH control program as it will guide the recently launched Breaking Transmission Strategy.
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Affiliation(s)
- Collins Okoyo
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
- School of Mathematics, University of Nairobi, Nairobi, Kenya
| | - Graham Medley
- Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Charles Mwandawiro
- Eastern and Southern Africa Centre of International Parasite Control, Kenya Medical Research Institute, Nairobi, Kenya
| | - Nelson Onyango
- School of Mathematics, University of Nairobi, Nairobi, Kenya
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19
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Sweeny AR, Clerc M, Pontifes PA, Venkatesan S, Babayan SA, Pedersen AB. Supplemented nutrition decreases helminth burden and increases drug efficacy in a natural host-helminth system. Proc Biol Sci 2021; 288:20202722. [PMID: 33468010 PMCID: PMC7893286 DOI: 10.1098/rspb.2020.2722] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/15/2020] [Indexed: 12/17/2022] Open
Abstract
Gastrointestinal (GI) helminths are common parasites of humans, wildlife, and livestock, causing chronic infections. In humans and wildlife, poor nutrition or limited resources can compromise an individual's immune response, predisposing them to higher helminth burdens. This relationship has been tested in laboratory models by investigating infection outcomes following reductions of specific nutrients. However, much less is known about how diet supplementation can impact susceptibility to infection, acquisition of immunity, and drug efficacy in natural host-helminth systems. We experimentally supplemented the diet of wood mice (Apodemus sylvaticus) with high-quality nutrition and measured resistance to the common GI nematode Heligmosomoides polygyrus. To test whether diet can enhance immunity to reinfection, we also administered anthelmintic treatment in both natural and captive populations. Supplemented wood mice were more resistant to H. polygyrus infection, cleared worms more efficiently after treatment, avoided a post-treatment infection rebound, produced stronger general and parasite-specific antibody responses, and maintained better body condition. In addition, when applied in conjunction with anthelmintic treatment, supplemented nutrition significantly reduced H. polygyrus transmission potential. These results show the rapid and extensive benefits of a well-balanced diet and have important implications for both disease control and wildlife health under changing environmental conditions.
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Affiliation(s)
- Amy R. Sweeny
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Melanie Clerc
- MRC Centre for Inflammation Research, The Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Paulina A. Pontifes
- Departamento de Etología, Fauna Silvestre y Animales de Laboratorio, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Avenida Ciudad Universitaria 3000, CP 04510 Coyoacán, Ciudad de México, México
| | - Saudamini Venkatesan
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Simon A. Babayan
- Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Amy B. Pedersen
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
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20
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Zeleke AJ, Bayih AG, Afework S, Gilleard JS. Treatment efficacy and re-infection rates of soil-transmitted helminths following mebendazole treatment in schoolchildren, Northwest Ethiopia. Trop Med Health 2020; 48:90. [PMID: 33292853 PMCID: PMC7659054 DOI: 10.1186/s41182-020-00282-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/02/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transmission of soil-transmitted helminth (STH) infection remains high in Ethiopia. This study aimed at assessing the therapeutic efficacy of mebendazole against soil-transmitted helminths and determining the re-infection rates of the parasites among schoolchildren in Northwest Ethiopia. METHODS A school-based cross-sectional study was conducted. Data was collected using a structured questionnaire. Stool specimens were examined using direct wet mount microscopy and Kato-Katz methods. Schoolchildren who tested positive for soil-transmitted helminths were treated with 500 mg single-dose of mebendazole. Cure and egg reduction rates were evaluated 2 to 3 weeks post treatment. Moreover, the re-infection rate of these parasites among those who were cured was determined 1 year after treatment. Data were analyzed using SPSS version 20. P value < 0.05 was considered as statistically significant. RESULT A drug efficacy study was conducted on 62, 52, and 14 children infected by Ascaris lumbricoides (A. lumbricoides), hookworm, and Trichuris trichiura (T. trichiura), respectively. The cure rates (CR) of mebendazole against A. lumbricoides, hookworm, and T. trichiura were found to be 96.9%, 23.1%, and, 28.6%, respectively. The egg reduction rate (ERR) of A. lumbricoides was found to be 99.6% whereas 49.6% and 56.3% were reported for hookworm and T. trichiura, respectively. Eighty schoolchildren who were treated and cured from any STH infections were included for the determination of re-infection rate. Out of 80 children, 36.3% (29/80) were found to be re-infected after 1 year: 22 (75.9%), 6 (20.7%), and 1 (1.3%) of study participants were re-infected with A. lumbricoides, hookworm, and both infections, respectively. All re-infections were grouped under the "light infection" category. CONCLUSION Mebendazole was found to be highly effective against A. lumbricoides, but had relatively low efficacy against hookworms and T. trichiura. These results bring into question the use of mebendazole in STH mass drug administration (MDA) programs in this region if albendazole, a drug with higher efficacy against hookworms, is available. Moreover, a significant number of treated children were re-infected with either or both of A. lumbricoides or hookworms 1 year after treatment emphasizing the need for better integrated intestinal helminthiasis control measures.
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Affiliation(s)
- Ayalew Jejaw Zeleke
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
| | - Abebe Genetu Bayih
- Department of Medical Parasitology, School of Biomedical and Laboratory Sciences, College of Medicine and Health Sciences, University of Gondar, Gondar, Ethiopia
- Armauer Hansen Research Institute, Addis Ababa, Ethiopia
| | - Solomon Afework
- Department of Internal Medicine, University of Gondar, Gondar, Ethiopia
| | - John S. Gilleard
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Calgary, Canada
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Hoogerwerf MA, Koopman JPR, Janse JJ, Langenberg MCC, van Schuijlenburg R, Kruize YCM, Brienen EAT, Manurung MD, Verbeek-Menken P, van der Beek MT, Westra IM, Meij P, Visser LG, van Lieshout L, de Vlas SJ, Yazdanbakhsh M, Coffeng LE, Roestenberg M. A Randomized Controlled Trial to Investigate Safety and Variability of Egg Excretion After Repeated Controlled Human Hookworm Infection. J Infect Dis 2020; 223:905-913. [PMID: 32645714 DOI: 10.1093/infdis/jiaa414] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Controlled human hookworm infections could significantly contribute to the development of a hookworm vaccine. However, current models are hampered by low and unstable egg output, reducing generalizability and increasing sample sizes. This study aims to investigate the safety, tolerability, and egg output of repeated exposure to hookworm larvae. METHODS Twenty-four healthy volunteers were randomized, double-blindly, to 1, 2, or 3 doses of 50 Necator americanus L3 larvae at 2-week intervals. Volunteers were monitored weekly and were treated with albendazole at week 20. RESULTS There was no association between larval dose and number or severity of adverse events. Geometric mean egg loads stabilized at 697, 1668, and 1914 eggs per gram feces for the 1 × 50L3, 2 × 50L3, and 3 × 50L3 group, respectively. Bayesian statistical modeling showed that egg count variability relative to the mean was reduced with a second infectious dose; however, the third dose did not increase egg load or decrease variability. We therefore suggest 2 × 50L3 as an improved challenge dose. Model-based simulations indicates increased frequency of stool sampling optimizes the power of hypothetical vaccine trials. CONCLUSIONS Repeated infection with hookworm larvae increased egg counts to levels comparable to the field and reduced relative variability in egg output without aggravating adverse events. CLINICAL TRIALS REGISTRATION NCT03257072.
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Affiliation(s)
| | - Jan Pieter R Koopman
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Jacqueline J Janse
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | | | | | - Yvonne C M Kruize
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Eric A T Brienen
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Mikhael D Manurung
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Petra Verbeek-Menken
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Martha T van der Beek
- Clinical Microbiology Laboratory, Leiden University Medical Center, Leiden, the Netherlands
| | - Inge M Westra
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, the Netherlands
| | - Pauline Meij
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, the Netherlands
| | - Leo G Visser
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sake J de Vlas
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Luc E Coffeng
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands.,Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
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Efficacy of a single dose versus a multiple dose regimen of Mebendazole against hookworm infections among school children: a randomized open-label trial. BMC Infect Dis 2020; 20:376. [PMID: 32460712 PMCID: PMC7251741 DOI: 10.1186/s12879-020-05097-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 05/15/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Despite the existence of a population-based control program using single dose albendazole or mebendazole as a preventive chemotherapy, hookworm transmission remains high. It causes a negative impact on the growth and school performance of children. In connection to this preventive chemotherapy, different studies produced conflicting results. This study aimed at evaluating the efficacy of single (500 mg) versus multiple doses (100 mg twice a day during three consecutive days) of mebendazole against hookworm infections among school-aged children. METHODS This randomized open-label clinical trial took place among school-aged children (6-14 years old) in Burie and Debre Elias towns, Northwest Ethiopia. Using simple randomization, eligible hookworm-positive children were allocated (1:1) to either a single or multiple dose treatment arms. Stool samples were collected and processed using McMaster method at baseline and follow-up period (14-21 days after treatment). Only laboratory technicians were blinded. The cure and egg reduction rates were the primary and secondary therapeutic outcome measures against hookworm infections, respectively. An independent t-test was used to compare group means, and logistic regression was used to calculate odds ratio (OR). P-value < 0.05 at 95% CI was considered statistically significant. RESULT One hundred eight children, 54 in each treatment arm had completed baseline data and received allocated treatment. One hundred three children had completed follow-up data records and included for the final efficacy analysis. Cure rate against hookworm was significantly higher in the multiple dose (96.1%) than in the single dose (30.8%) with OR = 55.125; 95% CI: 11.92-254.9; P < 0.001. The egg reduction rate in the multiple dose treatment arm (99.5%) was also significantly higher than in the single dose arm (68.9%) with difference t (101) =5.38; 95% CI 230.95-505.36; P < 0.001. CONCLUSION The single dose regimen of mebendazole for the treatment of hookworm infections showed poor cure and egg reduction rates, while the multiple doses revealed satisfactory. Although multiple dose regimen administration is a bit more complex than the single dose, we strongly encourage replacing it with multiple dose regimen during deworming programs in hookworm endemic areas. TRIAL REGISTRATION This trial is retrospectively registered in www.pactr.org, number PACTR201911466695052 on November 26, 2019.
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Abstract
BACKGROUND Ascaris lumbricoides is a common infection, and mainly affects children living in low-income areas. Water and sanitation improvement, health education, and drug treatment may help break the cycle of transmission, and effective drugs will reduce morbidity. OBJECTIVES To compare the efficacy and safety of anthelmintic drugs (albendazole, mebendazole, ivermectin) for treating people with Ascaris infection. SEARCH METHODS We searched the Cochrane Infectious Disease Group Specialized Register, CENTRAL, MEDLINE, Embase, LILACS, three other databases, and reference lists of included studies, without language restrictions, up to 4 July 2019. SELECTION CRITERIA Randomized controlled trials (RCT) that compared albendazole, mebendazole, and ivermectin in children and adults with confirmed Ascaris infection. DATA COLLECTION AND ANALYSIS Two review authors independently assessed studies for inclusion, assessed risk of bias, and extracted data from the included trials. A third review author checked the quality of data extraction. We used the Cochrane 'Risk of bias' assessment tool to determine the risk of bias in included trials. We used risk ratios (RRs) with 95% confidence intervals (CIs) to compare dichotomous outcomes in treatment and control groups. We used the fixed-effect model for studies with low heterogeneity and the random-effects model for studies with moderate to high heterogeneity. We assessed the certainty of the evidence using the GRADE approach. We used the control rate average to provide illustrative cure rates in the comparison groups. MAIN RESULTS We included 30 parallel-group RCTs, which enrolled 6442 participants from 17 countries across Africa, Asia, Central America and the Caribbean, and South America. Participants were from 28 days to 82 years of age, recruited from school, communities, and health facilities. Twenty studies were funded or co-funded by manufacturers, while 10 studies were independent of manufacturer funding. Twenty-two trials had a high risk of bias for one or two domains (blinding, incomplete outcome data, selective reporting). Single dose of albendazole (four trials), mebendazole (three trials) or ivermectin (one trial) was compared to placebo. Parasitological cure at 14 to 60 days was high in all the studies (illustrative cure of 93.0% in the anthelmintic group and 16.1% in the placebo group; RR 6.29, 95% CI 3.91 to 10.12; 8 trials, 1578 participants; moderate-certainty evidence). Single dose of albendazole is as effective as multiple doses of albendazole (illustrative cure of 93.2% with single dose, 94.3% with multiple doses; RR 0.98, 95% CI 0.92 to 1.05; 3 trials, 307 participants; high-certainty evidence); or as single dose of mebendazole (illustrative cure of 98.0% with albendazole, 96.9% with mebendazole; RR 1.01, 95% CI 1.00 to 1.02; 6 trials, 2131 participants; high-certainty evidence). Studies did not detect a difference between a single dose of albendazole and a single dose of ivermectin (cure rates of 87.8% with albendazole, 90.2% with ivermectin; RR 0.99, 95% CI 0.91 to 1.08; 3 trials, 519 participants; moderate-certainty evidence). Across all the studies, failure after single dose of albendazole ranged from 0.0% to 30.3%, mebendazole from 0.0% to 22.2%, and ivermectin from 0.0% to 21.6%. The egg reduction rate (ERR) measured up to 60 days after the treatment was high in all treated groups, regardless of the anthelmintic used (range 96% to 100%). It was not possible to evaluate parasitological cure by classes of infection intensity. No included trials reported complication or serious adverse events. Other adverse events were apparently similar among the compared anthelmintic groups (moderate- to low-certainty evidence). The most commonly reported other adverse events were nausea, vomiting, abdominal pain, diarrhoea, headache, and fever. AUTHORS' CONCLUSIONS Single-dose of albendazole, mebendazole, and ivermectin all appeared effective against Ascaris lumbricoides infection, yielding high parasitological cure and large reductions in eggs excreted, with no differences detected between them. The drugs appear to be safe to treat children and adults with confirmed Ascaris infection. There is little to choose between drugs and regimens in terms of cure or adverse events.
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Affiliation(s)
- Lucieni O Conterno
- State University of Campinas (UNICAMP)Medical School, Department of Internal Medicine, Infectious Diseases DivisionRua Tessália Vieira de Camargo, 126Cidade Universitária "Zeferino Vaz"CampinasSão PauloBrazil13083‐887
| | - Marilia D Turchi
- Federal University of GoiasDepartment of Public Health, Institute of Tropical Pathology and Public HealthRua Amorinopolis QdR2 Lt13 Residencial GoiasAlphaville FlamboyantGoianiaGoiasBrazil74884‐540
| | - Ione Corrêa
- Botucatu Medical School, UNESP ‐ Univ Estadual PaulistaDepartment of NursingDistrito de Rubião Júnior, s/nBotucatuSão PauloBrazil18603‐970
| | - Ricardo Augusto Monteiro de Barros Almeida
- Botucatu Medical School, UNESP ‐ Univ Estadual PaulistaDepartment of Tropical Diseases and Imaging DiagnosisAv. Prof. Montenegro, s/nDistrito de Rubiao JrBotucatuSao PauloBrazil18618‐970
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Jimenez Castro PD, Howell SB, Schaefer JJ, Avramenko RW, Gilleard JS, Kaplan RM. Multiple drug resistance in the canine hookworm Ancylostoma caninum: an emerging threat? Parasit Vectors 2019; 12:576. [PMID: 31818311 PMCID: PMC6902405 DOI: 10.1186/s13071-019-3828-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 11/30/2019] [Indexed: 12/21/2022] Open
Abstract
Background The canine hookworm, Ancylostoma caninum is the most prevalent and important intestinal nematode parasite of dogs in the USA. Hookworms are typically well controlled by treatment with all commonly used anthelmintics that are approved for this use in dogs. However, in the past few years, cases of recurrent/persistent canine hookworm infections appear to have dramatically increased, suggesting that anthelmintic resistance (AR) may have evolved in this parasite. These cases are highly overrepresented by greyhounds, but multiple other breeds are also represented. The aim of this study was to characterize several of these suspected resistant isolates using in vitro, genetic and clinical testing to determine if these cases represent true anthelmintic resistance in A. caninum. Methods Fecal samples containing hookworm eggs from three cases of persistent hookworm infections; one from a greyhound, one from a miniature schnauzer and one from a hound-mix, were received by our laboratory. These were then used to establish infections in laboratory dogs and to perform egg hatch assays (EHA) and larval development assays (LDA) for detecting resistance to benzimidazoles and macrocyclic lactones, respectively. Additional EHA and LDA were performed on eggs recovered from the laboratory-induced infections. Fecal egg count reduction tests were performed to detect resistance to pyrantel. Deep amplicon sequencing assays were developed to measure the frequency of non-synonymous single nucleotide polymorphisms (SNP) at codons 167, 198 and 200 of the A. caninum isotype-1 β-tubulin gene. Results Resistance ratios for the three A. caninum isolates tested ranged from 6.0 to > 100 and 5.5 to 69.8 for the EHA and LDA, respectively. Following treatment with pyrantel, reduction in faecal egg counts was negative or 0%. Deep amplicon sequencing of the isotype-1 β-tubulin gene identified a high frequency of resistance-associated SNPs at codon 167 in all three resistant isolates and in two additional clinical cases. Conclusions These data conclusively demonstrate multiple anthelmintic resistance in multiple independent isolates of A. caninum, strongly suggesting that this is an emerging problem in the USA. Furthermore, evidence suggest that these resistant hookworms originate from racing greyhound farms and kennels, though additional research is needed to confirm this. ![]()
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Affiliation(s)
- Pablo D Jimenez Castro
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA. .,Grupo de Parasitología Veterinaria, Universidad Nacional de Colombia, Bogotá, Colombia.
| | - Sue B Howell
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
| | - John J Schaefer
- School of Veterinary Medicine, Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, USA
| | - Russell W Avramenko
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - John S Gilleard
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ray M Kaplan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
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Tinkler SH. Preventive chemotherapy and anthelmintic resistance of soil-transmitted helminths - Can we learn nothing from veterinary medicine? One Health 2019; 9:100106. [PMID: 31956691 PMCID: PMC6957790 DOI: 10.1016/j.onehlt.2019.100106] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 09/23/2019] [Accepted: 09/24/2019] [Indexed: 12/21/2022] Open
Abstract
Current parasite control programs in veterinary species have moved away from mass anthelmintic treatment approaches due to the emergence of significant anthelmintic resistance (AR), and the availability of few classes of anthelmintics. A number of parallels between livestock and human helminths exist that warn of the risk of AR in human soil-transmitted helminthiases, yet current public health interventions continue to prioritize mass treatment strategies, a known risk factor for AR. This review discusses the existing parallels between human and animal helminth biology and management, along with current public health recommendations and strategies for helminth control in humans. The effectiveness of current recommendations and alternative management strategies are considered.
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Cheema HA, Waheed N, Saeed A. Rare presentation of haemobilia and Loeffler's pneumonia in a child by ascaris lumbricoides. BMJ Case Rep 2019; 12:12/8/e230198. [PMID: 31466983 DOI: 10.1136/bcr-2019-230198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ascariasis is a soil-sourced, second most common parasitic infection worldwide. Because of its wandering nature, it migrates from the intestine to other organs of the body like the lungs and biliary system. This results in complications such as biliary colic, acute cholecystitis, pyogenic cholangitis, liver abscesses, pancreatitis and loeffler's pneumonia. We report a unique case of an 8-year-old boy who presented with upper gastrointestinal bleed and chest infection. He was diagnosed as haemobilia and loeffler's pneumonia caused by ascaris lumbricoides.
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Affiliation(s)
- Huma Arshad Cheema
- Department of Pediatric Medicine, Division of Pediatric Gastroenterology, Hepatology & Nutrition, The Children's Hospital & The Institute of Child Health, Lahore, Pakistan
| | - Nadia Waheed
- Department of Pediatric Medicine, Division of Pediatric Gastroenterology, Hepatology & Nutrition, The Children's Hospital & The Institute of Child Health, Lahore, Pakistan
| | - Anjum Saeed
- Department of Pediatric Medicine, Division of Pediatric Gastroenterology, Hepatology & Nutrition, The Children's Hospital & The Institute of Child Health, Lahore, Pakistan
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Clinical evaluation for morbidity associated with soil-transmitted helminth infection in school-age children on Pemba Island, Tanzania. PLoS Negl Trop Dis 2019; 13:e0007581. [PMID: 31306433 PMCID: PMC6658009 DOI: 10.1371/journal.pntd.0007581] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 07/25/2019] [Accepted: 06/26/2019] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND More than 1.5 billion people are infected with soil-transmitted helminths (Ascaris lumbricoides, hookworm, Strongyloides stercoralis, and Trichuris trichiura), causing an estimated global burden in excess of 3 million disability-adjusted life years. However, the relationship between soil-transmitted helminth infection, adverse health consequences, and beneficial effects of deworming are not well understood. METHODOLOGY We pursued a detailed longitudinal clinical evaluation of school-age children to evaluate morbidity associated with soil-transmitted helminth infection and responses to treatment. This exploratory study was embedded into a randomized controlled trial. Overall, 434 children, aged 7-14 years, underwent a detailed medical history, physical examination, stool microscopy for soil-transmitted helminths, and hemoglobin (Hb) measurement at baseline. Medical history and stool examination were repeated at 3 and 18 weeks posttreatment. Additionally, Hb measurement was performed at the 18-week treatment follow-up. Logistic regression was employed to assess clinical factors associated with soil-transmitted helminth infection at baseline, and longitudinal data analysis to examine change in health outcomes following treatment over time. PRINCIPAL FINDINGS All enrolled children were infected with T. trichiura, and randomized into four different treatment interventions. None of the medical history, physical examination, and laboratory (i.e., Hb) findings were associated with A. lumbricoides, hookworm, or S. stercoralis infection at baseline. A composite of physical exam findings for anemia, including pallor of the conjunctiva, nail beds, and palmar creases predicted lower Hb values (-3.8 g/dl, 95% confidence interval (CI): -6.9, -0.6 g/dl). When examining longitudinal trends, we did not find improvements to Hb or face Wong-Baker Likert scale among children with soil-transmitted helminth infection compared to those without infection, although there was a slight trend toward improving Hb values after treating hookworm infection. CONCLUSIONS/SIGNIFICANCE Our study demonstrates the challenges of measuring morbidity in the context of soil-transmitted helminth infection and treatment, thus confirming the mainly subtle morbidity effects of infection.
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Patel C, Hürlimann E, Keller L, Hattendorf J, Sayasone S, Ali SM, Ame SM, Coulibaly JT, Keiser J. Efficacy and safety of ivermectin and albendazole co-administration in school-aged children and adults infected with Trichuris trichiura: study protocol for a multi-country randomized controlled double-blind trial. BMC Infect Dis 2019; 19:262. [PMID: 30885157 PMCID: PMC6421712 DOI: 10.1186/s12879-019-3882-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 03/05/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Soil-transmitted helminthiasis affects almost 2 billion people worldwide in tropical climates. Preventive chemotherapy, using the benzimidazoles (albendazole and mebendazole) is the current main recommended control strategy. Nevertheless, there is limited efficacy of these drugs against hookworm infection and, to a greater extent, against trichuriasis. We describe a protocol for a trial investigating the efficacy and safety of the co-administration of ivermectin and albendazole against trichuriasis. METHODS A double-blind, placebo-controlled randomized controlled trial will be conducted in three countries (Côte d'Ivoire, Tanzania and Lao PDR) with the aim to determine the efficacy, safety and extended effects of co-administered ivermectin and albendazole compared to standard albendazole monotherapy. We will enroll 600 participants aged 6-60 years in each setting. The primary outcome is cure rate (CR) against Trichuris trichiura infection as assessed by Kato-Katz 14-21 days after treatment. Secondary outcomes include CRs against concomitant soil-transmitted helminth (STH) infections (Ascaris lumbricoides, hookworm and Strongyloides stercoralis) and egg reduction rates (ERRs) against STH at 14-21 days, 180 days and 360 days. Tolerability of treatment, infection status assessed by polymerase chain reaction (PCR), and potential benefits of deworming on nutritional and morbidity indicators will be assessed. The primary analysis will include an available-case set and use logistic regression models adjusted for age, sex and weight. DISCUSSION This trial will provide robust results on the efficacy and safety of co-administration of ivermectin and albendazole with the aim to better inform WHO recommendations on control of STHs. Furthermore, secondary and explanatory outcomes will provide direct evidence on the extended effects of combination therapy and insight on the relationship between nutrition and morbidity parameters and infection status and intensity. TRIAL REGISTRATION NCT03527732 (date assigned: 17 May 2018).
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Affiliation(s)
- Chandni Patel
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Eveline Hürlimann
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ladina Keller
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jan Hattendorf
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Lao Tropical and Public Health Institute, Vientiane, Lao People’s Democratic Republic
| | - Said M Ali
- Public Health Laboratory Ivo de Carneri, Chake Chake, Zanzibar, Pemba Tanzania
| | - Shaali M Ame
- Public Health Laboratory Ivo de Carneri, Chake Chake, Zanzibar, Pemba Tanzania
| | - Jean T Coulibaly
- 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
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Clerc M, Babayan SA, Fenton A, Pedersen AB. Age affects antibody levels and anthelmintic treatment efficacy in a wild rodent. INTERNATIONAL JOURNAL FOR PARASITOLOGY-PARASITES AND WILDLIFE 2019; 8:240-247. [PMID: 30923672 PMCID: PMC6423487 DOI: 10.1016/j.ijppaw.2019.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 02/25/2019] [Accepted: 03/09/2019] [Indexed: 12/22/2022]
Abstract
The role of the host immune system in determining parasite burdens and mediating within-host parasite interactions has traditionally been studied in highly controlled laboratory conditions. This does, however, not reflect the diversity of individuals living in nature, which is often characterised by significant variation in host demography, such as host age, sex, and infection history. Whilst studies using wild hosts and parasites are beginning to give insights into the complex relationships between immunity, parasites and host demography, the cause-and-effect relationships often remain unknown due to a lack of high resolution, longitudinal data. We investigated the infection dynamics of two interacting gastrointestinal parasites of wild wood mice (Apodemus sylvaticus), the nematode Heligmosomoides polygyrus and the coccidian Eimeria hungaryensis, in order to assess the links between infection, coinfection, and the immunological dynamics of two antibodies (IgG1 and IgA). In an anthelmintic treatment experiment, mice were given a single oral dose of an anthelmintic treatment, or control dose, and then subsequently followed longitudinally over a period of 7–15 days to measure parasite burdens and antibody levels. Anthelmintic treatment successfully reduced burdens of H. polygyrus, but had no significant impact on E. hungaryensis. Treatment efficacy was driven by host age, with adult mice showing stronger reductions in burdens compared to younger mice. We also found that the relationship between H. polygyrus-specific IgG1 and nematode burden changed from positive in young mice to negative in adult mice. Our results highlight that a key host demographic factor like age could account for large parts of the variation in nematode burden and nematode-specific antibody levels observed in a naturally infected host population, possibly due to different immune responses in young vs. old animals. Given the variable success in community-wide de-worming programmes in animals and humans, accounting for the age-structure of a population could increase overall efficacy. Anthelmintic treatment reveals strong force of infection for H. polygyrus in wild wood mice. Anthelmintic treatment is more successful in younger compared to older mice. Relationship between IgG1 and H. polygyrus burden reverts with host age.
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Affiliation(s)
- Melanie Clerc
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK.,MRC Centre for Inflammation Research, Queen´s Medical Research Institute, University of Edinburgh UK, EH16 4TJ, UK
| | - Simon A Babayan
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Andy Fenton
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Amy B Pedersen
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, EH9 3FL, UK
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Sungkar S, Tambunan FB, Gozali MN, Kusumowidagdo G, Wahdini S. The effect of albendazole toward anemia in children with soil-transmitted helminths infection in a remote and endemic area. MEDICAL JOURNAL OF INDONESIA 2018. [DOI: 10.13181/mji.v27i4.2857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Background: Soil-transmitted helminths (STH) infections lead to nutritional disorder and anemia among children. Albendazole 400 mg is used to control STH, although it has a low cure rate for Trichuris trichiura. The effectiveness of albendazole could be increased by giving a dose of 400 mg for 3 consecutive days. The aim of the study was to investigate the effectiveness of the triple-dose albendazole 400 mg course in decreasing STH and anemia prevalence.Methods: This study used an experimental comparative design conducted in July 2016 and January 2017 in Perobatang Village, Southwest Sumba, Indonesia. Children aged 1–15 years were asked to collect fecal samples to be examined using a Kato-Katz method. Hemoglobin level (Hb) was tested using a rapid test diagnostic strip. STH positive subjects were given 400 mg of albendazole for 3 days witnessed by the researchers. Six months after, the stool samples and Hb levels were re-examined (post-test).Results: From the 156 subjects examined (pretest), the prevalence of Ascaris lumbricoides, Trichuris trichiura, and hookworm were 65.4%, 55.8%, and 15.4%, respectively, and the prevalence of anemia was 71.2%. On post-test, the prevalence of A. lumbricoides, T. trichiura, and hookworm decreased to 8.3%, 12.8%, and 0%, respectively, and the prevalence of anemia decreased to 25%. There was a significant difference in the prevalence of STH infection and anemia before and after the administration of triple-dose albendazole (p=0.001).Conclusion: The triple-dose albendazole is effective in reducing the prevalence of STH and anemia in children with STH infection.
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Becker SL, Liwanag HJ, Snyder JS, Akogun O, Belizario. V, Freeman MC, Gyorkos TW, Imtiaz R, Keiser J, Krolewiecki A, Levecke B, Mwandawiro C, Pullan RL, Addiss DG, Utzinger J. Toward the 2020 goal of soil-transmitted helminthiasis control and elimination. PLoS Negl Trop Dis 2018; 12:e0006606. [PMID: 30106975 PMCID: PMC6091919 DOI: 10.1371/journal.pntd.0006606] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Sören L. Becker
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Harvy Joy Liwanag
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Ateneo School of Medicine and Public Health, Ateneo de Manila University, Metro Manila, the Philippines
| | - Jedidiah S. Snyder
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
- Rollins School of Public Health, Emory University, Atlanta, Georgia, United States of America
| | - Oladele Akogun
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- Modibbo Adama University of Technology, Yola, Nigeria
| | - Vicente Belizario.
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- College of Public Health, University of the Philippines, Manila, the Philippines
| | - Matthew C. Freeman
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- Department of Environmental Health, Emory University, Atlanta, Georgia, United States of America
| | - Theresa W. Gyorkos
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada
| | - Rubina Imtiaz
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Alejandro Krolewiecki
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta, Oran, Argentina
| | - Bruno Levecke
- Department of Virology, Parasitology, and Immunology, Faculty of Veterinary Medicine, Ghent University, Ghent, Belgium
| | - Charles Mwandawiro
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- Kenya Medical Research Institute, Nairobi, Kenya
| | - Rachel L. Pullan
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - David G. Addiss
- Children Without Worms, The Task Force for Global Health, Decatur, Georgia, United States of America
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
- Soil-Transmitted Helminthiasis Advisory Committee, Decatur, Georgia, United States of America
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Babayan SA, Liu W, Hamilton G, Kilbride E, Rynkiewicz EC, Clerc M, Pedersen AB. The Immune and Non-Immune Pathways That Drive Chronic Gastrointestinal Helminth Burdens in the Wild. Front Immunol 2018; 9:56. [PMID: 29459856 PMCID: PMC5807686 DOI: 10.3389/fimmu.2018.00056] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 01/09/2018] [Indexed: 01/09/2023] Open
Abstract
Parasitic helminths are extremely resilient in their ability to maintain chronic infection burdens despite (or maybe because of) their hosts’ immune response. Explaining how parasites maintain these lifelong infections, identifying the protective immune mechanisms that regulate helminth infection burdens, and designing prophylactics and therapeutics that combat helminth infection, while preserving host health requires a far better understanding of how the immune system functions in natural habitats than we have at present. It is, therefore, necessary to complement mechanistic laboratory-based studies with studies on wild populations and their natural parasite communities. Unfortunately, the relative paucity of immunological tools for non-model species has held these types of studies back. Thankfully, recent progress in high-throughput ‘omics platforms provide powerful and increasingly practical means for immunologists to move beyond traditional lab-based model organisms. Yet, assigning both metabolic and immune function to genes, transcripts, and proteins in novel species and assessing how they interact with other physiological and environmental factors requires identifying quantitative relationships between their expression and infection. Here, we used supervised machine learning to identify gene networks robustly associated with burdens of the gastrointestinal nematode Heligmosomoides polygyrus in its natural host, the wild wood mice Apodemus sylvaticus. Across 34 mice spanning two wild populations and across two different seasons, we found 17,639 transcripts that clustered in 131 weighted gene networks. These clusters robustly predicted H. polygyrus burden and included well-known effector and regulatory immune genes, but also revealed a number of genes associated with the maintenance of tissue homeostasis and hematopoiesis that have so far received little attention. We then tested the effect of experimentally reducing helminth burdens through drug treatment on those putatively protective immune factors. Despite the near elimination of H. polygyrus worms, the treatment had surprisingly little effect on gene expression. Taken together, these results suggest that hosts balance tissue homeostasis and protective immunity, resulting in relatively stable immune and, consequently, parasitological profiles. In the future, applying our approach to larger numbers of samples from additional populations will help further increase our ability to detect the immune pathways that determine chronic gastrointestinal helminth burdens in the wild.
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Affiliation(s)
- Simon A Babayan
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Wei Liu
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | - Elizabeth Kilbride
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Evelyn C Rynkiewicz
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Melanie Clerc
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Amy B Pedersen
- Institute of Evolutionary Biology and Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Ásbjörnsdóttir KH, Ajjampur SSR, Anderson RM, Bailey R, Gardiner I, Halliday KE, Ibikounle M, Kalua K, Kang G, Littlewood DTJ, Luty AJF, Means AR, Oswald W, Pullan RL, Sarkar R, Schär F, Szpiro A, Truscott JE, Werkman M, Yard E, Walson JL. Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: The DeWorm3 cluster randomized trial protocol. PLoS Negl Trop Dis 2018; 12:e0006166. [PMID: 29346377 PMCID: PMC5773085 DOI: 10.1371/journal.pntd.0006166] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/14/2017] [Indexed: 12/23/2022] Open
Abstract
Current control strategies for soil-transmitted helminths (STH) emphasize morbidity control through mass drug administration (MDA) targeting preschool- and school-age children, women of childbearing age and adults in certain high-risk occupations such as agricultural laborers or miners. This strategy is effective at reducing morbidity in those treated but, without massive economic development, it is unlikely it will interrupt transmission. MDA will therefore need to continue indefinitely to maintain benefit. Mathematical models suggest that transmission interruption may be achievable through MDA alone, provided that all age groups are targeted with high coverage. The DeWorm3 Project will test the feasibility of interrupting STH transmission using biannual MDA targeting all age groups. Study sites (population ≥80,000) have been identified in Benin, Malawi and India. Each site will be divided into 40 clusters, to be randomized 1:1 to three years of twice-annual community-wide MDA or standard-of-care MDA, typically annual school-based deworming. Community-wide MDA will be delivered door-to-door, while standard-of-care MDA will be delivered according to national guidelines. The primary outcome is transmission interruption of the STH species present at each site, defined as weighted cluster-level prevalence ≤2% by quantitative polymerase chain reaction (qPCR), 24 months after the final round of MDA. Secondary outcomes include the endline prevalence of STH, overall and by species, and the endline prevalence of STH among children under five as an indicator of incident infections. Secondary analyses will identify cluster-level factors associated with transmission interruption. Prevalence will be assessed using qPCR of stool samples collected from a random sample of cluster residents at baseline, six months after the final round of MDA and 24 months post-MDA. A smaller number of individuals in each cluster will be followed with annual sampling to monitor trends in prevalence and reinfection throughout the trial. TRIAL REGISTRATION ClinicalTrials.gov NCT03014167.
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Affiliation(s)
- Kristjana Hrönn Ásbjörnsdóttir
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
| | | | - Roy M. Anderson
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Robin Bailey
- Clinical Research Department, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Iain Gardiner
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Katherine E. Halliday
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Moudachirou Ibikounle
- Département de Zoologie, Faculté des Sciences et Techniques, Université d'Abomey-Calavi 01BP526, Cotonou, Benin
| | - Khumbo Kalua
- Blantyre Institute for Community Outreach, Lions Sight First Eye Hospital, Blantyre, Malawi
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | | | - Adrian J. F. Luty
- MERIT UMR 216, Institut de Recherche pour le Développement, Paris, France
| | - Arianna Rubin Means
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
| | - William Oswald
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rachel L. Pullan
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Rajiv Sarkar
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Fabian Schär
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Adam Szpiro
- Department of Biostatistics, University of Washington, Seattle, United States
| | - James E. Truscott
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Marleen Werkman
- London Centre for Neglected Tropical Disease Research, Department of Infectious Disease Epidemiology, School of Public Health, St. Marys Campus, Imperial College London, London, United Kingdom
| | - Elodie Yard
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
| | - Judd L. Walson
- DeWorm3, Division of Life Sciences, Natural History Museum, London, United Kingdom
- Department of Global Health, University of Washington, Seattle, United States
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A´sbjo¨rnsdo´ttir KH, Means AR, Werkman M, Walson JL. Prospects for elimination of soil-transmitted helminths. Curr Opin Infect Dis 2017; 30:482-488. [PMID: 28700363 PMCID: PMC7680933 DOI: 10.1097/qco.0000000000000395] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE OF REVIEW Soil-transmitted helminths (STH) are endemic in 120 countries and are associated with substantial morbidity and loss of economic productivity. Although current WHO guidelines focus on morbidity control through mass drug administration (MDA), there is global interest in whether a strategy targeting disease elimination might be feasible in some settings. This review summarizes the prospects for switching from control to an elimination strategy. RECENT FINDINGS STH control efforts have reduced the intensity of infections in targeted populations with associated reductions in morbidity. However, adults are not frequently targeted and remain important reservoirs for reinfection of treated children. Recent modeling suggests that transmission interruption may be possible through expanded community-wide delivery of MDA, the feasibility of which has been demonstrated by other programs. However, these models suggest that high levels of coverage and compliance must be achieved. Potential challenges include the risk of prematurely dismantling STH programs and the potential increased risk of antihelminthic resistance. SUMMARY Elimination of STH may offer an opportunity to eliminate substantial STH-related morbidity while reducing resource needs of neglected tropical disease programs. Evidence from large community trials is needed to determine the feasibility of interrupting the transmission of STH in some geographic settings.
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Affiliation(s)
- Kristjana H. A´sbjo¨rnsdo´ttir
- DeWorm3, The Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, Washington, USA and
| | - Arianna R. Means
- DeWorm3, The Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, Washington, USA and
| | - Marleen Werkman
- DeWorm3, The Natural History Museum, London, UK
- Department of Infectious Disease Epidemiology, London Centre for Neglected Tropical Disease Research (LCNTDR), St. Mary’s Campus, Imperial College London, London, UK
| | - Judd L. Walson
- DeWorm3, The Natural History Museum, London, UK
- Department of Global Health, University of Washington, Seattle, Washington, USA and
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Amelio P, Portevin D, Reither K, Mhimbira F, Mpina M, Tumbo A, Nickel B, Marti H, Knopp S, Ding S, Penn-Nicholson A, Darboe F, Ohmiti K, Scriba TJ, Pantaleo G, Daubenberger C, Perreau M. Mixed Th1 and Th2 Mycobacterium tuberculosis-specific CD4 T cell responses in patients with active pulmonary tuberculosis from Tanzania. PLoS Negl Trop Dis 2017; 11:e0005817. [PMID: 28759590 PMCID: PMC5552332 DOI: 10.1371/journal.pntd.0005817] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 08/10/2017] [Accepted: 07/19/2017] [Indexed: 12/22/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) and helminth infections elicit antagonistic immune effector functions and are co-endemic in several regions of the world. We therefore hypothesized that helminth infection may influence Mtb-specific T-cell immune responses. We evaluated the cytokine profile of Mtb-specific T cells in 72 individuals with pulmonary TB disease recruited from two Sub-Saharan regions with high and moderate helminth burden i.e. 55 from Tanzania (TZ) and 17 from South Africa (SA), respectively. We showed that Mtb-specific CD4 T-cell functional profile of TB patients from Tanzania are primarily composed of polyfunctional Th1 and Th2 cells, associated with increased expression of Gata-3 and reduced expression of T-bet in memory CD4 T cells. In contrast, the cytokine profile of Mtb-specific CD4 T cells of TB patients from SA was dominated by single IFN-γ and dual IFN-γ/TNF-α and associated with TB-induced systemic inflammation and elevated serum levels of type I IFNs. Of note, the proportion of patients with Mtb-specific CD8 T cells was significantly reduced in Mtb/helminth co-infected patients from TZ. It is likely that the underlying helminth infection and possibly genetic and other unknown environmental factors may have caused the induction of mixed Th1/Th2 Mtb-specific CD4 T cell responses in patients from TZ. Taken together, these results indicate that the generation of Mtb-specific CD4 and CD8 T cell responses may be substantially influenced by environmental factors in vivo. These observations may have major impact in the identification of immune biomarkers of disease status and correlates of protection. Mycobacterium tuberculosis (Mtb) and helminth infections are co-endemic in several regions of the world and their immune responses may be mutually antagonistic. We therefore hypothesized that helminth infection would impact and potentially shape Mtb-specific T-cell responses and systemic inflammation in patients suffering from active pulmonary tuberculosis (TB) enrolled from two helminth endemic regions i.e. Tanzania (TZ) and South Africa (SA). In this study, we demonstrate for the first time that TB patients from SA and TZ harbor distinct immune responses to Mtb antigens. Indeed, we showed that Mtb-specific CD4 T-cell responses of TB patients from TZ were composed by a mixed T helper type 1 (Th1) and Th2 responses. In contrast, the cytokine profile of Mtb-specific CD4 T cells of TB patients from SA was dominated by Th1 cells and associated with TB-induced systemic inflammation and elevated serum levels of type I IFN. Taken together, these data indicate that Mtb-specific T-cell responses are diverse in human populations and can be strongly influenced by host and pathogen genetic background, co-infections and yet unknown environmental factors. Identification of correlates of risk and protection from TB disease will help in the rational development of protective T-cell based vaccines against TB, early monitoring TB treatment outcomes and focused follow up of high risk populations.
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Affiliation(s)
- Patrizia Amelio
- Service of Immunology and Allergy, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Damien Portevin
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Klaus Reither
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | | | | | - Beatrice Nickel
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Hanspeter Marti
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Song Ding
- EuroVacc Foundation, Lausanne, Switzerland
| | - Adam Penn-Nicholson
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, Division of Immunology, Department of Pathology, University of Cape Town, South Africa
| | - Fatoumatta Darboe
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, Division of Immunology, Department of Pathology, University of Cape Town, South Africa
| | - Khalid Ohmiti
- Service of Immunology and Allergy, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Thomas J. Scriba
- South African Tuberculosis Vaccine Initiative, Institute of Infectious Disease and Molecular Medicine, Division of Immunology, Department of Pathology, University of Cape Town, South Africa
| | - Giuseppe Pantaleo
- Service of Immunology and Allergy, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- SVRI, Lausanne, Switzerland
| | - Claudia Daubenberger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Matthieu Perreau
- Service of Immunology and Allergy, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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Barda B, Albonico M, Buonfrate D, Ame SM, Ali S, Speich B, Keiser J. Side Benefits of Mass Drug Administration for Lymphatic Filariasis on Strongyloides stercoralis Prevalence on Pemba Island, Tanzania. Am J Trop Med Hyg 2017; 97:681-683. [PMID: 28722622 DOI: 10.4269/ajtmh.17-0050] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Strongyloides stercoralis, although endemic in many countries, is not included in helminth control programs. Few data are available on the prevalence and morbidity linked to this infection. We compared data from two studies conducted in 1998 and 2013 on Pemba Island, Tanzania, involving 525 and 509 schoolchildren, respectively. In 1998, the diagnostic method used was Harada Mori, whereas in 2013 diagnosis was made by both Koga agar plate and Baermann methods. The prevalence registered was 41% in 1998 and 7% in 2013. This data suggest that the prevalence of S. stercoralis on Pemba was significantly reduced 7 years after the last ivermectin administration for preventive chemotherapy and underlines the importance and impact of large-scale preventive chemotherapy, which often goes beyond its actual target. Preventive chemotherapy with ivermectin should be recommended in areas where S. stercoralis is endemic.
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Affiliation(s)
- Beatrice Barda
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Marco Albonico
- Public Health Laboratory Ivo de Carneri, Chake-Chake, Tanzania.,Center for Tropical Diseases, Negrar Hospital, Verona, Italy
| | - Dora Buonfrate
- Center for Tropical Diseases, Negrar Hospital, Verona, Italy
| | - Shaali M Ame
- Public Health Laboratory Ivo de Carneri, Chake-Chake, Tanzania
| | - Said Ali
- Public Health Laboratory Ivo de Carneri, Chake-Chake, Tanzania
| | - Benjamin Speich
- University of Basel, Basel, Switzerland.,Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jennifer Keiser
- University of Basel, Basel, Switzerland.,Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
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Hotez P, Aksoy S. PLOS Neglected Tropical Diseases: Ten years of progress in neglected tropical disease control and elimination … More or less. PLoS Negl Trop Dis 2017; 11:e0005355. [PMID: 28426662 PMCID: PMC5398476 DOI: 10.1371/journal.pntd.0005355] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
This year PLOS Neglected Tropical Diseases (PLOS NTDs) celebrates its tenth anniversary following the publication of the first issue in 2007 [1]. When PLOS NTDs was founded, the framework of the neglected tropical diseases (NTDs) as an alternative to “other diseases” (as they were then referred to in the Millennium Development Goals) was just getting started—especially for Africa [2, 3]. In the decade since, PLOS NTDs has overseen enormous successes in NTD control and elimination. Here, we want to briefly review the ten year progress made towards the control or elimination of the diseases now identified by the WHO as NTDs. Many of the details are highlighted in PLOS NTDs papers cited here, but the summary information is based on the recently released Global Burden of Disease (GBD) Study 2015 (also launched with Gates Foundation support) that summarized past-decade changes in disease prevalence, mortality, or disability rates (from the years 2005 to 2015) [4–6], as well as the GBD Study 2013 that summarizes disease prevalence changes over a longer time horizon from 1990 to 2013 [7].
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Affiliation(s)
- Peter Hotez
- Texas Children’s Hospital Center for Vaccine Development, National School of Tropical Medicine at Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States of America
- Center for Health and Biosciences, James A. Baker III Institute for Public Policy, Rice University, Houston, Texas, United States of America
- Scowcroft Institute of International Affairs, Bush School of Government and Public Service, College Station, Texas, United States of America
- * E-mail: (PH); (SA)
| | - Serap Aksoy
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, Yale University, New Haven, Connecticut, United States of America
- * E-mail: (PH); (SA)
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Clarke NE, Clements ACA, Doi SA, Wang D, Campbell SJ, Gray D, Nery SV. Differential effect of mass deworming and targeted deworming for soil-transmitted helminth control in children: a systematic review and meta-analysis. Lancet 2017; 389:287-297. [PMID: 27979381 DOI: 10.1016/s0140-6736(16)32123-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 09/27/2016] [Accepted: 09/28/2016] [Indexed: 11/27/2022]
Abstract
BACKGROUND Soil-transmitted helminth infections are a major global health issue, causing substantial morbidity in the world's poorest populations. Regular delivery of anthelmintic drugs is the mainstay for global soil-transmitted helminth control. Deworming campaigns are often targeted to school-aged children, who are at high risk of soil-transmitted-helminth-associated morbidity. However, findings from modelling studies suggest that deworming campaigns should be expanded community-wide for effective control of soil-transmitted helminth transmission. We aimed to do a systematic review and meta-analysis to compare the effect of mass (community-wide) and targeted (children only) anthelmintic delivery strategies on soil-transmitted helminth prevalence in school-aged children. METHODS In this systematic review and meta-analysis, we searched MEDLINE, Embase, and Web of Science for articles published on or before Nov 5, 2015, reporting soil-transmitted helminth prevalence before and after distribution of albendazole or mebendazole, either targeted to children or delivered to the whole community. We excluded studies in which drug delivery was restricted to infected individuals or to a subset of the community or school, or if follow-up time was less than 3 months or greater than 18 months after drug delivery. We extracted data on study year, country, drug administration strategy, drug dose, number of deworming rounds, treatment coverage, diagnostic method, follow-up interval, and soil-transmitted helminth prevalence before and after treatment. We used inverse variance weighted generalised linear models, with prevalence reduction as the outcome variable, to examine the effect of mass versus targeted drug administration, as well as baseline prevalence, number of drug doses, and follow-up time. This study is registered with PROSPERO, number CRD42016026929. FINDINGS Of 10 538 studies identified, 56 studies were eligible for the systematic review and 38 of these were included in meta-analysis. Results of the regression models showed that mass deworming led to a significantly greater reduction in prevalence in children than targeted deworming, for both hookworm (odds ratio 4·6, 95% CI 1·8-11·6; p=0·0020) and Ascaris lumbricoides (16·4, 2·1-125·8; p=0·0092), with no effect seen for Trichuris trichiura. There was significant heterogeneity across studies; for targeted studies I2 was 97% for A lumbricoides and hookworm, and 96% for T trichiura, and for mass studies, I2 was 89% for A lumbricoides, 49% for hookworm, and 66% for T trichiura. INTERPRETATION The results of this meta-analysis suggest that expanding deworming programmes community-wide is likely to reduce the prevalence of soil-transmitted helminths in the high-risk group of school-aged children, which could lead to improved morbidity outcomes. These findings are in support of recent calls for re-evaluation of global soil-transmitted helminth control guidelines. FUNDING None.
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Affiliation(s)
- Naomi E Clarke
- Research School of Population Health, Australian National University, Canberra, ACT, Australia.
| | - Archie C A Clements
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Suhail A Doi
- Research School of Population Health, Australian National University, Canberra, ACT, Australia; College of Medicine, Qatar University, Doha, Qatar; School of Agricultural, Computational and Environmental Sciences, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Dongxu Wang
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Suzy J Campbell
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Darren Gray
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Susana V Nery
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
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Loukas A, Hotez PJ, Diemert D, Yazdanbakhsh M, McCarthy JS, Correa-Oliveira R, Croese J, Bethony JM. Hookworm infection. Nat Rev Dis Primers 2016; 2:16088. [PMID: 27929101 DOI: 10.1038/nrdp.2016.88] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Hookworms are soil-transmitted nematode parasites that can reside for many years in the small intestine of their human hosts; Necator americanus is the predominant infecting species. Adult worms feed on the blood of a host and can cause iron deficiency anaemia, especially in high-risk populations (children and women of childbearing age). Almost 500 million people in developing tropical countries are infected, and simulation models estimate that hookworm infection is responsible for >4 million disability-adjusted life years lost annually. Humans mount an immune response to hookworms, but it is mostly unsuccessful at removing adult worms from the bowel. Accordingly, the host switches to an immune-tolerant state that enables hookworms to reside in the gut for many years. Although anthelmintic drugs are available and widely used, their efficacy varies and the drugs do not prevent reinfection. Thus, other control strategies aimed at improving water quality, sanitation and hygiene are needed. In addition, efforts are underway to develop a human hookworm vaccine through public-private partnerships. However, hookworms could also be a resource; as hookworms have the capability to regulate the host's inflammation, researchers are experimentally infecting patients to treat some inflammatory diseases as an approach to discover new anti-inflammatory molecules. This area of endeavour might well yield new biotherapeutics for autoimmune and allergic diseases.
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Affiliation(s)
- Alex Loukas
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, Building E4, James Cook University, McGregor Rd, Smithfield, Cairns, Queensland 4878, Australia
| | - Peter J Hotez
- Departments of Pediatrics and Molecular Virology and Microbiology, National School of Tropical Medicine, Baylor College Of Medicine, Houston, Texas, USA.,Sabin Vaccine Institute, Houston, Texas, USA.,Texas Children's Hospital Center for Vaccine Development, Houston, Texas, USA
| | - David Diemert
- Department of Microbiology, Tropical Medicine and Immunology, George Washington University, Washington DC, USA.,Sabin Vaccine Institute, Washington DC, USA
| | - Maria Yazdanbakhsh
- Department of Parasitology, Leiden University Medical Centre, Leiden, The Netherlands
| | - James S McCarthy
- Queensland Institute of Medical Research (QIMR) Berghofer Medical Research Institute, Brisbane, Queensland, Australia.,University of Queensland, Brisbane, Queensland, Australia
| | | | - John Croese
- Centre for Biodiscovery and Molecular Development of Therapeutics, Australian Institute of Tropical Health and Medicine, Building E4, James Cook University, McGregor Rd, Smithfield, Cairns, Queensland 4878, Australia.,Department of Gastroenterology, Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Jeffrey M Bethony
- Department of Microbiology, Tropical Medicine and Immunology, George Washington University, Washington DC, USA
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StrongNet: An International Network to Improve Diagnostics and Access to Treatment for Strongyloidiasis Control. PLoS Negl Trop Dis 2016; 10:e0004898. [PMID: 27607192 PMCID: PMC5015896 DOI: 10.1371/journal.pntd.0004898] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Medley GF, Turner HC, Baggaley RF, Holland C, Hollingsworth TD. The Role of More Sensitive Helminth Diagnostics in Mass Drug Administration Campaigns: Elimination and Health Impacts. ADVANCES IN PARASITOLOGY 2016; 94:343-392. [PMID: 27756457 DOI: 10.1016/bs.apar.2016.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Diagnostics play a crucial role in determining treatment protocols and evaluating success of mass drug administration (MDA) programmes used to control soil-transmitted helminths (STHs). The current diagnostic, Kato-Katz, relies on inexpensive, reusable materials and can be used in the field, but only trained microscopists can read slides. This diagnostic always underestimates the true prevalence of infection, and the accuracy worsens as the true prevalence falls. We investigate how more sensitive diagnostics would impact on the management and life cycle of MDA programmes, including number of mass treatment rounds, health impact, number of unnecessary treatments and probability of elimination. We use an individual-based model of STH transmission within the current World Health Organization (WHO) treatment guidelines which records individual disability-adjusted life years (DALY) lost. We focus on Ascaris lumbricoides due to the availability of high-quality data on existing diagnostics. We show that the effect of improving the sensitivity of diagnostics is principally determined by the precontrol prevalence in the community. Communities at low true prevalence (<30%) and high true prevalence (>70%) do not benefit greatly from improved diagnostics. Communities with intermediate prevalence benefit greatly from increased chemotherapy application, both in terms of reduced DALY loss and increased probability of elimination. Our results suggest that programmes should be extended beyond school-age children, especially in high prevalence communities. Finally, we argue against using apparent or measured prevalence as an uncorrected proxy for true prevalence.
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Affiliation(s)
- G F Medley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - H C Turner
- Imperial College London, London, United Kingdom
| | - R F Baggaley
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - C Holland
- Trinity College Dublin, Dublin, Ireland
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