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Dale A, Xu G, Kopp SR, Jones MK, Kotze AC, Abdullah S. Pyrantel resistance in canine hookworms in Queensland, Australia. Vet Parasitol Reg Stud Reports 2024; 48:100985. [PMID: 38316510 DOI: 10.1016/j.vprsr.2024.100985] [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: 03/14/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 02/07/2024]
Abstract
Hookworms are the most common intestinal nematode parasites of dogs in Australia. The control of these parasites relies mostly on regular deworming with anthelmintics, with pyrantel-based dewormers being a relatively low cost and readily-available option for dog owners. Pyrantel resistance in canine hookworms in Australia was first reported in 2007, however pyrantel-based dewormers are still used against hookworm infection in dogs across Australia. The present study was conducted to evaluate the efficacy of pyrantel against hookworms infecting dogs housed in a shelter facility in Southeast Queensland which receives rescued or surrendered animals from greyhound rescue centres and dog shelters across this region. A total of 10 dogs were examined using the faecal egg count reduction test (FECRT). There was no reduction in FEC in any of the dogs following pyrantel treatment, with drug efficacies ranging from -0.9% to -283.3%. Given that these dogs originated from various sites across Southeast Queensland, the present study suggests that pyrantel resistance is widespread in this region, and hence this anthelmintic may not be a useful option for treatment of hookworm infections in dogs.
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Affiliation(s)
- Ashley Dale
- The University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Australia
| | - Geoffrey Xu
- The University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Australia
| | - Steven R Kopp
- The University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Australia
| | - Malcolm K Jones
- The University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Australia
| | - Andrew C Kotze
- CSIRO Agriculture and Food, Queensland Bioscience Precinct, St. Lucia, Brisbane, QLD 4067, Australia
| | - Swaid Abdullah
- The University of Queensland, School of Veterinary Science, Gatton, QLD 4343, Australia.
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Muñoz-Antoli C, Pérez P, Pavón A, Toledo R, Esteban JG. High intestinal parasite infection detected in children from Región Autónoma Atlántico Norte (R.A.A.N.) of Nicaragua. Sci Rep 2022; 12:5872. [PMID: 35393466 PMCID: PMC8990018 DOI: 10.1038/s41598-022-09756-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/24/2022] [Indexed: 11/09/2022] Open
Abstract
There is a lack of epidemiological information concerning intestinal parasitic infections, and especially in soil-transmitted helminths, occurring in some departments of Nicaragua. Up to now, this is the first study involving two nearby areas (Puerto Cabezas and Siuna municipalities) of the Región Autónoma Atlántico Norte (R.A.A.N.). One stool sample was analyzed by Kato-Katz, formaldehyde-ethyl acetate concentration method and modified Ziehl-Neelsen technique, and a simple questionnaire concerning demographic, sanitary and behavioral data was distributed among 735 children and evaluated. Overall prevalence of infection reached 97.0%, being the highest prevalences detected in all Nicaragua. The higher protozoan prevalence appears in Siuna (94.5%), a rural interior municipality, with a typical tropical monsoon climate, while the higher helminths rates were reached in Puerto Cabezas (92.8%), the urbanized coastal capital, with a typical tropical rainforest climate. No statistical differences were found with regard to sex. However, the 6-11-year age-group children presented the highest prevalences. Most T. trichiura infections (59.4%) were of light intensity, while 51.7% of Ascaris lumbricoides were of moderate intensity. Multivariable logistic regression analysis indicated that those who drink rainwater and walk barefoot were 2.9 and 2.5 times more likely to have helminth infections, respectively. Results from one geographical setting might not be applied to other nearby with different climatic conditions. The use of anthelmintic drugs only will not be sufficient to bring prevalence to low levels. It is necessary to design geographically more specific intervention, with communication and interaction between different disciplines (e.g. parasitology, biochemistry, molecular biology, epidemiology, public health, etc.) being imperative to reduce STH infection.
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Affiliation(s)
- Carla Muñoz-Antoli
- Área Parasitología, Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Facultad Farmacia, Universidad Valencia, Valencia, Spain.
| | - Paloma Pérez
- Área Parasitología, Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Facultad Farmacia, Universidad Valencia, Valencia, Spain
| | - Aleyda Pavón
- Departamento Bioanálisis Clínico, Instituto Politécnico de La Salud (IPS-Polisal), Universidad Nacional Autónoma de Nicaragua, Managua, Nicaragua
| | - Rafael Toledo
- Área Parasitología, Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Facultad Farmacia, Universidad Valencia, Valencia, Spain
| | - José Guillermo Esteban
- Área Parasitología, Departamento Farmacia y Tecnología Farmacéutica y Parasitología, Facultad Farmacia, Universidad Valencia, Valencia, Spain
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Functional Characterization of the Oxantel-Sensitive Acetylcholine Receptor from Trichuris muris. Pharmaceuticals (Basel) 2021; 14:ph14070698. [PMID: 34358124 PMCID: PMC8308736 DOI: 10.3390/ph14070698] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/10/2021] [Accepted: 07/16/2021] [Indexed: 12/05/2022] Open
Abstract
The human whipworm, Trichuris trichiura, is estimated to infect 289.6 million people globally. Control of human trichuriasis is a particular challenge, as most anthelmintics have a limited single-dose efficacy, with the striking exception of the narrow-spectrum anthelmintic, oxantel. We recently identified a novel ACR-16-like subunit from the pig whipworm, T. suis which gave rise to a functional acetylcholine receptor (nAChR) preferentially activated by oxantel. However, there is no ion channel described in the mouse model parasite T. muris so far. Here, we have identified the ACR-16-like and ACR-19 subunits from T. muris, and performed the functional characterization of the receptors in Xenopus laevis oocytes using two-electrode voltage-clamp electrophysiology. We found that the ACR-16-like subunit from T. muris formed a homomeric receptor gated by acetylcholine whereas the ACR-19 failed to create a functional channel. The subsequent pharmacological analysis of the Tmu-ACR-16-like receptor revealed that acetylcholine and oxantel were equally potent. The Tmu-ACR-16-like was more responsive to the toxic agonist epibatidine, but insensitive to pyrantel, in contrast to the Tsu-ACR-16-like receptor. These findings confirm that the ACR-16-like nAChR from Trichuris spp. is a preferential drug target for oxantel, and highlights the pharmacological difference between Trichuris species.
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Palmeirim MS, Specht S, Scandale I, Gander-Meisterernst I, Chabicovsky M, Keiser J. Preclinical and Clinical Characteristics of the Trichuricidal Drug Oxantel Pamoate and Clinical Development Plans: A Review. Drugs 2021; 81:907-921. [PMID: 33929716 PMCID: PMC8144136 DOI: 10.1007/s40265-021-01505-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/17/2021] [Indexed: 12/31/2022]
Abstract
Soil-transmitted helminths (Ascaris lumbricoides, hookworm and Trichuris trichiura) infect about one-fifth of the world's population. The currently available drugs are all highly efficacious against A. lumbricoides. However, they are only moderately efficacious against hookworm and poorly efficacious against T. trichiura. Oxantel, a tetrahydropyrimidine derivative discovered in the 1970s, has recently been brought back to our attention given its high efficacy against T. trichiura infections (estimated 76% cure rate and 85% egg reduction rate at a 20 mg/kg dose). This review summarizes the current knowledge on oxantel pamoate and its use against T. trichiura infections in humans. Oxantel pamoate acts locally in the human gastrointestinal tract and binds to the parasite's nicotinic acetylcholine receptor (nAChR), leading to a spastic paralysis of the worm and subsequent expulsion. The drug is metabolically stable, shows low permeability and low systemic bioavailability after oral use. Oxantel pamoate was found to be safe in humans, with only a few mild adverse events reported. Several clinical trials have investigated the efficacy of this drug against T. trichiura and suggest that oxantel pamoate is more efficacious against T. trichiura than the currently recommended drugs, which makes it a strong asset to the depleted drug armamentarium and could help delay or even prevent the development of resistance to existing drugs. We highlight existing data to support the use of oxantel pamoate against T. trichiura infections.
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Affiliation(s)
- Marta S Palmeirim
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland
- University of Basel, P.O. Box, 4003, Basel, Switzerland
| | - Sabine Specht
- Drugs for Neglected Diseases Initiative, 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | - Ivan Scandale
- Drugs for Neglected Diseases Initiative, 15 Chemin Louis-Dunant, 1202, Geneva, Switzerland
| | | | - Monika Chabicovsky
- MC Toxicology Consulting GmbH, Siebensterngasse 31/8, 1070, Vienna, Austria
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, P.O. Box, 4002, Basel, Switzerland.
- University of Basel, P.O. Box, 4003, Basel, Switzerland.
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Budiapsari PI, Swastika IK, Masyeni S. Prevalence of Soil-transmitted Helminths Infection in Students of Klungkung, Bali, after Mass Treatment with AlbendazolePrevalence of Soil-transmitted Helminths Infection in Students of Klungkung, Bali, after Mass Treatment with Albendazole. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.6266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The success of the anti-helminth mass treatment use Albendazole makes detection of soil transmitted helminth infections even more difficult to do microscopically. It is hoped that the molecular method was able to help increase the detectability of Soil Transmitted Helminth infection. The research aimed is to evaluate effectiveness of Albendazole administration in Bali, to identify the presence of β-tubulin gene as molecular diagnosis of STHs infection among children who treated by Albendazole. This study is a cross-sectional study that recruits elementary school children aged 6-12 years as subjects. Stool examination was carried out using the Kato-Katz technique, then followed by a molecular method using the B-tubulin gene as the target gene. The results showed that only 1 sample out of 140 examined using Kato-Katz was positive for Trichuris trichiura. 30 samples were then extracted from the faeces and performed Polymerase Chain Reaction. A total of 4 positive samples detected the B-tubulin Ascaris lumbricoides gene and 1 positive sample of the B-tubulin Trichuris trichiura gene. In conclusion, albendazole is still effective to treat STH infection, the molecular method has a higher detectability than the microscopic method.
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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: 8] [Impact Index Per Article: 2.7] [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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Hansen TVA, Cirera S, Neveu C, Courtot E, Charvet CL, Calloe K, Klaerke DA, Martin RJ. The narrow-spectrum anthelmintic oxantel is a potent agonist of a novel acetylcholine receptor subtype in whipworms. PLoS Pathog 2021; 17:e1008982. [PMID: 33544769 PMCID: PMC7891710 DOI: 10.1371/journal.ppat.1008982] [Citation(s) in RCA: 6] [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: 09/12/2020] [Revised: 02/18/2021] [Accepted: 01/13/2021] [Indexed: 12/28/2022] Open
Abstract
In the absence of efficient alternative strategies, the control of parasitic nematodes, impacting human and animal health, mainly relies on the use of broad-spectrum anthelmintic compounds. Unfortunately, most of these drugs have a limited single-dose efficacy against infections caused by the whipworm, Trichuris. These infections are of both human and veterinary importance. However, in contrast to a wide range of parasitic nematode species, the narrow-spectrum anthelmintic oxantel has a high efficacy on Trichuris spp. Despite this knowledge, the molecular target(s) of oxantel within Trichuris is still unknown. In the distantly related pig roundworm, Ascaris suum, oxantel has a small, but significant effect on the recombinant homomeric Nicotine-sensitive ionotropic acetylcholine receptor (N-AChR) made up of five ACR-16 subunits. Therefore, we hypothesized that in whipworms, a putative homolog of an ACR-16 subunit, can form a functional oxantel-sensitive receptor. Using the pig whipworm T. suis as a model, we identified and cloned a novel ACR-16-like subunit and successfully expressed the corresponding homomeric channel in Xenopus laevis oocytes. Electrophysiological experiments revealed this receptor to have distinctive pharmacological properties with oxantel acting as a full agonist, hence we refer to the receptor as an O-AChR subtype. Pyrantel activated this novel O-AChR subtype moderately, whereas classic nicotinic agonists surprisingly resulted in only minor responses. We observed that the expression of the ACR-16-like subunit in the free-living nematode Caenorhabditis elegans conferred an increased sensitivity to oxantel of recombinant worms. We demonstrated that the novel Tsu-ACR-16-like receptor is indeed a target for oxantel, although other receptors may be involved. These finding brings new insight into the understanding of the high sensitivity of whipworms to oxantel, and highlights the importance of the discovery of additional distinct receptor subunit types within Trichuris that can be used as screening tools to evaluate the effect of new synthetic or natural anthelmintic compounds.
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Affiliation(s)
- Tina V. A. Hansen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
- INRAE, Université de Tours, ISP, Nouzilly, France
| | - Susanna Cirera
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Cédric Neveu
- INRAE, Université de Tours, ISP, Nouzilly, France
| | | | | | - Kirstine Calloe
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Dan A. Klaerke
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Richard J. Martin
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
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Keller L, Palmeirim MS, Ame SM, Ali SM, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and Safety of Ascending Dosages of Moxidectin and Moxidectin-albendazole Against Trichuris trichiura in Adolescents: A Randomized Controlled Trial. Clin Infect Dis 2021; 70:1193-1201. [PMID: 31044235 DOI: 10.1093/cid/ciz326] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/22/2019] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Preventive chemotherapy is the main strategy to control soil-transmitted helminth (STH) infections. Albendazole and mebendazole are ubiquitously used, but they are not sufficiently effective against Trichuris trichiura. Moxidectin might be a useful addition to the small drug armamentarium. However, the optimal dosage of moxidectin alone and in combination with albendazole against T. trichiura and other STHs has not yet been determined. METHODS A Phase II, randomized, placebo-controlled, dose-finding trial was conducted in 2 secondary schools on Pemba Island, Tanzania. Using a computer-generated list, T. trichiura-infected adolescents were randomly assigned to 7 treatment arms: 8, 16, or 24 mg of moxidectin monotherapy; 8, 16, or 24 mg of moxidectin plus 400 mg of albendazole combination therapy; or placebo. The primary outcome was cure rate (CR) against T. trichiura, analyzed 13 to 20 days after treatment by quadruple Kato-Katz thick smears. RESULTS A total of 290 adolescents were enrolled (41 or 42 per arm). CRs against T. trichiura were 43, 46, and 44% for 8, 16, and 24 mg of moxidectin alone, respectively; 60, 62, and 66% for the same moxidectin dosages plus 400 mg of albendazole, respectively; and 12% for placebo. The moxidectin-albendazole arms also revealed higher CRs and egg reduction rates against hookworm than the monotherapy arms. Moxidectin and its combination with albendazole were well tolerated. CONCLUSIONS Moxidectin-albendazole is superior to moxidectin. There is no benefit of using doses above 8 mg, which is the recommended dose for onchocerciasis. The moxidectin-albendazole combination of 8 mg plus 400 mg should be investigated further to develop recommendations for appropriate control of STH infections. CLINICAL TRIALS REGISTRATION NCT03501251.
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Affiliation(s)
- Ladina Keller
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Marta S Palmeirim
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Shaali M Ame
- Public Health Laboratory Ivo de Carneri, Chake Chake, Republic of Tanzania
| | - Said M Ali
- Public Health Laboratory Ivo de Carneri, Chake Chake, Republic of Tanzania
| | - Maxim Puchkov
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology, , Basel, Switzerland
| | - Jörg Huwyler
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology, , Basel, Switzerland
| | - Jan Hattendorf
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland.,University of Basel, Basel, Switzerland
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Kaji MD, Geary TG, Beech RN. A Functional Comparison of Homopentameric Nicotinic Acetylcholine Receptors (ACR-16) Receptors From Necator americanus and Ancylostoma ceylanicum. Front Mol Neurosci 2020; 13:601102. [PMID: 33324163 PMCID: PMC7725692 DOI: 10.3389/fnmol.2020.601102] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/04/2020] [Indexed: 12/24/2022] Open
Abstract
Effective control of hookworm infections in humans and animals relies on using a small group of anthelmintics. Many of these drugs target cholinergic ligand-gated ion channels, yet the direct activity of anthelmintics has only been studied in a subset of these receptors, primarily in the non-parasitic nematode, Caenorhabditis elegans. Here we report the characterization of a homopentameric ionotropic acetylcholine receptor (AChR), ACR-16, from Necator americanus and Ancylostoma ceylanicum, the first known characterization of human hookworm ion channels. We used two-electrode voltage clamp electrophysiology in Xenopus laevis oocytes to determine the pharmacodynamics of cholinergics and anthelmintics on ACR-16 from both species of hookworm. The A. ceylanicum receptor (Ace-ACR-16) was more sensitive to acetylcholine (EC50 = 20.64 ± 0.32 μM) and nicotine (EC50 = 24.37 ± 2.89 μM) than the N. americanus receptor (Nam-ACR-16) (acetylcholine EC50 = 170.1 ± 19.23 μM; nicotine EC50 = 597.9 ± 59.12 μM), at which nicotine was a weak partial agonist (% maximal acetylcholine response = 30.4 ± 7.4%). Both receptors were inhibited by 500 μM levamisole (Ace-ACR-16 = 65.1 ± 14.3% inhibition, Nam-ACR-16 = 79.5 ± 7.7% inhibition), and responded to pyrantel, but only Ace-ACR-16 responded to oxantel. We used in silico homology modeling to investigate potential structural differences that account for the differences in agonist binding and identified a loop E isoleucine 130 of Nam-ACR-16 as possibly playing a role in oxantel insensitivity. These data indicate that key functional differences exist among ACR-16 receptors from closely related species and suggest mechanisms for differential drug sensitivity.
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Affiliation(s)
- Mark D. Kaji
- Institute of Parasitology, McGill University, Montreal, QC, Canada
| | - Timothy G. Geary
- Institute of Parasitology, McGill University, Montreal, QC, Canada
- School of Biological Sciences, Queen’s University-Belfast, Belfast, United Kingdom
| | - Robin N. Beech
- Institute of Parasitology, McGill University, Montreal, QC, Canada
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10
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Moser W, Keiser J, Speich B, Sayasone S, Knopp S, Hattendorf J. One mean to rule them all? The arithmetic mean based egg reduction rate can be misleading when estimating anthelminthic drug efficacy in clinical trials. PLoS Negl Trop Dis 2020; 14:e0008185. [PMID: 32267856 PMCID: PMC7170292 DOI: 10.1371/journal.pntd.0008185] [Citation(s) in RCA: 8] [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: 08/17/2019] [Revised: 04/20/2020] [Accepted: 03/01/2020] [Indexed: 11/19/2022] Open
Abstract
Animal and human helminth infections are highly prevalent around the world, with only few anthelminthic drugs available. The anthelminthic drug performance is expressed by the cure rate and the egg reduction rate. However, which kind of mean should be used to calculate the egg reduction rate remains a controversial issue. We visualized the distributions of egg counts of different helminth species in 7 randomized controlled trials and asked a panel of experts about their opinion on the egg burden and drug efficacy of two different treatments. Simultaneously, we calculated infection intensities and egg reduction rates using different types of means: arithmetic, geometric, trimmed, winsorized and Hölder means. Finally, we calculated the agreement between expert opinion and the different means. We generated 23 different trial arm pairs, which were judged by 49 experts. Among all investigated means, the arithmetic mean showed poorest performance with only 64% agreement with expert opinion (bootstrap confidence interval [CI]: 60−68). Highest agreement of 94% (CI: 86−96) was reached by the Hölder mean M0.2, followed by the geometric mean (91%, CI: 85−94). Winsorized and trimmed means showed a rather poor performance (e.g. winsorization with 0.1 cut-off showed 85% agreement, CI: 78−87), but they performed reasonably well after excluding treatment arms with a small number of patients. In clinical trials with moderate sample size, the currently recommended arithmetic mean does not necessarily rank anthelminthic efficacies in the same order as might be obtained from expert evaluation of the same data. Estimates based on the arithmetic mean should always be reported together with an estimate, which is more robust to outliers, e.g. the geometric mean. Besides cure rates, egg reduction rates represent an important indicator of anthelminthic drug efficacy in clinical trials. However, there is an ongoing controversy whether the arithmetic or the geometric mean should be used for its calculation. The arithmetic mean is problematic in skewed distributions mainly because the mean is sensitive to outliers, whereas the geometric mean does not correspond to our intuitive interpretation of average reduction. Several studies tried to compare the performance of different means but they relied on assumptions, which favored one approach over another. Despite the ongoing debate, the World Health Organization (WHO) recommends the arithmetic mean to calculate egg reduction rates. To overcome limitations from previous studies, we visualized data from several clinical trials and asked a panel of experts to compare drug efficacy of two different treatments. Afterwards, we estimated efficacy by using different means. Finally, we calculated the raw agreement between expert opinion and the different means. From all investigated methods to calculate efficacy, the arithmetic mean showed the poorest performance in terms of agreement with expert opinion. In anthelminthic human drug trials, which are characterized by small sample size and non-adherence, estimates more robust to outliers should be reported to assess drug efficacy performance.
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Affiliation(s)
- Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Benjamin Speich
- Centre for Statistics in Medicine, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, United Kingdom
- Basel Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Somphou Sayasone
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- Lao Tropical and Public Health Institute, Vientiane, Lao People’s Democratic Republic
| | - Stefanie Knopp
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Jan Hattendorf
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland
- * E-mail:
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11
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Clarke NE, Doi SAR, Wangdi K, Chen Y, Clements ACA, Nery SV. Efficacy of Anthelminthic Drugs and Drug Combinations Against Soil-transmitted Helminths: A Systematic Review and Network Meta-analysis. Clin Infect Dis 2020; 68:96-105. [PMID: 29788074 DOI: 10.1093/cid/ciy423] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/11/2018] [Indexed: 12/30/2022] Open
Abstract
Background Periodic mass distribution of benzimidazole anthelminthic drugs is the key strategy to control soil-transmitted helminths (STHs) globally. However, benzimidazoles have low efficacy against Trichuris trichiura, and there are concerns about benzimidazole resistance potentially emerging in humans. Therefore, identifying alternative drug regimens is a pressing priority. We present a systematic review and network meta-analysis comparing the efficacy of 21 different anthelminthic drug regimens, including standard, novel, and combination treatments. Methods We searched PubMed, Medline, Embase, Web of Science, and Cochrane databases and identified studies comparing anthelminthic treatments to each other or placebo. The outcomes calculated were relative risk (RR) of cure and difference in egg reduction rates (dERR). We used an automated generalized pairwise modeling framework to generate mixed treatment effects against a common comparator, the current standard treatment (single-dose albendazole). Results Our search identified 4876 studies, of which 114 were included in the meta-analysis. Results identified several drug combinations with higher efficacy than single-dose albendazole for T. trichiura, including albendazole-ivermectin (RR of cure, 3.22 [95% confidence interval {CI}, 1.84-5.63]; dERR, 0.97 [95% CI, .21-1.74]), albendazole-oxantel pamoate (RR, 5.07 [95% CI, 1.65-15.59]; dERR, 0.51 [95% CI, .50-.52]), mebendazole-ivermectin (RR, 3.37 [95% CI, 2.20-5.16]), and tribendimidine-oxantel pamoate (RR, 4.06 [95% CI, 1.30-12.64]). Conclusions There are several promising drug combinations that may enhance the impact of STH control programs on T. trichiura, without compromising efficacy against Ascaris lumbricoides and hookworm. We suggest further, large-scale trials of these drug combinations and consideration of their use in STH control programs where T. trichiura is present. International Prospective Register of Systematic Reviews Registration CRD42016050739.
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Affiliation(s)
- Naomi E Clarke
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Suhail A R Doi
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Department of Population Medicine, College of Medicine, Qatar University, Doha
| | - Kinley Wangdi
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Yingxi Chen
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory
| | - Archie C A Clements
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Faculty of Health Sciences, Curtin University, Perth, Western Australia
| | - Susana V Nery
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory.,Kirby Institute, University of New South Wales, Sydney, Australia
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12
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Welch VA, Ghogomu E, Hossain A, Riddle A, Gaffey M, Arora P, Dewidar O, Salam R, Cousens S, Black R, Hollingsworth TD, Horton S, Tugwell P, Bundy D, Castro MC, Elliott A, Friis H, Le HT, Liu C, Rousham EK, Rohner F, King C, Sartono E, Supali T, Steinmann P, Webb E, Wieringa F, Winnichagoon P, Yazdanbakhsh M, Bhutta ZA, Wells G. Mass deworming for improving health and cognition of children in endemic helminth areas: A systematic review and individual participant data network meta-analysis. CAMPBELL SYSTEMATIC REVIEWS 2019; 15:e1058. [PMID: 37131850 PMCID: PMC8356492 DOI: 10.1002/cl2.1058] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Background Soil transmitted (or intestinal) helminths and schistosomes affect millions of children worldwide. Objectives To use individual participant data network meta-analysis (NMA) to explore the effects of different types and frequency of deworming drugs on anaemia, cognition and growth across potential effect modifiers. Search Methods We developed a search strategy with an information scientist to search MEDLINE, CINAHL, LILACS, Embase, the Cochrane Library, Econlit, Internet Documents in Economics Access Service (IDEAS), Public Affairs Information Service (PAIS), Social Services Abstracts, Global Health CABI and CAB Abstracts up to March 27, 2018. We also searched grey literature, websites, contacted authors and screened references of relevant systematic reviews. Selection Criteria We included randomised and quasirandomised deworming trials in children for deworming compared to placebo or other interventions with data on baseline infection. Data Collection and Analysis We conducted NMA with individual participant data (IPD), using a frequentist approach for random-effects NMA. The covariates were: age, sex, weight, height, haemoglobin and infection intensity. The effect estimate chosen was the mean difference for the continuous outcome of interest. Results We received data from 19 randomized controlled trials with 31,945 participants. Overall risk of bias was low. There were no statistically significant subgroup effects across any of the potential effect modifiers. However, analyses showed that there may be greater effects on weight for moderate to heavily infected children (very low certainty evidence). Authors' Conclusions This analysis reinforces the case against mass deworming at a population-level, finding little effect on nutritional status or cognition. However, children with heavier intensity infections may benefit more. We urge the global community to adopt calls to make data available in open repositories to facilitate IPD analyses such as this, which aim to assess effects for the most vulnerable individuals.
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Affiliation(s)
- Vivian A. Welch
- Centre for Global HealthBruyère Research InstituteOttawaOntarioCanada
- School of EpidemiologyPublic Health and Preventive Medicine, University of OttawaOttawaOntarioCanada
| | | | - Alomgir Hossain
- Cardiovascular Research MethodsUniversity of Ottawa Heart InstituteOttawaOntarioCanada
| | - Alison Riddle
- School of EpidemiologyPublic Health and Preventive Medicine, University of OttawaOttawaOntarioCanada
| | - Michelle Gaffey
- Hospital for Sick ChildrenUniversity of TorontoTorontoOntarioCanada
| | - Paul Arora
- Public Health Agency of Canada in the National Public Health Laboratory and Dalla Lana School of Public HealthUniversity of TorontoTorontoOntarioCanada
| | - Omar Dewidar
- Bruyère Research InstituteUniversity of OttawaOttawaOntarioCanada
| | - Rehana Salam
- South Australian Health and Medical Research InstituteUniversity of AdelaideAdelaideAustralia
| | - Simon Cousens
- London School of Hygiene and Tropical Medicine (LSHTM)LondonUK
| | - Robert Black
- Department of International HealthJohns Hopkins School of Hygiene and Public HealthBaltimoreMaryland
| | - T. Déirdre Hollingsworth
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Sue Horton
- School of Public Health and Health SystemsUniversity of WaterlooWaterlooOntarioCanada
| | - Peter Tugwell
- School of EpidemiologyPublic Health and Preventive Medicine, University of OttawaOttawaOntarioCanada
- Center for Global Health, WHO Collaborating Centre for Knowledge Translation and Health Technology Assessment in Health EquityBruyère Research InstituteOttawaOntarioCanada
| | | | | | - Alison Elliott
- Medical Research Council/Uganda Virus Research InstituteLondon School of Hygiene and Tropical Medicine Uganda Research UnitEntebbeUganda
| | - Henrik Friis
- Department of Human NutritionUniversity of CopenhagenFrederiksbergDenmark
| | - Huong T. Le
- Institute for Preventive Medicine and Public HealthHanoi Medical UniversityHanoiVietnam
| | - Chengfang Liu
- School of Advanced Agricultural Sciences (SAAS)China Center for Agricultural Policy (CCAP), Peking UniversityBeijingChina
| | - Emily K. Rousham
- School of Sport, Exercise and Health SciencesLoughborough UniversityLeicestershireUK
| | | | - Charles King
- Department of PediatricsUniversity of CaliforniaLa JollaCalifornia
| | - Erliyani Sartono
- Department of ParasitologyLeiden University Medical CenterLeidenThe Netherlands
| | - Taniawati Supali
- Department Parasitology, Faculty of MedicineUniversitas IndonesiaJakartaIndonesia
| | - Peter Steinmann
- Swiss Tropical and Public Health InstituteUniversity of BaselBaselSwitzerland
| | - Emily Webb
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population HealthLondon School of Hygiene and Tropical MedicineLondonUK
| | - Franck Wieringa
- UMR204 NutripassInstitute de Recherche pour le DéveloppementMontpellierFrance
| | - Pattanee Winnichagoon
- Community/International Nutrition, Institute of NutritionMahidol UniversityNakhon PathomThailand
| | - Maria Yazdanbakhsh
- Department of ParasitologyLeiden University Medical CenterLeidenThe Netherlands
| | - Zulfiqar A. Bhutta
- Centre for Global Child Health, The Hospital for Sick Children, Center of Excellence in Women and Child HealthAga Khan UniversityKarachiPakistan
| | - George Wells
- Cardiovascular Research MethodsUniversity of Ottawa Heart InstituteOttawaOntarioCanada
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Taylor‐Robinson DC, Maayan N, Donegan S, Chaplin M, Garner P. Public health deworming programmes for soil-transmitted helminths in children living in endemic areas. Cochrane Database Syst Rev 2019; 9:CD000371. [PMID: 31508807 PMCID: PMC6737502 DOI: 10.1002/14651858.cd000371.pub7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND The World Health Organization (WHO) recommends treating all school children at regular intervals with deworming drugs in areas where helminth infection is common. Global advocacy organizations claim routine deworming has substantive health and societal effects beyond the removal of worms. In this update of the 2015 edition we included six new trials, additional data from included trials, and addressed comments and criticisms. OBJECTIVES To summarize the effects of public health programmes to regularly treat all children with deworming drugs on child growth, haemoglobin, cognition, school attendance, school performance, physical fitness, and mortality. SEARCH METHODS We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; Embase; LILACS; the metaRegister of Controlled Trials (mRCT); reference lists; and registers of ongoing and completed trials up to 19 September 2018. SELECTION CRITERIA We included randomized controlled trials (RCTs) and quasi-RCTs that compared deworming drugs for soil-transmitted helminths (STHs) with placebo or no treatment in children aged 16 years or less, reporting on weight, height, haemoglobin, and formal tests of cognition. We also sought data on other measures of growth, school attendance, school performance, physical fitness, and mortality. DATA COLLECTION AND ANALYSIS At least two review authors independently assessed the trials for inclusion, risk of bias, and extracted data. We analysed continuous data using the mean difference (MD) with 95% confidence intervals (CIs). Where data were missing, we contacted trial authors. We stratified the analysis based on the background burden of STH infection. We used outcomes at time of longest follow-up. We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS We identified 51 trials, including 10 cluster-RCTs, that met the inclusion criteria. One trial evaluating mortality included over one million children, and the remaining 50 trials included a total of 84,336 participants. Twenty-four trials were in populations categorized as high burden, including nine trials in children selected because they were helminth-stool positive; 18 with intermediate burden; and nine as low burden.First or single dose of deworming drugsFourteen trials reported on weight after a single dose of deworming drugs (4970 participants, 14 RCTs). The effects were variable. There was little or no effect in studies conducted in low and intermediate worm burden groups. In the high-burden group, there was little or no effect in most studies, except for a large effect detected from one study area in Kenya reported in two trials carried out over 30 years ago. These trials result in qualitative heterogeneity and uncertainty in the meta-analysis across all studies (I2 statistic = 90%), with GRADE assessment assessed as very low-certainty, which means we do not know if a first dose or single dose of deworming impacts on weight.For height, most studies showed little or no effect after a single dose, with one of the two trials in Kenya from 30 years ago showing a large average difference (2621 participants, 10 trials, low-certainty evidence). Single dose probably had no effect on average haemoglobin (MD 0.10 g/dL, 95% CI 0.03 lower to 0.22 higher; 1252 participants, five trials, moderate-certainty evidence), or on average cognition (1596 participants, five trials, low-certainty evidence). The data are insufficient to know if there is an effect on school attendance and performance (304 participants, one trial, low-certainty evidence), or on physical fitness (280 participants, three trials, very low-certainty evidence). No trials reported on mortality.Multiple doses of deworming drugsThe effect of regularly treating children with deworming drugs given every three to six months on weight was reported in 18 trials, with follow-up times of between six months and three years; there was little or no effect on average weight in all but two trials, irrespective of worm prevalence-intensity. The two trials with large average weight gain included one in the high burden area in Kenya carried out over 30 years ago, and one study from India in a low prevalence area where subsequent studies in the same area did not show an effect. This heterogeneity causes uncertainty in any meta-analysis (I2 = 78%). Post-hoc analysis excluding trials published prior to 2000 gave an estimate of average difference in weight gain of 0.02 kg (95%CI from 0.04 kg loss to 0.08 gain, I2 = 0%). Thus we conclude that we do not know if repeated doses of deworming drugs impact on average weight, with a fewer older studies showing large gains, and studies since 2000 showing little or no average gain.Regular treatment probably had little or no effect on the following parameters: average height (MD 0.02 cm higher, 95% CI 0.09 lower to 0.13 cm higher; 13,700 participants, 13 trials, moderate-certainty evidence); average haemoglobin (MD 0.01 g/dL lower; 95% CI 0.05 g/dL lower to 0.07 g/dL higher; 5498 participants, nine trials, moderate-certainty evidence); formal tests of cognition (35,394 participants, 8 trials, moderate-certainty evidence); school performance (34,967 participants, four trials, moderate-certainty evidence). The evidence assessing an effect on school attendance is inconsistent, and at risk of bias (mean attendance 2% higher, 95% CI 5% lower to 8% higher; 20,650 participants, three trials, very low-certainty evidence). No trials reported on physical fitness. No effect was shown on mortality (1,005,135 participants, three trials, low-certainty evidence). AUTHORS' CONCLUSIONS Public health programmes to regularly treat all children with deworming drugs do not appear to improve height, haemoglobin, cognition, school performance, or mortality. We do not know if there is an effect on school attendance, since the evidence is inconsistent and at risk of bias, and there is insufficient data on physical fitness. Studies conducted in two settings over 20 years ago showed large effects on weight gain, but this is not a finding in more recent, larger studies. We would caution against selecting only the evidence from these older studies as a rationale for contemporary mass treatment programmes as this ignores the recent studies that have not shown benefit.The conclusions of the 2015 edition have not changed in this update.
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Affiliation(s)
| | - Nicola Maayan
- Independent consultantLondonUK
- Cochrane ResponseLondonUK
| | - Sarah Donegan
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesLiverpoolMerseysideUKL3 5QA
| | - Marty Chaplin
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesLiverpoolMerseysideUKL3 5QA
| | - Paul Garner
- Liverpool School of Tropical MedicineDepartment of Clinical SciencesLiverpoolMerseysideUKL3 5QA
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14
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Owada K, Nielsen M, Lau CL, Yakob L, Clements ACA, Leonardo L, Soares Magalhães RJ. Functional illiteracy burden in soil-transmitted helminth (STH) endemic regions of the Philippines: An ecological study and geographical prediction for 2017. PLoS Negl Trop Dis 2019; 13:e0007494. [PMID: 31226111 PMCID: PMC6588226 DOI: 10.1371/journal.pntd.0007494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 05/26/2019] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infections remain highly endemic across the Philippines, and are believed to be important contributors to delayed cognitive development of school-aged children. Identification of communities where children are at risk of functional illiteracy is important for the attainment of Sustainable Development Goals target for literacy. We aimed to quantify the associations between the spatial variation of STH infections and functional literacy indicators adjusting for other important contributors, and identify priority areas in the Philippines in need of interventions. METHODOLOGY/PRINCIPAL FINDINGS We used data from 11,313 school-aged children on functional literacy indicators collected in 2008. Nested fixed-effects multinomial regression models were built to determine associations between STH endemicity and geographical distribution of functional literacy, adjusting for demographics, household level variables, and the prevalence of malaria. Bayesian multinomial geostatistical models were built to geographically predict the prevalence of each level of functional literacy. The number of school-aged children belonging to each of the functional literacy indicator classes was forecast for 2017. We estimated 4.20% of functional illiteracy burden among school-aged children in Mindanao might be averted by preventing T. trichiura infections. Areas predicted with the highest prevalence of functional illiteracy were observed in localised areas of the eastern region of the Visayas, and the south-eastern portion of Mindanao. CONCLUSIONS/SIGNIFICANCE The study demonstrates significant geographical variation in burden of functional illiteracy in school-aged children associated with STH infections suggesting that targeted helminth control could potentially promote the development of cognitive function of school-aged children in the Philippines. The benefits of a spatially targeted strategy should be tested by future studies.
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Affiliation(s)
- Kei Owada
- School of Medicine, The University of Queensland, South Brisbane, Queensland, Australia
- Children’s Health and Environment Program, Child Health Research Centre, The University of Queensland, South Brisbane, Queensland, Australia
- Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
| | - Mark Nielsen
- School of Psychology, The University of Queensland, St Lucia, Queensland, Australia
- Faculty of Humanities, University of Johannesburg, Auckland Park, South Africa
| | - Colleen L. Lau
- Children’s Health and Environment Program, Child Health Research Centre, The University of Queensland, South Brisbane, Queensland, Australia
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Laith Yakob
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Archie C. A. Clements
- Research School of Population Health, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Lydia Leonardo
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Manila, Philippines
| | - Ricardo J. Soares Magalhães
- Children’s Health and Environment Program, Child Health Research Centre, The University of Queensland, South Brisbane, Queensland, Australia
- Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
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15
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Abstract
The soil-transmitted helminths (STHs), Ascaris lumbricoides, hookworm and Trichuris trichiura are common in areas with warm and moist climates with little access to adequate water, sanitation, and hygiene affecting the poorest populations. The current control strategy of the World Health Organization is preventive chemotherapy (PC), i.e., the administration of the two benzimidazoles (albendazole and mebendazole) using single, oral doses to at risk populations without prior diagnosis. The recent success of PC is threatened by anthelmintic drug resistance and the low efficacy of the drugs against hookworm (mebendazole) and T. trichiura (albendazole and mebendazole). Only a handful of alternative drugs with anthelmintic properties are available, however, none of the drugs show high efficacy against all three STHs. The combination of two drugs with different activity profiles presents an attractive alternative, which could prevent the development of drug resistance and increase the efficacy compared to monotherapy. In this review, we summarize the efficacy of current and alternative anthelmintics, coadministrations and triple drug therapies assessed by means of network meta-analysis including only randomized controlled trials. Our results highlight that coadministrations have improved efficacy over monotherapy and the necessity of adapting current STH control strategies for the successful continuation of PC programs.
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16
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Owada K, Lau CL, Leonardo L, Clements ACA, Yakob L, Nielsen M, Carabin H, Soares Magalhães RJ. Spatial distribution and populations at risk of A. lumbricoides and T. trichiura co-infections and infection intensity classes: an ecological study. Parasit Vectors 2018; 11:535. [PMID: 30285906 PMCID: PMC6171148 DOI: 10.1186/s13071-018-3107-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 09/11/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Soil-transmitted helminth (STH) infections are highly prevalent in the Philippines. Mapping the prevalence and high-intensity of STH co-infections can help guide targeted intervention programmes to reduce morbidity, especially among vulnerable school-aged children. In this study, we aimed to predict the spatial distribution of the prevalence of Ascaris lumbricoides and Trichuris trichiura co-infection and infection intensity classes in the Philippines to identify populations most in need of interventions. METHODS Data on STH infections from 29,919 individuals during the nationwide parasitological survey in 2005 to 2007 were included in the analysis. To geographically predict the prevalence of A. lumbricoides and T. trichiura co-infections and infection intensity classes, Bayesian multinomial geostatistical models were built including age, sex, environmental variables and a geostatistical random effect. The number of individuals co-infected and belonging to each of the infection intensity classes in 2017 was forecast by combining our predictive prevalence maps with population density maps. RESULTS Our models showed that school-aged children (5-19 years) are most at risk of A. lumbricoides and T. trichiura co-infections and of moderate/high infection intensity compared to other age groups. We identified target provinces where the likelihood of STH-associated morbidity was highest: Luzon (Bulacan, Benguet, Cavite, Sorsogon, Metropolitan Manila, Pampanga and Rizal), the Visayas (Cebu, Iloilo, Leyte and Negros Occidental), and in Mindanao (Agusan Del Norte, Davao Del Sur, Davao Oriental, Lanao Del Sur, Maguindanao, Misamis Oriental, Sulu and Zamboanga Del Sur). Luzon had the highest estimated number of school-aged children with A. lumbricoides and T. trichiura co-infections (estimated total 89,400), followed by the Visayas (38,300) and Mindanao (20,200). CONCLUSIONS Our study provided epidemiological evidence to highlight national priority areas for controlling co-infections and high intensity infections in the Philippines. Our maps could assist more geographically targeted interventions to reduce the risk of STH-associated morbidity in the Philippines.
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Affiliation(s)
- Kei Owada
- School of Medicine, The University of Queensland, QLD, South Brisbane, Australia. .,Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, QLD, South Brisbane, Australia.
| | - Colleen L Lau
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, QLD, South Brisbane, Australia.,Research School of Population Health, Australian National University, ACT, Canberra, Australia
| | - Lydia Leonardo
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Manila, Philippines
| | - Archie C A Clements
- Research School of Population Health, Australian National University, ACT, Canberra, Australia
| | - Laith Yakob
- Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
| | - Mark Nielsen
- School of Psychology, The University of Queensland, QLD, St Lucia, Australia.,Faculty of Humanities, University of Johannesburg, Auckland Park, South Africa
| | - Hélène Carabin
- Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma, USA
| | - Ricardo J Soares Magalhães
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, QLD, South Brisbane, Australia.,Spatial Epidemiology Laboratory, School of Veterinary Science, The University of Queensland, QLD, Gatton, Australia
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New Advances in the Treatment of Trichuriasis. CURRENT TREATMENT OPTIONS IN INFECTIOUS DISEASES 2018. [DOI: 10.1007/s40506-018-0169-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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18
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Barda B, Ame SM, Ali SM, Albonico M, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and tolerability of moxidectin alone and in co-administration with albendazole and tribendimidine versus albendazole plus oxantel pamoate against Trichuris trichiura infections: a randomised, non-inferiority, single-blind trial. THE LANCET. INFECTIOUS DISEASES 2018; 18:864-873. [DOI: 10.1016/s1473-3099(18)30233-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 12/26/2022]
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Schulz JD, Moser W, Hürlimann E, Keiser J. Preventive Chemotherapy in the Fight against Soil-Transmitted Helminthiasis: Achievements and Limitations. Trends Parasitol 2018; 34:590-602. [DOI: 10.1016/j.pt.2018.04.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 04/26/2018] [Accepted: 04/27/2018] [Indexed: 02/06/2023]
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Moser W, Sayasone S, Xayavong S, Bounheuang B, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and tolerability of triple drug therapy with albendazole, pyrantel pamoate, and oxantel pamoate compared with albendazole plus oxantel pamoate, pyrantel pamoate plus oxantel pamoate, and mebendazole plus pyrantel pamoate and oxantel pamoate against hookworm infections in school-aged children in Laos: a randomised, single-blind trial. THE LANCET. INFECTIOUS DISEASES 2018; 18:729-737. [DOI: 10.1016/s1473-3099(18)30220-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 02/27/2018] [Accepted: 03/13/2018] [Indexed: 11/28/2022]
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De Rycker M, Baragaña B, Duce SL, Gilbert IH. Challenges and recent progress in drug discovery for tropical diseases. Nature 2018; 559:498-506. [PMID: 30046073 PMCID: PMC6129172 DOI: 10.1038/s41586-018-0327-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023]
Abstract
Infectious tropical diseases have a huge effect in terms of mortality and morbidity, and impose a heavy economic burden on affected countries. These diseases predominantly affect the world's poorest people. Currently available drugs are inadequate for the majority of these diseases, and there is an urgent need for new treatments. This Review discusses some of the challenges involved in developing new drugs to treat these diseases and highlights recent progress. While there have been notable successes, there is still a long way to go.
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Affiliation(s)
- Manu De Rycker
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK
| | - Beatriz Baragaña
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK
| | - Suzanne L Duce
- Medicines Monitoring Unit (MEMO), Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Ian H Gilbert
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences, University of Dundee, Dundee, UK.
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Palmeirim MS, Hürlimann E, Knopp S, Speich B, Belizario V, Joseph SA, Vaillant M, Olliaro P, Keiser J. Efficacy and safety of co-administered ivermectin plus albendazole for treating soil-transmitted helminths: A systematic review, meta-analysis and individual patient data analysis. PLoS Negl Trop Dis 2018; 12:e0006458. [PMID: 29702653 PMCID: PMC5942849 DOI: 10.1371/journal.pntd.0006458] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 05/09/2018] [Accepted: 04/18/2018] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The soil-transmitted helminths (STH), Ascaris lumbricoides, Trichuris trichiura and hookworms, infect 1.5 billion people worldwide and cause an estimated burden of 3.3 million disability-adjusted life years (DALYs). Current control strategies focus on morbidity reduction through preventive chemotherapy (PC) but the most commonly used recommended drugs (albendazole and mebendazole) are particularly inefficacious against T. trichiura. This, together with the threat of emerging drug resistance, calls for new control strategies, including co-administration with other anthelminthics. Ivermectin plus albendazole is widely used against lymphatic filariasis, but its efficacy and safety against STH infections has not yet been fully understood. METHODS AND FINDINGS We conducted a systematic literature review and meta-analysis on the efficacy and safety of ivermectin-albendazole co-administration in five different databases (i.e. PubMed, ISI Web of Science, ScienceDirect, CENTRAL and clinicaltrials.gov) from 1960 to January 2018. Four studies reporting efficacy of ivermectin-albendazole against STH infections and five studies on its safety met the selection criteria and were included for quantitative analysis. Ivermectin-albendazole was significantly associated with lower risk (risk ratio (RR) = 0.44, 95% confidence interval (CI) = 0.31-0.62) for T. trichiura infection after treatment compared to albendazole alone. The co-administration revealed no or only a marginal benefit on cure and egg reduction rates over albendazole alone for A. lumbricoides and hookworm infections. Adverse events (AEs) occurring after ivermectin-albendazole co-administration were mostly mild and transient. Overall, the number of individuals reporting any AE was not different (RR = 1.09, 95% CI = 0.87-1.36) in co-treated and albendazole-treated patients. However, although not statistically significant, sub-group analysis showed a tendency for slightly more AEs in patients with filariasis treated with ivermectin-albendazole compared to those treated with albendazole alone (RR = 1.29, 95% CI = 0.81-2.05). CONCLUSIONS Our findings suggest a good tolerability and higher efficacy of ivermectin-albendazole against T. trichiura compared to the current standard single-dose albendazole treatment, which supports the use of this co-administration in PC programs. Large-scale definitive randomized controlled trials are required to confirm our results.
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Affiliation(s)
- Marta S. Palmeirim
- 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
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Benjamin Speich
- Basel Institute for Clinical Epidemiology and Biostatistics, Department of Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland
| | - Vicente Belizario
- Department of Parasitology, College of Public Health, University of the Philippines Manila, Metro Manila, Philippines
| | | | | | - Piero Olliaro
- Special Programme for Research & Training in Tropical Diseases (TDR), World Health Organization, Geneva, Switzerland
| | - Jennifer Keiser
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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Jourdan PM, Lamberton PHL, Fenwick A, Addiss DG. Soil-transmitted helminth infections. Lancet 2018; 391:252-265. [PMID: 28882382 DOI: 10.1016/s0140-6736(17)31930-x] [Citation(s) in RCA: 374] [Impact Index Per Article: 62.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 06/13/2017] [Accepted: 06/23/2017] [Indexed: 12/13/2022]
Abstract
More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections.
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Affiliation(s)
- Peter Mark Jourdan
- Schistosomiasis Control Initiative, Imperial College London, St Mary's Campus, London, UK; DEWORM3, Natural History Museum, London, UK; Norwegian Centre for Imported and Tropical Diseases, Department of Infectious Diseases, Oslo University Hospital, Ullevål, Oslo, Norway
| | - Poppy H L Lamberton
- Department of Infectious Disease Epidemiology, Imperial College London, St Mary's Campus, London, UK; Institute of Biodiversity, Animal Health and Comparative Medicine, The University of Glasgow, Glasgow, UK; Wellcome Centre for Molecular Parasitology, The University of Glasgow, Glasgow, UK.
| | - Alan Fenwick
- Schistosomiasis Control Initiative, Imperial College London, St Mary's Campus, London, UK
| | - David G Addiss
- The Task Force for Global Health, Decatur, GA, USA; Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, USA
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Moser W, Schindler C, Keiser J. Efficacy of recommended drugs against soil transmitted helminths: systematic review and network meta-analysis. BMJ 2017; 358:j4307. [PMID: 28947636 PMCID: PMC5611648 DOI: 10.1136/bmj.j4307] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Objective To evaluate efficacies of anthelmintic drugs against soil transmitted helminths in terms of cure rates and egg reduction rates.Design Systematic review and network meta-analysis.Data Sources PubMed, ISI Web of Science, Embase, ScienceDirect, the Cochrane Central Register of Clinical Trials, and the World Health Organization library database from 1960 until 31 December 2016.Study selection Randomised controlled trials evaluating the efficacy of a single dose regimen of albendazole, mebendazole, levamisole, and pyrantel pamoate against Ascaris lumbricoides, hookworm (Necator americanus and Ancylostoma duodenale) and Trichuris trichiura. The primary outcomes included cure rates analysed by network meta-analysis with mixed logistic regression models and egg reduction rates with mixed linear models.Results 55 and 46 randomised controlled trials were included in the analysis of cure rates and egg reduction rates, respectively. All drugs were highly efficacious against A lumbricoides Albendazole showed the highest efficacy against hookworm infections with a cure rate of 79.5% (95% confidence interval 71.5% to 85.6%) and an egg reduction rate of 89.6% (81.9% to 97.3%). All drugs had low efficacy against T trichiura, with mebendazole showing the highest cure rate of 42.1% (25.9% to 60.2%) and egg reduction rate of 66.0% (54.6% to 77.3%). Estimates for the years 1995 and 2015 showed significant reductions in efficacy of albendazole against T trichiura: by 2015 the egg reduction rates fell from 72.6% (53.7% to 91.5%) to 43.4% (23.5% to 63.3%; P=0.049) and the cure rates fell from 38.6% (26.2% to 52.7%) to 16.4 (7.7% to 31.3%; P=0.027).Conclusions All four currently recommended drugs show limitations in their efficacy profile. While only albendazole showed good efficacy against hookworm infection, all drugs had low efficacy against T trichiura The decrease in efficacy of albendazole against T trichiura over the past two decades is of concern. The findings indicate the need for strengthening efforts to develop new drug treatments, with a particular focus on drugs against T trichiura.
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Affiliation(s)
- Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Christian Schindler
- University of Basel, Basel, Switzerland
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, PO Box, CH-4002 Basel, Switzerland
- University of Basel, Basel, Switzerland
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Moser W, Coulibaly JT, Ali SM, Ame SM, Amour AK, Yapi RB, Albonico M, Puchkov M, Huwyler J, Hattendorf J, Keiser J. Efficacy and safety of tribendimidine, tribendimidine plus ivermectin, tribendimidine plus oxantel pamoate, and albendazole plus oxantel pamoate against hookworm and concomitant soil-transmitted helminth infections in Tanzania and Côte d'Ivoire: a randomised, controlled, single-blinded, non-inferiority trial. THE LANCET. INFECTIOUS DISEASES 2017; 17:1162-1171. [PMID: 28864027 DOI: 10.1016/s1473-3099(17)30487-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 06/30/2017] [Accepted: 07/18/2017] [Indexed: 01/31/2023]
Abstract
BACKGROUND Preventive chemotherapy is the current strategy to control soil-transmitted helminth infections (caused by Ascaris lumbricoides, hookworm, and Trichuris trichiura). But, to improve efficacy and avoid emerging resistance, new drugs are warranted. Tribendimidine has shown good anthelmintic efficacy and is therefore a frontrunner for monotherapy and combination chemotherapy. METHODS We did a randomised, controlled, single-blinded, non-inferiority trial on Pemba Island, Tanzania, and in Côte d'Ivoire. We recruited adolescents aged 15-18 years from four primary schools on Pemba, and school attendees and non-schoolers from two districts in Côte d'Ivoire. Only hookworm-positive participants were randomly assigned (1:1:1:1) to single, oral doses of tribendimidine 400 mg plus placebo (tribendimidine monotherapy), tribendimidine 400 mg plus ivermectin 200 μg/kg, tribendimidine 400 mg plus oxantel pamoate 25 mg/kg, or albendazole 400 mg plus oxantel pamoate 25 mg/kg. Randomisation was done via a computer-generated list in block sizes of four or eight. Participants were asked to provide two stool samples on 2 consecutive days at baseline and again 14-21 days at follow-up. The primary outcome was the difference in egg-reduction rates (ERRs; ie, the geometric mean reduction) in hookworm egg counts between treatment groups, measured by the Kato-Katz technique. Differences in coadministrated treatment groups were assessed for non-inferiority with a margin of -3% to albendazole plus oxantel pamoate based on the available-case population, analysed by intention to treat. Safety was assessed 3 h and 24 h after treatment. This study is registered with ISRCTN (number 14373201). FINDINGS Between July 26, and Dec 23, 2016, we treated 636 hookworm-positive participants, and outcome data were available for 601 participants (151 assigned to tribendimidine monotherapy, 154 to tribendimidine plus ivermectin, 148 to tribendimidine plus oxantel pamoate, and 148 to albendazole plus oxantel pamoate). Tribendimidine plus ivermectin was non-inferior to albendazole plus oxantel pamoate (ERRs 99·5% [95% CI 99·2-99·7] vs 96·0% [93·9-97·4]; difference 3·52 percentage points [2·05-5·65]). Likewise, tribendimidine plus oxantel pamoate was non-inferior to albendazole plus oxantel pamoate (ERRs 96·5% [95% CI 94·9 to 97·6] vs 96·0% [93·9 to 97·4]; difference 0·48 percentage points [-1·61 to 2·88]). 3 h after treatment, headache (n=50 [8%]) and vertigo (n=37 [6%]) were the most widely reported symptoms; 24 h after treatment, 50 (8%) patients reported vertigo and 41 (7%) reported headache. Mainly mild adverse events were reported with peak numbers (n=111 [18%]) at 24 h after treatment. Three participants had moderate adverse events 3 h after treatment: two (<1%) had vertigo and one (<1%) had headache, and two had moderate adverse events 24 h after treatment: one (<1%) had vomiting and one (<1%) had vomiting plus diarrhoea. INTERPRETATION Tribendimidine in combination with either ivermectin or oxantel pamoate had a similar, non-inferior efficacy profile as albendazole plus oxantel pamoate, hence tribendimidine will be a useful addition to the depleted anthelmintic drug armamentarium. FUNDING Swiss National Science Foundation.
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Affiliation(s)
- Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland
| | - Jean T Coulibaly
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland; Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Said M Ali
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Shaali M Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Amour K Amour
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania
| | - Richard B Yapi
- Centre Suisse de Recherches Scientifiques, Abidjan, Côte d'Ivoire
| | - Marco Albonico
- Centre for Tropical Diseases, Sacro Cuore Hospital, Negrar Verona, and University of Turin, Turin, Italy
| | - Maxim Puchkov
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | - Jörg Huwyler
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Technology, University of Basel, Basel, Switzerland
| | - Jan Hattendorf
- Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, and University of Basel, Basel, Switzerland.
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Partridge FA, Murphy EA, Willis NJ, Bataille CJR, Forman R, Heyer-Chauhan N, Marinič B, Sowood DJC, Wynne GM, Else KJ, Russell AJ, Sattelle DB. Dihydrobenz[e][1,4]oxazepin-2(3H)-ones, a new anthelmintic chemotype immobilising whipworm and reducing infectivity in vivo. PLoS Negl Trop Dis 2017; 11:e0005359. [PMID: 28182663 PMCID: PMC5321434 DOI: 10.1371/journal.pntd.0005359] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 02/22/2017] [Accepted: 01/26/2017] [Indexed: 01/07/2023] Open
Abstract
Trichuris trichiura is a human parasitic whipworm infecting around 500 million people globally, damaging the physical growth and educational performance of those infected. Current drug treatment options are limited and lack efficacy against the worm, preventing an eradication programme. It is therefore important to develop new treatments for trichuriasis. Using Trichuris muris, an established model for T. trichiura, we screened a library of 480 novel drug-like small molecules for compounds causing paralysis of the ex vivo adult parasite. We identified a class of dihydrobenz[e][1,4]oxazepin-2(3H)-one compounds with anthelmintic activity against T. muris. Further screening of structurally related compounds and resynthesis of the most potent molecules led to the identification of 20 active dihydrobenzoxazepinones, a class of molecule not previously implicated in nematode control. The most active immobilise adult T. muris with EC50 values around 25–50μM, comparable to the existing anthelmintic levamisole. The best compounds from this chemotype show low cytotoxicity against murine gut epithelial cells, demonstrating selectivity for the parasite. Developing a novel oral pharmaceutical treatment for a neglected disease and deploying it via mass drug administration is challenging. Interestingly, the dihydrobenzoxazepinone OX02983 reduces the ability of embryonated T. muris eggs to establish infection in the mouse host in vivo. Complementing the potential development of dihydrobenzoxazepinones as an oral anthelmintic, this supports an alternative strategy of developing a therapeutic that acts in the environment, perhaps via a spray, to interrupt the parasite lifecycle. Together these results show that the dihydrobenzoxazepinones are a new class of anthelmintic, active against both egg and adult stages of Trichuris parasites. They demonstrate encouraging selectivity for the parasite, and importantly show considerable scope for further optimisation to improve potency and pharmacokinetic properties with the aim of developing a clinical agent. Trichuris trichiura is a human parasitic whipworm infecting around 500 million people globally and having major consequences on the physical growth and educational performance of those infected. Current drug treatment options are limited and lack efficacy against the worm. Critically, they lack the effectiveness that would allow for a practical program for eradication of this parasite. It is therefore important to develop new treatments for trichuriasis. We screened for molecules that could paralyse the adult of a closely related mouse parasite, and identified a class of compounds, the dihydrobenzoxazepinones, not previously implicated as anthelmintics. Importantly, our compounds are active against the parasite but show only low toxicity against mouse cells, demonstrating selectivity for the parasite. Dihydrobenzoxazepinones could be developed as potential pharmaceutical treatments for trichuriasis. Since developing and deploying new drugs for neglected diseases by mass administration is challenging, we also explored whether the compounds could potentially be used to interrupt the Trichuris lifecycle by acting on eggs. Our dihydrobenzoxazepinone compounds reduced the ability of T. muris eggs to establish infection in their mouse host. This supports an environmental spray strategy for the control of Trichuris targeting their eggs in environmental hotspots such as latrines.
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Affiliation(s)
- Frederick A. Partridge
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Emma A. Murphy
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Nicky J. Willis
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Carole J. R. Bataille
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Ruth Forman
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Narinder Heyer-Chauhan
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
| | - Bruno Marinič
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Daniel J. C. Sowood
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Graham M. Wynne
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
| | - Kathryn J. Else
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
| | - Angela J. Russell
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
| | - David B. Sattelle
- Centre for Respiratory Biology, UCL Respiratory, Division of Medicine, University College London, London, United Kingdom
- * E-mail: (KJE); (AJR); (DBS)
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Hansen TVA, Hansen M, Nejsum P, Mejer H, Denwood M, Thamsborg SM. Glucose Absorption by the Bacillary Band of Trichuris muris. PLoS Negl Trop Dis 2016; 10:e0004971. [PMID: 27588682 PMCID: PMC5010283 DOI: 10.1371/journal.pntd.0004971] [Citation(s) in RCA: 16] [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: 04/25/2016] [Accepted: 08/10/2016] [Indexed: 12/20/2022] Open
Abstract
Background A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown. Methodology We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG) and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose. Principal Findings Glucose had a positive effect on both the motility (p < 0.001) and metabolic activity (p < 0.001) of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing. Conclusions/Significance Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development. The human whipworm, Trichuris trichiura is prevalent in many tropical and subtropical countries and is believed to infect more than 460 million people worldwide. Treatment with single-dose albendazole or mebendazole is the current control strategy for human trichuriasis. This strategy, however, has a poor-to-mediocre treatment effect. The reason for the low treatment efficacy has been assessed in various ways, including genetic analysis, and both in vitro and in vivo pharmacological studies. However, these studies have not been conclusive and did not evaluate whether the biology of Trichuris spp. may have an impact on the inadequate treatment efficacy. To assess a possible reason for this, we here explore the absorptive function of a specialised structure, named the bacillary band. We found that glucose was absorbed by the band and accumulated within the worm independent of oral ingestion, and we speculate that anthelmintics may enter the worm by the same route. If this is the case, this new insight may be used to optimise drug formulations of current and/or future anthelmintic drugs in the treatment of human trichuriasis.
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Affiliation(s)
- Tina V. A. Hansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
- * E-mail:
| | - Michael Hansen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg, Denmark
| | - Peter Nejsum
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Helena Mejer
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Matthew Denwood
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Stig M. Thamsborg
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
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Speich B, Moser W, Ali SM, Ame SM, Albonico M, Hattendorf J, Keiser J. Efficacy and reinfection with soil-transmitted helminths 18-weeks post-treatment with albendazole-ivermectin, albendazole-mebendazole, albendazole-oxantel pamoate and mebendazole. Parasit Vectors 2016; 9:123. [PMID: 26935065 PMCID: PMC4776366 DOI: 10.1186/s13071-016-1406-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Accepted: 02/24/2016] [Indexed: 11/12/2022] Open
Abstract
Background Preventive chemotherapy with albendazole or mebendazole is the current strategy to control soil-transmitted helminth (STH) infections (i.e. Ascaris lumbricoides, hookworm and Trichuris trichiura). STH reinfections, in particular A. lumbricoides and T. trichiura occur rapidly after treatment with the standard drugs. However, their low efficacy against T. trichiura, made an accurate assessment of reinfection patterns impossible. Methods In 2013 a randomised controlled trial was conducted on Pemba Island, Tanzania. School-aged children diagnosed positive for T. trichiura, were randomly allocated to (i) albendazole-ivermectin; (ii) albendazole-mebendazole; (iii) albendazole-oxantel pamoate; or (iv) mebendazole. Here we report the efficacy [cure rates (CR) and egg-reduction rates (ERR)], reinfection rates and new infections determined 18 weeks post-treatment. Results For a total of 405 children complete baseline and follow-up data were available. Similar to the efficacy determined after 3 weeks, 18 weeks after treatment albendazole-oxantel pamoate showed a significantly higher efficacy against T. trichiura (CR: 54.0 %, 95 % CI: 43.7–64.0; ERR: 98.6 %, 95 % CI: 97.8–99.2) compared to the other treatment arms. Children treated with albendazole-oxantel pamoate or albendazole-ivermectin had fewer moderate infections compared to children treated with albendazole. The reinfection rates 18 weeks post-treatment among all treatment arms were 37.2 % for T. trichiura (95 % CI: 28.3–46.8), 34.6 % for A. lumbricoides (95 % CI: 27.3–42.3) and 25.0 % for hookworms (95 % CI: 15.5–36.6). Conclusion The moderate reinfection rates with STHs 18 weeks post-treatment support the concept of regular anthelminthic treatment in highly endemic settings. Combination chemotherapy might achieve decreased morbidity in children since in the albendazole plus oxantel pamoate and albendazole plus ivermectin treatment arms only few moderate T. trichiura infections remained. Further trials should investigate the long term efficacy of albendazole-oxantel pamoate (i.e. 6 and 12 month post-treatment) and after several rounds of treatment in order to develop recommendations for appropriate control approaches for STH infections. Trial registration Current Controlled Trials ISRCTN80245406 Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1406-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Benjamin Speich
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Wendelin Moser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
| | - Said M Ali
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania.
| | - Shaali M Ame
- Laboratory Division, Public Health Laboratory-Ivo de Carneri, Chake Chake, Tanzania.
| | | | - Jan Hattendorf
- University of Basel, Basel, Switzerland. .,Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
| | - Jennifer Keiser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland. .,University of Basel, Basel, Switzerland.
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