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Tukwarlba I, Aninagyei E, Mavis PD, Attoh J, Duedu KO, Kumi J, Ampem-Danso E, Acheampong DO. Point-of-care circulating cathodic antigen positivity and associated factors in school children one year after mass praziquantel administration in an endemic district in Ghana. Heliyon 2024; 10:e28529. [PMID: 38596068 PMCID: PMC11002594 DOI: 10.1016/j.heliyon.2024.e28529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 03/11/2024] [Accepted: 03/20/2024] [Indexed: 04/11/2024] Open
Abstract
Background Mass drug administration of praziquantel is expected to reduce Schistosome carriage in treated children in endemic communities. However, the effectiveness of this annual exercise has not been assessed in Ghana. Therefore, this study aimed to detect viable Schistosoma mansoni infection using point-of-care circulating cathodic antigen (POC-CCA) positivity as proxy and associated factors in children previously treated with praziquantel in an endemic municipality in Ghana. Materials and methods This cross-sectional study was done in the Assin Central municipality in the Central Region of Ghana. School children, less than 16 years of age, treated with 40 mg/kg of praziquantel (treatment period: February-March 2019), provided early morning urine (∼40 mL) and stool (∼4 g) samples. Immediately, POC-CCA (ICT International, South Africa) was done, while S. mansoni ova were detected in formalin fixed samples using microscopy later. Additionally, participant's socio-demographic information and factors associated with S, mansoni infection transmission were collected from each child. Results A total of 520 children participated in the study (males-51.9%, majority age range [9-11 years, 34.4%]). Overall, 244 (46.9%) were positive for urinary CCA with no S. mansoni detected by microscopy. POC-CCA positivity was higher in females (48.4%), children with 2-3 siblings (49.3%), children aged 6-8-year range (55.4%) and residents of Brofoyedur (52%). However, age (x2 = 16.1, p = 0.0003) and town of residence (x2 = 11.7, p = 0.019) associated with CCA positivity. Further, location of water body (x2 = 16.4, p = 0.008), frequency of water contact (x2 = 12.3, p = 0.015) and handling of the Biomphalaria intermediate host (x2 = 5.1, p = 0.024) associated with POC-CCA outcome. Conclusion About 47% of the school children were positive for CCA, one year after mass praziquantel administration in the Assin Central municipality. Varied factors associated with the post-praziquantel administration POC-CCA positivity. This study should be replicated in other endemic areas to identify groups at risk of parasite persistence or reinfection to inform modification of control and preventive measures.
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Affiliation(s)
- Isaac Tukwarlba
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Enoch Aninagyei
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Volta Region, Ghana
| | - Puopelle Dakorah Mavis
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Juliana Attoh
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Kwabena Obeng Duedu
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Volta Region, Ghana
- College of Life Sciences, Birmingham City University, City South Campus, Birmingham, United Kingdom
| | - Justice Kumi
- Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, University of Ghana Legon, Accra, Ghana
| | - Eunice Ampem-Danso
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
- Department of Clinical Pathology, Noguchi Memorial Institute for Medical Research, University of Ghana Legon, Accra, Ghana
| | - Desmond Omane Acheampong
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
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Alemu G, Amor A, Nibret E, Munshea A, Anegagrie M. Efficacy and safety of prazequantel for the treatment of Schistosoma mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia. PLoS One 2024; 19:e0298332. [PMID: 38437215 PMCID: PMC10911589 DOI: 10.1371/journal.pone.0298332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/22/2024] [Indexed: 03/06/2024] Open
Abstract
BACKGROUND Schistosoma mansoni and S. haematobium infections have been public health problems in Ethiopia, S. mansoni being more prevalent. To reduce the burden of schistosomiasis, a national school-based prazequantel (PZQ) mass drug administration (MDA) program has been implemented since November 2015. Nevertheless, S. mansoni infection is still a major public health problem throughout the country. Reduced efficacy of PZQ is reported by a few studies in Ethiopia, but adequate data in different geographical settings is lacking. Hence, this study aimed to assess the efficacy and safety of PZQ for the treatment of S. mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia. METHODS A school-based single-arm prospective cohort study was conducted from February to June, 2023 among 130 S. mansoni-infected school-aged children (SAC). Forty-two, 37, and 51 S. mansoni-infected SAC were recruited from purposely selected schools located in low, moderate, and high transmission districts, respectively. School-aged children who were tested positive both by Kato Katz (KK) using stool samples and by the point of care circulating cathodic antigen (POC-CCA) test using urine samples at baseline were treated with a standard dose of PZQ and followed for 21 days for the occurrence of adverse events. After three weeks post-treatment, stool and urine samples were re-tested using KK and POC-CCA. Then the cure rate (CR), egg reduction rate (ERR), and treatment-associated adverse events were determined. The data were analyzed using SPSS version 21. RESULTS Out of the total 130 study participants, 110 completed the follow-up. The CR and ERR of PZQ treatment were 88.2% (95%CI: 82.7-93.6) and 93.5% (95%CI: 85.4-98.5), respectively, by KK. The CR of PZQ based on the POC-CCA test was 70.9% (95%CI: 62.7-79.1) and 75.5% (95%CI: 67.3-83.6) depending on whether the interpretation of 'trace' results was made as positive or negative, respectively. After treatment on the 21st day, 78 and 83 participants tested negative both by KK and POC-CCA, with respective interpretations of 'trace' POC-CCA test results as positive or negative. The CR in low, moderate and high transmission settings was 91.7%, 91.2% and 82.5%, respectively (p = 0.377) when evaluated by KK. The CR among SAC with a light infection at baseline (95.7%) by KK was higher than that of moderate (81.5%) and heavy (64.3%) infections (χ2 = 12.53, p = 0.002). Twenty-six (23.6%) participants manifested at least one adverse event. Eleven (10.0%), eight (7.3%), six (5.5%), and three (2.7%) participants complained about abdominal pain, nausea, headache, and anorexia, respectively. All adverse events were mild, needing no intervention. Occurrence of adverse events was slightly higher in high endemic areas (32.5%) than moderate (23.5%) and low endemic areas (p = 0.279). CONCLUSIONS A single dose of 40 mg/kg PZQ was efficacious and safe for the treatment of S. mansoni infection when it was evaluated by the KK test, but a lower efficacy was recorded when it was evaluated by the POC-CCA test. However, the POC-CCA test's specificity, clearance time of CCA from urine after treatment, and interpretation of weakly reactive (trace) test results need further research.
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Affiliation(s)
- Getaneh Alemu
- Department of Medical Laboratory Science, College of Medicine and Health Sciences, Bahir Dar University, Bahir Dar, Ethiopia
| | - Arancha Amor
- Mundo Sano Foundation and Institute of Health Carlos III, Madrid, Spain
| | - Endalkachew Nibret
- Biology Department, Science College, Bahir Dar University, Bahir Dar, Ethiopia
- Health Biotechnology Division, Institute of Biotechnology (IoB), Bahir Dar University, Bahir Dar, Ethiopia
| | - Abaineh Munshea
- Biology Department, Science College, Bahir Dar University, Bahir Dar, Ethiopia
- Health Biotechnology Division, Institute of Biotechnology (IoB), Bahir Dar University, Bahir Dar, Ethiopia
| | - Melaku Anegagrie
- Mundo Sano Foundation and Institute of Health Carlos III, Madrid, Spain
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Tadele T, Astatkie A, Tadesse BT, Makonnen E, Aklillu E, Abay SM. Efficacy and safety of praziquantel treatment against Schistosoma mansoni infection among pre-school age children in southern Ethiopia. Trop Med Health 2023; 51:72. [PMID: 38124206 PMCID: PMC10731898 DOI: 10.1186/s41182-023-00562-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 12/09/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Preventive chemotherapy with a single dose of praziquantel given to an all-at-risk population through mass drug administration is the cornerstone intervention to control and eliminate schistosomiasis as a public health problem. This intervention mainly targets school age children, and pre-school age children (pre-SAC) are excluded from receiving preventive chemotherapy, partly due to scarcity of data on praziquantel treatment outcomes. METHODS We conducted active efficacy and safety surveillance of praziquantel treatment among 240 Schistosoma mansoni-infected pre-SAC who received a single dose of praziquantel (40 mg/kg) in southern Ethiopia. The study outcomes were egg reduction rates (ERR) and cure rates (CRs) four weeks after treatment using the Kato-Katz technique and treatment-associated adverse events (AEs) that occurred within 8 days post-treatment. RESULTS The overall ERR was 93.3% (WHO reference threshold ≥ 90%), while the CR was 85.2% (95% CI = 80.0-89.5%). Baseline S. mansoni infection intensity was significantly associated with CRs, 100% among light infected than moderate (83.4%) or heavy (29.4%) infected children. An increase of 100 in baseline S. mansoni egg count per gram of stool resulted in a 26% (95% CI: 17%, 34%) reduction in the odds of cure. The incidence of experiencing at least one type of AE was 23.1% (95% CI: 18.0%, 29.0%). Stomachache, diarrhea, and nausea were the most common AEs. AEs were mild-to-moderate grade and transient. Pre-treatment moderate (ARR = 3.2, 95% CI: 1.69, 6.14) or heavy infection intensity (ARR = 6.5, 95% CI: 3.62, 11.52) was a significant predictor of AEs (p < 0.001). Sex, age, or soil-transmitted helminth coinfections were not significant predictors of CR or AEs. CONCLUSIONS Single-dose praziquantel is tolerable and effective against S. mansoni infection among pre-SAC, and associated AEs are mostly mild-to-moderate and transient. However, the reduced CR in heavily infected and AEs in one-fourth of S. mansoni-infected pre-SAC underscores the need for safety and efficacy monitoring, especially in moderate-to-high infection settings. Integrating pre-SACs in the national deworming programs is recommended to accelerate the elimination of schistosomiasis as a public health problem.
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Affiliation(s)
- Tafese Tadele
- School of Public Health, College of Medicine and Health Sciences, Hawassa University, P.O. Box 1560, Hawassa, Ethiopia
| | - Ayalew Astatkie
- School of Public Health, College of Medicine and Health Sciences, Hawassa University, P.O. Box 1560, Hawassa, Ethiopia
| | - Birkneh Tilahun Tadesse
- Department of Pediatrics, College of Medicine and Health Sciences, Hawassa University, P.O. Box 1560, Hawassa, Ethiopia
| | - Eyasu Makonnen
- Center for Innovative Drug Development and Therapeutic Trials for Africa, College of Health Sciences, Addis Ababa University, P.O. Box 9086, Addis Ababa, Ethiopia
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box 9086, Addis Ababa, Ethiopia
| | - Eleni Aklillu
- Department of Global Public Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
| | - Solomon Mequanente Abay
- Department of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, P.O. Box 9086, Addis Ababa, Ethiopia
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Bayoumi AMA, Ismail MAM, Mahmoud SS, Soliman ASA, Mousa AMA, Yousof HASA. The potential curative and hepatoprotective effects of platelet rich plasma on liver fibrosis in Schistosoma mansoni experimentally infected mice. J Parasit Dis 2023; 47:349-362. [PMID: 37193508 PMCID: PMC10182195 DOI: 10.1007/s12639-023-01576-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 03/03/2023] [Indexed: 04/05/2023] Open
Abstract
Trapped Schistosoma mansoni eggs trigger fibrotic liver disease that can continue to liver cirrhosis and failure. This work evaluates the outcome of platelet rich plasma (PRP) on S. mansoni-induced liver fibrosis by intraperitoneal (IP) and intrahepatic (IH) routes with/without Praziquantel (PZQ) treatment. Swiss albino mice (n = 162) were divided into non-infected (n = 66) and infected (n = 96) groups, then subdivided into non-treated and treated subgroups with PRP(IP), PRP(IH) 6th and 10th weeks post-infection, PZQ, PZQ + PRP(IP) and PZQ + PRP(IH) 6th and 10th weeks post-infection. Effects of treatments were evaluated by parasitological, histopathological and Immunohistochemical assessments. In the early assessment (12th week post-infection) of infected-treated groups, the mean granuloma number showed significant reduction in groups treated with PZQ + PRP (IH) 10th week, PRP (IP), PZQ + PRP (IP) and PZQ + PRP (IH) 6th week (33.33%, 33%, 27.77% and 27.22%, respectively). Furthermore, the mean granuloma diameter showed significant reduction in groups treated with PRP (IH) 10th week and PZQ + PRP (IP) (24.17% and 15.5%, respectively). Also, the fibrotic index showed significant reduction in groups treated with PZQ + PRP (IP), PRP (IP) and PZQ + PRP (IH) 6th week (48.18%, 46.81% and 41.36%, respectively). Transforming growth factor β1(TGF-β1) expression was in correlation with parasitological and histopathological results. Diminished TGF-β1 expression was mostly in infected groups treated with PZQ + PRP (IP), PZQ + PRP (IH) 6th week and PRP (IP) (88.63%, 88.63% and 77.27%, respectively). In the late assessment (14th week post-infection) of infected treated groups, TGF-β1expression was reduced in groups treated with PZQ, PRP (IH) 10th weeks, PRP (IP) (83.33%, 66.66%, 33.33% respectively). PRP showed promising anti-fibrotic effects on S. mansoni-induced liver fibrosis.
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Affiliation(s)
- Angham M. A. Bayoumi
- Medical Parasitology Department, Faculty of Medicine, Damietta University, Damietta, Egypt
| | - Mousa A. M. Ismail
- Medical Parasitology Department, Kasr Al-Ainy Faculty of Medicine, Cairo University, Kasr Al-Ainy St, Cairo, 11562 Egypt
| | - Soheir S. Mahmoud
- Parasitology Department, Theodor Bilharz Research Institute, Imbaba, Giza, Egypt
| | | | - Amr M. A. Mousa
- Pathology Department, Faculty of Medicine, October 6 University, 6th of October City, Egypt
| | - Hebat-Allah S. A. Yousof
- Medical Parasitology Department, Kasr Al-Ainy Faculty of Medicine, Cairo University, Kasr Al-Ainy St, Cairo, 11562 Egypt
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Gebreyesus TD, Makonnen E, Tadele T, Mekete K, Gashaw H, Gerba H, Aklillu E. Efficacy and safety of praziquantel preventive chemotherapy in Schistosoma mansoni infected school children in Southern Ethiopia: A prospective cohort study. Front Pharmacol 2023; 14:968106. [PMID: 36937860 PMCID: PMC10014719 DOI: 10.3389/fphar.2023.968106] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 02/13/2023] [Indexed: 03/05/2023] Open
Abstract
Background: The World Health Organization recommends efficacy and safety surveillance of anti-helminths used in mass drug administration campaigns. We evaluated the effectiveness of single-dose praziquantel against Schistosoma mansoni infection, and the safety of praziquantel plus albendazole preventive chemotherapy (PC) in Schistosoma mansoni infected school children (n = 512) in Southern Ethiopia. Method: Stool examinations were done using thick smear Kato-Katz at baseline, week-4, and week-8 of post-Mass drug administration (MDA) to assess praziquantel efficacy. Participants were followed for MDA-associated adverse events up to day 7 of post-MDA. The primary and secondary study outcomes were praziquantel efficacy (parasitological cure and egg reduction rates) and MDA-associated adverse events (AEs), respectively. Result: The overall cure rates at week-4 and week-8 were 89.1% (95%CI = 86.1-91.7) and 87.5% (95%CI = 83.6-90.8), respectively. Cure rates among moderate-to-heavily infected children were significantly lower (p = 0.001) compared to those with light infection at week-4 (84.4% vs. 91.1%, p = 0.03) and week-8 (78.6% vs. 91.9%, respectively). Older children had a higher cure rate than younger ones at week-8 (90.1% vs. 79.5%, p = 0.01). Among those who were Schistosoma egg-free (cured) at week 4, 7.8% became egg-positive at week 8. The overall egg reduction rate (ERR) at week-4 and week-8 were 93.5% and 91.3%, respectively, being lower among the 5-9 years old age groups (p = 0.01) at week-8. The proportion of children who remained schistosoma egg-positive throughout the study follow-up period was 4.6%, and their ERR at week-4 and week-8 was 50% and 51%, respectively, which is below the 90% World Health Organization threshold for efficacy. The incidence of experiencing at least one type of MDA-associated AEs were 17.0% (95%CI = 13.8%-20.5%); abdominal pain, headache, and vomiting were the most common. The proportion of mild, moderate, and severe AEs was 63.2%, 26.3%, and 10.5%, respectively. Females experienced more AEs than males (p = 0.03). Conclusion: Single-dose praziquantel is still effective for the treatment of intestinal schistosomiasis. Praziquantel and albendazole preventive chemotherapy is safe and tolerable, and associated AEs are mostly mild-to-moderate and transient. However, the reduced PZQ effectiveness in moderate-to-heavy infection and observed AEs in about one-fifth of infected children underscores the need for better treatment strategies and surveillance for early detection of parasite resistance and management of AEs.
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Affiliation(s)
- Tigist Dires Gebreyesus
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
- Ethiopian Food and Drug Authority, Addis Ababa, Ethiopia
| | - Eyasu Makonnen
- Center for Innovative Drug Development and Therapeutic Trials for Africa, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
- Departments of Pharmacology and Clinical Pharmacy, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Tafesse Tadele
- College of Medicine and Health Sciences, Hawassa University, Hawassa, Ethiopia
| | | | - Habtamu Gashaw
- Ethiopian Food and Drug Authority, Addis Ababa, Ethiopia
| | - Heran Gerba
- Ethiopian Food and Drug Authority, Addis Ababa, Ethiopia
| | - Eleni Aklillu
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Eleni Aklillu,
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Wang N, Peng HQ, Gao CZ, Cheng YH, Sun MT, Qu GL, Webster JP, Lu DB. In vivo efficiency of praziquantel treatment of single-sex Schistosoma japonicum aged three months old in mice. Int J Parasitol Drugs Drug Resist 2022; 20:129-134. [PMID: 36403362 PMCID: PMC9771832 DOI: 10.1016/j.ijpddr.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/08/2022] [Accepted: 11/08/2022] [Indexed: 11/14/2022]
Abstract
Schistosomiasis is a major neglected tropical disease mainly caused by Schistosoma haematobium, S. japonicum and S. mansoni, and results in the greatest disease burden. Mass drug administration (MDA) with praziquantel (PZQ), a single drug only available for the disease, has played a vital role in schistosomiasis control. Therefore, any possibility of selection of the parasites for PZQ resistance or low sensitivity may hamper the 2030's target of global disease elimination. We had experimentally demonstrated the long-term survival and reproductive potential of single-sex (of either sex) S. japonicum infections in definitive hosts mice. What has not yet been adequately addressed is whether the long live single-sex schistosomes remain sensitive to PZQ, and what reproduction potential for those schistosomes surviving treatment may have. We therefore performed experimental mice studies to explore the treatment effectiveness of PZQ (at total doses of 200 or 400 mg/kg, corresponding to the sub-standard or standard treatment doses in humans) for single-sex S. japonicum aged three months old. The results showed that no treatment efficiency was observed on female schistosomes, whereas on male schistosomes only at PZQ 400 mg/kg a significant higher efficiency in reducing worm burdens was observed. Moreover, either schistosome males or females surviving PZQ treatment remained their reproduction potential as normal. The results indicate that long (i.e., three months) live single-sex S. japonicum can easily survive the current treatment strategy, and moreover, any schistosomes, if with PZQ resistance or low sensitivity, could be easily transmitted in nature. Therefore, in order to realize the target for the national and the global schistosomiasis elimination, there is undoubtedly a great need for refining PZQ administration and dosage, looking for alternative therapies, and/or developing vaccines against schistosome.
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Affiliation(s)
- Ning Wang
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China
| | - Han-Qi Peng
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China
| | - Chang-Zhe Gao
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China
| | - Yu-Heng Cheng
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China
| | - Meng-Tao Sun
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China
| | - Guo-Li Qu
- Key Laboratory of National Health and Family Planning Commission on Parasitic Disease Control and Prevention, Jiangsu Provincial Key Laboratory on Parasite and Vector Control Technology, Jiangsu Institute of Parasitic Diseases, Wuxi, China
| | - Joanne P Webster
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Department of Pathology and Population Sciences, Royal Veterinary College, University of London, London, United Kingdom.
| | - Da-Bing Lu
- Department of Epidemiology and Statistics, School of Public Health, Soochow University, Suzhou, China.
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Nogueira RA, Lira MGS, Licá ICL, Frazão GCCG, Dos Santos VAF, Filho ACCM, Rodrigues JGM, Miranda GS, Carvalho RC, Nascimento FRF. Praziquantel: An update on the mechanism of its action against schistosomiasis and new therapeutic perspectives. Mol Biochem Parasitol 2022; 252:111531. [PMID: 36375598 DOI: 10.1016/j.molbiopara.2022.111531] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 11/03/2022] [Accepted: 11/10/2022] [Indexed: 11/13/2022]
Abstract
Praziquantel (PZQ) is the drug of choice for the treatment of all forms of schistosomiasis, although its mechanisms of action are not completely understood. PZQ acts largely on adult worms. This narrative literature review describes what is known about the mechanisms of action of PZQ against schistosomes from in vitro and in vivo studies and highlights the molecular targets in parasites and immune responses induced in definitive hosts by this drug. Moreover, new therapeutic uses of PZQ are discussed. Studies have demonstrated that in addition to impacting voltage-operated Ca2 + channels, PZQ may interact with other schistosome molecules, such as myosin regulatory light chain, glutathione S-transferase, and transient receptor potential channels. Following PZQ administration, increased T regulatory type 1 (Tr1) cell differentiation and decreased inflammation were observed, indicating that PZQ promotes immunoregulatory pathways. Although PZQ is widely used in mass drug administration schemes, the existence of resistant parasites has not been proven; however, it is a concern that should be constantly investigated in human populations. In addition, we discuss studies that evaluate health applications of PZQ (other than helminth infection), such as its effect in cancer therapy and its adjuvant action in vaccines against viruses.
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Affiliation(s)
- Ranielly Araujo Nogueira
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil
| | - Maria Gabriela Sampaio Lira
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil; Department of Education, Federal Institute of Education, Science and Technology of Maranhão, Zé Doca, MA, Brazil
| | - Irlla Correia Lima Licá
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil
| | | | - Vitor Augusto Ferreira Dos Santos
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil
| | | | - João Gustavo Mendes Rodrigues
- Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil
| | - Guilherme Silva Miranda
- Department of Education, Federal Institute of Education, Science and Technology of Maranhão, São Raimundo das Mangabeiras, MA, Brazil
| | - Rafael Cardoso Carvalho
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil
| | - Flávia Raquel Fernandes Nascimento
- Graduate Program in Health Sciences, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil; Department of Pathology, Center for Biological and Health Sciences, Federal University of Maranhão, São Luís, MA, Brazil.
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Summers S, Bhattacharyya T, Allan F, Stothard JR, Edielu A, Webster BL, Miles MA, Bustinduy AL. A review of the genetic determinants of praziquantel resistance in Schistosoma mansoni: Is praziquantel and intestinal schistosomiasis a perfect match? FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.933097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Schistosomiasis is a neglected tropical disease (NTD) caused by parasitic trematodes belonging to the Schistosoma genus. The mainstay of schistosomiasis control is the delivery of a single dose of praziquantel (PZQ) through mass drug administration (MDA) programs. These programs have been successful in reducing the prevalence and intensity of infections. Due to the success of MDA programs, the disease has recently been targeted for elimination as a public health problem in some endemic settings. The new World Health Organization (WHO) treatment guidelines aim to provide equitable access to PZQ for individuals above two years old in targeted areas. The scale up of MDA programs may heighten the drug selection pressures on Schistosoma parasites, which could lead to the emergence of PZQ resistant schistosomes. The reliance on a single drug to treat a disease of this magnitude is worrying should drug resistance develop. Therefore, there is a need to detect and track resistant schistosomes to counteract the threat of drug resistance to the WHO 2030 NTD roadmap targets. Until recently, drug resistance studies have been hindered by the lack of molecular markers associated with PZQ resistance. This review discusses recent significant advances in understanding the molecular basis of PZQ action in S. mansoni and proposes additional genetic determinants associated with PZQ resistance. PZQ resistance will also be analyzed in the context of alternative factors that may decrease efficacy within endemic field settings, and the most recent treatment guidelines recommended by the WHO.
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Clark J, Moses A, Nankasi A, Faust CL, Moses A, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Carruthers LV, Francoeur R, Tukahebwa EM, Prada JM, Lamberton PHL. Reconciling Egg- and Antigen-Based Estimates of Schistosoma mansoni Clearance and Reinfection: A Modeling Study. Clin Infect Dis 2022; 74:1557-1563. [PMID: 34358299 PMCID: PMC9070857 DOI: 10.1093/cid/ciab679] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Despite decades of interventions, 240 million people have schistosomiasis. Infections cannot be directly observed, and egg-based Kato-Katz thick smears lack sensitivity, affected treatment efficacy and reinfection rate estimates. The point-of-care circulating cathodic antigen (referred to from here as POC-CCA+) test is advocated as an improvement on the Kato-Katz method, but improved estimates are limited by ambiguities in the interpretation of trace results. METHOD We collected repeated Kato-Katz egg counts from 210 school-aged children and scored POC-CCA tests according to the manufacturer's guidelines (referred to from here as POC-CCA+) and the externally developed G score. We used hidden Markov models parameterized with Kato-Katz; Kato-Katz and POC-CCA+; and Kato-Katz and G-Scores, inferring latent clearance and reinfection probabilities at four timepoints over six-months through a more formal statistical reconciliation of these diagnostics than previously conducted. Our approach required minimal but robust assumptions regarding trace interpretations. RESULTS Antigen-based models estimated higher infection prevalence across all timepoints compared with the Kato-Katz model, corresponding to lower clearance and higher reinfection estimates. Specifically, pre-treatment prevalence estimates were 85% (Kato-Katz; 95% CI: 79%-92%), 99% (POC-CCA+; 97%-100%) and 98% (G-Score; 95%-100%). Post-treatment, 93% (Kato-Katz; 88%-96%), 72% (POC-CCA+; 64%-79%) and 65% (G-Score; 57%-73%) of those infected were estimated to clear infection. Of those who cleared infection, 35% (Kato-Katz; 27%-42%), 51% (POC-CCA+; 41%-62%) and 44% (G-Score; 33%-55%) were estimated to have been reinfected by 9-weeks. CONCLUSIONS Treatment impact was shorter-lived than Kato-Katz-based estimates alone suggested, with lower clearance and rapid reinfection. At 3 weeks after treatment, longer-term clearance dynamics are captured. At 9 weeks after treatment, reinfection was captured, but failed clearance could not be distinguished from rapid reinfection. Therefore, frequent sampling is required to understand these important epidemiological dynamics.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | | | | | - Christina L Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Adriko Moses
- Vector Control Division, Ministry of Health, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Uganda
| | | | | | - Lauren V Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science & Engineering, University of Chester, Chester, United Kingdom
| | | | - Joaquin M Prada
- Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Poppy H L Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
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10
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Clark J, Moses A, Nankasi A, Faust CL, Adriko M, Ajambo D, Besigye F, Atuhaire A, Wamboko A, Rowel C, Carruthers LV, Francoeur R, Tukahebwa EM, Lamberton PHL, Prada JM. Translating From Egg- to Antigen-Based Indicators for Schistosoma mansoni Elimination Targets: A Bayesian Latent Class Analysis Study. FRONTIERS IN TROPICAL DISEASES 2022; 3:825721. [PMID: 35784267 PMCID: PMC7612949 DOI: 10.3389/fitd.2022.825721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Schistosomiasis is a parasitic disease affecting over 240-million people. World Health Organization (WHO) targets for Schistosoma mansoni elimination are based on Kato-Katz egg counts, without translation to the widely used, urine-based, point-of-care circulating cathodic antigen diagnostic (POC-CCA). We aimed to standardize POC-CCA score interpretation and translate them to Kato-Katz-based standards, broadening diagnostic utility in progress towards elimination. A Bayesian latent-class model was fit to data from 210 school-aged-children over four timepoints pre- to six-months-post-treatment. We used 1) Kato-Katz and established POC-CCA scoring (Negative, Trace, +, ++ and +++), and 2) Kato-Katz and G-Scores (a new, alternative POC-CCA scoring (G1 to G10)). We established the functional relationship between Kato-Katz counts and POC-CCA scores, and the score-associated probability of true infection. This was combined with measures of sensitivity, specificity, and the area under the curve to determine the optimal POC-CCA scoring system and positivity threshold. A simulation parametrized with model estimates established antigen-based elimination targets. True infection was associated with POC-CCA scores of ≥ + or ≥G3. POC-CCA scores cannot predict Kato-Katz counts because low infection intensities saturate the POC-CCA cassettes. Post-treatment POC-CCA sensitivity/specificity fluctuations indicate a changing relationship between egg excretion and antigen levels (living worms). Elimination targets can be identified by the POC-CCA score distribution in a population. A population with ≤2% ++/+++, or ≤0.5% G7 and above, indicates achieving current WHO Kato-Katz-based elimination targets. Population-level POC-CCA scores can be used to access WHO elimination targets prior to treatment. Caution should be exercised on an individual level and following treatment, as POC-CCAs lack resolution to discern between WHO Kato-Katz-based moderate- and high-intensity-infection categories, with limited use in certain settings and evaluations.
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Affiliation(s)
- Jessica Clark
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Arinaitwe Moses
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Andrina Nankasi
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Christina L. Faust
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Moses Adriko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Diana Ajambo
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Fred Besigye
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Arron Atuhaire
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Aidah Wamboko
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Candia Rowel
- Vector Control Division, Ministry of Health, Kampala, Uganda
| | - Lauren V. Carruthers
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Rachel Francoeur
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- Faculty of Science and Engineering, University of Chester, Chester, United Kingdom
| | | | - Poppy H. L. Lamberton
- Wellcome Centre for Integrative Parasitology, Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Joaquin M. Prada
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
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11
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Berger DJ, Crellen T, Lamberton PHL, Allan F, Tracey A, Noonan JD, Kabatereine NB, Tukahebwa EM, Adriko M, Holroyd N, Webster JP, Berriman M, Cotton JA. Whole-genome sequencing of Schistosoma mansoni reveals extensive diversity with limited selection despite mass drug administration. Nat Commun 2021; 12:4776. [PMID: 34362894 PMCID: PMC8346512 DOI: 10.1038/s41467-021-24958-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 07/06/2021] [Indexed: 02/07/2023] Open
Abstract
Control and elimination of the parasitic disease schistosomiasis relies on mass administration of praziquantel. Whilst these programmes reduce infection prevalence and intensity, their impact on parasite transmission and evolution is poorly understood. Here we examine the genomic impact of repeated mass drug administration on Schistosoma mansoni populations with documented reduced praziquantel efficacy. We sequenced whole-genomes of 198 S. mansoni larvae from 34 Ugandan children from regions with contrasting praziquantel exposure. Parasites infecting children from Lake Victoria, a transmission hotspot, form a diverse panmictic population. A single round of treatment did not reduce this diversity with no apparent population contraction caused by long-term praziquantel use. We find evidence of positive selection acting on members of gene families previously implicated in praziquantel action, but detect no high frequency functionally impactful variants. As efforts to eliminate schistosomiasis intensify, our study provides a foundation for genomic surveillance of this major human parasite.
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Affiliation(s)
- Duncan J Berger
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
- Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Herts, UK.
| | - Thomas Crellen
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK
- Big Data Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Poppy H L Lamberton
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK
- Institute for Biodiversity, Animal Health, and Comparative Medicine, and Wellcome Centre for Integrative Parasitology, University of Glasgow, Glasgow, UK
| | - Fiona Allan
- The Natural History Museum, Department of Life Sciences, London, UK
| | - Alan Tracey
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Jennifer D Noonan
- Institute of Parasitology, Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, Quebec, Canada
| | - Narcis B Kabatereine
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Edridah M Tukahebwa
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Moses Adriko
- Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda
| | - Nancy Holroyd
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK
| | - Joanne P Webster
- Department of Pathology and Pathogen Biology, Centre for Emerging, Endemic and Exotic Diseases, Royal Veterinary College, University of London, Herts, UK.
- Imperial College London, Department of Infectious Disease Epidemiology, London, UK.
| | - Matthew Berriman
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
| | - James A Cotton
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire, UK.
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12
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de Carvalho Augusto R, Merad N, Rognon A, Gourbal B, Bertrand C, Djabou N, Duval D. Molluscicidal and parasiticidal activities of Eryngium triquetrum essential oil on Schistosoma mansoni and its intermediate snail host Biomphalaria glabrata, a double impact. Parasit Vectors 2020; 13:486. [PMID: 32967724 PMCID: PMC7513307 DOI: 10.1186/s13071-020-04367-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/17/2020] [Indexed: 12/29/2022] Open
Abstract
Background Freshwater snails are the intermediate hosts of a large variety of trematode flukes such as Schistosoma mansoni responsible for one of the most important parasitic diseases caused by helminths, affecting 67 million people worldwide. Recently, the WHO Global Vector Control Response 2017–2030 (GVCR) programme reinforced its message for safer molluscicides as part of required strategies to strengthen vector control worldwide. Here, we present the essential oil from Eryngium triquetrum as a powerful product with molluscicide and parasiticide effect against S. mansoni and the snail intermediate host Biomphalaria glabrata. Methods In the present study, we describe using several experimental approaches, the chemical composition of E. triquetrum essential oil extract and its biological effects against the snail B. glabrata and its parasite S. mansoni. Vector and the free-swimming larval stages of the parasite were exposed to different oil concentrations to determine the lethal concentration required to produce a mortality of 50% (LC50) and 90% (LC90). In addition, toxic activity of this essential oil was analyzed against embryos of B. glabrata snails by monitoring egg hatching and snail development. Also, short-time exposure to sublethal molluscicide concentrations on S. mansoni miracidia was performed to test a potential effect on parasite infectivity on snails. Mortality of miracidia and cercariae of S. mansoni is complete for 5, 1 and 0.5 ppm of oil extract after 1 and 4 h exposure. Results The major chemical component found in E. triquetrum oil determined by GC-FID and GC/MS analyses is an aliphatic polyacetylene molecule, the falcarinol with 86.9–93.1% of the total composition. The LC50 and LC90 values for uninfected snails were 0.61 and 1.02 ppm respectively for 24 h exposure. At 0.5 ppm, the essential oil was two times more toxic to parasitized snails with a mortality rate of 88.8 ± 4.8%. Moderate embryonic lethal effects were observed at the concentration of 1 ppm. Severe surface damage in miracidia was observed with a general loss of cilia that probably cause their immobility. Miracidia exposed 30 min to low concentration of plant extract (0.1 ppm) were less infective with 3.3% of prevalence compare to untreated with a prevalence of 44%. Conclusions Essential oil extracted from E. triquetrum and falcarinol must be considered as a promising product for the development of new interventions for schistosomiasis control and could proceed to be tested on Phase II according to the WHO requirements. ![]()
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Affiliation(s)
- Ronaldo de Carvalho Augusto
- University Perpignan Via Domitia, IHPE, UMR 5244, CNRS, IFREMER, Perpignan, France.,University Montpellier, IHPE, UMR 5244, CNRS, IFREMER, Montpellier, France
| | - Nadjiya Merad
- Faculté des Sciences, Département de Chimie, Université de Tlemcen, Laboratoire COSNA, Tlemcen, Algeria
| | - Anne Rognon
- University Perpignan Via Domitia, IHPE, UMR 5244, CNRS, IFREMER, Perpignan, France.,University Montpellier, IHPE, UMR 5244, CNRS, IFREMER, Montpellier, France
| | - Benjamin Gourbal
- University Perpignan Via Domitia, IHPE, UMR 5244, CNRS, IFREMER, Perpignan, France.,University Montpellier, IHPE, UMR 5244, CNRS, IFREMER, Montpellier, France
| | - Cédric Bertrand
- EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan, France.,Laboratoire d'Excellence «CORAIL», Université de Perpignan, Perpignan, France.,S.A.S. AkiNaO, Perpignan, France
| | - Nassim Djabou
- Faculté des Sciences, Département de Chimie, Université de Tlemcen, Laboratoire COSNA, Tlemcen, Algeria.
| | - David Duval
- University Perpignan Via Domitia, IHPE, UMR 5244, CNRS, IFREMER, Perpignan, France. .,University Montpellier, IHPE, UMR 5244, CNRS, IFREMER, Montpellier, France.
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13
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Impacts of host gender on Schistosoma mansoni risk in rural Uganda-A mixed-methods approach. PLoS Negl Trop Dis 2020; 14:e0008266. [PMID: 32401770 PMCID: PMC7219705 DOI: 10.1371/journal.pntd.0008266] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 04/02/2020] [Indexed: 12/12/2022] Open
Abstract
Background The World Health Organization identified Uganda as one of the 10 highly endemic countries for schistosomiasis. Annual mass drug administration (MDA) with praziquantel has led to a decline in intensity of Schistosoma mansoni infections in several areas. However, as hotspots with high (re)infection rates remain, additional research on risk factors and implementing interventions to complement MDA are required to further reduce disease burden in these settings. Through a mixed-methods study we aimed to gain deeper understanding of how gender may impact risk and reinfection in order to inform disease control programmes and ascertain if gender-specific interventions may be beneficial. Methodology/Principal findings In Bugoto, Mayuge District, Eastern Uganda we conducted ethnographic observations (n = 16) and examined epidemiology (n = 55) and parasite population genetics (n = 16) in school-aged children (SAC), alongside a community-wide household survey (n = 130). Water contact was frequent at home, school and in the community and was of domestic, personal care, recreational, religious or commercial nature. Qualitative analysis of type of activity, duration, frequency, level of submersion and water contact sites in children showed only few behavioural differences in water contact between genders. However, survey data revealed that adult women carried out the vast majority of household tasks involving water contact. Reinfection rates (96% overall) and genetic diversity were high in boys (pre-He = 0.66; post-He = 0.67) and girls (pre-He = 0.65; post-He = 0.67), but no differences in reinfection rates (p = 0.62) or genetic diversity by gender before (p = 0.54) or after (p = 0.97) treatment were found. Conclusions/Significance This mixed methods approach showed complementary findings. Frequent water exposure with few differences between boys and girls was mirrored by high reinfection rates and genetic diversity in both genders. Disease control programmes should consider the high reinfection rates among SAC in remaining hotspots of schistosomiasis and the various purposes and settings in which children and adults are exposed to water. Globally, over 230 million people are infected with schistosomiasis, an infectious disease caused by parasitic helminths. Humans can get infected when they contact water which contains Schistosoma parasites. Although the disease can be treated with a drug, people get rapidly reinfected in certain high-transmission settings. Drug treatment alone may not be sufficient to eliminate this disease and additional interventions such as health promotion or improvements in water and sanitation need to be scaled up. To provide recommendations to these control programmes we carried out interdisciplinary research in Eastern Uganda to understand the influence of gender on schistosomiasis risk. We found that the water contact behaviour of boys and girls is quite similar, and we did not see differences in reinfection or genetic diversity of the parasite between boys and girls. Differences in water contact between genders is greater in adults, and further research is required for these individuals. In this setting, infection rates are high in school-aged children and there are no differences between genders. These results emphasise improved control efforts for all school-aged children in communities like these. Our interdisciplinary approach provided complementary findings. Such an integrated approach can therefore have more power to meaningfully inform policy on schistosomiasis control.
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14
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Hoekstra PT, Casacuberta-Partal M, van Lieshout L, Corstjens PLAM, Tsonaka R, Assaré RK, Silué KD, Meité A, N’Goran EK, N’Gbesso YK, Amoah AS, Roestenberg M, Knopp S, Utzinger J, Coulibaly JT, van Dam GJ. Efficacy of single versus four repeated doses of praziquantel against Schistosoma mansoni infection in school-aged children from Côte d'Ivoire based on Kato-Katz and POC-CCA: An open-label, randomised controlled trial (RePST). PLoS Negl Trop Dis 2020; 14:e0008189. [PMID: 32196506 PMCID: PMC7112237 DOI: 10.1371/journal.pntd.0008189] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/01/2020] [Accepted: 03/02/2020] [Indexed: 11/21/2022] Open
Abstract
Background Preventive chemotherapy with praziquantel (PZQ) is the cornerstone of schistosomiasis control. However, a single dose of PZQ (40 mg/kg) does not cure all infections. Repeated doses of PZQ at short intervals might increase efficacy in terms of cure rate (CR) and intensity reduction rate (IRR). Here, we determined the efficacy of a single versus four repeated treatments with PZQ on Schistosoma mansoni infection in school-aged children from Côte d’Ivoire, using two different diagnostic tests. Methods An open-label, randomized controlled trial was conducted from October 2018 to January 2019. School-aged children with a confirmed S. mansoni infection based on Kato-Katz (KK) and point-of-care circulating cathodic antigen (POC-CCA) urine cassette test were randomly assigned to receive either a single or four repeated doses of PZQ, administered at two-week intervals. The primary outcome was the difference in CR between the two treatment arms, measured by triplicate KK thick smears 10 weeks after the first treatment. Secondary outcomes included CR estimated by POC-CCA, IRR by KK and POC-CCA, and safety of repeated PZQ administration. Principal findings During baseline screening, 1,022 children were assessed for eligibility of whom 153 (15%) had a detectable S. mansoni infection, and hence, were randomized to the standard treatment group (N = 70) and the intense treatment group (N = 83). Based on KK, the CR was 42% (95% confidence interval (CI) 31–52%) in the standard treatment group and 86% (95% CI 75–92%) in the intense treatment group. Observed IRR was 72% (95% CI 55–83%) in the standard treatment group and 95% (95% CI 85–98%) in the intense treatment group. The CR estimated by POC-CCA was 18% (95% CI 11–27%) and 36% (95% CI 26–46%) in the standard and intense treatment group, respectively. Repeated PZQ treatment did not result in a higher number of adverse events. Conclusion/significance The observed CR using KK was significantly higher after four repeated treatments compared to a single treatment, without an increase in adverse events. Using POC-CCA, the observed CR was significantly lower than measured by KK, indicating that PZQ may be considerably less efficacious as concluded by KK. Our findings highlight the need for reliable and more accurate diagnostic tools, which are essential for monitoring treatment efficacy, identifying changes in transmission, and accurately quantifying the intensity of infection in distinct populations. In addition, the higher CR in the intense treatment group suggests that more focused and intense PZQ treatment can help to advance schistosomiasis control. Trial registration www.clinicaltrials.govNCT02868385. The previously established efficacy of the widely used drug praziquantel (PZQ) against schistosomiasis might have been overestimated due to the use of inaccurate diagnostic methods. Repeated PZQ treatment at short intervals in areas with ongoing transmission could more effectively target non-susceptible schistosomula as they will have matured into drug susceptible worms within a few weeks. In the current study, we aimed to determine the cure rate (CR) of repeated PZQ, measured by the Kato-Katz (KK) technique and the point-of-care circulating cathodic antigen (POC-CCA) test, respectively. An open-label, randomized controlled trial was conducted assigning 153 school-aged children with a confirmed Schistosoma mansoni infection to two groups, one receiving a single PZQ treatment, while the second group received four repeated PZQ treatments, given at two-week intervals. Based on the KK test, the CR was significantly higher after four repeated treatments compared to a single treatment. When using POC-CCA, a diagnostic method that has not been utilized before in studies assessing the efficacy of four repeated PZQ treatments, the CR was much lower, even after four repeated PZQ treatments. Our results indicate that worms are still present after multiple PZQ treatments and that PZQ might be less efficacious than previously published.
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Affiliation(s)
- Pytsje T. Hoekstra
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- * E-mail:
| | | | - Lisette van Lieshout
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
| | - Paul L. A. M. Corstjens
- Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, the Netherlands
| | - Roula Tsonaka
- Department of Biomedical Data Sciences, Leiden University Medical Center, Leiden, the Netherlands
| | - Rufin K. Assaré
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Kigbafori D. Silué
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Aboulaye Meité
- Programme National de Lutte contre les Maladies Tropicales Négligées à Chimiothérapie Préventive, Ministère de la Santé et de l’Hygiène Publique, Abidjan, Côte d’Ivoire
| | - Eliézer K. N’Goran
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
| | - Yves K. N’Gbesso
- Département d’Agboville, Centre de Santé Urbain d’Azaguié, Azaguié, Côte d’Ivoire
| | - Abena S. Amoah
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Population Health, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Malawi Epidemiology and Intervention Research Unit, Chilumba, Karonge District, Malawi
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Leiden, the Netherlands
| | - Stefanie Knopp
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Jean T. Coulibaly
- Centre Suisse de Recherches Scientifiques en Côte d’Ivoire, Abidjan, Côte d’Ivoire
- Unité de Formation et de Recherche Biosciences, Université Félix Houphouët-Boigny, Abidjan, Côte d’Ivoire
- Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Govert J. van Dam
- Department of Parasitology, Leiden University Medical Center, Leiden, the Netherlands
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15
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Islam MT, Martorell M, Salehi B, Setzer WN, Sharifi-Rad J. Anti-Schistosoma mansoni effects of essential oils and their components. Phytother Res 2020; 34:1761-1769. [PMID: 32067278 DOI: 10.1002/ptr.6643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/25/2019] [Accepted: 01/31/2020] [Indexed: 01/18/2023]
Abstract
Schistosoma mansoni is endemic in 55 countries around the world. S. mansoni is a water-borne parasite of humans belonging to the group of blood flukes. Generally, schistosomiasis is treated with praziquantel, which results in frequent treatment failures and reinfections. Essential oils have diverse biological effects, including antimicrobial, antiprotozoal and antiparasitic. This review aimed at summarizing available in vitro, in vivo and clinical trials showing evidence and mechanisms of actions of essential oils and their derivatives acting against S. mansoni. The findings suggest that a number of essential oils and/or their components act against S. mansoni. Essential oils and/or their derivatives may be one of the potential sources of antischistosomal drugs.
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Affiliation(s)
- Muhammad Torequl Islam
- Department for Management of Science and Technology Development, Ton Duc Thang University, Ho Chi Minh City, Vietnam.,Faculty of Pharmacy, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Miquel Martorell
- Department of Nutrition and Dietetics, Faculty of Pharmacy, University of Concepcion, Concepcion, Chile.,Universidad de Concepción, Unidad de Desarrollo Tecnológico (UDT), Concepción, Chile
| | - Bahare Salehi
- Student Research Committee, School of Medicine, Bam University of Medical Sciences, Bam, Iran
| | - William N Setzer
- Department of Chemistry, University of Alabama in Huntsville, Huntsville, AL, 35899, USA.,Aromatic Plant Research Center, 230 N 1200 E, Suite 100, Lehi, UT, 84043, USA
| | - Javad Sharifi-Rad
- Phytochemistry Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Insufficiency of annual praziquantel treatment to control Schistosoma mansoni infections in adult women: A longitudinal cohort study in rural Tanzania. PLoS Negl Trop Dis 2019; 13:e0007844. [PMID: 31751333 PMCID: PMC6894890 DOI: 10.1371/journal.pntd.0007844] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 12/05/2019] [Accepted: 10/14/2019] [Indexed: 01/03/2023] Open
Abstract
Background Current World Health Organization (WHO) guidelines recommend annual mass drug administration using praziquantel in areas with high schistosome endemicity. Yet little is known about incidence and reinfection rates after treatment in women with frequent exposure to schistosomes. We sought to quantify response to anti-schistosome treatment and incident S. mansoni infections in a cohort of rural women living in a schistosome-endemic area of northwest Tanzania. Methods and principal findings We enrolled women with and without S. mansoni infection into a 12-month longitudinal cohort. Every 3 months, women were tested for schistosome infection using microscopic examinations for ova on filtered urine, Kato Katz slides, and serum Circulating Anodic Antigen (CAA). Those with schistosome infection received treatment with praziquantel 40 mg/kg according to the standard of care. We studied 35 women who were S. mansoni positive by stool microscopy and 46 women without schistosome infection who returned for at least one follow-up. Of the women who were initially infected, 14 (40%) were schistosome-positive at a follow-up visit. Four women developed incident infections, for a cumulative incidence of 8.7% and incidence rate of 0.99 per 100 person-months throughout the year among initially uninfected women. Only 3 women were egg-positive at any follow-up. Women with persistent, recurrent, or incident infection during the study period were significantly younger (p = 0.032) and had fewer children than women who remained uninfected or those who cleared the infection and did not experience recurrence (p = 0.003). Having fewer children remained significant after controlling for age (p = 0.023). There was no difference in initial intensity of infection by CAA or stool egg count, HIV status, or socioeconomic status. Although most water contact behaviors were comparable between the two groups, women with recurrent or incident schistosome infections were significantly more likely to have recently swum in the lake (p = 0.023). Conclusions Our data suggests that annual praziquantel treatment reduces intensity of schistosome infections but is insufficient in providing stable parasite eradication in over a third of women in endemic communities. Furthermore, microscopy lacks adequate sensitivity to evaluate efficacy of treatment in this population. Our work demonstrates that further investigation into treatment efficacy and reinfection rates is warranted and suggests that increased frequency of praziquantel treatment is needed to improve cure rates in high-risk populations. Schistosomiasis is a parasitic infection transmitted through contaminated water that primarily affects the gastrointestinal and urogenital tracts. Previous studies in Tanzania have shown that adult women infected with schistosomes also have a higher risk of contracting HIV. Although it is recommended that people living in areas where they are exposed to schistosomes be treated with praziquantel once a year, the rate of new infections or reinfection after treatment in adult women is not known. We followed a group of schistosome-infected women and an uninfected control group for 12 months. They were tested for schistosomes every 3 months, and treated with praziquantel if they were infected. Over 40% of the women tested positive for schistosome infection at some point during the follow-up period, and the majority of them were from the group that was infected at the beginning of the study. These women may not have fully cleared the infection after one treatment, or they may be more susceptible to reinfection due to variations in their immune systems. Further studies are recommended to investigate whether a higher frequency of treatment is needed to control schistosome infection in adult women, especially given that reducing schistosome infection may help to reduce HIV risk in populations similar to ours.
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Chevalier FD, Le Clec’h W, McDew-White M, Menon V, Guzman MA, Holloway SP, Cao X, Taylor AB, Kinung'hi S, Gouvras AN, Webster BL, Webster JP, Emery AM, Rollinson D, Garba Djirmay A, Al Mashikhi KM, Al Yafae S, Idris MA, Moné H, Mouahid G, Hart PJ, LoVerde PT, Anderson TJC. Oxamniquine resistance alleles are widespread in Old World Schistosoma mansoni and predate drug deployment. PLoS Pathog 2019; 15:e1007881. [PMID: 31652296 PMCID: PMC6834289 DOI: 10.1371/journal.ppat.1007881] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 11/06/2019] [Accepted: 09/16/2019] [Indexed: 01/10/2023] Open
Abstract
Do mutations required for adaptation occur de novo, or are they segregating within populations as standing genetic variation? This question is key to understanding adaptive change in nature, and has important practical consequences for the evolution of drug resistance. We provide evidence that alleles conferring resistance to oxamniquine (OXA), an antischistosomal drug, are widespread in natural parasite populations under minimal drug pressure and predate OXA deployment. OXA has been used since the 1970s to treat Schistosoma mansoni infections in the New World where S. mansoni established during the slave trade. Recessive loss-of-function mutations within a parasite sulfotransferase (SmSULT-OR) underlie resistance, and several verified resistance mutations, including a deletion (p.E142del), have been identified in the New World. Here we investigate sequence variation in SmSULT-OR in S. mansoni from the Old World, where OXA has seen minimal usage. We sequenced exomes of 204 S. mansoni parasites from West Africa, East Africa and the Middle East, and scored variants in SmSULT-OR and flanking regions. We identified 39 non-synonymous SNPs, 4 deletions, 1 duplication and 1 premature stop codon in the SmSULT-OR coding sequence, including one confirmed resistance deletion (p.E142del). We expressed recombinant proteins and used an in vitro OXA activation assay to functionally validate the OXA-resistance phenotype for four predicted OXA-resistance mutations. Three aspects of the data are of particular interest: (i) segregating OXA-resistance alleles are widespread in Old World populations (4.29–14.91% frequency), despite minimal OXA usage, (ii) two OXA-resistance mutations (p.W120R, p.N171IfsX28) are particularly common (>5%) in East African and Middle-Eastern populations, (iii) the p.E142del allele has identical flanking SNPs in both West Africa and Puerto Rico, suggesting that parasites bearing this allele colonized the New World during the slave trade and therefore predate OXA deployment. We conclude that standing variation for OXA resistance is widespread in S. mansoni. It has been argued that drug resistance is unlikely to spread rapidly in helminth parasites infecting humans. This is based, at least in part, on the premise that resistance mutations are rare or absent within populations prior to treatment, and take a long time to reach appreciable frequencies because helminth parasite generation time is long. This argument is critically dependent on the starting frequency of resistance alleles–if high levels of “standing variation” for resistance are present prior to deployment of treatment, resistance may spread rapidly. We examined frequencies of oxamniquine resistance alleles present in Schistosoma mansoni from Africa and the Middle East where oxamniquine has seen minimal use. We found that oxamniquine resistance alleles are widespread in the Old World, ranging from 4.29% in the Middle East to 14.91% in East African parasite populations. Furthermore, we show that resistance alleles from West African and the Caribbean schistosomes share a common origin, suggesting that these alleles travelled to the New World with S. mansoni during the transatlantic slave trade. Together, these results demonstrate extensive standing variation for oxamniquine resistance. Our results have important implications for both drug treatment policies and drug development efforts, and demonstrate the power of molecular surveillance approaches for guiding helminth control.
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Affiliation(s)
- Frédéric D. Chevalier
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
- * E-mail: (FDC); (TJCA)
| | - Winka Le Clec’h
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Marina McDew-White
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Vinay Menon
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
| | - Meghan A. Guzman
- Departments of Pathology and University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Stephen P. Holloway
- Biochemistry & Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Xiaohang Cao
- Biochemistry & Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Alexander B. Taylor
- Biochemistry & Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- X-ray Crystallography Core Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Safari Kinung'hi
- National Institute for Medical Research, Mwanza, United Republic of Tanzania
| | - Anouk N. Gouvras
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial Collge, London, United Kingdom
- Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - Bonnie L. Webster
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial Collge, London, United Kingdom
- Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - Joanne P. Webster
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial Collge, London, United Kingdom
- Centre for Emerging, Endemic and Exotic Diseases (CEEED), Royal Veterinary College, University of London, United Kingdom
| | - Aidan M. Emery
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial Collge, London, United Kingdom
- Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - David Rollinson
- London Centre for Neglected Tropical Disease Research (LCNDTR), Imperial Collge, London, United Kingdom
- Wolfson Wellcome Biomedical Laboratories, Natural History Museum, London, United Kingdom
| | - Amadou Garba Djirmay
- Réseau International Schistosomiases Environnemental Aménagement et Lutte (RISEAL), Niamey, Niger
- World Health Organization, Geneva, Switzerland
| | - Khalid M. Al Mashikhi
- Directorate General of Health Services, Dhofar Governorate, Salalah, Sultanate of Oman
| | - Salem Al Yafae
- Directorate General of Health Services, Dhofar Governorate, Salalah, Sultanate of Oman
| | | | - Hélène Moné
- Host-Pathogen-Environment Interactions laboratory, University of Perpignan, Perpignan, France
| | - Gabriel Mouahid
- Host-Pathogen-Environment Interactions laboratory, University of Perpignan, Perpignan, France
| | - P. John Hart
- Biochemistry & Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
- X-ray Crystallography Core Laboratory, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Philip T. LoVerde
- Departments of Pathology and University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Timothy J. C. Anderson
- Texas Biomedical Research Institute, San Antonio, Texas, United States of America
- * E-mail: (FDC); (TJCA)
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18
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Augusto RDC, Duval D, Grunau C. Effects of the Environment on Developmental Plasticity and Infection Success of Schistosoma Parasites - An Epigenetic Perspective. Front Microbiol 2019; 10:1475. [PMID: 31354641 PMCID: PMC6632547 DOI: 10.3389/fmicb.2019.01475] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 06/13/2019] [Indexed: 12/20/2022] Open
Abstract
Evidence of how environmental cues affect the phenotypes of, and compatibility between Schistosoma mansoni and their hosts come from studies in environmental parasitology and research on host diet and chemotherapeutic treatment. Schistosomes deal with a multitude of signals from the water environment as well as cues that come from their hosts, particularly in response to molecules that serve to recognize and destroy them, i.e., those molecules that arise from their hosts' immune systems. These interactions shape, not only the parasite's morphology, metabolism and behavior in the short-term, but also their infection success and development into different stage-specific phenotypes later in their life cycle, through the modification of the parasite's inheritance system. Developmental phenotypic plasticity of S. mansoni is based on epigenetic mechanisms which are also sensitive to environmental cues, but are poorly understood. Here, we argue that specific cues from the environment could lead to changes in parasite development and infectivity, and consequently, environmental signals that come from environmental control measures could be used to influence S. mansoni dynamics and transmission. This approach poses a challenge since epigenetic modification can lead to unexpected and undesired outcomes. However, we suggest that a better understanding of how environmental cues are interpreted by epigenome during schistosome development and host interactions could potentially be applied to control parasite's virulence. We review evidence about the role of environmental cues on the phenotype of S. mansoni and the compatibility between this parasite and its intermediate and definitive hosts.
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19
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Blanton RE. Population Structure and Dynamics of Helminthic Infection: Schistosomiasis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.ame-0009-2019. [PMID: 31325285 PMCID: PMC6650164 DOI: 10.1128/microbiolspec.ame-0009-2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Indexed: 11/20/2022] Open
Abstract
While disease and outbreaks are mainly clonal for bacteria and other asexually reproducing organisms, sexual reproduction in schistosomes and other helminths usually results in unique individuals. For sexually reproducing organisms, the traits conserved in clones will instead be conserved in the group of organisms that tends to breed together, the population. While the same tools are applied to characterize DNA, how results are interpreted can be quite different at times (see another article in this collection, http://www.asmscience.org/content/journal/microbiolspec/10.1128/microbiolspec.AME-0002-2018). It is difficult to know what the real effect any control program has on the parasite population without assessing the health of this population, how they respond to the control measure, and how they recover, if they do. This review, part of the Microbiology Spectrum Curated Collection: Advances in Molecular Epidemiology of Infectious Diseases, concentrates on one approach using pooled samples to study schistosome populations and shows how this and other approaches have contributed to our understanding of this parasite family's biology and epidemiology. *This article is part of a curated collection.
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Affiliation(s)
- Ronald E Blanton
- Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44120
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20
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Sanchez MC, Cupit PM, Bu L, Cunningham C. Transcriptomic analysis of reduced sensitivity to praziquantel in Schistosoma mansoni. Mol Biochem Parasitol 2019; 228:6-15. [PMID: 30658180 DOI: 10.1016/j.molbiopara.2018.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 11/19/2022]
Abstract
Schistosomiasis is an intravascular parasitic infection estimated to affect over 206 million people, the majority of whom live in Africa where the trematode worms Schistosoma mansoni and Schistosoma haematobium are the major causative agents. While a number of drugs have been used to treat schistosomiasis, praziquantel (PZQ) is the only one that is widely available, relatively cheap, and easy to use. The reliance on a single drug for the treatment of such a prevalent disease is a cause for concern due to the potential for resistance to render PZQ ineffective. In this study, we examine the transcriptome of three generations of a laboratory strain of S. mansoni (PR1) whose susceptibility to PZQ has been diminished across 9 passages through exposure to increasing sub-lethal doses of the drug. Miracidial susceptibility was significantly reduced after exposure to 2 × 50 mg/Kg PZQ during the first passage. Susceptibility of worms in vivo was first assessed during passage 5 when mice infected with PZQ-selected schistosomes were dosed with a lethal dose of 3 × 300 mg/kg PZQ resulting in only a 10% reduction in worm number compared to control treatment. The emergence of reduced sensitivity was marked by a shift in sex ratio from a predominantly male to a female population, a reduction in the length of females and ultimately the loss of the PZQ-selected line after passage 9. Analysis of differentially regulated transcripts did not suggest that any particular gene product or pathway was associated with drug resistance suggesting either a loss of function mutation to a single gene or an epistatic interaction of multiple gene products as the underlying cause of reduced susceptibility.
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Affiliation(s)
| | - Pauline M Cupit
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA, USA
| | - Lijing Bu
- Dept. of Biology, University of New Mexico, Albuquerque, NM, USA
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Viana M, Faust CL, Haydon DT, Webster JP, Lamberton PHL. The effects of subcurative praziquantel treatment on life-history traits and trade-offs in drug-resistant Schistosoma mansoni. Evol Appl 2018; 11:488-500. [PMID: 29636801 PMCID: PMC5891057 DOI: 10.1111/eva.12558] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/24/2017] [Indexed: 02/03/2023] Open
Abstract
Natural selection acts on all organisms, including parasites, to maximize reproductive fitness. Drug resistance traits are often associated with life-history costs in the absence of treatment. Schistosomiasis control programmes rely on mass drug administration to reduce human morbidity and mortality. Although hotspots of reduced drug efficacy have been reported, resistance is not widespread. Using Bayesian state-space models (SSMs) fitted to data from an in vivo laboratory system, we tested the hypothesis that the spread of resistant Schistosoma mansoni may be limited by life-history costs not present in susceptible counterparts. S. mansoni parasites from a praziquantel-susceptible (S), a praziquantel-resistant (R) or a mixed line of originally resistant and susceptible parasites (RS) were exposed to a range of praziquantel doses. Parasite numbers at each life stage were quantified in their molluscan intermediate and murine definitive hosts across four generations, and SSMs were used to estimate key life-history parameters for each experimental group over time. Model outputs illustrated that parasite adult survival and fecundity in the murine host decreased across all lines, including R, with increasing drug pressure. Trade-offs between adult survival and fecundity were observed in all untreated lines, and these remained strong in S with praziquantel pressure. In contrast, trade-offs between adult survival and fecundity were lost under praziquantel pressure in R. As expected, parasite life-history traits within the molluscan host were complex, but trade-offs were demonstrated between parasite establishment and cercarial output. The observed trade-offs between generations within hosts, which were modified by praziquantel treatment in the R line, could limit the spread of R parasites under praziquantel pressure. Whilst such complex life-history costs may be difficult to detect using standard empirical methods, we demonstrate that SSMs provide robust estimates of life-history parameters, aiding our understanding of costs and trade-offs of resistant parasites within this system and beyond.
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Affiliation(s)
- Mafalda Viana
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Christina L. Faust
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Wellcome Centre for Molecular ParasitologyUniversity of GlasgowGlasgowUK
| | - Daniel T. Haydon
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Joanne P. Webster
- London Centre for Neglected Tropical Disease ResearchDepartment of Infectious Disease EpidemiologySchool of Public HealthImperial College LondonLondonUK
- Centre for Endemic, Emerging and Exotic DiseasesThe Royal Veterinary CollegeUniversity of LondonLondonUK
| | - Poppy H. L. Lamberton
- Institute for Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- London Centre for Neglected Tropical Disease ResearchDepartment of Infectious Disease EpidemiologySchool of Public HealthImperial College LondonLondonUK
- Wellcome Centre for Molecular ParasitologyUniversity of GlasgowGlasgowUK
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22
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Bergquist R, Zhou XN, Rollinson D, Reinhard-Rupp J, Klohe K. Elimination of schistosomiasis: the tools required. Infect Dis Poverty 2017; 6:158. [PMID: 29151362 PMCID: PMC5694902 DOI: 10.1186/s40249-017-0370-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 10/19/2017] [Indexed: 11/13/2022] Open
Abstract
Background Historically, the target in the schistosomiasis control has shifted from infection to morbidity, then back to infection, but now as a public health problem, before moving on to transmission control. Currently, all endemic countries are encouraged to increase control efforts and move towards elimination as required by the World Health Organization (WHO) roadmap for the global control of the neglected tropical diseases (NTDs) and the WHA65.21 resolution issued by the World Health Assembly. However, schistosomiasis prevalence is still alarmingly high and the global number of disability-adjusted life years (DALYs) due to this infection has in fact increased due to inclusion of some ‘subtle’ clinical symptoms not previously counted. Main body There is a need to restart and improve efforts to reach the elimination goal. To that end, the first conference of the Global Schistosomiasis Alliance (GSA) Research Working Group was held in mid-June 2016 in Shanghai, People’s Republic of China. It reviewed current progress in schistosomiasis control and elimination, identified pressing operational research gaps that need to be addressed and discussed new tools and strategies required to make elimination a reality. The articles emanating from the lectures and discussions during this meeting, together with some additional invited papers, have been collected as a special issue of the ‘Infectious Diseases of Poverty’ entitled ‘Schistosomiasis Research: Providing the Tools Needed for Elimination’, consisting of 26 papers in all. This paper refers to these papers and discusses critical questions arising at the conference related to elimination of schistosomiasis. Conclusion The currently most burning questions are the following: Can schistosomiasis be eliminated? Does it require better, more highly sensitive diagnostics? What is the role of preventive chemotherapy at the elimination stage? Is praziquantel sufficient or do we need new drugs? Contemplating these questions, it is felt that the heterogeneity of the endemic areas in the world requires WHO policies to be upgraded instituting new, differentiated guidelines. Electronic supplementary material The online version of this article (doi: 10.1186/s40249-017-0370-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Xiao-Nong Zhou
- National Institute of Parasitic Diseases Chinese Center for Disease Control and Prevention, Shanghai, 200025, China.
| | - David Rollinson
- Department of Life Sciences, The Natural History Museum, London, SW7 5BD, UK
| | | | - Katharina Klohe
- Global Schistosomiasis Alliance, Westenriederstrasse 10, 80331, Munich, Germany
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