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Menéndez Fernández-Miranda C, Fernández-Suárez J, García Pérez A, Boga JA, Rodríguez-Pérez M, Rodríguez-Guardado A. Dientamoeba fragilis: An emerging pathogen. ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA (ENGLISH ED.) 2025; 43:219-226. [PMID: 40180476 DOI: 10.1016/j.eimce.2025.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Accepted: 08/23/2024] [Indexed: 04/05/2025]
Abstract
Dientamoeba fragilis is a protozoan of the gastrointestinal tract, very prevalent in our environment and responsible for diverse clinical symptoms mainly abdominal pain, diarrhoea and eosinophilia, although some infected patients are asymptomatic. Since the first description just a century ago, there are many unanswered questions: its different morphologies and the role of each of them, its actual prevalence, the mode of transmission, its pathogenicity, or the treatment of choice, continue to be source of controversy. Risk factors associated with infection by D. fragilis are: contact with children, residence in a rural area, and co-infection by Enterobius vermicularis. New molecular diagnostic techniques in the form of commercial multi-diagnostic panels are now considered first choice techniques. Paromomycin show higher cure rates, than metronidazole.
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Affiliation(s)
| | - Jonathan Fernández-Suárez
- Servicio de Microbiología, Hospital Universitario Central de Asturias, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
| | - Alicia García Pérez
- Servicio de Medicina Interna, Hospital Universitario San Agustín, Avilés, Spain
| | - José Antonio Boga
- Servicio de Microbiología, Hospital Universitario Central de Asturias, Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain
| | - Mercedes Rodríguez-Pérez
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain; Microbiology Unit, Hospital Universitario Central de Asturias, Spain
| | - Azucena Rodríguez-Guardado
- Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain; Infectious Diseases Unit, Hospital Universitario Central de Asturias, Spain.
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Hazenberg HMJL, Mank TG, Band C, Euser SM, van Soest EJ. A prospective analysis of clinical and parasitological outcomes after treatment or a wait-and-see approach of Dientamoeba fragilis infection in an adult general practice population. Eur J Clin Microbiol Infect Dis 2025; 44:143-150. [PMID: 39540993 DOI: 10.1007/s10096-024-04989-3] [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: 03/18/2024] [Accepted: 11/06/2024] [Indexed: 11/16/2024]
Abstract
PURPOSE Dientamoeba fragilis is a protozoan frequently encountered in stool samples globally. It is debated whether Dientamoeba fragilis carries pathogenic capacities. This study prospectively analyses clinical and parasitological outcomes after treatment or a wait-and-see approach of Dientamoeba fragilis infection in a general practice adult population. METHODS In this prospective observational cohort study 113 adult patients with a positive Polymerase Chain Reaction (PCR) test result for D. fragilis (T0) in a primary care setting, were followed-up longitudinally with a control PCR-test and microscopic stool examination at 30 days (T1) and 90 days (T2) after inclusion. Standardized patient-reported questionnaires including treatment details and the adjusted Irritable Bowel Syndrome-Severity Score (IBS-SS) were retrieved at T0, T1 and T2. RESULTS Parasitology and questionnaires were retrieved from 87 participants at T0 and T1, and 74 at T2. Treated patients(n = 64) more often tested PCR negative at T1 (64.1% vs. 16.4%, p < 0.001) and T2 (67.3% vs. 5.3%, p < 0.001) compared to untreated patients. No difference in decline in IBS-SS was seen comparing the treatment and non-treatment groups at T1 (p = 0.403) or T2 (p = 1.00). CONCLUSION A short and long term increased parasitological clearance is shown with treatment of clioquinol or metronidazole compared with no treatment. A clear and significant correlation between parasitological cure and decline of clinical complaints as reported by the participants could not be established.
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Affiliation(s)
- Hanna M J L Hazenberg
- Department of Gastroenterology and Hepatology Spaarne Gasthuis Hoofddorp, Hoofddorp, The Netherlands
| | - Theo G Mank
- Department of Epidemiology, Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, Haarlem, 2035 RC, The Netherlands
| | - Caterina Band
- Department of Gastroenterology and Hepatology Spaarne Gasthuis Hoofddorp, Hoofddorp, The Netherlands
| | - Sjoerd M Euser
- Department of Epidemiology, Regional Public Health Laboratory Kennemerland, Boerhaavelaan 26, Haarlem, 2035 RC, The Netherlands.
| | - Ellert J van Soest
- Department of Gastroenterology and Hepatology Spaarne Gasthuis Hoofddorp, Hoofddorp, The Netherlands
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Pietilä JP, Häkkinen TA, Pakarinen L, Ollgren J, Kantele A. Treatment of Dientamoeba fragilis: A retrospective Finnish analysis of faecal clearance and clinical cure comparing four antiprotozoal drugs. New Microbes New Infect 2023; 54:101179. [PMID: 37786407 PMCID: PMC10542007 DOI: 10.1016/j.nmni.2023.101179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 09/08/2023] [Accepted: 09/09/2023] [Indexed: 10/04/2023] Open
Abstract
Background Dientamoeba fragilis (DF), the most common intestinal protozoal pathogen in affluent countries, causes asymptomatic or symptomatic infections with severity ranging from mild to disabling. Currently, many studies of treatment options only have small sample sizes and report results that are partly contradictory. Methods Investigating data retrieved from Helsinki University Hospital and Helsinki City patient records, we searched for the most effective antiprotozoal in treating DF infections. To study microbiological clearance of DF, we collected laboratory results of control samples from patients given one of four commonly used antiprotozoals: doxycycline, metronidazole, paromomycin, or secnidazole. For patients symptomatic prior to antiprotozoal treatment, we also retrieved data on clinical outcomes. Furthermore, we explored factors associated with faecal clearance and clinical cure. Results A total of 369 patients (median age 38) and 492 treatment episodes were included. Paromomycin (n = 297) proved effective (clearance rate 83%), showing strong association with faecal clearance (aOR 18.08 [7.24-45.16], p < 0.001). For metronidazole the rate was 42% (n = 84), for secnidazole 37% (n = 79), and doxycycline 22% (n = 32). In pairwise comparisons, paromomycin outdid the three other regimens (p < 0.001, χ2 test). Faecal clearance was associated with clinical cure (aOR 5.85 [3.02-11.32], p < 0.001). Conclusions Faecal clearance, strongly associated with clinical cure, is most effectively achieved with a course of paromomycin, followed by metronidazole, secnidazole and doxycycline. Our findings will be useful in devising treatment guidelines for adults with symptomatic D. fragilis infection.
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Affiliation(s)
- Jukka-Pekka Pietilä
- Meilahti Vaccine Research Center MeVac, Department of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tuuve A Häkkinen
- Meilahti Vaccine Research Center MeVac, Department of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Laura Pakarinen
- Department of Infectious Diseases, Inflammation Center, Helsinki University Hospital, Helsinki, Finland
- Department of Social Services and Health Care, City of Helsinki, Finland
| | - Jukka Ollgren
- Department of Health Security, Finnish Institute for Health and Welfare, Helsinki, Finland
| | - Anu Kantele
- Meilahti Vaccine Research Center MeVac, Department of Infectious Diseases, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Human Microbiome Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Infectious Diseases, Inflammation Center, Helsinki University Hospital, Helsinki, Finland
- Finnish Multidisciplinary Center of Excellence in Antimicrobial Resistance Research, FIMAR, University of Helsinki, Helsinki, Finland
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Clemente L, Pasut M, Carlet R, Ruscio M, Fontana F. Dientamoeba fragilis in the North-East of Italy: Prevalence study and treatment. Parasitol Int 2020; 80:102227. [PMID: 33137500 DOI: 10.1016/j.parint.2020.102227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 09/19/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
Dientamoeba fragilis is an intestinal protozoan, an inhabitant of the human gastrointestinal tract, with a worldwide distribution. The reported prevalence of D. fragilis varies worldwide in different populations between 0.3% and 82.9%, and its role as a pathogen is still unclear. The parasite has been identified in the faeces of asymptomatic patients and with different acute and chronic symptoms, like abdominal pain, diarrhoea, flatulence, nausea and vomiting. The aims of this study were to evaluate the prevalence of D. fragilis in the North-East of Italy, and the clinical improvement of symptoms after recommended treatment with paromomycin or metronidazole. Furthermore, a literature review of D. fragilis prevalence studies in Italy was carried out to show the Italian situation. Of 575 enrolled people, 85 (14.8%) were positive for D. fragilis. The most prevalent symptoms were abdominal pain 28.2%, anal itching 27.1%, watery diarrhoea 18.8%, meteorism 16.5% and nausea/lack of appetite 14.1%. The high rate of anal itching was unexpected, because it wasn't a common symptom. 32 patients were co-infected with B. hominis (37.7%) and three with G. lamblia (3.5%). Our study showed paromomycin had a high efficacy for treatment of D. fragilis infections 100.0% (45/45), while caution must be used when using metronidazole 53.3% (24/40). We recommend paromomycin for empirical treatment, given its great effectiveness in our population.
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Affiliation(s)
- Libera Clemente
- Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), Trieste, Italy.
| | - Mariangela Pasut
- Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), Trieste, Italy
| | - Romina Carlet
- Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), Trieste, Italy
| | - Maurizio Ruscio
- Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), Trieste, Italy
| | - Francesco Fontana
- Division of Laboratory Medicine, University Hospital Giuliano Isontina (ASU GI), Trieste, Italy
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Roshan N, Clancy A, Gunaratne AW, LeBusque A, Pilarinos D, Borody TJ. Two-day enema antibiotic therapy for parasite eradication and resolution of symptoms. World J Gastroenterol 2020; 26:3792-3799. [PMID: 32774058 PMCID: PMC7383847 DOI: 10.3748/wjg.v26.i26.3792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/14/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Blastocystis hominis (B. hominis) and Dientamoeba fragilis (D. fragilis) are two protozoan parasites of human bowel that are found throughout the world. There is still debate about the pathogenicity of these protozoans, despite them being commonly associated with gastrointestinal symptoms and can cause health issue in both children and adults. These parasites are usually transmitted through faecal-oral contact particularly under poor hygiene conditions or food/water contamination. Once a person is infected, the parasites live in the large intestine and are passed in the faeces.
AIM To investigate the effect of triple antibiotic therapy using enema infusion in the treatment of B. hominis and D. fragilis infections.
METHODS This retrospective longitudinal study was conducted in a single medical centre, which included fifty-four patients (≥ 18 years) who were positive for D. fragilis, B. hominis or both between 2017 and 2018. The treatment consisted of triple antibiotics that were infused over two consecutive days through rectal enema. Faecal samples were collected from participants pre- and post-treatment and were tested for parasites using microscopy and polymerase chain reaction. Patients’ symptoms were recorded prior and after the treatment as well as patient demographic data.
RESULTS Patients (n = 54), were either positive for B. hominis (37%), D. fragilis (35%) or both (28%). All patients completed the two-day treatment and no serious adverse effect was reported. The most common side effect experienced by the patients during the treatment was urine discolouration which was cleared by six weeks of follow-up. Common symptoms reported prior to treatment were diarrhoea, abdominal pain, constipation and fatigue. Other symptoms included abdominal discomfort, dizziness and blood in the stool. Eighty-nine percent of patients completed a final stool test post-treatment. At six weeks post-treatment, 79% of patients cleared the parasites from their faeces. Symptoms such as abdominal discomfort, dizziness and blood in the stool decreased significantly at both seven days and six weeks post-treatment (P < 0.040). The enema retention time, bowel preparation, previous antibiotic treatment or previous gastrointestinal problems had no significant effect on parasite eradication.
CONCLUSION Overall, eradication of parasites and improvement of clinical outcomes were observed in treated patients, showing the efficacy of this combination to eradicate the parasites and provide positive clinical outcome.
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Affiliation(s)
- Niloufar Roshan
- Centre for Digestive Diseases, New South Wales 2046, Australia
| | - Annabel Clancy
- Centre for Digestive Diseases, New South Wales 2046, Australia
| | | | | | | | - Thomas J Borody
- Centre for Digestive Diseases, New South Wales 2046, Australia
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Burgaña A, Abellana R, Yordanov SZ, Kazan R, Pérez Ortiz AM, Ramos CC, Hernández CG, Rivero MM, Gonçalves AQ, Padilla E, Pérez J, García-Puig R, Perez-Porcuna TM. Paromomycin is superior to metronidazole in Dientamoeba fragilis treatment. Int J Parasitol Drugs Drug Resist 2019; 11:95-100. [PMID: 31759244 PMCID: PMC6880088 DOI: 10.1016/j.ijpddr.2019.10.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/27/2019] [Accepted: 10/28/2019] [Indexed: 01/29/2023]
Abstract
Dientamoeba fragilis is a trichomonad parasite of the human intestine that is found worldwide. However, the biological cycle and transmission of this parasite have yet to be elucidated. Although its pathogenic capacity has been questioned, there is increasing evidence that clinical manifestations vary greatly. Different therapeutic options with antiparasitic drugs are currently available; however, very few studies have compared the effectiveness of these drugs. In the present longitudinal study, we evaluate 13,983 copro-parasitological studies using light microscopy of stools, during 2013-2015, in Terrassa, Barcelona (Spain). A total of 1150 (8.2%) presented D. fragilis. Of these, 739 episodes were finally analyzed: those that involved a follow-up parasitology test up to 3 months later, corresponding to 586 patients with gastrointestinal symptoms (53% under 15 years of age). Coinfection by Blastocystis hominis was present in 33.6% of the subjects. Our aim was to compare therapeutic responses to different antiparasitic drugs and the factors associated with the persistence of D. fragilis post-treatment. Gender, age, and other intestinal parasitic coinfections were not associated with parasite persistence following treatment. Metronidazole was the therapeutic option in most cases, followed by paromomycin: 65.4% and 17.5% respectively. Paromomycin was found to be more effective at eradicating parasitic infection than metronidazole (81.8% vs. 65.4%; p = 0.007), except in children under six years of age (p = 0.538). Although Dientamoeba fragilis mainly produces mild clinical manifestations, the high burden of infection means we require better understanding of its epidemiological cycle and pathogenicity, as well as adequate therapeutic guidelines in order to adapt medical care and policies to respond to this health problem.
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Affiliation(s)
- Ander Burgaña
- Atenció Primària, Fundació Assistencial Mútua Terrassa, Terrassa, Spain
| | - Rosa Abellana
- Departament Fonaments Clínics, Universitat de Barcelona, Barcelona, Spain
| | | | - Rabee Kazan
- Atenció Primària, Fundació Assistencial Mútua Terrassa, Terrassa, Spain
| | | | | | | | | | - Alessandra Queiroga Gonçalves
- Unitat de Suport a la Recerca Terres de l'Ebre, Fundació Institut Universitari per a la recerca a l'Atenció Primària de Salut Jordi Gol i Gurina (IDIAPJGol), Tortosa, Spain; Unitat Docent de Medicina de Família i Comunitària Tortosa-Terres de l'Ebre, Institut Català de la Salut, Tortosa, Spain
| | - Emma Padilla
- Àrea de Microbiologia de CATLAB, Terrassa, Spain
| | - Josefa Pérez
- Àrea de Microbiologia de CATLAB, Terrassa, Spain
| | - Roger García-Puig
- Unitat de Gastroenterologia, Hepatologia i Nutrició Pediàtrica, Mútua Terrassa, Terrassa, Spain
| | - Tomas M Perez-Porcuna
- Atenció Primària, Fundació Assistencial Mútua Terrassa, Terrassa, Spain; Unitat de Salut Internacional, Departament de Pediatria, Fundació Recerca Mútua Terrassa, Atenció Primària, Hospital Universitari Mútua Terrassa, Universitat de Barcelona, Terrassa, Spain.
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Menéndez C, Fernández-Suarez J, Boga Ribeiro JA, Rodríguez-Pérez M, Vázquez F, Gonzalez-Sotorrios N, Rodríguez-Guardado A. Epidemiological and clinical characteristics of Dientamoeba fragilis infection. Enferm Infecc Microbiol Clin 2019; 37:290-295. [DOI: 10.1016/j.eimc.2018.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 07/26/2018] [Accepted: 07/31/2018] [Indexed: 11/29/2022]
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Does Dientamoeba fragilis cause diarrhea? A systematic review. Parasitol Res 2018; 117:971-980. [PMID: 29404747 DOI: 10.1007/s00436-018-5771-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/22/2018] [Indexed: 10/18/2022]
Abstract
It remains controversial whether Dientamoeba fragilis is a commensal parasite or a pathogen. The objective of this systematic review was to establish the strength of the evidence that Dientamoeba fragilis would cause diarrhea. A search was performed for studies that reported either the association between D. fragilis detection in stools and diarrhea or diarrhea outcomes with D. fragilis therapy or challenge. Data from seven studies of specific populations reported that 22% had D. fragilis in stools of which only 23% had diarrhea. Eleven studies of stool samples submitted to laboratories reported that 4.3% of individuals had D. fragilis of which 54% had diarrhea. Twelve studies reported that D. fragilis was detected from 1.6% of individuals with diarrhea and 9.6% of diarrheal stools. Five studies analyzed the prevalence of D. fragilis in individuals with and without diarrhea; the two with a statistically significant difference between groups had discordant results. The only cohort study with an appropriate control group reported diarrhea in a higher proportion of children with D. fragilis than in controls. No D. fragilis treatment studies included diarrhea as an outcome. There were only two challenge studies involving one person each. In conclusion, the evidence that D. fragilis would cause diarrhea or that treatment would hasten diarrhea resolution is inconclusive.
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Stark D, Barratt J, Chan D, Ellis JT. Dientamoeba fragilis, the Neglected Trichomonad of the Human Bowel. Clin Microbiol Rev 2016; 29:553-80. [PMID: 27170141 PMCID: PMC4861990 DOI: 10.1128/cmr.00076-15] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Dientamoeba fragilis is a protozoan parasite of the human bowel, commonly reported throughout the world in association with gastrointestinal symptoms. Despite its initial discovery over 100 years ago, arguably, we know less about this peculiar organism than any other pathogenic or potentially pathogenic protozoan that infects humans. The details of its life cycle and mode of transmission are not completely known, and its potential as a human pathogen is debated within the scientific community. Recently, several major advances have been made with respect to this organism's life cycle and molecular biology. While many questions remain unanswered, these and other recent advances have given rise to some intriguing new leads, which will pave the way for future research. This review encompasses a large body of knowledge generated on various aspects of D. fragilis over the last century, together with an update on the most recent developments. This includes an update on the latest diagnostic techniques and treatments, the clinical aspects of dientamoebiasis, the development of an animal model, the description of a D. fragilis cyst stage, and the sequencing of the first D. fragilis transcriptome.
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Affiliation(s)
- Damien Stark
- Division of Microbiology, Sydpath, St Vincent's Hospital, Darlinghurst, NSW, Australia
| | - Joel Barratt
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
| | - Douglas Chan
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
| | - John T Ellis
- School of Life Sciences and the I3 Institute, University of Technology Sydney, Broadway, NSW, Australia
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El-Taweel HA. Understanding drug resistance in human intestinal protozoa. Parasitol Res 2015; 114:1647-59. [DOI: 10.1007/s00436-015-4423-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 03/05/2015] [Indexed: 01/07/2023]
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Sekar U, Shanthi M. Blastocystis: Consensus of treatment and controversies. Trop Parasitol 2013; 3:35-9. [PMID: 23961439 PMCID: PMC3745668 DOI: 10.4103/2229-5070.113901] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/24/2013] [Indexed: 12/14/2022] Open
Abstract
Blastocystis is a highly controversial protozoan parasite. It has been variably regarded as a commensal and pathogen. Scientists have for decades wondered whether it is truly an enteropathogen and if it is observed in symptomatic patients whether treatment is required because patient recovery and improvement has been noted even without any treatment. Though associated with self-limiting infection, treatment is warranted in many patients due to persistence of symptoms. This particularly holds true for children and adults who are immuno compromised. Several drugs have been used to treat Blastocystis but each one of them has produced widely variable rates of clinical cure and eradication of the parasite from the feces. Based on the studies carried out in vitro and clinical responses obtained in patients, metronidazole appears to be the most effective drug for Blastocystis infection. However, the therapy is complicated due to different dosages and regimens adopted and the unresponsiveness to treatment observed in several sections of the population studied. Recently, the finding of different subsets of Blastocystis exhibiting resistance to metronidazole and associated with variable degrees of symptoms has underscored the importance of typing the subsets of the parasite in order to foretell the clinical response and the need to treat. Till date, the mode of action of the drugs used and the mechanism of resistance is not entirely known and is a topic of speculation. Other drugs with anti Blastocystis activity and used in therapy includes trimethoprim sulfamethoxazole and nitazoxanide. Several other compounds have also been evaluated for the treatment either alone or in combination with the first or second line drugs. A lot of interest has also been generated on the role of probiotics particularly Saccharomyces boularrdii and other natural food compounds on eradication of the parasite. This review provides a comprehensive overview of antimicrobials used to target Blastocystis and discusses the issues pertaining to drug resistance, treatment failure, reinfection, and the current views on treatment modalities.
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Affiliation(s)
- Uma Sekar
- Department of Microbiology, Sri Ramachandra Medical College and Research Institute, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India
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Gray TJ, Kwan YL, Phan T, Robertson G, Cheong EYL, Gottlieb T. Dientamoeba fragilis: a family cluster of disease associated with marked peripheral eosinophilia. Clin Infect Dis 2013; 57:845-8. [PMID: 23759351 DOI: 10.1093/cid/cit389] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dientamoeba fragilis has emerged as an important and underrecognized cause of gastrointestinal illness. We report a familial cluster of D. fragilis associated with marked peripheral eosinophilia and gastrointestinal symptoms. Dientamoeba fragilis infection should be considered in the setting of unexplained eosinophilia. If confirmed, screening of household members should be considered.
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Affiliation(s)
- Timothy James Gray
- Department of Microbiology and Infectious Diseases, Concord Repatriation General Hospital, Concord, NSW 2139, Australia.
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van Hellemond JJ, Molhoek N, Koelewijn R, Wismans PJ, van Genderen PJJ. Is paromomycin the drug of choice for eradication of Blastocystis in adults? J Infect Chemother 2012; 19:545-8. [PMID: 23053509 DOI: 10.1007/s10156-012-0496-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 09/26/2012] [Indexed: 11/25/2022]
Abstract
Blastocystis is a protozoan parasite of controversial clinical significance that is often detected in stools of patients with gastrointestinal complaints. Patients infected with Blastocystis and persistent, unexplained gastrointestinal complaints are often treated with the intention to eradicate Blastocystis. However, there is no consensus on the most effective drug. We performed a retrospective follow-up study with a large cohort of patients in which the natural disease course and efficacy of treatment with either paromomycin, clioquinol, or metronidazole were evaluated. With an eradication rate of 77 %, treatment with paromomycin appeared significantly more effective than treatment with clioquinol (38 %), metronidazole (38 %), or no treatment (22 %). This study showed that (1) Blastocystis was frequently observed in the stools of our patient group (34 %), (2) spontaneous clearance of Blastocystis infections occurred only in a small proportion of patients (22 %), and therefore (3) drug treatment is required for more efficient eradication of Blastocystis. Paromomycin exhibited superior performance in comparison to both metronidazole and clioquinol.
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Affiliation(s)
- Jaap J van Hellemond
- Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Centre and Harbour Hospital, P.O. Box 2040, Rotterdam, 3000 CA, The Netherlands.
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Nagata N, Marriott D, Harkness J, Ellis JT, Stark D. Current treatment options for Dientamoeba fragilis infections. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2012; 2:204-15. [PMID: 24533282 DOI: 10.1016/j.ijpddr.2012.08.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/06/2012] [Accepted: 08/07/2012] [Indexed: 12/20/2022]
Abstract
Dientamoeba fragilis belongs to the trichomonad group of protozoan parasites and it has been implicated as a cause of gastrointestinal disease with world-wide prevalences ranging from 0.5% to 16%. The majority of patients with dientamoebiasis present with gastrointestinal complaints. Chronic symptoms are common with up to a third of patients exhibiting persistent diarrhoea. Numerous studies have successfully demonstrated parasite clearance, coupled with complete resolution of clinical symptoms following treatment with various antiparasitic compounds. Treatments reported to be successful for dientamoebiasis include carbarsone, diphetarsone, tetracyclines, paromomycin, erythromycin, hydroxyquinolines and the 5-nitroimidazoles, including metronidazole, secnidazole, tinidazole and ornidazole. It is of note that most current treatment data is based only on small number of case reports. No large scale double blind randomised placebo controlled trials testing the efficacy of antimicrobial agents against D. fragilis has been undertaken highlighting the need for further study. In addition there is very little in vitro susceptibility data available for the organism making some current treatment options questionable. The aim of this review is to critically discuss all treatment options currently available for dientamoebiasis.
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Affiliation(s)
- Noriyuki Nagata
- Division of Microbiology, SydPath, St. Vincent's Hospital, Darlinghurst, Australia ; University of Technology Sydney, School of Medical and Molecular Biosciences, Broadway, Australia
| | - Deborah Marriott
- Division of Microbiology, SydPath, St. Vincent's Hospital, Darlinghurst, Australia ; University of Technology Sydney, School of Medical and Molecular Biosciences, Broadway, Australia
| | - John Harkness
- Division of Microbiology, SydPath, St. Vincent's Hospital, Darlinghurst, Australia ; University of Technology Sydney, School of Medical and Molecular Biosciences, Broadway, Australia
| | - John T Ellis
- University of Technology Sydney, School of Medical and Molecular Biosciences, Broadway, Australia ; University of Technology Sydney, iThree Institute, Broadway, Australia
| | - Damien Stark
- Division of Microbiology, SydPath, St. Vincent's Hospital, Darlinghurst, Australia ; University of Technology Sydney, School of Medical and Molecular Biosciences, Broadway, Australia
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