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Uiterwijk M, Nijsse R, Kooyman FNJ, Wagenaar JA, Mughini-Gras L, Ploeger HW. Host factors associated with Giardia duodenalis infection in dogs across multiple diagnostic tests. Parasit Vectors 2019; 12:556. [PMID: 31752993 PMCID: PMC6873540 DOI: 10.1186/s13071-019-3810-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 11/15/2019] [Indexed: 12/03/2022] Open
Abstract
Background The aim of this study was to assess potential associations between Giardia duodenalis infection in dogs, as determined by three diagnostic tests, and dog’s group of origin, fecal consistency, age, sex, neuter status, and co-infections with other gastrointestinal parasites. Methods Fecal samples from 1291 dogs from four groups (household, shelter, hunting and clinical dogs) were tested with qPCR, rapid enzyme immunochromatographic assay (IDEXX SNAP®Giardia), and direct immunofluorescence (DFA, Merifluor) for presence of G. duodenalis. Moreover, fecal samples were tested with centrifugation sedimentation flotation (CSF) coproscopical analysis for presence of gastrointestinal parasites. Associations were expressed as odds ratios (ORs). Results Several significant associations were found, of which a few were consistent for all three tests and Giardia positivity in general (positive with at least one of these tests). Dogs older than one year were significantly less likely to test positive for Giardia than younger dogs. Group-housed dogs, especially hunting dogs, were significantly more likely to test positive for Giardia compared to household and clinical dogs. A consistently significant association with Trichuris appeared to be driven by the high prevalence in hunting dogs. Although there was no significant association between loose stool and Giardia infection in the overall population, household dogs were significantly more likely to test Giardia-positive when having loose stool. Overall, Giardia-positive dogs with loose stool shed significantly more cysts, both determined semi-quantitatively with CSF and quantitatively by qPCR, than positive dogs with no loose stool. When other gastrointestinal parasites were present, significantly fewer cysts were detected with CSF, but this was not confirmed with qPCR. Conclusion Giardia is the most common gastrointestinal parasite in Dutch dogs, except for hunting dogs, in which Trichuris and strongyle-type eggs (hookworms) prevailed. Giardia infection was not significantly associated with loose stool, except for household dogs. Young dogs and group-housed dogs were significantly more often Giardia-positive. These associations were consistent across diagnostic tests. Young dogs, clinical dogs and dogs with loose stool shed Giardia cysts in the highest numbers. If another gastrointestinal parasite was present lower numbers of cysts were observed by microscope (CSF), but not with a molecular method (qPCR).
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Affiliation(s)
- Mathilde Uiterwijk
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,The Netherlands Food and Consumer Product Safety Authority (NVWA), Centre Monitoring Vectors, Wageningen, The Netherlands
| | - Rolf Nijsse
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Frans N J Kooyman
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jaap A Wagenaar
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.,Wageningen Bioveterinary Research, Lelystad, The Netherlands
| | - Lapo Mughini-Gras
- National Institute for Public Health and the Environment (RIVM), Centre for Infectious Disease Control (CIb), Bilthoven, The Netherlands.,Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Harm W Ploeger
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
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2
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Aw JYH, Clarke NE, McCarthy JS, Traub RJ, Amaral S, Huque MH, Andrews RM, Gray DJ, Clements ACA, Vaz Nery S. Giardia duodenalis infection in the context of a community-based deworming and water, sanitation and hygiene trial in Timor-Leste. Parasit Vectors 2019; 12:491. [PMID: 31627736 PMCID: PMC6798381 DOI: 10.1186/s13071-019-3752-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/14/2019] [Indexed: 12/26/2022] Open
Abstract
Background Giardiasis is a common diarrhoeal disease caused by the protozoan Giardia duodenalis. It is prevalent in low-income countries in the context of inadequate access to water, sanitation and hygiene (WASH), and is frequently co-endemic with neglected tropical diseases such as soil-transmitted helminth (STH) infections. Large-scale periodic deworming programmes are often implemented in these settings; however, there is limited evidence for the impact of regular anthelminthic treatment on G. duodenalis infection. Additionally, few studies have examined the impact of WASH interventions on G. duodenalis. Methods The WASH for WORMS cluster randomised controlled trial was conducted in remote communities in Manufahi municipality, Timor-Leste, between 2012 and 2016. All study communities received four rounds of deworming with albendazole at six-monthly intervals. Half were randomised to additionally receive a community-level WASH intervention following study baseline. We measured G. duodenalis infection in study participants every six months for two years, immediately prior to deworming, as a pre-specified secondary outcome of the trial. WASH access and behaviours were measured using questionnaires. Results There was no significant change in G. duodenalis prevalence in either study arm between baseline and the final study follow-up. We found no additional benefit of the community-level WASH intervention on G. duodenalis infection (relative risk: 1.05, 95% CI: 0.72–1.54). Risk factors for G. duodenalis infection included living in a household with a child under five years of age (adjusted odds ratio, aOR: 1.35, 95% CI: 1.04–1.75), living in a household with more than six people (aOR: 1.32, 95% CI: 1.02–1.72), and sampling during the rainy season (aOR: 1.23, 95% CI: 1.04–1.45). Individuals infected with the hookworm Necator americanus were less likely to have G. duodenalis infection (aOR: 0.71, 95% CI: 0.57–0.88). Conclusions Prevalence of G. duodenalis was not affected by a community WASH intervention or by two years of regular deworming with albendazole. Direct household contacts appear to play a dominant role in driving transmission. We found evidence of antagonistic effects between G. duodenalis and hookworm infection, which warrants further investigation in the context of global deworming efforts. Trial registration Australian New Zealand Clinical Trials Registry, ACTRN12614000680662. Registered 27 June 2014, retrospectively registered. https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366540.![]()
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Affiliation(s)
- Jessica Y H Aw
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Naomi E Clarke
- Research School of Population Health, Australian National University, Canberra, ACT, Australia. .,The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, NSW, Australia.
| | - James S McCarthy
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Salvador Amaral
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Md Hamidul Huque
- The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, NSW, Australia
| | - Ross M Andrews
- Research School of Population Health, Australian National University, Canberra, ACT, Australia.,Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
| | - Darren J Gray
- Research School of Population Health, Australian National University, Canberra, ACT, Australia
| | - Archie C A Clements
- Research School of Population Health, Australian National University, Canberra, ACT, Australia.,Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Susana Vaz Nery
- Research School of Population Health, Australian National University, Canberra, ACT, Australia.,The Kirby Institute for Infection and Immunity in Society, University of New South Wales, Sydney, NSW, Australia
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3
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Mohamed N, Muse A, Wordofa M, Abera D, Mesfin A, Wolde M, Desta K, Tsegaye A, Taye B. Increased Prevalence of Cestode Infection Associated with History of Deworming among Primary School Children in Ethiopia. Am J Trop Med Hyg 2019; 101:641-649. [PMID: 31333166 DOI: 10.4269/ajtmh.19-0284] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Mass deworming of school-aged children with anthelmintics has been recognized as an effective approach for reducing the burden of soil-transmitted helminth (STH) infections. However, the consequences of this intervention on nontargeted parasite populations sharing the same gastrointestinal niche are unclear. We conducted a cross-sectional survey among three primary schools in Sululta town, Ethiopia, to examine the association between students' histories of deworming treatment in the past 6 months and the prevalence of cestode and protozoan infections. An interviewer-led questionnaire administered to parents provided information on sociodemographic factors, and deworming status was ascertained from school records. Stool samples were collected from 525 children for microscopic examination. The independent associations of "any cestode" (positive either for Hymenolepis nana or Taenia spp. eggs) and "any protozoan" (positive either for Giardia lamblia or Entamoeba histolytica/Entamoeba dispar) with history of deworming were examined using logistic regression. Overall, 25.9% of children were infected with at least one intestinal parasite of which H. nana was the most common. In multivariate analyses, deworming in the past 6 months was positively associated with increased odds of both "any protozoan" and "any cestode" infections; the latter reached statistical significance (AOR = 1.83, 95% CI: 0.69-4.86, P = 0.220, AOR = 3.82, 95% CI: 1.17-12.73, P = 0.029, respectively). If this observed association is causal, a greater understanding of interspecies interactions within the gastrointestinal niche may elucidate possible consequences of mass deworming treatments against STHs on coexisting nontargeted parasites.
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Affiliation(s)
- Nader Mohamed
- Department of Biology, Colgate University, Hamilton, New York
| | - Anna Muse
- Department of Biology, Colgate University, Hamilton, New York
| | - Moges Wordofa
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Dessie Abera
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Abiyot Mesfin
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mistire Wolde
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Kassu Desta
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Aster Tsegaye
- Department of Medical Laboratory Sciences, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Bineyam Taye
- Department of Biology, Colgate University, Hamilton, New York
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4
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Campbell SJ, Nery SV, D'Este CA, Gray DJ, McCarthy JS, Traub RJ, Andrews RM, Llewellyn S, Vallely AJ, Williams GM, Amaral S, Clements ACA. Water, sanitation and hygiene related risk factors for soil-transmitted helminth and Giardia duodenalis infections in rural communities in Timor-Leste. Int J Parasitol 2016; 46:771-779. [PMID: 27616734 DOI: 10.1016/j.ijpara.2016.07.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Revised: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 10/21/2022]
Abstract
There is little evidence on prevalence or risk factors for soil transmitted helminth infections in Timor-Leste. This study describes the epidemiology, water, sanitation and hygiene, and socioeconomic risk factors of STH and intestinal protozoa amongst communities in Manufahi District, Timor-Leste. As part of a cluster randomised controlled trial, a baseline cross-sectional survey was conducted across 18 villages, with data from six additional villages. Stool samples were assessed for soil transmitted helminth and protozoal infections using quantitative PCR (qPCR) and questionnaires administered to collect water, sanitation and hygiene and socioeconomic data. Risk factors for infection were assessed using multivariable mixed-effects logistic regression, stratified by age group (preschool, school-aged and adult). Overall, soil transmitted helminth prevalence was 69% (95% Confidence Interval 67-71%), with Necator americanus being most common (60%; 95% Confidence Interval 58-62%) followed by Ascaris spp. (24%; 95% Confidence Interval 23-26%). Ascaris-N. americanus co-infection was common (17%; 95% Confidence Interval 15%-18%). Giardia duodenalis was the main protozoan identified (13%; 95% Confidence Interval 11-14%). Baseline water, sanitation and hygiene infrastructure and behaviours were poor. Although risk factors varied by age of participants and parasite species, risk factors for N. americanus infection included, generally, age in years, male sex, and socioeconomic quintile. Risk factors for Ascaris included age in years for children, and piped water to the yard for adults. In this first known assessment of community-based prevalence and associated risk factors in Timor-Leste, soil transmitted helminth infections were highly prevalent, indicating a need for soil transmitted helminth control. Few associations with water, sanitation and hygiene were evident, despite water, sanitation and hygiene being generally poor. In our water, sanitation and hygiene we will investigate implications of improving WASH on soil transmitted helminth infection in impoverished communities.
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Affiliation(s)
- Suzy J Campbell
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia.
| | - Susana V Nery
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia
| | - Catherine A D'Este
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia
| | - Darren J Gray
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia; Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Brisbane, QLD 4006, Australia; School of Public Health, University of Queensland, Herston Rd, Brisbane, QLD 4006, Australia
| | - James S McCarthy
- School of Public Health, University of Queensland, Herston Rd, Brisbane, QLD 4006, Australia; Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Brisbane, QLD 4006, Australia
| | - Rebecca J Traub
- Faculty of Veterinary and Agricultural Science, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Ross M Andrews
- Menzies School of Health Research, Charles Darwin University, Ellengowan Dr, Casuarina, NT 0810, Australia
| | - Stacey Llewellyn
- Clinical Tropical Medicine Laboratory, QIMR Berghofer Medical Research Institute, 300 Herston Rd, Brisbane, QLD 4006, Australia
| | - Andrew J Vallely
- Kirby Institute, University of New South Wales, Wallace Wurth Building, High St, Kensington, NSW 2052, Australia
| | - Gail M Williams
- School of Public Health, University of Queensland, Herston Rd, Brisbane, QLD 4006, Australia
| | - Salvador Amaral
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia
| | - Archie C A Clements
- Research School of Population Health, College of Medicine, Biology and Environment, The Australian National University, 62 Mills Rd, Acton, ACT 2601, Australia
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5
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Leung JM, Hong CTT, Trung NHD, Thi HN, Minh CNN, Thi TV, Hong DT, Man DNH, Knowles SCL, Wolbers M, Hoang NLT, Thwaites G, Graham AL, Baker S. The impact of albendazole treatment on the incidence of viral- and bacterial-induced diarrhea in school children in southern Vietnam: study protocol for a randomized controlled trial. Trials 2016; 17:279. [PMID: 27266697 PMCID: PMC4896038 DOI: 10.1186/s13063-016-1406-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 05/25/2016] [Indexed: 11/14/2022] Open
Abstract
Background Anthelmintics are one of the more commonly available classes of drugs to treat infections by parasitic helminths (especially nematodes) in the human intestinal tract. As a result of their cost-effectiveness, mass school-based deworming programs are becoming routine practice in developing countries. However, experimental and clinical evidence suggests that anthelmintic treatments may increase susceptibility to other gastrointestinal infections caused by bacteria, viruses, or protozoa. Hypothesizing that anthelmintics may increase diarrheal infections in treated children, we aim to evaluate the impact of anthelmintics on the incidence of diarrheal disease caused by viral and bacterial pathogens in school children in southern Vietnam. Methods/design This is a randomized, double-blinded, placebo-controlled trial to investigate the effects of albendazole treatment versus placebo on the incidence of viral- and bacterial-induced diarrhea in 350 helminth-infected and 350 helminth-uninfected Vietnamese school children aged 6–15 years. Four hundred milligrams of albendazole, or placebo treatment will be administered once every 3 months for 12 months. At the end of 12 months, all participants will receive albendazole treatment. The primary endpoint of this study is the incidence of diarrheal disease assessed by 12 months of weekly active and passive case surveillance. Secondary endpoints include the prevalence and intensities of helminth, viral, and bacterial infections, alterations in host immunity and the gut microbiota with helminth and pathogen clearance, changes in mean z scores of body weight indices over time, and the number and severity of adverse events. Discussion In order to reduce helminth burdens, anthelmintics are being routinely administered to children in developing countries. However, the effects of anthelmintic treatment on susceptibility to other diseases, including diarrheal pathogens, remain unknown. It is important to monitor for unintended consequences of drug treatments in co-infected populations. In this trial, we will examine how anthelmintic treatment impacts host susceptibility to diarrheal infections, with the aim of informing deworming programs of any indirect effects of mass anthelmintic administrations on co-infecting enteric pathogens. Trial registration ClinicalTrials.gov: NCT02597556. Registered on 3 November 2015. Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1406-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jacqueline M Leung
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Chau Tran Thi Hong
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam
| | - Nghia Ho Dang Trung
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam.,Department of Infectious Diseases, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Hoa Nhu Thi
- Department of Parasitology and Mycology, Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam
| | - Chau Nguyen Ngoc Minh
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam
| | - Thuy Vu Thi
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam
| | - Dinh Thanh Hong
- Cu Chi Preventive Medicine Centre, Ho Chi Minh City, Vietnam
| | | | - Sarah C L Knowles
- Department of Pathology and Pathogen Biology, The Royal Veterinary College, Hertfordshire, UK
| | - Marcel Wolbers
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine, University of Oxford, Oxford, UK
| | - Nhat Le Thanh Hoang
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam
| | - Guy Thwaites
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine, University of Oxford, Oxford, UK
| | - Andrea L Graham
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Quan 5, Ho Chi Minh City, Vietnam. .,Centre for Tropical Medicine, University of Oxford, Oxford, UK. .,The London School of Hygiene and Tropical Medicine, London, UK.
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6
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Abstract
The microaerophilic parasite Giardia lamblia is a causative agent of dysentery affecting hundreds of millions of people around the globe every year. The symptoms of the disease, commonly referred to as giardiasis, are diarrhea, nausea, and malabsorption. Treatment of giardiasis is exclusively based on chemotherapy with antigiardial drugs, including metronidazole, albendazole, and nitazoxanide. In this review, all drugs currently used in the treatment of Giardia infections are discussed with a special emphasis on treatment failure and drug resistance.
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7
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Blackwell AD, Martin M, Kaplan H, Gurven M. Antagonism between two intestinal parasites in humans: the importance of co-infection for infection risk and recovery dynamics. Proc Biol Sci 2013; 280:20131671. [PMID: 23986108 DOI: 10.1098/rspb.2013.1671] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Co-infection may affect transmission and recovery from infection, but remains an understudied element of disease ecology, particularly with regard to antagonism between parasites sharing a host. Helminth and giardia infections are often endemic in the same populations and both occupy the small intestine; yet few studies have examined interactions between these parasites. We report on helminth-giardia co-infections in a panel study of forager-horticulturalists in the Bolivian lowlands. Parasites were identified in faecal samples from 3275 participants, collected during 5235 medical exams over 6 years. Longitudinal co-infection patterns were examined using logistic mixed and multi-state Markov models. The most prevalent infections were hookworm (56%), Giardia lamblia (30%) and Ascaris lumbricoides (15%). Cross-sectionally, hookworm and A. lumbricoides were negatively associated with G. lamblia (OR = 0.60; OR = 0.65, respectively). Longitudinally, giardia infection was less likely in helminth-infected individuals (HR: 0.46). Infection with helminths was also less likely for individuals infected with giardia (HR: 0.71). Finally, treatment with mebendazole reduced subsequent hookworm infections, but resulted in a marginal increase in the odds of G. lamblia infection. Our results provide evidence for an antagonistic relationship between helminths and giardia, and suggest that co-infection should be considered in disease transmission models and treatment decisions.
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Affiliation(s)
- Aaron D Blackwell
- Department of Anthropology, University of California, Santa Barbara, CA 93106-3210, USA.
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Parasites or cohabitants: cruel omnipresent usurpers or creative "éminences grises"? J Parasitol Res 2011; 2011:214174. [PMID: 21785696 PMCID: PMC3140032 DOI: 10.1155/2011/214174] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 04/06/2011] [Indexed: 12/31/2022] Open
Abstract
This paper presents many types of interplays between parasites and the host, showing the history of parasites, the effects of parasites on the outcome of wars, invasions, migrations, and on the development of numerous regions of the globe, and the impact of parasitic diseases on the society and on the course of human evolution. It also emphasizes the pressing need to change the look at the parasitism phenomenon, proposing that the term “cohabitant” is more accurate than parasite, because every living being, from bacteria to mammals, is a consortium of living beings in the pangenome. Even the term parasitology should be replaced by cohabitology because there is no parasite alone and host alone: both together compose a new adaptive system: the parasitized-host or the cohabitant-cohabited being. It also suggests switching the old paradigm based on attrition and destruction, to a new one founded on adaptation and living together.
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9
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Abstract
Giardia lamblia, the cause of human giardiasis, is among the most common intestinal protozoa worldwide. Human infection may range from asymptomatic shedding of giardial cysts to symptomatic giardiasis, being responsible for abdominal cramps, nausea, acute or chronic diarrhoea, with malabsorption and failure of children to thrive. At present, treatment options include the nitroimidazoles derivatives; especially metronidazole, which has been the mainstay of treatment for decades and is still widely used. The increasing number of reports of refractory cases with this group of drugs and other antigiardial agents, has raised concern and led to a search for other compounds, some of which have arisen due to the introduction of drugs initially addressed to other diseases. The present article examines some of the most important points of antigiardial pharmacotherapy available at present and the future prospects of development of new agents.
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Affiliation(s)
- Angel A Escobedo
- Jefe del departamento de Microbiología y Parasitología, Hospital Pediatrico Universitario Pedro Borrás, Ciudad de La Habana, CP, Cuba.
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10
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Canete R, Escobedo AA, Gonzalez ME, Almirall P. Randomized clinical study of five days apostrophe therapy with mebendazole compared to quinacrine in the treatment of symptomatic giardiasis in children. World J Gastroenterol 2006; 12:6366-70. [PMID: 17072963 PMCID: PMC4088148 DOI: 10.3748/wjg.v12.i39.6366] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To compare the efficacy and safety of five days apostrophe therapy of mebendazole (MBZ) versus quinacrine (QC) on human giardiasis in children.
METHODS: A clinical trial was carried out in paediatric patients (aged 5-15 years) with confirmed symptomatic G. duodenalis mono-infection. Patients were randomly assigned to receive either MBZ [200 mg taken three times per day (TID) (n = 61)] or QC [2 mg/kg bodyweight tid (n = 61)], both for five days. Follow-up faecal samples were obtained at 3, 5 and 7 d after the end of the treatment.
RESULTS: Although the frequency of cure was higher for QC (83.6%) than for MBZ (78.7%), the difference was not statistically significant (P > 0.05). Adverse events were reported more in the QC group (P < 0.05), all of them transient and self-limiting.
CONCLUSION: Despite final cure rates ocurring lower than expected, the overall results of this study reconfirmed the efficacy of MBZ in giardiasis and also indicate that, although comparable to QC, at least in this setting the 5 d course of MBZ did not appear to improve the cure rates in this intestinal parasitic infection.
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Affiliation(s)
- Roberto Canete
- Hygiene, Epidemiology and Microbiology Centre, Matanzas City, Cuba
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Argüello-García R, Cruz-Soto M, Romero-Montoya L, Ortega-Pierres G. Variability and variation in drug susceptibility among Giardia duodenalis isolates and clones exposed to 5-nitroimidazoles and benzimidazoles in vitro. J Antimicrob Chemother 2004; 54:711-21. [PMID: 15347633 DOI: 10.1093/jac/dkh388] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES We analysed, in a cell-by-cell study, the in vitro susceptibility of Giardia duodenalis strains, including Mexican isolates and their clones to 5-nitroimidazoles and benzimidazoles. METHODS Fluorogenic dye staining (FDA-PI) and cell morphology (CM) assays, two fast and direct techniques, replaced the indirect 'gold standard' method (subculture in liquid medium) in the evaluation of 5-nitroimidazoles and benzimidazoles, respectively. RESULTS Under these conditions, the activity of several 5-nitroimidazole and benzimidazole derivatives was consistent with their known efficacy, but parasite stocks exhibited a greater variability in response to 5-nitroimidazoles compared with benzimidazoles. Also, consecutive progenies from single stocks maintained in continuous subculture in drug-free media displayed changes (variations) in the proportions of drug resistant (R/T) subpopulations when exposed to sublethal concentrations of 5-nitroimidazoles and benzimidazoles. These were again more variable upon exposure to 5-nitroimidazoles than to benzimidazoles. Variations were not due to drug susceptibility shifts in parent trophozoites since analysis of cytokinetic processes showed a predominant pattern of susceptible/susceptible or resistant/resistant daughters, whereas susceptible/resistant daughters were scarce. CONCLUSIONS Our observations support the idea that G. duodenalis cultures exhibit variations in their response to 5-nitroimidazoles and benzimidazoles as a result of a drug-independent competition between drug-susceptible and drug-resistant subpopulations when parasites are subcultured.
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Affiliation(s)
- Raúl Argüello-García
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados-IPN, Apartado Postal 14-740 07360 México, DF, México
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Escobedo AA, Cañete R, Gonzalez ME, Pareja A, Cimerman S, Almirall P. A randomized trial comparing mebendazole and secnidazole for the treatment of giardiasis. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2003; 97:499-504. [PMID: 12930613 DOI: 10.1179/000349803235002380] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To compare the efficacy of the two drugs in the treatment of giardiasis, 146 children (aged 5-15 years) with confirmed Giardia lamblia infection were randomly allotted to treatment with mebendazole (200 mg three times daily for 3 days) or secnidazole (30 mg/kg, in a single dose). Parasitological response to treatment was evaluated in each child by the microscopical examination of faecal samples collected 3, 5 and 7 days after he or she had completed treatment. Although the frequency of cure was higher for secnidazole (79.4%) than for mebendazole (78.1%), the difference was not statistically significant (P > 0.05). Both treatment regimens were well tolerated, with only mild, transient and self-limiting side-effects reported. Mebendazole may be preferable to secnidazole in the treatment of giardiasis cases who have an history of intolerance to 5-nitromidazoles, and where infections with Giardia and soil-transmitted helminths frequently co-occur.
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Affiliation(s)
- A A Escobedo
- Departamento de Parasitología, Hospital Pediátrico Pedro Borrás, Calle F No. 616 esquina a 27, Plaza, Ciudad de La Habana, CP 10400, Cuba.
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Abstract
Giardia lamblia is both the most common intestinal parasite in the United States and a frequent cause of diarrheal illness throughout the world. In spite of its recognition as an important human pathogen, there have been relatively few agents used in therapy. This paper discusses each class of drugs used in treatment, along with their mechanism of action, in vitro and clinical efficacy, and side effects and contraindications. Recommendations are made for the preferred treatment in different clinical situations. The greatest clinical experience is with the nitroimidazole drugs, i.e., metronidazole, tinidazole, and ornidazole, which are highly effective. A 5- to 7-day course of metronidazole can be expected to cure over 90% of individuals, and a single dose of tinidazole or ornidazole will cure a similar number. Quinacrine, which is no longer produced in the United States, has excellent efficacy but may be poorly tolerated, especially in children. Furazolidone is an effective alternative but must be administered four times a day for 7 to 10 days. Paromomycin may be used during early pregnancy, because it is not systematically absorbed, but it is not always effective. Patients who have resistant infection can usually be cured by a prolonged course of treatment with a combination of a nitroimidazole with quinacrine.
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Affiliation(s)
- T B Gardner
- Division of Infectious Diseases, University of Connecticut Health Center, Farmington, Connecticut 06030-3212, USA
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