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Florescu DF, Sandkovsky U. Cryptosporidium infection in solid organ transplantation. World J Transplant 2016; 6:460-471. [PMID: 27683627 PMCID: PMC5036118 DOI: 10.5500/wjt.v6.i3.460] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 04/22/2016] [Accepted: 06/16/2016] [Indexed: 02/05/2023] Open
Abstract
Diarrhea is a common complication in solid organ transplant (SOT) recipients and may be attributed to immunosuppressive drugs or infectious organisms such as bacteria, viruses or parasites. Cryptosporidium usually causes self-limited diarrhea in immunocompetent hosts. Although it is estimated that cryptosporidium is involved in about 12% of cases of infectious diarrhea in developing countries and causes approximately 748000 cases each year in the United States, it is still an under recognized and important cause of infectious diarrhea in SOT recipients. It may run a protracted course with severe diarrhea, fluid and electrolyte depletion and potential for organ failure. Although diagnostic methodologies have improved significantly, allowing for fast and accurate identification of the parasite, treatment of the disease is difficult because antiparasitic drugs have modest activity at best. Current management includes fluid and electrolyte replacement, reduction of immunosuppression and single therapy with Nitazoxanide or combination therapy with Nitazoxanide and other drugs. Future drug and vaccine development may add to the currently poor armamentarium to manage the disease. The current review highlights key epidemiological, diagnostic and management issues in the SOT population.
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Müller I, Yap P, Steinmann P, Damons BP, Schindler C, Seelig H, Htun NSN, Probst-Hensch N, Gerber M, du Randt R, Pühse U, Walter C, Utzinger J. Intestinal parasites, growth and physical fitness of schoolchildren in poor neighbourhoods of Port Elizabeth, South Africa: a cross-sectional survey. Parasit Vectors 2016; 9:488. [PMID: 27595566 PMCID: PMC5011914 DOI: 10.1186/s13071-016-1761-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
Background As traditional lifestyle and diets change with social and economic development, disadvantaged communities in low- and middle-income countries increasingly face a double burden of communicable and non-communicable diseases. We studied the relationship between physical fitness and infections with soil-transmitted helminths (STHs), intestinal protozoa and Helicobacter pylori among schoolchildren in Port Elizabeth, South Africa. Methods We conducted a cross-sectional survey among 1009 children, aged 9 to 12 years, from eight primary schools in socioeconomically disadvantaged neighbourhoods of Port Elizabeth. Physical fitness was determined using field-deployable tests of the Eurofit fitness test battery. Stool samples were analysed with the Kato-Katz thick smear technique to diagnose STHs and with rapid diagnostic tests (RDTs) to detect intestinal protozoa and H. pylori infections. Haemoglobin (Hb) levels were assessed and anthropometric indicators determined. Results Complete data were available for 934 children (92 %). In two schools, high STH prevalences were found (Ascaris lumbricoides 60 and 72 %; Trichuris trichiura 65 % each). For boys and girls co-infected with A. lumbricoides and T. trichiura (n = 155) the maximal oxygen uptake (VO2 max) was estimated to be 50.1 and 47.2 ml kg-1 min-1, compared to 51.5 and 47.4 ml kg-1 min-1 for their non-infected peers (n = 278), respectively. On average, children without helminth infections had greater body mass (P = 0.011), height (P = 0.009) and a higher body mass index (P = 0.024) and were less often stunted (P = 0.006), but not significantly less wasted compared to their peers with a single or dual species infection. Among 9-year-old boys, a negative correlation between helminth infections and VO2 max, grip strength and standing broad jump distance was observed (P = 0.038). The overall mean Hb level was 122.2 g l-1. In the two schools with the highest prevalence of STHs the Hb means were 119.7 and 120.5 g l-1, respectively. Conclusions Intestinal parasite infections appear to have a small but significant negative effect on the physical fitness of infected children, as expressed by their maximal oxygen uptake. We observed a clear impact on anthropometric indicators. Electronic supplementary material The online version of this article (doi:10.1186/s13071-016-1761-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ivan Müller
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Peiling Yap
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Institute of Infectious Disease and Epidemiology, Tan Tock Seng Hospital, 308433, Singapore, Singapore
| | - Peter Steinmann
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Bruce P Damons
- Faculty of Education, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa.,Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Christian Schindler
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Harald Seelig
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Nan S N Htun
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Nicole Probst-Hensch
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland.,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland
| | - Markus Gerber
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Rosa du Randt
- Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Uwe Pühse
- University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.,Department of Sport, Exercise and Health, University of Basel, St. Jakobsturm, Birsstrasse 320B, CH-4056, Basel, Switzerland
| | - Cheryl Walter
- Department of Human Movement Science, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth, 6031, South Africa
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, , CH-4002, Basel, Switzerland. .,University of Basel, P.O. Box, , CH-4003, Basel, Switzerland.
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103
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Epidemiology of Cryptosporidiosis and Giardiasis: What Pediatricians Need to Know. CURRENT TROPICAL MEDICINE REPORTS 2016. [DOI: 10.1007/s40475-016-0081-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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104
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Pérez-Cordón G, Robinson G, Nader J, Chalmers RM. Discovery of new variable number tandem repeat loci in multiple Cryptosporidium parvum genomes for the surveillance and investigation of outbreaks of cryptosporidiosis. Exp Parasitol 2016; 169:119-28. [PMID: 27523797 DOI: 10.1016/j.exppara.2016.08.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 08/09/2016] [Accepted: 08/10/2016] [Indexed: 01/28/2023]
Abstract
Cryptosporidium parvum is a protozoan parasite causing gastro-intestinal disease (cryptosporidiosis) in humans and animals. The ability to investigate sources of contamination and routes of transmission by characterization and comparison of isolates in a cost- and time-efficient manner will help surveillance and epidemiological investigations, but as yet there is no standardised multi-locus typing scheme. To systematically identify variable number tandem repeat (VNTR) loci, which have been shown to provide differentiation in moderately conserved species, we interrogated the reference C. parvum Iowa II genome and seven other C. parvum genomes using a tandem repeat finder software. We identified 28 loci that met criteria defined previously for robust typing schemes for inter-laboratory surveillance, that had potential for generating PCR amplicons analysable on most fragment sizing platforms: repeats ≥6 bp, occurring in tandem in a single repeat region, and providing a total amplicon size of <300 bp including 50 bp for the location of the forward and reverse primers. The qualifying loci will be further investigated in vitro for consideration as preferred loci in the development of a robust VNTR scheme.
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Affiliation(s)
- Gregorio Pérez-Cordón
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK
| | - Guy Robinson
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK; Swansea University Medical School, Grove Building, Swansea University, Singleton Park, Swansea, SA2 8PP, UK
| | - Johanna Nader
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Rachel M Chalmers
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, SA2 8QA, UK; Swansea University Medical School, Grove Building, Swansea University, Singleton Park, Swansea, SA2 8PP, UK.
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105
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Hofstra N, Vermeulen LC. Impacts of population growth, urbanisation and sanitation changes on global human Cryptosporidium emissions to surface water. Int J Hyg Environ Health 2016; 219:599-605. [PMID: 27358259 DOI: 10.1016/j.ijheh.2016.06.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 06/11/2016] [Accepted: 06/13/2016] [Indexed: 01/06/2023]
Abstract
Cryptosporidium is a pathogenic protozoan parasite and is a leading cause of diarrhoea worldwide. The concentration of Cryptosporidium in the surface water is a determinant for probability of exposure and the risk of disease. Surface water concentrations are expected to change with population growth, urbanisation and changes in sanitation. The objective of this paper is to assess the importance of future changes in population, urbanisation and sanitation on global human emissions of Cryptosporidium to surface water. The GloWPa-Crypto H1 (the Global Waterborne Pathogen model for Human Cryptosporidium emissions version 1) model is presented and run for 2010 and with scenarios for 2050. The new scenarios are based on the Shared Socio-economic Pathways (SSPs) developed for the climate community. The scenarios comprise assumptions on sanitation changes in line with the storylines and population and urbanisation changes from the SSPs. In SSP1 population growth is limited, urbanisation large and sanitation and waste water treatment strongly improve. SSP1* is the same as SSP1, but waste water treatment does not improve. SSP3 sees large population growth, moderate urbanisation and sanitation and waste water treatment fractions that are the same as in 2010. Total global Cryptosporidium emissions to surface water for 2010 are estimated to be 1.6×1017 oocysts per year, with hotspots in the most urbanised parts of the world. In 2050 emissions are expected to decrease by 24% or increase by 52% and 70% for SSP1, SSP3 and SSP1* respectively. The emissions increase in all scenarios for countries in the Middle East and Africa (MAF) region, while emissions in large parts in Europe decrease in scenarios SSP1 and SSP3. Improving sanitation by connecting the population to sewers, should be combined with waste water treatment, otherwise (SSP1*) emissions in 2050 are expected to be much larger than in a situation with strong population growth and slow development of safe water and improved sanitation (SSP3). The results show that population increase, urbanisation and changes in sanitation should be considered when water quality and resulting health risks are estimated by water managers or public health specialists.
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Affiliation(s)
- Nynke Hofstra
- Environmental Systems Analysis Group, Wageningen University, Wageningen, The Netherlands.
| | - Lucie C Vermeulen
- Environmental Systems Analysis Group, Wageningen University, Wageningen, The Netherlands
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106
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Sow SO, Muhsen K, Nasrin D, Blackwelder WC, Wu Y, Farag TH, Panchalingam S, Sur D, Zaidi AKM, Faruque ASG, Saha D, Adegbola R, Alonso PL, Breiman RF, Bassat Q, Tamboura B, Sanogo D, Onwuchekwa U, Manna B, Ramamurthy T, Kanungo S, Ahmed S, Qureshi S, Quadri F, Hossain A, Das SK, Antonio M, Hossain MJ, Mandomando I, Nhampossa T, Acácio S, Omore R, Oundo JO, Ochieng JB, Mintz ED, O’Reilly CE, Berkeley LY, Livio S, Tennant SM, Sommerfelt H, Nataro JP, Ziv-Baran T, Robins-Browne RM, Mishcherkin V, Zhang J, Liu J, Houpt ER, Kotloff KL, Levine MM. The Burden of Cryptosporidium Diarrheal Disease among Children < 24 Months of Age in Moderate/High Mortality Regions of Sub-Saharan Africa and South Asia, Utilizing Data from the Global Enteric Multicenter Study (GEMS). PLoS Negl Trop Dis 2016; 10:e0004729. [PMID: 27219054 PMCID: PMC4878811 DOI: 10.1371/journal.pntd.0004729] [Citation(s) in RCA: 165] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/02/2016] [Indexed: 11/18/2022] Open
Abstract
Background The importance of Cryptosporidium as a pediatric enteropathogen in developing countries is recognized. Methods Data from the Global Enteric Multicenter Study (GEMS), a 3-year, 7-site, case-control study of moderate-to-severe diarrhea (MSD) and GEMS-1A (1-year study of MSD and less-severe diarrhea [LSD]) were analyzed. Stools from 12,110 MSD and 3,174 LSD cases among children aged <60 months and from 21,527 randomly-selected controls matched by age, sex and community were immunoassay-tested for Cryptosporidium. Species of a subset of Cryptosporidium-positive specimens were identified by PCR; GP60 sequencing identified anthroponotic C. parvum. Combined annual Cryptosporidium-attributable diarrhea incidences among children aged <24 months for African and Asian GEMS sites were extrapolated to sub-Saharan Africa and South Asian regions to estimate region-wide MSD and LSD burdens. Attributable and excess mortality due to Cryptosporidium diarrhea were estimated. Findings Cryptosporidium was significantly associated with MSD and LSD below age 24 months. Among Cryptosporidium-positive MSD cases, C. hominis was detected in 77.8% (95% CI, 73.0%-81.9%) and C. parvum in 9.9% (95% CI, 7.1%-13.6%); 92% of C. parvum tested were anthroponotic genotypes. Annual Cryptosporidium-attributable MSD incidence was 3.48 (95% CI, 2.27–4.67) and 3.18 (95% CI, 1.85–4.52) per 100 child-years in African and Asian infants, respectively, and 1.41 (95% CI, 0.73–2.08) and 1.36 (95% CI, 0.66–2.05) per 100 child-years in toddlers. Corresponding Cryptosporidium-attributable LSD incidences per 100 child-years were 2.52 (95% CI, 0.33–5.01) and 4.88 (95% CI, 0.82–8.92) in infants and 4.04 (95% CI, 0.56–7.51) and 4.71 (95% CI, 0.24–9.18) in toddlers. We estimate 2.9 and 4.7 million Cryptosporidium-attributable cases annually in children aged <24 months in the sub-Saharan Africa and India/Pakistan/Bangladesh/Nepal/Afghanistan regions, respectively, and ~202,000 Cryptosporidium-attributable deaths (regions combined). ~59,000 excess deaths occurred among Cryptosporidium-attributable diarrhea cases over expected if cases had been Cryptosporidium-negative. Conclusions The enormous African/Asian Cryptosporidium disease burden warrants investments to develop vaccines, diagnostics and therapies. Cryptosporidium is a protozoan that causes diarrhea and malnutrition in young children in developing countries, and is associated with diarrhea cases and outbreaks in developed countries. To date, limited information exists on the burden of Cryptosporidium diarrheal disease in sub-Saharan Africa and South Asia, where most diarrheal disease deaths occur. We estimated the burden of Cryptosporidium-diarrhea and associated deaths in these regions using data from the Global Enteric Multicenter Study (GEMS). Cryptosporidium was associated with diarrhea mainly in children aged <24 months. Infections began in the first few months of life but clinical episodes of Cryptosporidium-associated diarrhea illness peaked at age 6–11 months. The annual number of Cryptosporidium-attributable diarrhea episodes was estimated at 2.9 and 4.7 million in children aged <24 months in sub-Saharan Africa and in the India/Pakistan/Bangladesh/Afghanistan/Nepal region of South Asia, respectively. In both regions combined, Cryptosporidium is estimated to contribute to approximately 202,000 deaths per year, and to ~59,000 more deaths in Cryptosporidium-attributable cases than if those cases had been negative for Cryptosporidium. Our study highlights the enormous burden attributable to Cryptosporidium in Africa and Asia, which underscores the need for developing vaccines and treatments to reduce this burden.
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Affiliation(s)
- Samba O. Sow
- Centre pour le Développement des Vaccins, Bamako, Mali
| | - Khitam Muhsen
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Dilruba Nasrin
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - William C. Blackwelder
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Yukun Wu
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Emergent Biosolutions, Gaithersburg, Maryland, United States of America
| | - Tamer H. Farag
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sandra Panchalingam
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Anita K. M. Zaidi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Abu S. G. Faruque
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Debasish Saha
- Medical Research Council (United Kingdom) Unit, Fajara, Gambia
- GSK Vaccines, Wavre, Belgium
| | - Richard Adegbola
- Medical Research Council (United Kingdom) Unit, Fajara, Gambia
- GSK Vaccines, Wavre, Belgium
| | - Pedro L. Alonso
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- Instituto Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Robert F. Breiman
- Global Disease Detection Division, Kenya Office of the US Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Quique Bassat
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | | | - Doh Sanogo
- Centre pour le Développement des Vaccins, Bamako, Mali
| | | | - Byomkesh Manna
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - Suman Kanungo
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shahnawaz Ahmed
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Shahida Qureshi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Farheen Quadri
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Anowar Hossain
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Sumon K. Das
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Martin Antonio
- Medical Research Council (United Kingdom) Unit, Fajara, Gambia
| | | | - Inacio Mandomando
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- Instituto Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique
| | - Tacilta Nhampossa
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- Instituto Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique
| | - Sozinho Acácio
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- Instituto Nacional de Saúde, Ministério de Saúde, Maputo, Mozambique
| | - Richard Omore
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Joseph O. Oundo
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - John B. Ochieng
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Eric D. Mintz
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ciara E. O’Reilly
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Lynette Y. Berkeley
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sofie Livio
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Sharon M. Tennant
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Halvor Sommerfelt
- Centre of Intervention Science in Maternal and Child Health, Centre for International Health, University of Bergen, Bergen, and Department of International Public Health, Norwegian Institute of Public Health, Oslo, Norway
| | - James P. Nataro
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Tomer Ziv-Baran
- Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel
| | - Roy M. Robins-Browne
- Department of Microbiology and Immunology, The University of Melbourne, Murdoch Children’s Research Institute, Royal Children's Hospital, Parkville, Victoria, Australia
| | - Vladimir Mishcherkin
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jixian Zhang
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Jie Liu
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Eric R. Houpt
- Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America
| | - Karen L. Kotloff
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Myron M. Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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107
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Thivierge K, Iqbal A, Dixon B, Dion R, Levesque B, Cantin P, Cédilotte L, Ndao M, Proulx JF, Yansouni CP. Cryptosporidium hominis Is a Newly Recognized Pathogen in the Arctic Region of Nunavik, Canada: Molecular Characterization of an Outbreak. PLoS Negl Trop Dis 2016; 10:e0004534. [PMID: 27058742 PMCID: PMC4825996 DOI: 10.1371/journal.pntd.0004534] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/21/2016] [Indexed: 01/11/2023] Open
Abstract
Background Cryptosporidium is a leading cause of childhood diarrhea in low-resource settings, and has been repeatedly associated with impaired physical and cognitive development. In May 2013, an outbreak of diarrhea caused by Cryptosporidium hominis was identified in the Arctic region of Nunavik, Quebec. Human cryptosporidiosis transmission was previously unknown in this region, and very few previous studies have reported it elsewhere in the Arctic. We report clinical, molecular, and epidemiologic details of a multi-village Cryptosporidium outbreak in the Canadian Arctic. Methodology/Principal Findings We investigated the occurrence of cryptosporidiosis using a descriptive study of cases with onset between April 2013 and April 2014. Cases were defined as Nunavik inhabitants of any age presenting with diarrhea of any duration, in whom Cryptosporidium oocysts were detected by stool microscopy in a specialised reference laboratory. Cryptosporidium was identified in stool from 51 of 283 individuals. The overall annual incidence rate (IR) was 420 / 100,000 inhabitants. The IR was highest among children aged less than 5 years (1290 /100,000 persons). Genetic subtyping for stool specimens from 14/51 cases was determined by DNA sequence analysis of the 60 kDa glycoprotein (gp60) gene. Sequences aligned with C. hominis subtype Id in all cases. No common food or water source of infection was identified. Conclusions/Significance In this first observed outbreak of human cryptosporidiosis in this Arctic region, the high IR seen is cause for concern about the possible long-term effects on growth and development of children in Inuit communities, who face myriad other challenges such as overcrowding and food-insecurity. The temporal and geographic distribution of cases, as well as the identification of C. hominis subtype Id, suggest anthroponotic rather than zoonotic transmission. Barriers to timely diagnosis delayed the recognition of human cryptosporidiosis in this remote setting. In mid-2013, an outbreak of moderate-to-severe diarrhea caused by Cryptosporidium was identified in the Arctic region of Nunavik, Quebec, and it predominantly affected young children. Cryptosporidium is a leading cause of childhood diarrhea in low-resource settings, but was previously unknown in this region. This is important because cryptosporidiosis has been repeatedly associated with impaired growth and development, and may interact with other challenges currently faced by children in remote Arctic communities, such as overcrowding and food-insecurity. Although animals in the Arctic have previously been found to harbour Cryptosporidium parvum, which can infect both animals and humans, we found that the Cryptosporidium identified in the stool of affected people all belonged to the species C. hominis, which is only known to infect humans. Together with the temporal and geographic distribution of cases, this suggests that cryptosporidiosis in this outbreak was transmitted person-to-person, rather than acquired from contact with animals. The emergence of Cryptosporidium infections in Arctic communities may have public health impacts beyond the occurrence of diarrhea.
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Affiliation(s)
- Karine Thivierge
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Canada
| | - Asma Iqbal
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, Canada
| | - Brent Dixon
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, Canada
| | - Réjean Dion
- Laboratoire de santé publique du Québec, Institut national de santé publique du Québec, Sainte-Anne-de-Bellevue, Canada
| | - Benoît Levesque
- Direction de la santé environnementale et de la toxicologie, Institut national de santé publique du Québec, Québec City, Canada
| | - Philippe Cantin
- Centre d’expertise en analyse environnementale du Québec, Ministère du Développement durable, de l’Environnement, et de la Lutte contre les changements climatiques, Québec City, Canada
| | - Lyne Cédilotte
- J.D. MacLean Centre for Tropical Diseases, McGill University Health Centre, Montreal, Canada
- Department of Medical Microbiology, McGill University Health Centre, Montreal, Canada
| | - Momar Ndao
- National Reference Center for Parasitology, Montreal, Canada
| | - Jean-François Proulx
- Department of Public Health, Nunavik Regional Board of Health and Social Services, Kuujjuaq, Canada
| | - Cedric P. Yansouni
- J.D. MacLean Centre for Tropical Diseases, McGill University Health Centre, Montreal, Canada
- Department of Medical Microbiology, McGill University Health Centre, Montreal, Canada
- * E-mail:
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108
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Highly specific detection of Cryptosporidium spp. oocysts in human stool samples by undemanding and inexpensive phase contrast microscopy. Parasitol Res 2015; 115:1229-34. [DOI: 10.1007/s00436-015-4859-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/27/2015] [Indexed: 10/22/2022]
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de Lucio A, Merino FJ, Martínez-Ruiz R, Bailo B, Aguilera M, Fuentes I, Carmena D. Molecular genotyping and sub-genotyping of Cryptosporidium spp. isolates from symptomatic individuals attending two major public hospitals in Madrid, Spain. INFECTION GENETICS AND EVOLUTION 2015; 37:49-56. [PMID: 26518912 DOI: 10.1016/j.meegid.2015.10.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 10/09/2015] [Accepted: 10/26/2015] [Indexed: 02/04/2023]
Abstract
Infections by members of the protozoan genus Cryptosporidium are among the most common causes of human gastrointestinal illness worldwide. In Spain cryptosporidiosis is not a compulsory notifiable disease, so the actual burden of the infection in both clinical and general populations remains largely unknown. We present here data on the diversity and frequency of the Cryptosporidium species and sub-genotypes identified in symptomatic individuals seeking medical care in two major hospitals in Madrid, Spain, between December 2013 and January 2015. Initial detection of the parasite was conducted on a total of 122 stool samples collected from 120 patients by microscopy with modified Ziehl-Neelsen and/or immunochromatographic tests. We used immunofluorescence, PCR-based methods and sequence analyses of the 60-kDa (GP60) glycoprotein and the small subunit ribosomal RNA (SSU rRNA) genes for confirmatory purposes and to characterize Cryptosporidium isolates. A total of 110 patients were confirmed with cryptosporidiosis. Overall, 101 isolates were successfully sub-genotyped at the GP60 locus, and an additional seven at the SSU rRNA locus. The analyses of all amplicons defined 10 distinct sequence types representing the GP60 family sub-genotypes IbA10G2 (78.7%), IeA11G3T3 (3.7%) of C. hominis, and the GP60 family sub-types IIaA15G2R1 (5.6%), IIaA18G6R1 (0.9%), IIcA5G3a (0.9%), IIdA18G1 (0.9%), IIdA19G1 (0.9%), IIdA21G1 (0.9%), and IIdA22G1 (0.9%) of C. parvum. A single isolate was assigned to C. felis (0.9%), two C. parvum isolates (1.9%) could not be characterized at the sub-genotype level and an additional four isolates (3.7%) were not typable. These results strongly suggest that transmission of cryptosporidiosis is mostly anthroponotic in origin in the clinical sample under study. We expect that our molecular epidemiological data will make a significant contribution to unravel the actual epidemiological situation of cryptosporidiosis in Spain, providing health care and policy makers with solid baseline information to unavoidably improve the national surveillance system and allocate additional resources to research, diagnosis, and treatment of cryptosporidiosis.
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Affiliation(s)
- Aida de Lucio
- Parasitology Service, National Centre for Microbiology, Carlos III Health Institute, Majadahonda, Madrid, Spain
| | - Francisco J Merino
- Microbiology Service, University Hospital Severo Ochoa, Leganés, Madrid, Spain
| | - Rocío Martínez-Ruiz
- Microbiology and Clinical Parasitology Service, University Hospital Puerta de Hierro, Majadahonda, Madrid, Spain
| | - Begoña Bailo
- Parasitology Service, National Centre for Microbiology, Carlos III Health Institute, Majadahonda, Madrid, Spain
| | - María Aguilera
- Parasitology Service, National Centre for Microbiology, Carlos III Health Institute, Majadahonda, Madrid, Spain
| | - Isabel Fuentes
- Parasitology Service, National Centre for Microbiology, Carlos III Health Institute, Majadahonda, Madrid, Spain
| | - David Carmena
- Parasitology Service, National Centre for Microbiology, Carlos III Health Institute, Majadahonda, Madrid, Spain.
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Huston CD, Spangenberg T, Burrows J, Willis P, Wells TNC, van Voorhis W. A Proposed Target Product Profile and Developmental Cascade for New Cryptosporidiosis Treatments. PLoS Negl Trop Dis 2015; 9:e0003987. [PMID: 26447884 PMCID: PMC4598153 DOI: 10.1371/journal.pntd.0003987] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Christopher D. Huston
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont, United States of America
- * E-mail:
| | | | | | - Paul Willis
- Medicines for Malaria Venture, Geneva, Switzerland
| | | | - Wesley van Voorhis
- Medicines for Malaria Venture, Geneva, Switzerland
- Department of Medicine, University of Washington School of Medicine, Seattle, Washington, United States of America
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111
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Zhang H, Zhu G. Quantitative RT-PCR assay for high-throughput screening (HTS) of drugs against the growth of Cryptosporidium parvum in vitro. Front Microbiol 2015; 6:991. [PMID: 26441920 PMCID: PMC4585199 DOI: 10.3389/fmicb.2015.00991] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 09/04/2015] [Indexed: 12/20/2022] Open
Abstract
Our laboratory has previously developed a qRT-PCR assay to assess drug efficacy on the growth of Cryptosporidium parvum in vitro by detecting the levels of parasite 18S rRNA. This approach displayed up to four orders of magnitude of linear dynamic range and was much less labor-intensive than the traditional microscopic methods. However, conventional qRT-PCR protocol is not very amendable to high-throughput analysis when total RNA needs to be purified by lengthy, multi-step procedures. Recently, several commercial reagents are available for preparing cell lysates that could be directly used in downstream qRT-PCR analysis (e.g., Ambion Cell-to-cDNA kit and Bio-Rad iScript sample preparation reagent). Using these reagents, we are able to adapt the qRT-PCR assay into high-throughput screening of drugs in vitro (i.e., 96-well and 384-well formats for the cultivation of parasites and qRT-PCR detection, respectively). This qRT-PCR protocol is able to give a >150-fold linear dynamic range using samples isolated from cells infected with various numbers of parasites. The new assay is also validated by the NIH-recommended intra-plate, inter-plate, and inter-day uniformity tests. The robustness and effectiveness of the assay are also confirmed by evaluating the anti-cryptosporidial efficacy of paromomycin and by a small scale screening of compounds.
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Affiliation(s)
- Haili Zhang
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University College Station, TX, USA
| | - Guan Zhu
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University College Station, TX, USA
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112
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Ludington JG, Ward HD. Systemic and Mucosal Immune Responses to Cryptosporidium-Vaccine Development. CURRENT TROPICAL MEDICINE REPORTS 2015; 2:171-180. [PMID: 26279971 PMCID: PMC4535728 DOI: 10.1007/s40475-015-0054-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cryptosporidium spp is a major cause of diarrheal disease worldwide, particularly in malnourished children and untreated AIDS patients in developing countries in whom it can cause severe, chronic and debilitating disease. Unfortunately, there is no consistently effective drug for these vulnerable populations and no vaccine, partly due to a limited understanding of both the parasite and the host immune response. In this review, we will discuss our current understanding of the systemic and mucosal immune responses to Cryptosporidium infection, discuss the feasibility of developing a Cryptosporidium vaccine and evaluate recent advances in Cryptosporidium vaccine development strategies.
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Affiliation(s)
- Jacob G. Ludington
- Tufts University Sackler School of Graduate Biomedical Sciences and Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center
| | - Honorine D. Ward
- Tufts University Sackler School of Graduate Biomedical Sciences and Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center
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113
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Sparks H, Nair G, Castellanos-Gonzalez A, White AC. Treatment of Cryptosporidium: What We Know, Gaps, and the Way Forward. CURRENT TROPICAL MEDICINE REPORTS 2015; 2:181-187. [PMID: 26568906 DOI: 10.1007/s40475-015-0056-9] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cryptosporidiosis is increasingly recognized as an important global health concern. While initially reported in immunocompromised such as AIDS patients, cryptosporidiosis has now been documented as a major cause of childhood diarrhea and an important factor in childhood malnutrition. Currently, nitazoxanide is the only proven anti-parasitic treatment for Cryptosporidium infections. However, it is not effective in severely immunocompromised patients and there is limited data in infants. Immune reconstitution or decreased immunosuppression is critical to therapy in AIDS and transplant patients. This limitation of treatment options presents a major public health challenge given the important burden of disease. Repurposing of drugs developed for other indications and development of inhibitors for novel targets offer hope for improved therapies, but none have advanced to clinical studies.
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Affiliation(s)
- Hayley Sparks
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch Galveston, 301 University Boulevard, Route 0435, Galveston, TX 77555-0435 USA, TeL 1-409-747-0236, FAX 1-409-772-6527
| | - Gayatri Nair
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch Galveston, 301 University Boulevard, Route 0435, Galveston, TX 77555-0435 USA, TeL 1-409-747-0236, FAX 1-409-772-6527
| | - Alejandro Castellanos-Gonzalez
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch Galveston, 301 University Boulevard, Route 0435, Galveston, TX 77555-0435 USA, TeL 1-409-747-0236, FAX 1-409-772-6527
| | - A Clinton White
- Infectious Disease Division, Department of Internal Medicine, University of Texas Medical Branch Galveston, 301 University Boulevard, Route 0435, Galveston, TX 77555-0435 USA, TeL 1-409-747-0236, FAX 1-409-772-6527
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114
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Mohaghegh MA, Jafari R, Ghomashlooyan M, Mirzaei F, Azami M, Falahati M, Salehi F. Soil Contamination With Oocysts of Cryptosporidium spp. in Isfahan, Central Iran. INTERNATIONAL JOURNAL OF ENTERIC PATHOGENS 2015. [DOI: 10.17795/ijep29105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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115
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Destura RV, Cena RB, Galarion MJH, Pangilinan CM, Arevalo GM, Alba ROC, Petronio JAG, Salem GM, Schwem B, Sevilleja JEAD. Advancing Cryptosporidium Diagnostics from Bench to Bedside. CURRENT TROPICAL MEDICINE REPORTS 2015. [DOI: 10.1007/s40475-015-0055-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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116
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Iqbal A, Goldfarb DM, Slinger R, Dixon BR. Prevalence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis in diarrhoeic patients in the Qikiqtani Region, Nunavut, Canada. Int J Circumpolar Health 2015; 74:27713. [PMID: 26095244 PMCID: PMC4475686 DOI: 10.3402/ijch.v74.27713] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/30/2015] [Accepted: 05/30/2015] [Indexed: 11/17/2022] Open
Abstract
Background Although the prevalences of infection with the protozoan parasites Cryptosporidium spp. and Giardia duodenalis in humans appear to be relatively high in the Canadian North, their transmission patterns are poorly understood. Objective To determine the detection rate and the molecular characteristics of Cryptosporidium spp. and Giardia duodenalis in diarrhoeic patients in the Qikiqtani (Baffin Island) Region of Nunavut, Canada, in order to better understand the burden of illness and the potential mechanisms of transmission. Study design/methods Diarrhoeal stool specimens (n=108) submitted to the Qikiqtani General Hospital for clinical testing were also tested for the presence of Cryptosporidium spp. and Giardia duodenalis using epifluorescence microscopy and polymerase chain reaction (PCR). DNA sequencing and restriction fragment length polymorphism (RFLP) analyses were performed on PCR-positive specimens to determine the species, genotypes and sub-genotypes of the parasites. Results Cryptosporidium was detected in 15.7% of the diarrhoeic patients, while Giardia was detected in 4.6%. DNA sequencing of a fragment of the small subunit rRNA gene indicated that all of the Cryptosporidium amplicons had a 100% homology to C. parvum, and a gp60 assay showed that all aligned with C. parvum sub-genotype IIa. Microsatellite analysis revealed 3 cases of sub-genotype IIaA15G2R1, 2 of IIaA15G1R and 1 case each of sub-genotypes IIaA16G1R1 and IIaA15R1. For Giardia, results based on the amplification of both the 16S rRNA gene and the gdh gene were generally in agreement, and both DNA sequencing and RFLP demonstrated the presence of the G. duodenalis Assemblage B genotype. Conclusions Both C. parvum and G. duodenalis Assemblage B were present in human diarrhoeal stool specimens from Nunavut, which was suggestive of zoonotic transmission, although human-to-human transmission cannot be ruled out. To fully understand the public health significance of the different Cryptosporidium and Giardia species and genotypes in diarrhoeic patients, it will be imperative to establish the extent of genetic diversity within these parasites through comprehensive studies of the molecular epidemiology of cryptosporidiosis and giardiasis in the Nunavut region.
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Affiliation(s)
- Asma Iqbal
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, ON, Canada
| | - David M Goldfarb
- Department of Pathology, British Columbia Children's Hospital, Vancouver, BC, Canada
| | - Robert Slinger
- Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, ON, Canada
| | - Brent R Dixon
- Bureau of Microbial Hazards, Food Directorate, Health Canada, Ottawa, ON, Canada;
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Andersson S, Sikora P, Karlberg ML, Winiecka-Krusnell J, Alm E, Beser J, Arrighi RB. It's a dirty job — A robust method for the purification and de novo genome assembly of Cryptosporidium from clinical material. J Microbiol Methods 2015; 113:10-2. [DOI: 10.1016/j.mimet.2015.03.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/19/2015] [Accepted: 03/19/2015] [Indexed: 10/23/2022]
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118
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Hol WGJ. Three-dimensional structures in the design of therapeutics targeting parasitic protozoa: reflections on the past, present and future. Acta Crystallogr F Struct Biol Commun 2015; 71:485-99. [PMID: 25945701 PMCID: PMC4427157 DOI: 10.1107/s2053230x15004987] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/11/2015] [Indexed: 11/10/2022] Open
Abstract
Parasitic protozoa cause a range of diseases which threaten billions of human beings. They are responsible for tremendous mortality and morbidity in the least-developed areas of the world. Presented here is an overview of the evolution over the last three to four decades of structure-guided design of inhibitors, leads and drug candidates aiming at targets from parasitic protozoa. Target selection is a crucial and multi-faceted aspect of structure-guided drug design. The major impact of advances in molecular biology, genome sequencing and high-throughput screening is touched upon. The most advanced crystallographic techniques, including XFEL, have already been applied to structure determinations of drug targets from parasitic protozoa. Even cryo-electron microscopy is contributing to our understanding of the mode of binding of inhibitors to parasite ribosomes. A number of projects have been selected to illustrate how structural information has assisted in arriving at promising compounds that are currently being evaluated by pharmacological, pharmacodynamic and safety tests to assess their suitability as pharmaceutical agents. Structure-guided approaches are also applied to incorporate properties into compounds such that they are less likely to become the victim of resistance mechanisms. A great increase in the number of novel antiparasitic compounds will be needed in the future. These should then be combined into various multi-compound therapeutics to circumvent the diverse resistance mechanisms that render single-compound, or even multi-compound, drugs ineffective. The future should also see (i) an increase in the number of projects with a tight integration of structural biology, medicinal chemistry, parasitology and pharmaceutical sciences; (ii) the education of more `medicinal structural biologists' who are familiar with the properties that compounds need to have for a high probability of success in the later steps of the drug-development process; and (iii) the expansion of drug-development capabilities in middle- and low-income countries.
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Affiliation(s)
- Wim G. J. Hol
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, USA
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119
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Abeywardena H, Jex AR, Gasser RB. A perspective on Cryptosporidium and Giardia, with an emphasis on bovines and recent epidemiological findings. ADVANCES IN PARASITOLOGY 2015; 88:243-301. [PMID: 25911369 PMCID: PMC7103119 DOI: 10.1016/bs.apar.2015.02.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cryptosporidium and Giardia are two common aetiological agents of infectious enteritis in humans and animals worldwide. These parasitic protists are usually transmitted by the faecal-oral route, following the ingestion of infective stages (oocysts or cysts). An essential component of the control of these parasitic infections, from a public health perspective, is an understanding of the sources and routes of transmission in different geographical regions. Bovines are considered potential sources of infection for humans, because species and genotypes of Cryptosporidium and Giardia infecting humans have also been isolated from cattle in molecular parasitological studies. However, species and genotypes of Cryptosporidium and Giardia of bovids, and the extent of zoonotic transmission in different geographical regions in the world, are still relatively poorly understood. The purpose of this article is to (1) provide a brief background on Cryptosporidium and Giardia, (2) review some key aspects of the molecular epidemiology of cryptosporidiosis and giardiasis in animals, with an emphasis on bovines, (3) summarize research of Cryptosporidium and Giardia from cattle and water buffaloes in parts of Australasia and Sri Lanka, considering public health aspects and (4) provide a perspective on future avenues of study. Recent studies reinforce that bovines harbour Cryptosporidium and Giardia that likely pose a human health risk and highlight the need for future investigations of the biology, population genetics and transmission dynamics of Cryptosporidium and Giardia in cattle, water buffaloes and other ruminants in different geographical regions, the fate and transport of infective stages following their release into the environment, as well as for improved strategies for the control and prevention of cryptosporidiosis and giardiasis, guided by molecular epidemiological studies.
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Affiliation(s)
- Harshanie Abeywardena
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Aaron R. Jex
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Robin B. Gasser
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
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Eibach D, Krumkamp R, Al-Emran HM, Sarpong N, Hagen RM, Adu-Sarkodie Y, Tannich E, May J. Molecular characterization of Cryptosporidium spp. among children in rural Ghana. PLoS Negl Trop Dis 2015; 9:e0003551. [PMID: 25749411 PMCID: PMC4352007 DOI: 10.1371/journal.pntd.0003551] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 01/21/2015] [Indexed: 11/24/2022] Open
Abstract
Background The relevance of Cryptosporidium infections for the burden of childhood diarrhoea in endemic settings has been shown in recent years. This study describes Cryptosporidium subtypes among symptomatic and asymptomatic children in rural Ghana to analyse subtype-specific demographic, geographical, seasonal and clinical differences in order to inform appropriate control measures in endemic areas. Methodology/Principal Findings Stool samples were collected from 2232 children below 14 years of age presenting with and without gastrointestinal symptoms at the Agogo Presbyterian Hospital in the rural Ashanti region of Ghana between May 2007 and September 2008. Samples were screened for Cryptosporidium spp. by PCR and isolates were classified into subtypes based on sequence differences in the gp60 gene. Subtype specific frequencies for age, sex, location and season have been determined and associations with disease symptoms have been analysed within a case-control study. Cryptosporidium infections were diagnosed in 116 of 2232 (5.2%) stool samples. Subtyping of 88 isolates revealed IIcA5G3 (n = 26, 29.6%), IbA13G3 (n = 17, 19.3%) and IaA21R3 (n = 12, 13.6%) as the three most frequent subtypes of the two species C. hominis and C. parvum, known to be transmitted anthroponotically. Infections peak at early rainy season with 67.9% and 50.0% of infections during the months April, May and June for 2007 and 2008 respectively. C. hominis infection was mainly associated with diarrhoea (odds ratio [OR] = 2.4; 95% confidence interval [CI]: 1.2–4.9) whereas C. parvum infection was associated with both diarrhoea (OR = 2.6; CI: 1.2–5.8) and vomiting (OR = 3.1; 95% CI: 1.5–6.1). Conclusions/Significance Cryptosporidiosis is characterized by seasonal anthroponotic transmission of strains typically found in Sub-Saharan Africa. The infection mainly affects young infants, with vomiting and diarrhoea being one of the leading symptoms in C. parvum infection. Combining molecular typing and clinical data provides valuable information for physicians and is able to track sources of infections. Cryptosporidium spp. are a frequent cause of diarrhoea worldwide. While both animal-to-human and human-to-human transmission has been reported from industrialized countries, human-to-human transmission clearly prevails in Sub-Saharan Africa. However, data on the distribution of zoonotic and human subtypes is limited for rural African regions, where children are in very close contact to animals. We conducted a case-control study with 2232 stool samples from symptomatic and asymptomatic children living in the rural Ashanti region of Ghana. The combination of molecular typing results and clinical data helped to untangle transmission routes and to analyze the association of clinical symptoms with specific Cryptosporidium subtypes. Our study results demonstrate seasonal transmission with no clusters of specific subtypes. All subtypes detected have so far been only encountered from human specimens, strongly suggesting a predominantly human-human transmission among children living in the rural Ghana, despite close contact to livestock. Therefore, public health control programmes need to primarily focus on hygienic conditions among young infants below the age of two years. Of interest for practicing physicians, vomiting is a frequent symptom, especially in C. parvum infections.
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Affiliation(s)
- Daniel Eibach
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
- * E-mail:
| | - Ralf Krumkamp
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
| | - Hassan M. Al-Emran
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Nimako Sarpong
- Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana
| | - Ralf Matthias Hagen
- Department of Tropical Medicine at the BNITM, German Armed Forces Hospital of Hamburg, Hamburg, Germany
| | - Yaw Adu-Sarkodie
- Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
| | - Jürgen May
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
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Krumkamp R, Sarpong N, Schwarz NG, Adelkofer J, Loag W, Eibach D, Hagen RM, Adu-Sarkodie Y, Tannich E, May J. Gastrointestinal infections and diarrheal disease in Ghanaian infants and children: an outpatient case-control study. PLoS Negl Trop Dis 2015; 9:e0003568. [PMID: 25738935 PMCID: PMC4349824 DOI: 10.1371/journal.pntd.0003568] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 01/27/2015] [Indexed: 01/28/2023] Open
Abstract
Introduction Diarrheal diseases are among the most frequent causes of morbidity and mortality in children worldwide, especially in resource-poor areas. This case-control study assessed the associations between gastrointestinal infections and diarrhea in children from rural Ghana. Methods Stool samples were collected from 548 children with diarrhea and from 686 without gastrointestinal symptoms visiting a hospital from 2007–2008. Samples were analyzed by microscopy and molecular methods. Results The organisms most frequently detected in symptomatic cases were Giardia lamblia, Shigella spp./ enteroinvasive Escherichia coli (EIEC), and Campylobacter jejuni. Infections with rotavirus (adjusted odds ratio [aOR] = 8.4; 95% confidence interval [CI]: 4.3–16.6), C. parvum/hominis (aOR = 2.7; 95% CI: 1.4–5.2) and norovirus (aOR = 2.0; 95%CI: 1.3–3.0) showed the strongest association with diarrhea. The highest attributable fractions (AF) for diarrhea were estimated for rotavirus (AF = 14.3%; 95% CI: 10.9–17.5%), Shigella spp./EIEC (AF = 10.5%; 95% CI: 3.5–17.1%), and norovirus (AF = 8.2%; 95% CI 3.2–12.9%). Co-infections occurred frequently and most infections presented themselves independently of other infections. However, infections with E. dispar, C. jejuni, and norovirus were observed more often in the presence of G. lamblia. Conclusions Diarrheal diseases in children from a rural area in sub-Saharan Africa are mainly due to infections with rotavirus, Shigella spp./EIEC, and norovirus. These associations are strongly age-dependent, which should be considered when diagnosing causes of diarrhea. The presented results are informative for both clinicians treating gastrointestinal infections as well as public health experts designing control programs against diarrheal diseases. Gastrointestinal infections are frequent in many low-income countries. However, their role in diarrheal diseases is still under discussion. Many epidemiological studies focus on individuals with diarrheal symptoms only, ignoring the fact that infections may progress asymptomatically as well. In order to identify infectious agents associated with diarrhea it is imperative to consider cases without symptoms as a control group. We conducted a case-control study, including 548 children with diarrhea and 651 children without gastrointestinal symptoms in order to untangle the role of gastrointestinal infections in diarrheal disease. As shown in other studies infections with rotavirus, Shigella spp./EIEC and norovirus are responsible for the main diarrhea burden. Co-infections are frequently observed in our study group and some organisms occur more frequently in the presence of a second one. Especially Giardia lamblia, which is not associated with diarrhea, is more often observed along with Campylobacter jejuni and norovirus, which are responsible for a high number of diarrheal episodes. This may be of particular interest since G. lamblia is, with a frequency of 40% within the study group, the most prevalent organism observed. Furthermore, the high number of co-infections challenged the identification of causative pathogens since diagnosing a particular isolate may not rule out the effect of another potentially infectious agent in diarrheal disease. We observed a strong effect of age on the course of an infection, which may guide clinicians when diagnosing causes of diarrhea.
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Affiliation(s)
- Ralf Krumkamp
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
- * E-mail:
| | - Nimako Sarpong
- Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana
| | | | - Julia Adelkofer
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Wibke Loag
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Daniel Eibach
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
| | - Ralf Matthias Hagen
- Department of Tropical Medicine at the BNITM, German Armed Forces Hospital of Hamburg, Hamburg, Germany
| | - Yaw Adu-Sarkodie
- Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
| | - Jürgen May
- Bernhard Nocht Institute for Tropical Medicine (BNITM), Hamburg, Germany
- German Center for Infection Research (DZIF), partner site Hamburg-Borstel-Lübeck, Germany
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Abstract
PURPOSE OF REVIEW To highlight new findings on the relevance of gastrointestinal protozoan infections to global public health in low-income and middle-income countries and suggest new large-scale interventions. RECENT FINDINGS New disease burden assessments and epidemiological studies highlight the role of the major intestinal protozoa as important etiologic disease agents in low-income and middle-income countries. Despite their prevalence and adverse health impact, such information has not yet translated to the implementation of large-scale interventions as exist for helminth infections and other neglected tropical diseases. There are also several key research and development questions that must be addressed for intestinal protozoan infections and the potential need for new tools, for example, drugs, diagnostics, and vaccines. Additional studies have identified new and emerging species of intestinal protozoa relevant to global public health such as Dientamoeba fragilis and Blastocystis hominis and how they too might emerge as important gastrointestinal pathogens in the coming years. SUMMARY New and emerging information on intestinal protozoa are reviewed with emphasis on aspects considered relevant to global health policymakers including prospects for scaling up interventions against intestinal protozoan infections in resource-poor countries.
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Nausea, Vomiting, and Noninflammatory Diarrhea. MANDELL, DOUGLAS, AND BENNETT'S PRINCIPLES AND PRACTICE OF INFECTIOUS DISEASES 2015. [PMCID: PMC7173487 DOI: 10.1016/b978-1-4557-4801-3.00100-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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124
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Norman FF, Monge-Maillo B, Martínez-Pérez Á, Perez-Molina JA, López-Vélez R. Parasitic infections in travelers and immigrants: part I protozoa. Future Microbiol 2015; 10:69-86. [DOI: 10.2217/fmb.14.105] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
ABSTRACT The growth in international commerce, travel and migration contribute to the global emergence of certain parasitic infections. Importation of vectors and food products may contribute to the emergence of protozoan infections in nonendemic countries. Infections such as malaria are potentially fatal, especially in nonimmune patients, and outcome depends largely on timely diagnosis and treatment. Diagnosis/management of imported parasitic infections may be complex especially as some patients may have underlying immunosuppressive conditions such as HIV infection. Major challenges concern the development of improved diagnostic techniques, safer/more effective drug therapies and identification of biological markers of progression and response to treatment. Imported parasitic diseases which may be transmitted vertically or through blood transfusion/organ donation could become a public health priority in the near future. Climate change may affect arthropod distribution and facilitate the spread of protozoan vector-borne diseases. The first part of this review focuses on protozoan infections in travelers and immigrants.
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Affiliation(s)
- Francesca F Norman
- Tropical Medicine & Clinical Parasitology, Infectious Diseases Department, Ramon y Cajal Hospital, Ctra. De Colmenar, Km 9.1, 28034 Madrid, Spain
| | - Begoña Monge-Maillo
- Tropical Medicine & Clinical Parasitology, Infectious Diseases Department, Ramon y Cajal Hospital, Ctra. De Colmenar, Km 9.1, 28034 Madrid, Spain
| | - Ángela Martínez-Pérez
- Tropical Medicine & Clinical Parasitology, Infectious Diseases Department, Ramon y Cajal Hospital, Ctra. De Colmenar, Km 9.1, 28034 Madrid, Spain
| | - Jose A Perez-Molina
- Tropical Medicine & Clinical Parasitology, Infectious Diseases Department, Ramon y Cajal Hospital, Ctra. De Colmenar, Km 9.1, 28034 Madrid, Spain
| | - Rogelio López-Vélez
- Tropical Medicine & Clinical Parasitology, Infectious Diseases Department, Ramon y Cajal Hospital, Ctra. De Colmenar, Km 9.1, 28034 Madrid, Spain
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125
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Cook WJ, Senkovich O, Hernandez A, Speed H, Chattopadhyay D. Biochemical and structural characterization of Cryptosporidium parvum Lactate dehydrogenase. Int J Biol Macromol 2014; 74:608-19. [PMID: 25542170 DOI: 10.1016/j.ijbiomac.2014.12.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/04/2014] [Accepted: 12/05/2014] [Indexed: 10/24/2022]
Abstract
The protozoan parasite Cryptosporidium parvum causes waterborne diseases worldwide. There is no effective therapy for C. parvum infection. The parasite depends mainly on glycolysis for energy production. Lactate dehydrogenase is a major regulator of glycolysis. This paper describes the biochemical characterization of C. parvum lactate dehydrogenase and high resolution crystal structures of the apo-enzyme and four ternary complexes. The ternary complexes capture the enzyme bound to NAD/NADH or its 3-acetylpyridine analog in the cofactor binding pocket, while the substrate binding site is occupied by one of the following ligands: lactate, pyruvate or oxamate. The results reveal distinctive features of the parasitic enzyme. For example, C. parvum lactate dehydrogenase prefers the acetylpyridine analog of NADH as a cofactor. Moreover, it is slightly less sensitive to gossypol inhibition compared with mammalian lactate dehydrogenases and not inhibited by excess pyruvate. The active site loop and the antigenic loop in C. parvum lactate dehydrogenase are considerably different from those in the human counterpart. Structural features and enzymatic properties of C. parvum lactate dehydrogenase are similar to enzymes from related parasites. Structural comparison with malate dehydrogenase supports a common ancestry for the two genes.
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Affiliation(s)
- William J Cook
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Olga Senkovich
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Agustin Hernandez
- Instituto de Bioquímica Vegetal y Fotosintesis (CSIC/U. Sevilla), Avda. Americo Vespucio 49, Seville 41092, Spain
| | - Haley Speed
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Debasish Chattopadhyay
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Department of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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Sarkar R, Kattula D, Francis MR, Ajjampur SSR, Prabakaran AD, Jayavelu N, Muliyil J, Balraj V, Naumova EN, Ward HD, Kang G. Risk factors for cryptosporidiosis among children in a semi urban slum in southern India: a nested case-control study. Am J Trop Med Hyg 2014; 91:1128-37. [PMID: 25331810 DOI: 10.4269/ajtmh.14-0304] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The risk factors for acquisition of cryptosporidial infection in resource-poor settings are poorly understood. A nested case-control study was conducted to assess factors associated with childhood cryptosporidiosis (detected by stool polymerase chain reaction) in an endemic, Indian slum community using data from two community-based studies with 580 children followed prospectively until their second birthday. Factors were assessed for overall cryptosporidiosis (N = 406), and for multiple (N = 208), asymptomatic (N = 243), and symptomatic (N = 163) infections, respectively. Presence of older siblings (odds ratio [OR] = 1.88, P = 0.002) and stunting at 6 months of age (OR = 1.74, P = 0.019) were important risk factors for childhood cryptosporidiosis. Always boiling drinking water before consumption, the use of a toilet by all members of the family, and maternal age ≥ 23 years were protective. These results provide insights into acquisition of childhood cryptosporidiosis in settings with poor environmental sanitation, contaminated public water supply systems, and close human-animal contact. Disease control strategies will require a multifaceted approach.
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Affiliation(s)
- Rajiv Sarkar
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Deepthi Kattula
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Mark R Francis
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Sitara S R Ajjampur
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Ashok D Prabakaran
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Nithya Jayavelu
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Jayaprakash Muliyil
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Vinohar Balraj
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Elena N Naumova
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Honorine D Ward
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India; Community Health Department, Christian Medical College, Vellore, India; Department of Civil and Environmental Engineering, Tufts University School of Engineering, Medford, Massachusetts; Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts
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127
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Checkley W, White AC, Jaganath D, Arrowood MJ, Chalmers RM, Chen XM, Fayer R, Griffiths JK, Guerrant RL, Hedstrom L, Huston CD, Kotloff KL, Kang G, Mead JR, Miller M, Petri WA, Priest JW, Roos DS, Striepen B, Thompson RCA, Ward HD, Van Voorhis WA, Xiao L, Zhu G, Houpt ER. A review of the global burden, novel diagnostics, therapeutics, and vaccine targets for cryptosporidium. THE LANCET. INFECTIOUS DISEASES 2014; 15:85-94. [PMID: 25278220 DOI: 10.1016/s1473-3099(14)70772-8] [Citation(s) in RCA: 611] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cryptosporidium spp are well recognised as causes of diarrhoeal disease during waterborne epidemics and in immunocompromised hosts. Studies have also drawn attention to an underestimated global burden and suggest major gaps in optimum diagnosis, treatment, and immunisation. Cryptosporidiosis is increasingly identified as an important cause of morbidity and mortality worldwide. Studies in low-resource settings and high-income countries have confirmed the importance of cryptosporidium as a cause of diarrhoea and childhood malnutrition. Diagnostic tests for cryptosporidium infection are suboptimum, necessitating specialised tests that are often insensitive. Antigen-detection and PCR improve sensitivity, and multiplexed antigen detection and molecular assays are underused. Therapy has some effect in healthy hosts and no proven efficacy in patients with AIDS. Use of cryptosporidium genomes has helped to identify promising therapeutic targets, and drugs are in development, but methods to assess the efficacy in vitro and in animals are not well standardised. Partial immunity after exposure suggests the potential for successful vaccines, and several are in development; however, surrogates of protection are not well defined. Improved methods for propagation and genetic manipulation of the organism would be significant advances.
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Affiliation(s)
- William Checkley
- Program in Global Disease Epidemiology and Control, Department of International Health, Johns Hopkins University, Baltimore, MD, USA; Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
| | - A Clinton White
- Division of Infectious Diseases, University of Texas Medical Branch, Galveston, TX, USA
| | - Devan Jaganath
- Program in Global Disease Epidemiology and Control, Department of International Health, Johns Hopkins University, Baltimore, MD, USA
| | | | - Rachel M Chalmers
- National Cryptosporidium Reference Unit, Public Health Wales, Swansea, UK
| | - Xian-Ming Chen
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, USA
| | - Ronald Fayer
- Environmental Microbial Food Safety Laboratory, USDA, Beltsville, MD, USA
| | - Jeffrey K Griffiths
- Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA
| | - Richard L Guerrant
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | - Lizbeth Hedstrom
- Department of Biology and Department of Chemistry, Brandeis University, Waltham, MA, USA
| | | | - Karen L Kotloff
- Division of Infectious Disease and Tropical Pediatrics, Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gagandeep Kang
- Division of Gastrointestinal Sciences, Christian Medical College, Vellore, India
| | - Jan R Mead
- Department of Pediatrics, Emory University, Atlanta, GA, USA; Atlanta VA Medical Center, Decatur, GA, USA
| | - Mark Miller
- Fogarty International Center, National Institutes of Health, Bethesda, MD, USA
| | - William A Petri
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
| | | | - David S Roos
- Department of Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Boris Striepen
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, USA
| | - R C Andrew Thompson
- School of Veterinary and Life Sciences, Murdoch University, Perth, WA, Australia
| | - Honorine D Ward
- Division of Geographic Medicine and Infectious Diseases, Tufts Medical Center Boston, MA, USA
| | - Wesley A Van Voorhis
- Allergy and Infectious Diseases Division, Departments of Medicine, Global Health, and Microbiology, University of Washington, Seattle, WA, USA
| | - Lihua Xiao
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Guan Zhu
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX, USA
| | - Eric R Houpt
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA
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128
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Wang L, Xue X, Li J, Zhou Q, Yu Y, Du A. Cryptosporidiosis in broiler chickens in Zhejiang Province, China: molecular characterization of oocysts detected in fecal samples. ACTA ACUST UNITED AC 2014; 21:36. [PMID: 25075975 PMCID: PMC4115479 DOI: 10.1051/parasite/2014035] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Accepted: 06/26/2014] [Indexed: 11/14/2022]
Abstract
Cryptosporidium is one of the most important parasites in poultry, and this pathogen can infect more than 30 avian species. The present study investigated the infection rate of Cryptosporidium among broiler chicken flocks. A total of 385 fecal samples from broiler chickens in 7 regions of Zhejiang Province collected from November 2010 to January 2012 were examined by microscopy. Thirty-eight (10%) samples were positive for Cryptosporidium infection, and 3 genotypes (Cryptosporidium baileyi, Cryptosporidium meleagridis, and avian genotype II) were identified by PCR and sequencing. A phylogenetic tree of the isolates was analyzed. These results suggest that cryptosporidiosis is widespread in poultry in Zhejiang Province, and is a potential threat to public health as well as the economy. This is the first report about the infection rate and molecular characterization of Cryptosporidium in broiler chickens in Zhejiang.
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Affiliation(s)
- Lengmei Wang
- Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Xue Xue
- Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Jianqiu Li
- Hangzhou College of Commerce, Zhejiang Gongshang University, Hangzhou, Zhejiang 310012, PR China
| | - Qianjin Zhou
- Faculty of Life Science and Technology, Ningbo University, Ningbo, Zhejiang 315211, PR China
| | - Yingchao Yu
- Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
| | - Aifang Du
- Institute of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China
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129
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Sarkar R, Tate JE, Ajjampur SSR, Kattula D, John J, Ward HD, Kang G. Burden of diarrhea, hospitalization and mortality due to cryptosporidial infections in Indian children. PLoS Negl Trop Dis 2014; 8:e3042. [PMID: 25058664 PMCID: PMC4109911 DOI: 10.1371/journal.pntd.0003042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 06/10/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Cryptosporidium spp. is a common, but under-reported cause of childhood diarrhea throughout the world, especially in developing countries. A comprehensive estimate of the burden of cryptosporidiosis in resource-poor settings is not available. METHODOLOGY/PRINCIPAL FINDINGS We used published and unpublished studies to estimate the burden of diarrhea, hospitalization and mortality due to cryptosporidial infections in Indian children. Our estimates suggest that annually, one in every 6-11 children <2 years of age will have an episode of cryptosporidial diarrhea, 1 in every 169-633 children will be hospitalized and 1 in every 2890-7247 children will die due to cryptosporidiosis. Since there are approximately 42 million children <2 years of age in India, it is estimated that Cryptosporidium results in 3.9-7.1 million diarrheal episodes, 66.4-249.0 thousand hospitalizations, and 5.8-14.6 thousand deaths each year. CONCLUSIONS/SIGNIFICANCE The findings of this study suggest a high burden of cryptosporidiosis among children <2 years of age in India and makes a compelling case for further research on transmission and prevention modalities of Cryptosporidium spp. in India and other developing countries.
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Affiliation(s)
- Rajiv Sarkar
- Christian Medical College, Vellore, Tamil Nadu, India
| | - Jacqueline E. Tate
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | | | - Jacob John
- Christian Medical College, Vellore, Tamil Nadu, India
| | - Honorine D. Ward
- Christian Medical College, Vellore, Tamil Nadu, India
- Tufts Medical Center, Boston, Massachusetts, United States of America
| | - Gagandeep Kang
- Christian Medical College, Vellore, Tamil Nadu, India
- * E-mail:
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130
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Bessoff K, Spangenberg T, Foderaro JE, Jumani RS, Ward GE, Huston CD. Identification of Cryptosporidium parvum active chemical series by Repurposing the open access malaria box. Antimicrob Agents Chemother 2014; 58:2731-9. [PMID: 24566188 PMCID: PMC3993250 DOI: 10.1128/aac.02641-13] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 02/20/2014] [Indexed: 01/19/2023] Open
Abstract
The apicomplexan parasites Cryptosporidium parvum and Cryptosporidium hominis are major etiologic agents of human cryptosporidiosis. The infection is typically self-limited in immunocompetent adults, but it can cause chronic fulminant diarrhea in immunocompromised patients and malnutrition and stunting in children. Nitazoxanide, the current standard of care for cryptosporidiosis, is only partially efficacious for children and is no more effective than a placebo for AIDS patients. Unfortunately, financial obstacles to drug discovery for diseases that disproportionately affect low-income countries and technical limitations associated with studies of Cryptosporidium biology impede the development of better drugs for treating cryptosporidiosis. Using a cell-based high-throughput screen, we queried the Medicines for Malaria Venture (MMV) Open Access Malaria Box for activity against C. parvum. We identified 3 novel chemical series derived from the quinolin-8-ol, allopurinol-based, and 2,4-diamino-quinazoline chemical scaffolds that exhibited submicromolar potency against C. parvum. Potency was conserved in a subset of compounds from each scaffold with varied physicochemical properties, and two of the scaffolds identified exhibit more rapid inhibition of C. parvum growth than nitazoxanide, making them excellent candidates for further development. The 2,4-diamino-quinazoline and allopurinol-based compounds were also potent growth inhibitors of the related apicomplexan parasite Toxoplasma gondii, and a good correlation was observed in the relative activities of the compounds in the allopurinol-based series against T. gondii and C. parvum. Taken together, these data illustrate the utility of the Open Access Malaria Box as a source of both potential leads for drug development and chemical probes to elucidate basic biological processes in C. parvum and other apicomplexan parasites.
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Affiliation(s)
- Kovi Bessoff
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | | | - Jenna E. Foderaro
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Rajiv S. Jumani
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, USA
| | - Gary E. Ward
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, USA
| | - Christopher D. Huston
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
- Cell, Molecular, and Biomedical Sciences Graduate Program, University of Vermont, Burlington, Vermont, USA
- Department of Medicine, University of Vermont, Burlington, Vermont, USA
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131
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Validation of IMP dehydrogenase inhibitors in a mouse model of cryptosporidiosis. Antimicrob Agents Chemother 2013; 58:1603-14. [PMID: 24366728 DOI: 10.1128/aac.02075-13] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Cryptosporidium parasites are a major cause of diarrhea and malnutrition in the developing world, a frequent cause of waterborne disease in the developed world, and a potential bioterrorism agent. Currently, available treatment is limited, and Cryptosporidium drug discovery remains largely unsuccessful. As a result, the pharmacokinetic properties required for in vivo efficacy have not been established. We have been engaged in a Cryptosporidium drug discovery program targeting IMP dehydrogenase (CpIMPDH). Here, we report the activity of eight potent and selective inhibitors of CpIMPDH in the interleukin-12 (IL-12) knockout mouse model, which mimics acute human cryptosporidiosis. Two compounds displayed significant antiparasitic activity, validating CpIMPDH as a drug target. The best compound, P131 (250 mg/kg of body weight/day), performed equivalently to paromomycin (2,000 mg/kg/day) when administered in a single dose and better than paromomycin when administered in three daily doses. One compound, A110, appeared to promote Cryptosporidium infection. The pharmacokinetic, uptake, and permeability properties of the eight compounds were measured. P131 had the lowest systemic distribution but accumulated to high concentrations within intestinal cells. A110 had the highest systemic distribution. These observations suggest that systemic distribution is not required, and may be a liability, for in vivo antiparasitic activity. Intriguingly, A110 caused specific alterations in fecal microbiota that were not observed with P131 or vehicle alone. Such changes may explain how A110 promotes parasitemia. Collectively, these observations suggest a blueprint for the development of anticryptosporidial therapy.
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Kurniawan A, Dwintasari SW, Connelly L, Nichols RA, Yunihastuti E, Karyadi T, Djauzi S. Cryptosporidium species from human immunodeficiency–infected patients with chronic diarrhea in Jakarta, Indonesia. Ann Epidemiol 2013; 23:720-3. [DOI: 10.1016/j.annepidem.2013.07.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Revised: 07/11/2013] [Accepted: 07/22/2013] [Indexed: 11/17/2022]
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133
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Burbacher TM, Grant KS, Worlein J, Ha J, Curnow E, Juul S, Sackett GP. Four decades of leading-edge research in the reproductive and developmental sciences: the Infant Primate Research Laboratory at the University of Washington National Primate Research Center. Am J Primatol 2013; 75:1063-83. [PMID: 23873400 PMCID: PMC5452618 DOI: 10.1002/ajp.22175] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 05/31/2013] [Accepted: 05/31/2013] [Indexed: 12/20/2022]
Abstract
The Infant Primate Research Laboratory (IPRL) was established in 1970 at the University of Washington as a visionary project of Dr. Gene (Jim) P. Sackett. Supported by a collaboration between the Washington National Primate Research Center and the Center on Human Development and Disability, the IPRL operates under the principle that learning more about the causes of abnormal development in macaque monkeys will provide important insights into the origins and treatment of childhood neurodevelopmental disabilities. Over the past 40 years, a broad range of research projects have been conducted at the IPRL. Some have described the expression of normative behaviors in nursery-reared macaques while others have focused on important biomedical themes in child health and development. This article details the unique scientific history of the IPRL and the contributions produced by research conducted in the laboratory. Past and present investigations have explored the topics of early rearing effects, low-birth-weight, prematurity, birth injury, epilepsy, prenatal neurotoxicant exposure, viral infection (pediatric HIV), diarrheal disease, vaccine safety, and assisted reproductive technologies. Data from these studies have helped advance our understanding of both risk and resiliency in primate development. New directions of research at the IPRL include the production of transgenic primate models using our embryonic stem cell-based technology to better understand and treat heritable forms of human intellectual disabilities such as fragile X.
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Affiliation(s)
- Thomas M. Burbacher
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, 98195 USA
- Center on Human Development and Disability, University of Washington, Seattle, WA, 98195 USA
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
| | - Kimberly S. Grant
- Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, WA, 98195 USA
- Center on Human Development and Disability, University of Washington, Seattle, WA, 98195 USA
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
| | - Julie Worlein
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
| | - James Ha
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
- Department of Psychology, School of Arts and Sciences, University of Washington, Seattle, WA, 98195 USA
| | - Eliza Curnow
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
| | - Sandra Juul
- Center on Human Development and Disability, University of Washington, Seattle, WA, 98195 USA
- Department of Pediatrics, School of Medicine, University of Washington, Seattle, WA, 98195 USA
| | - Gene P. Sackett
- Center on Human Development and Disability, University of Washington, Seattle, WA, 98195 USA
- Washington National Primate Research Center, University of Washington, Seattle, WA 98195 USA
- Department of Psychology, School of Arts and Sciences, University of Washington, Seattle, WA, 98195 USA
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Pierce MC, Weigum SE, Jaslove JM, Richards-Kortum R, Tkaczyk TS. Optical systems for point-of-care diagnostic instrumentation: analysis of imaging performance and cost. Ann Biomed Eng 2013; 42:231-40. [PMID: 24097204 DOI: 10.1007/s10439-013-0918-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 09/24/2013] [Indexed: 01/02/2023]
Abstract
One of the key elements in point-of-care (POC) diagnostic test instrumentation is the optical system required for signal detection and/or imaging. Many tests which use fluorescence, absorbance, or colorimetric optical signals are under development for management of infectious diseases in resource limited settings, where the overall size and cost of the device is of critical importance. At present, high-performance lenses are expensive to fabricate and difficult to obtain commercially, presenting barriers for developers of in vitro POC tests or microscopic image-based diagnostics. We recently described a compact "hybrid" objective lens incorporating both glass and plastic optical elements, with a numerical aperture of 1.0 and field-of-view of 250 μm. This design concept may potentially enable mass-production of high-performance, low-cost optical systems which can be easily incorporated in the readout path of existing and emerging POC diagnostic assays. In this paper, we evaluate the biological imaging performance of these lens systems in three broad POC diagnostic application areas; (1) bright field microscopy of histopathology slides, (2) cytologic examination of blood smears, and (3) immunofluorescence imaging. We also break down the fabrication costs and draw comparisons with other miniature optical systems. The hybrid lenses provided images with quality comparable to conventional microscopy, enabling examination of neoplastic pathology and infectious parasites including malaria and cryptosporidium. We describe how these components can be produced at below $10 per unit in full-scale production quantities, making these systems well suited for use within POC diagnostic instrumentation.
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Affiliation(s)
- Mark C Pierce
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, 599 Taylor Road, Piscataway, NJ, 08854, USA
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Castellanos-Gonzalez A, White AC, Ojo KK, Vidadala RSR, Zhang Z, Reid MC, Fox AMW, Keyloun KR, Rivas K, Irani A, Dann SM, Fan E, Maly DJ, Van Voorhis WC. A novel calcium-dependent protein kinase inhibitor as a lead compound for treating cryptosporidiosis. J Infect Dis 2013; 208:1342-8. [PMID: 23878324 DOI: 10.1093/infdis/jit327] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cryptosporidium parasites infect intestinal cells, causing cryptosporidiosis. Despite its high morbidity and association with stunting in the developing world, current therapies for cryptosporidiosis have limited efficacy. Calcium-dependent protein kinases (CDPKs) are essential enzymes in the biology of protozoan parasites. CDPK1 was cloned from the genome of Cryptosporidium parvum, and potent and specific inhibitors have been developed based on structural studies. In this study, we evaluated the anti-Cryptosporidium activity of a novel CDPK1 inhibitor, 1294, and demonstrated that 1294 significantly reduces parasite infection in vitro, with a half maximal effective concentration of 100 nM. Pharmacokinetic studies revealed that 1294 is well absorbed, with a half-life supporting daily administration. Oral therapy with 1294 eliminated Cryptosporidium parasites from 6 of 7 infected severe combined immunodeficiency-beige mice, and the parasites did not recur in these immunosuppressed mice. Mice treated with 1294 had less epithelial damage, corresponding to less apoptosis. Thus, 1294 is an important lead for the development of drugs for treatment of cryptosporidiosis.
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136
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Identification and characterization of Cryptosporidium parvum Clec, a novel C-type lectin domain-containing mucin-like glycoprotein. Infect Immun 2013; 81:3356-65. [PMID: 23817613 DOI: 10.1128/iai.00436-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Cryptosporidium species are waterborne apicomplexan parasites that cause diarrheal disease worldwide. Although the mechanisms underlying Cryptosporidium-host cell interactions are not well understood, mucin-like glycoproteins of the parasite are known to mediate attachment and invasion in vitro. We identified C. parvum Clec (CpClec), a novel mucin-like glycoprotein that contains a C-type lectin domain (CTLD) and has orthologs in C. hominis and C. muris. CTLD-containing proteins are ligand-binding proteins that function in adhesion and signaling and are present in a wide range of organisms, from humans to viruses. However, this is the first report of a CTLD-containing protein in protozoa and in Apicomplexa. CpClec is predicted to be a type 1 membrane protein, with a CTLD, an O-glycosylated mucin-like domain, a transmembrane domain, and a cytoplasmic tail containing a YXX sorting motif. The predicted structure of CpClec displays several characteristics of canonical CTLD-containing proteins, including a long loop region hydrophobic core associated with calcium-dependent glycan binding as well as predicted calcium- and glycan-binding sites. CpClec expression during C. parvum infection in vitro is maximal at 48 h postinfection, suggesting that it is developmentally regulated. The 120-kDa mass of native CpClec is greater than predicted, most likely due to O-glycosylation. CpClec is localized to the surface of the apical region and to dense granules of sporozoites and merozoites. Taken together, these findings, along with the known functions of C. parvum mucin-like glycoproteins and of CTLD-containing proteins, strongly implicate a significant role for CpClec in Cryptosporidium-host cell interactions.
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137
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Lipid synthesis in protozoan parasites: a comparison between kinetoplastids and apicomplexans. Prog Lipid Res 2013; 52:488-512. [PMID: 23827884 DOI: 10.1016/j.plipres.2013.06.003] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 06/16/2013] [Accepted: 06/17/2013] [Indexed: 12/22/2022]
Abstract
Lipid metabolism is of crucial importance for pathogens. Lipids serve as cellular building blocks, signalling molecules, energy stores, posttranslational modifiers, and pathogenesis factors. Parasites rely on a complex system of uptake and synthesis mechanisms to satisfy their lipid needs. The parameters of this system change dramatically as the parasite transits through the various stages of its life cycle. Here we discuss the tremendous recent advances that have been made in the understanding of the synthesis and uptake pathways for fatty acids and phospholipids in apicomplexan and kinetoplastid parasites, including Plasmodium, Toxoplasma, Cryptosporidium, Trypanosoma and Leishmania. Lipid synthesis differs in significant ways between parasites from both phyla and the human host. Parasites have acquired novel pathways through endosymbiosis, as in the case of the apicoplast, have dramatically reshaped substrate and product profiles, and have evolved specialized lipids to interact with or manipulate the host. These differences potentially provide opportunities for drug development. We outline the lipid pathways for key species in detail as they progress through the developmental cycle and highlight those that are of particular importance to the biology of the pathogens and/or are the most promising targets for parasite-specific treatment.
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138
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Chalmers RM, Katzer F. Looking for Cryptosporidium: the application of advances in detection and diagnosis. Trends Parasitol 2013; 29:237-51. [PMID: 23566713 PMCID: PMC7106352 DOI: 10.1016/j.pt.2013.03.001] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 02/27/2013] [Accepted: 03/01/2013] [Indexed: 01/18/2023]
Abstract
The protozoan Cryptosporidium is a major public and animal health concern. Young children, immunocompromised people, and pre-weaning animals are especially vulnerable, but treatment options are limited and there is no vaccine. A laboratory diagnosis is required to confirm cases of cryptosporidiosis, and species and genotype determination is essential in distinguishing human from non-human sources, understanding transmission, and strengthening the epidemiological evidence for causative links in outbreaks. However, testing is not consistent, as demonstrated by investigation of a significant increase in cases in some European countries during 2012. Many methods employed are laborious and time-consuming; recent advances, translated into diagnostic assays, can improve testing and facilitate typing to support clinical and environmental investigations.
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Affiliation(s)
- Rachel M Chalmers
- Cryptosporidium Reference Unit, Public Health Wales Microbiology, Singleton Hospital, Swansea, UK.
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140
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Barry MA, Weatherhead JE, Hotez PJ, Woc-Colburn L. Childhood parasitic infections endemic to the United States. Pediatr Clin North Am 2013; 60:471-85. [PMID: 23481112 DOI: 10.1016/j.pcl.2012.12.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endemic parasitic infections in the United States are more frequent than is commonly perceived. Intestinal parasitic infection with Cryptosporidium, Dientamoeba, and Giardia occurs most often in children in northern states during the summer months. Zoonotic Toxocara and Toxoplasma parasitic infections are more frequent in southern states, in African Americans, and in populations with lower socioeconomic status. Approximately 300, 000 people in the United States have Trypanosoma cruzi infection. Local, vector-borne transmission of T cruzi and Leishmania infections has been documented in southern states. Parasitic diseases endemic to the United States are not uncommon but are understudied.
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Affiliation(s)
- Meagan A Barry
- Interdepartmental Program in Translational Biology and Molecular Medicine, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX 77030, USA
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