Volume 13, Number 1—January 2007
Correlation between Subtypes of Cryptosporidium parvum in Humans and Risk
|Cases/variable||Cases, n (%)||Controls, n (%)||Odds ratio||95% CI||p value|
|All Cryptosporidium parvum strains|
|Touch or handle any farm animals|
|Yes||24 (34)||43 (11)||2.653||1.113–6.323||0.028|
|Yes||24 (36)||249 (50)||0.317||0.140–0.719||0.005|
|Eat raw vegetables|
|Yes||7 (12)||157 (44)||0.222||0.086–0.572||0.001|
|Only ML1–242 strains|
|Touch or handle any farm animals|
|Yes||21 (43)||43 (11)|
|Yes||17 (37)||249 (50)||0.425||0.164–1.104||0.079|
|Eat raw vegetables|
|Yes||4 (10)||157 (44)||0.141||0.042–0.474||0.001|
*CI, confidence interval. Also included in the models were age and Health Authority of residence.
- McLauchlin J, Amar C, Pedraza-Díaz S, Nichols GL. Molecular epidemiological analysis of Cryptosporidium spp. in the United Kingdom: results of genotyping Cryptosporidium spp. in 1705 fecal samples from humans and 105 fecal samples from livestock animals.J Clin Microbiol. 2000;38:3984–90.
- The development of a national collection for oocysts of Cryptosporidium. Foundation for Water Research, Marlow, Bucks, UK, 2002 [cited 2006 Oct 11]. Available from http://www.fwr.org/
- Chen X-M, Keithly JS, Paya CV, LaRusso NF. Cryptosporidiosis.N Engl J Med. 2002;346:1723–31.
- Health Protection Agency. 2006 [cited 2006 Oct 11]. Available from http://www.hpa.org.uk/
- Hunter PR, Nichols G. The epidemiology and clinical features of cryptosporidium infection in immune-compromised patients.Clin Microbiol Rev. 2002;15:145–54.
- Hunter PR, Hughes S, Woodhouse S, Raj N, Syed Q, Chalmers RM, Health sequelae of human cryptosporidiosis in immunocompetent patients.Clin Infect Dis. 2004;39:504–10.
- Xiao L, Rayer R, Ryan U, Upton SJ. Cryptosporidium taxonomy: recent advances and implications for public health.Clin Microbiol Rev. 2004;17:72–97.
- Aeillo AE, Xiao L, Limor JR, Liu C, Abrahamson MS, Lal AA. Microsatellite analysis of the human and bovine genotypes of Cryptosporidium parvum.J Eukaryot Microbiol. 1999;46:46S–7.
- Cacciò S, Homan W, Camilli R, Traldi G, Kortbeek T, Pozio E. A microsatellite marker reveals population heterogeneity within human and animal genotypes of Cryptosporidium parvum.Parasitology. 2000;120:237–44.
- Cacciò S, Spano F, Pozio E. Large sequence variation at two microsatellite loci among zoonotic (genotype C) isolates of Cryptosporidium parvum.Int J Parasitol. 2001;31:1082–6.
- Enemark HL, Ahrens P, Juel CD, Petersen E, Petersen RF, Andersen JS, Molecular characterization of Danish Cryptosporidium parvum isolates.Parasitology. 2002;125:331–41.
- Mallon M, MacLeod A, Wastling J, Smith H, Reilly B, Tait A. Population structures and the role of genetic exchange in the zoonotic pathogen Cryptosporidium parvum.J Mol Evol. 2003;56:407–17.
- Mallon ME, MacLeod A, Wastling JM, Smith H, Tait A. Multilocus genotyping of Cryptosporidium parvum Type 2: population genetics and sub-structuring.Infect Genet Evol. 2003;3:207–18.
- Gasser RB. Abs EL-Osta Y, Prepens S, Chalmers RM. An improved “cold SSCP” for the genotypic and subgenotypic characterisation of Cryptosporidium.Mol Cell Probes. 2004;18:329–32.
- Strong WB, Gut J, Nelson RG. Cloning and sequence analysis of a highly polymorphic Cryptosporidium parvum gene encoding a 60-kilodalton glycoprotein and characterization of its 15- and 45-kilodalton zoite surface antigen products.Infect Immun. 2000;68:4117–34.
- Alves M, Xiao L, Sulaiman I, Lal AA, Matos O, Antunes F. Subgenotype analysis of Cryptosporidium isolates from humans, cattle, and zoo ruminants in Portugal.J Clin Microbiol. 2003;41:2744–7.
- Blasdall SA, Ongerth JE, Ashbolt NJ. Differentiation of Cryptosporidium parvum subtypes in calves of four dairy herds by a novel microsatellite-telomere PCR with PAGE. Proceedings of Cryptosporidium from Molecules to Disease, 7–12 October 2001, Fremantle, Australia. Melbourne: Water Services Association of Australia; 2001.
- Blasdall SA, Ongerth JE, Ashbolt NJ. Sub-species differentiation among Type 2 bovine C. parvum isolates using a RAPD microsatellite + telomere primer scheme. Proceedings of IWA World Water Congress, Berlin. 2001.London: International Water Association; 2001.
- Hunter PR, Hughes LS, Woodhouse S, Syed Q, Verlander N, Chalmers RM. Case-control study of sporadic cryptosporidiosis with genotyping.Emerg Infect Dis. 2004;10:1241–9.
- Casemore DP, Armstrong M, Sands RL. Laboratory diagnosis of cryptosporidiosis.J Clin Pathol. 1985;38:1337–41.
- Elwin K, Chalmers RM, Roberts R, Guy EC, Casemore DP. The modification of a rapid method for the identification of gene-specific polymorphisms in Cryptosporidium parvum, and application to clinical and epidemiological investigations.Appl Environ Microbiol. 2001;67:5581–4.
- Spano F, Putignani L, McLauchlin J, Casemore DP, Crisanti A. PCR-RFLP analysis of the Cryptosporidium oocyst wall protein (COWP) gene discriminates between C. wrairi and C. parvum, and between C. parvum isolates of human and animal origin.FEMS Microbiol Lett. 1997;150:209–17.
- Xiao L, Singh A, Limor J, Graczyk TK, Gradus S, Lal A. Molecular characterization of Cryptosporidium oocysts in samples of raw surface water and wastewater.Appl Environ Microbiol. 2001;67:1097–101.
- Morgan UM, Constantine CC, Forbes DA, Thompson RCA. Differentiation between human and animal isolates of Cryptosporidium parvum using rDNA sequencing and direct PCR analysis.J Parasitol. 1997;83:825–30.
- Investigation of. Cryptosporidium clinical isolates and analysis with epidemiological data. Foundation for Water Research, Marlow, Bucks, UK, 2005 [cited 2006 Oct 11]. Available from http://www.fwr.org/
- Establishing the relationship between farm restocking and cryptosporidia: the Caldew catchment study. Foundation for Water Research, Marlow, Bucks, UK, 2005 [cited 2006 Oct 11]. Available from http://www.fwr.org/
- Hunter PR, Gaston MA. A numerical index of the discriminatory ability of typing systems: an application of Simpson’s index of diversity.J Clin Microbiol. 1988;26:2465–6.
- Hunter PR, Fraser CAM. Application of the theory of adaptive polymorphism to the ecology and epidemiology of pathogenic yeasts.Appl Environ Microbiol. 1990;56:2219–22.
- Tanriverdi S, Widmer G. Differential evolution of repetitive sequences in Cryptosporidium parvum and Cryptosporidium hominis.Infect Genet Evol. 2006;6:113–22.
- Robinson G. Investigating the public health significance of Cryptosporidium in the enivironment [PhD dissertation]. Cardiff (UK): University of Wales College of Medicine; 2005.
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