Volume 92, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



is one of the most commonly identified parasites in stool samples. Although relatively easy to treat, giardiasis can be difficult to detect as it presents similar to other diarrheal diseases. Here, we present a recombinase polymerase amplification-based (RPAG) assay to detect the presence of in stool samples. The RPAG assay was characterized on the bench top using stool samples spiked with cysts where it showed a limit-of-detection nearly as low as the gold standard polymerase chain reaction assay. The RPAG assay was then tested in the highlands of Peru on 104 stool samples collected from the surrounding communities where it showed 73% sensitivity and 95% specificity against a polymerase chain reaction and microscopy composite gold standard. Further improvements in clinical sensitivity will be needed for the RPAG assay to have clinical relevance.


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  1. Walker CL, Rudan I, Liu L, Nair H, Theodoratou E, Bhutta ZA, O'Brien KL, Campbell H, Black RE, , 2013. Global burden of childhood pneumonia and diarrhea. Lancet 381: 14051416.[Crossref] [Google Scholar]
  2. Ross AG, Olds GR, Cripps AW, Farrar JJ, McManus DP, , 2013. Enteropathogens and chronic illness in returning travelers. N Engl J Med 368: 18171825.[Crossref] [Google Scholar]
  3. WHO, 2012. Cryptosporidiosis Surveillance - United States, 2009–2010 and Giardiasis Surveillance - United States, 2009–2010. Morbidity and Mortality Weekly Report: Centers for Disease Control and Prevention 61: 1319. [Google Scholar]
  4. Ignatius R, Gahutu JB, Klotz C, Steininger C, Shyirambere C, Lyng M, Musemakweri A, Aebischer T, Martus P, Harms G, Mockenhaupt FP, , 2012. High prevalence of Giardia duodenalis assemblage B infection and association with underweight in Rwandan children. Plos Negl Trop Dis 6: e1677.[Crossref] [Google Scholar]
  5. Ankarklev J, Jerlstrom-Hultqvist J, Ringqvist E, Troell K, Svard SG, , 2010. Behind the smile: cell biology and disease mechanisms of Giardia species. Nat Rev Microbiol 8: 413422. [Google Scholar]
  6. Kotloff KL, Nataro JP, Blackwelder WC, Nasrin D, Farag TH, Panchalingam S, Wu Y, Sow SO, Sur D, Breiman RF, Faruque AS, Zaidi AK, Saha D, Alonso PL, Tamboura B, Sanogo D, Onwuchekwa U, Manna B, Ramamurthy T, Kanungo S, Ochieng JB, Omore R, Oundo JO, Hossain A, Das SK, Ahmed S, Qureshi S, Quadri F, Adegbola RA, Antonio M, Hossain MJ, Akinsola A, Mandomando I, Nhampossa T, Acacio S, Biswas K, O'Reilly CE, Mintz ED, Berkeley LY, Muhsen K, Sommerfelt H, Robins-Browne RM, Levine MM, , 2013. Burden and aetiology of diarrheal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study. Lancet 382: 209222.[Crossref] [Google Scholar]
  7. Fletcher SM, Stark D, Harkness J, Ellisa J, , 2012. Enteric protozoa in the developed world: a public health perspective. Clin Microbiol Rev 25: 420449.[Crossref] [Google Scholar]
  8. Huang DB, White AC, , 2006. An updated review on Cryptosporidium and Giardia . Gastroenterol Clin North Am 35: 291314.[Crossref] [Google Scholar]
  9. Garcia LS, Shimizu RY, Novak S, Carroll M, Chan F, , 2003. Commercial assay for detection of Giardia lamblia and Cryptosporidium parvum antigens in human fecal specimens by rapid solid-phase qualitative immunochromatography. J Clin Microbiol 41: 209212.[Crossref] [Google Scholar]
  10. Garcia LS, Shimizu RY, , 1997. Evaluation of nine immunoassay kits (enzyme immunoassay and direct fluorescence) for detection of Giardia lamblia and Cryptosporidium parvum in human fecal specimens. J Clin Microbiol 35: 15261529. [Google Scholar]
  11. Taniuchi M, Verweij JJ, Noor Z, Sobuz SU, van Lieshout L, Petri WA, Haque R, Houpt ER, , 2011. High throughput multiplex PCR and probe-based detection with luminex beads for seven intestinal parasites. Am J Trop Med Hyg 84: 332337.[Crossref] [Google Scholar]
  12. Compton J, , 1991. Nucleic-acid sequence-based amplification. Nature 350: 9192.[Crossref] [Google Scholar]
  13. Notomi T, Okayama H, Masubuchi H, Yonekawa T, Watanabe K, Amino N, Hase T, , 2000. Loop-mediated isothermal amplification of DNA. Nucleic Acids Res 28: E63.[Crossref] [Google Scholar]
  14. Demidov VV, , 2002. Rolling-circle amplification in DNA diagnostics: the power of simplicity. Expert Rev Mol Diagn 2: 542548.[Crossref] [Google Scholar]
  15. Craw P, Balachandran W, , 2012. Isothermal nucleic acid amplification technologies for point-of-care diagnostics: a critical review. Lab Chip 12: 24692486.[Crossref] [Google Scholar]
  16. Piepenburg O, Williams CH, Stemple DL, Armes NA, , 2006. DNA detection using recombination proteins. PLoS Biol 4: e204.[Crossref] [Google Scholar]
  17. Rohrman B, Richards-Kortum R, , 2012. A paper and plastic device for performing recombinase polymerase amplification of HIV DNA. Lab Chip 12: 30823088.[Crossref] [Google Scholar]
  18. TwistDx Inc., 2012. Our Technology. Available at: http://www.twistdx.co.uk/our_technology/. Accessed June 27, 2012. [Google Scholar]
  19. WHO Diseases SaIPUDoCoT, 2004. Training Manual on Diagnosis of Intestinal Parasites. , ed. Geneva: World Health Organization. Available at: http://whqlibdoc.who.int/hq/1998/WHO_CTD_SIP_98.2.pdf. [Google Scholar]
  20. Crannell ZA, Castellanos-Gonzalez A, Irani A, Rohrman B, White AC, Richards-Kortum R, , 2014. Nucleic acid test to diagnose cryptosporidiosis: lab assessment in animal and patient specimens. Anal Chem 86: 25652571.[Crossref] [Google Scholar]
  21. Rohrman BA, Leautaud V, Molyneux E, Richards-Kortum RR, , 2012. A lateral flow assay for quantitative detection of amplified HIV-1 RNA. PLoS ONE 7: e45611.[Crossref] [Google Scholar]
  22. Stroup S, Tongjai S, Swai N, Maro A, Kibiki G, Houpt ER, , 2012. Dual probe DNA capture for sensitive real-time PCR detection of Cryptosporidium and Giardia . Mol Cell Probes 26: 104106.[Crossref] [Google Scholar]
  23. Calderaro A, Gorrini C, Montecchini S, Peruzzi S, Piccolo G, Rossi S, Gargiulo F, Manca N, Dettori G, Chezzi C, , 2010. Evaluation of a real-time polymerase chain reaction assay for the laboratory diagnosis of giardiasis. Diagn Microbiol Infect Dis 66: 261267.[Crossref] [Google Scholar]
  24. Monteiro L, Bonnemaison D, Vekris A, Petry KG, Bonnet J, Vidal R, Cabrita J, Megraud F, , 1997. Complex polysaccharides as PCR inhibitors in feces: Helicobacter pylori model. J Clin Microbiol 35: 995998. [Google Scholar]

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Supplementary PDF

  • Received : 18 Sep 2014
  • Accepted : 18 Nov 2014
  • Published online : 04 Mar 2015

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