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Determination of cut-off cycle threshold values in routine RT–PCR assays to assist differential diagnosis of norovirus in children hospitalized for acute gastroenteritis

  • N. V. TRANG (a1), M. CHOISY (a2) (a3), T. NAKAGOMI (a4), N. T. M. CHINH (a5), Y. H. DOAN (a4), T. YAMASHIRO (a6) (a7), J. E. BRYANT (a3) (a8), O. NAKAGOMI (a4) and D. D. ANH (a1)...

Summary

Norovirus (NV) is an important cause of acute gastroenteritis in children, but is also frequently detected in asymptomatic children, which complicates the interpretation of NV detection results in both the clinical setting and population prevalence studies. A total of 807 faecal samples from children aged <5 years hospitalized for acute gastroenteritis were collected in Thai Binh, Vietnam, from January 2011 to September 2012. Real-time RT–PCR was used to detect and quantify NV-RNA in clinical samples. A bimodal distribution of cycle threshold (Ct) values was observed in which the lower peak was assumed to represent cases for which NV was the causal agent of diarrhoea, whereas the higher peak was assumed to represent cases involving an alternative pathogen other than NV. Under these assumptions, we applied finite-mixture modelling to estimate a threshold of Ct <21·36 (95% confidence interval 20·29–22·46) to distinguish NV-positive patients for which NV was the likely cause of diarrhoea. We evaluated the validity of the threshold through comparisons with NV antigen ELISA results, and comparisons of Ct values in patients co-infected with rotavirus. We conclude that the use of an appropriate cut-off value in the interpretation of NV real-time RT–PCR results may improve differential diagnosis of enteric infections, and could contribute to improved estimates of the burden of NV disease.

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Copyright

This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.

Corresponding author

* Author for correspondence: Dr O. Nakagomi, Division of Molecular Epidemiology, Graduate School of Biomedical Science, Nagasaki University, Japan. (Email: onakagom@nagasaki-u.ac.jp) [O.N.] (Email: ducanhnihe@hn.vnn.vn) [D.D.A]

References

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1. Patel, MM, et al. Systematic literature review of role of noroviruses in sporadic gastroenteritis. Emerging Infectious Diseases 2008; 14: 12241231.
2. Black, RE, et al. Global, regional, and national causes of child mortality in 2008: a systematic analysis. Lancet 2010; 375: 19691987.
3. Oh, DY, Gaedicke, G, Schreier, E. Viral agents of acute gastroenteritis in German children: prevalence and molecular diversity. Journal of Medical Virology 2003; 71: 8293.
4. Amar, CF, et al. Detection by PCR of eight groups of enteric pathogens in 4,627 faecal samples: re-examination of the English case-control Infectious Intestinal Disease Study (1993–1996). European Journal of Clinical Microbiology and Infectious Diseases 2007; 26: 311323.
5. Colomba, C, et al. Norovirus and gastroenteritis in hospitalized children, Italy. Emerging Infectious Diseases 2007; 13: 13891391.
6. Schnagl, RD, et al. Prevalence and genomic variation of Norwalk-like viruses in central Australia in 1995–1997. Acta Virologica 2000; 44: 265271.
7. Nguyen, TA, et al. Norovirus and sapovirus infections among children with acute gastroenteritis in Ho Chi Minh City during 2005–2006. Journal of Tropical Pediatrics 2008; 54: 102113.
8. Trang, NV, et al. Detection and molecular characterization of noroviruses and sapoviruses in children admitted to hospital with acute gastroenteritis in Vietnam. Journal of Medical Virology 2012; 84: 290297.
9. Tamura, T, et al. Molecular epidemiological study of rotavirus and norovirus infections among children with acute gastroenteritis in Nha Trang, Vietnam, December 2005-June 2006. Japanese Journal of Infectious Diseases 2010; 63: 405411.
10. My, PV, et al. Endemic norovirus infections in children, Ho Chi Minh City, Vietnam, 2009–2010. Emerging Infectious Diseases 2013; 19: 977980.
11. O'Ryan, ML, et al. Symptomatic and asymptomatic rotavirus and norovirus infections during infancy in a Chilean birth cohort. Pediatric Infectious Disease Journal 2009; 28: 879884.
12. Zhang, S, et al. Symptomatic and asymptomatic infections of rotavirus, norovirus, and adenovirus among hospitalized children in Xi'an, China. Journal of Medical Virolology 2011.
13. Garcia, C, et al. Asymptomatic norovirus infection in Mexican children. Journal of Clinical Microbiology 2006; 44: 29973000.
14. Ayukekbong, J, et al. Enteric viruses in healthy children in Cameroon: viral load and genotyping of norovirus strains. Journal of Medical Virology 2011; 83: 21352142.
15. Cheon, DS, et al. Seasonal prevalence of asymptomatic norovirus infection in Korean children. Foodborne Pathogens and Diseases 2010; 7: 14271430.
16. Bucardo, F, et al. Asymptomatic norovirus infections in Nicaraguan children and its association with viral properties and histo-blood group antigens. Pediatric Infectious Disease Journal 2010; 29: 934939.
17. Kotloff, KL, et al. Burden and aetiology of diarrhoeal disease in infants and young children in developing countries (the Global Enteric Multicenter Study, GEMS): a prospective, case-control study. Lancet 2013; 382: 209222.
18. Patel, MM, et al. Noroviruses: a comprehensive review. Journal of Clinical Virology 2009; 44: 18.
19. Barreira, DM, et al. Viral load and genotypes of noroviruses in symptomatic and asymptomatic children in Southeastern Brazil. Journal of Clinical Virology 2010; 47: 6064.
20. Marshall, JA, et al. High level excretion of Norwalk-like virus following resolution of clinical illness. Pathology 2001; 33: 5052.
21. Levine, MM, Robins-Browne, RM. Factors that explain excretion of enteric pathogens by persons without diarrhea. Clinical Infectious Diseases 2012; 55 (Suppl. 4): S303311.
22. Cheng, WX, et al. Human bocavirus in children hospitalized for acute gastroenteritis: a case-control study. Clinical Infectious Diseases 2008; 47: 161167.
23. Ramani, S, et al. Comparison of viral load and duration of virus shedding in symptomatic and asymptomatic neonatal rotavirus infections. Journal of Medical Virology 2010; 82: 18031807.
24. Kageyama, T, et al. Broadly reactive and highly sensitive assay for Norwalk-like viruses based on real-time quantitative reverse transcription PCR. Journal of Clinical Microbiology 2003; 41: 15481557.
25. Neesanant, P, et al. Optimization of one-step real-time reverse transcription-polymerase chain reaction assays for norovirus detection and molecular epidemiology of noroviruses in Thailand. Journal of Virological Methods 2013; 194: 317325.
26. Vinje, J, Hamidjaja, RA, Sobsey, MD. Development and application of a capsid VP1 (region D) based reverse transcription PCR assay for genotyping of genogroup I and II noroviruses. Journal of Virological Methods 2004; 116: 109117.
27. Kroneman, A, et al. Proposal for a unified norovirus nomenclature and genotyping. Archives of Virology 2013; 158: 20592068.
28. Schlattmann, P. Medical Applications of Finite Mixture Models. Heidelberg: Springer Verlag, 2009.
29. Do, CB, Batzoglou, S. What is the expectation maximization algorithm? Nature Biotechnology 2008; 26: 897899.
30. Oakes, D. Direct calculation of the information matrix via the EM algorithm. Journal of Royal Statistic Society 1999: 479482.
31. RCoreTeam. R: A language and environment for statistical computing. R Foundation for Statistical Computing. R Foundation: Vienna, Austria. 2013.
32. Phillips, G, et al. Diagnosing norovirus-associated infectious intestinal disease using viral load. BMC Infectious Diseases 2009; 9: 63.
33. Elfving, K, et al. Real-time PCR threshold cycle (Ct) cut-offs help to identify agents causing acute childhood diarrhea in Zanzibar. Journal of Clinical Microbiology 2014.
34. Costantini, V, et al. Diagnostic accuracy and analytical sensitivity of IDEIA Norovirus assay for routine screening of human norovirus. Journal of Clinical Microbiology 2010; 48: 27702778.

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Determination of cut-off cycle threshold values in routine RT–PCR assays to assist differential diagnosis of norovirus in children hospitalized for acute gastroenteritis

  • N. V. TRANG (a1), M. CHOISY (a2) (a3), T. NAKAGOMI (a4), N. T. M. CHINH (a5), Y. H. DOAN (a4), T. YAMASHIRO (a6) (a7), J. E. BRYANT (a3) (a8), O. NAKAGOMI (a4) and D. D. ANH (a1)...

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