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

Determination of cut-off cycle threshold values in routine RT-PCR assays to assist differential diagnosis of norovirus in children hospitalized for acute gastroenteritis Trang N. V. auteur aut IRD Choisy Marc auteur aut IRD Nakagomi T. auteur aut IRD Chinh N. T. M. auteur aut IRD Doan Y. H. auteur aut IRD Yamashiro T. auteur aut IRD Bryant J. E. auteur aut IRD Nakagomi O. auteur aut IRD Anh D. D. auteur aut IRD text journalArticle eng text/pdf born digital access 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 (C-t) 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 C-t <2136 (95% confidence interval 2029-2246) 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 C-t 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. specialized Caliciviruses diarrhoea estimating disease prevalence gastrointestinal infections modelling VIET NAM 020 050 052 Epidemiology and Infection 143 15 3292-3299 2015 0950-2688 https://www.documentation.ird.fr/hor/fdi:010065392 10.1017/s095026881500059x 0950-2688 [F B010065392] https://www.documentation.ird.fr/hor/fdi:010065392 https://www.documentation.ird.fr/intranet/publi/2015/11/010065392.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2015-12-04 2017-08-23 fdi:010065392 fre