Rapid diagnosis of Zika virus through saliva and urine by Loop-mediated isothermal amplification (LAMP)

Talita Castro,Maite Sabalza,Cheryl Barber,William Abrams,Antonio Charlys Da Costa,Flavio Augusto De Pádua Milagres,Paulo Henrique Braz-Silva,Daniel Malamud,Marina Gallottini

doi:10.1080/20002297.2018.1510712

Abstract

ABSTRACT Background: Zika virus (ZIKV) is a single-stranded RNA virus and member of the Flaviviridae family. Recent studies have reported that saliva can be an important alternative to detect ZIKV. Saliva requires less processing than blood greatly simplifying the assay. Loop-mediated Isothermal Amplification (LAMP) is a rapid assay that detects nucleic acids, including ZIKV RNA. Aim: The aim of this study was to evaluate the efficacy of saliva and urine to diagnose ZIKV infection in subjects during the acute phase, through ZIKV RNA detection by LAMP. Method: A total of 131 samples (68 saliva and 63 urine samples) from 69 subjects in the acute phase of ZIKV infection, and confirmed positive for ZIKV by blood analysis through real time-PCR, were collected and analyzed by Reverse Transcriptase Loop-mediated Isothermal Amplification (RT-LAMP). Results: From the 68 saliva samples, 45 (66.2%) were positive for ZIKV with an average time to positivity (Tp) of 13.5 min, and from the 63 urine samples, 25 (39.7%) were positive with the average Tp of 15.8 min. Saliva detected more samples (p = 0.0042) and had faster Tp (p = 0.0176) as compared with urine. Conclusion: Saliva proved to be a feasible alternative to diagnose ZIKV infection during the acute phase by LAMP.

Highlights

Zika virus (ZIKV) is a single-stranded RNA virus and member of the Flaviviridae family [1]
The aim of this study was to evaluate the efficacy of saliva and urine to diagnose ZIKV infection in subjects during the acute phase, utilizing Loop-mediated Isothermal Amplification (LAMP) to detect ZIKV RNA
131 samples (68 from saliva and 63 from urine) were collected and analyzed from 69 Brazilian subjects of all ages that met the inclusion criteria of presenting specific symptoms and signs for ZIKV, such as fever, cutaneous rash, headache, conjunctivitis, myalgia and arthralgia; and had confirmed positive for ZIKV and negative for Dengue and Chikungunya virus infection by blood analysis utilizing quantitative polymerase chain reaction (qPCR), following the criteria described by Lanciotti et al 2008 [16]

Summary

Introduction

Zika virus (ZIKV) is a single-stranded RNA virus and member of the Flaviviridae family [1] It is transmitted among humans usually by Aedes mosquito species, but dissemination by sexual transmission [2], perinatal [3] and blood transfusion [4] have been reported. Since the first report of ZIKV in saliva [9], studies have suggested that saliva could be an important alternative sample to detect ZIKV infection [5,9,10,11,12]. Zika virus (ZIKV) is a single-stranded RNA virus and member of the Flaviviridae family. Recent studies have reported that saliva can be an important alternative to detect ZIKV. Loop-mediated Isothermal Amplification (LAMP) is a rapid assay that detects nucleic acids, including ZIKV RNA

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Results

Conclusion