We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
LGC Clinical Diagnostics

Download Mobile App





Molecular Test Detects Three Arboviruses in Plasma Samples

By LabMedica International staff writers
Posted on 04 Aug 2016
Currently, multiple arboviruses are circulating in Brazil: Zika, chikungunya and dengue and they have similar clinical pictures, which can lead to misdiagnosis based on clinical grounds alone.

Detection tests for viral ribonucleic acid (RNA) such as the quantitative reverse transcription polymerase chain reaction (RT-qPCR) can reliably and specifically distinguish the three viruses and the specific diagnosis can be important in anticipating, preventing, and managing complications.

Scientists at the Laboratório Sabin (Brasília, Brazil) and their colleagues collected 90 plasma samples from the routine arbovirus laboratory, 20 positive for Zika (RT-qPCR), six positive for chikungunya (RT-qPCR), 18 positive for dengue nonstructural protein 1 antigen test (NS-1) and 46 negative for all three viruses. More...
Nucleic acids were extracted from 1mL of sample by using an automated DNA extractor. An in-vitro transcribed random RNA sequence, which is not found in the nature, was spiked into plasmas during the nucleic acids extraction to function as a process control. Primers/probes for chikungunya were specifically designed for this study.

Zika, chikungunya and dengue viruses were assessed simultaneously by RT-qPCR, but in independent reaction wells. The control RNA was co-amplified in all instances. The viral loads of specific samples were quantified against a serial dilution of synthetic single-stranded DNA (ssDNA) and the limits of detection of each assay were determined by probit regression analysis. To investigate the precision of the assays, three samples at ~72, ~7.2 and ~0.72 copies/mL of each viruses were evaluated by using the Clinical and Laboratory Standards Institute (CLSI) EP12-A2 method during five days in quadruplicate by two operators.

The investigators reported that the limits of detection were 26 copies/mL for Zika, 23.5 copies/mL, for chikungunya and 25.6 copies/mL for dengue. The ~72, ~7.2 and ~0.72 copies/mL samples yielded 18/20 (90%), 2/20 (10%) and 1/20 (5%) positive results for Zika, 18/20 (90%), 4/20 (20%) and 0/20 (0%) positive results for chikungunya and 20/20 (100%), 16/20 (80%) and 0/20 (0%) positive results for dengue, respectively. The total, positive and negative agreements between compared methods were 95.5%, 90% and 97.5 for Zika, 100% for all methods for chikungunya and 95.6%, 100% and 94.5%, for dengue, respectively. No cross-reaction was observed.

The authors concluded that the RT-PCR method for simultaneous detection of Zika, chikungunya and dengue viruses is highly sensitive, all assays showed limit of detection below 50 copies/mL. Moreover, cut-off regions were characterized and acceptable precisions were observed for positive (~72 copies/mL and above) and negative (~0.72 copies/mL and below) results. Finally, the agreements with the comparative methods were very good, above 90% of concordance in all instances. The study was presented at the 68th American Association of Clinical Chemistry (AACC) Annual Scientific Meeting held July 31 to August 4, 2016, in Philadelphia, PA, USA.

Related Links:
Laboratório Sabin
American Association of Clinical Chemistry

Gold Member
Flocked Fiber Swabs
Puritan® Patented HydraFlock®
Verification Panels for Assay Development & QC
Seroconversion Panels
New
Calprotectin Test
CALiaGold
New
Nutating Mixer
Enduro MiniMix
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Clinical Chemistry

view channel
Image: The POC device rapidly predicts neonatal respiratory disease at birth in the NICU (Photo courtesy of SIME Diagnostics)

AI-Powered Lung Maturity Test Identifies Newborns at Higher Risk of Respiratory Distress

Each year, approximately 300,000 babies in the United States are born between 32 and 36 weeks' gestation, according to national health data. This group is at an elevated risk for respiratory distress,... Read more

Hematology

view channel
Image: CitoCBC is the world first cartridge-based CBC to be granted CLIA Waived status by FDA (Photo courtesy of CytoChip)

Disposable Cartridge-Based Test Delivers Rapid and Accurate CBC Results

Complete Blood Count (CBC) is one of the most commonly ordered lab tests, crucial for diagnosing diseases, monitoring therapies, and conducting routine health screenings. However, more than 90% of physician... Read more

Immunology

view channel
Image: The cancer stem cell test can accurately choose more effective treatments (Photo courtesy of University of Cincinnati)

Stem Cell Test Predicts Treatment Outcome for Patients with Platinum-Resistant Ovarian Cancer

Epithelial ovarian cancer frequently responds to chemotherapy initially, but eventually, the tumor develops resistance to the therapy, leading to regrowth. This resistance is partially due to the activation... Read more

Pathology

view channel
Image: A biomarker discovery pipeline has shown promise as a noninvasive method of diagnosing CRC (Photo courtesy of NCI Center for Cancer Research)

Machine Learning Tool Enables Noninvasive Diagnosis and Monitoring of Colorectal Cancer

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States when considering both genders. Colonoscopy remains the gold standard for CRC diagnosis, but it is invasive,... Read more

Technology

view channel
Image: Scanning electron microscopy images showing 3D micro-printed Limacon-shaped whispering-gallery-mode microcavities with different amounts of deformation (Photo courtesy of A. Ping Zhang/PolyU)

Tiny Microlaser Sensors with Supercharged Biosensing Ability to Enable Early Disease Diagnosis

Optical whispering-gallery-mode microlaser sensors function by trapping light within tiny microcavities. When target molecules bind to the cavity, they induce subtle changes in the laser’s frequency, allowing... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.