scholarly journals Evaluation of Altona Diagnostics RealStar Zika Virus Reverse Transcription-PCR Test Kit for Zika Virus PCR Testing

2017 ◽  
Vol 55 (5) ◽  
pp. 1576-1584 ◽  
Author(s):  
Arnaud G. L'Huillier ◽  
Ernesto Lombos ◽  
Elaine Tang ◽  
Stephen Perusini ◽  
Alireza Eshaghi ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Zika Virus ◽  
Sanger Sequencing ◽  
Diagnostic Testing ◽  
Large Set ◽  
Reverse Transcription Pcr ◽  
Test Kit ◽  
The U.S ◽  
Pcr Test ◽  
Dual Target

ABSTRACT With the emerging Zika virus (ZIKV) epidemic, accessible real-time reverse transcription-PCR (rRT-PCR) assays are needed to streamline testing. The commercial Altona Diagnostics RealStar ZIKV rRT-PCR test kit (Altona PCR) has been approved for emergency use authorization by the U.S. FDA. Our aim was to verify the Altona PCR by comparing it to the CDC-designed dual-target ZIKV rRT-PCR reference assay (reference PCR) and describe the demographics of patients tested for ZIKV by rRT-PCR in Ontario, Canada. A large set of clinical specimens was tested for ZIKV by the Altona PCR and the reference PCR. Positive or equivocal specimens underwent PCR and Sanger sequencing targeting the ZIKV NS5 gene. A total of 671 serum specimens were tested by the reference PCR: 58 (8.6%) were positive, 193 (28.8%) were equivocal, and 420 (62.6%) were negative. Ninety percent of the reference PCR-positive patients were tested in the first 5 days after symptom onset. The Altona PCR was performed on 284/671 specimens tested by the reference PCR. The Altona PCR was positive for 53/58 (91%) reference PCR-positive specimens and 16/193 (8%) reference PCR-equivocal specimens; the ZIKV NS5 PCR was positive for all 68 Altona PCR-positive specimens and negative for all 181 Altona PCR-negative specimens that underwent the NS5 PCR. The Altona PCR has very good sensitivity (91%) and specificity (97%) compared to the reference PCR. The Altona PCR can be used for ZIKV diagnostic testing and has less extensive verification requirements than a laboratory-developed test.

scholarly journals Diagnostic Testing for Zika Virus: a Postoutbreak Update

2018 ◽  
Vol 56 (4) ◽  
Author(s):  
Elitza S. Theel ◽  
D. Jane Hata
Keyword(s):  
Drug Administration ◽  
Zika Virus ◽  
Food And Drug Administration ◽  
Diagnostic Testing ◽  
Clinical Disease ◽  
Diagnostic Assays ◽  
Molecular Assays ◽  
The Past ◽  
The U.S

ABSTRACT Since the emergence and dissemination of Zika virus (ZIKV) in late 2015, our understanding of the biology, transmission, clinical disease, and potential sequelae associated with infection has markedly expanded. Over the past 2 years, the number of diagnostic assays for ZIKV has increased from none in 2015 to 5 serological assays and 14 molecular assays in 2017, all with emergency use authorization granted through the U.S. Food and Drug Administration. Here we provide an update on ZIKV, addressing what we have collectively learned since the outbreak began, including a summary of currently available diagnostic assays for this virus.

scholarly journals Comparison of Four Serological Methods and Two Reverse Transcription-PCR Assays for Diagnosis and Surveillance of Zika Virus Infection

2018 ◽  
Vol 56 (3) ◽  
Author(s):  
Angel Balmaseda ◽  
José Victor Zambrana ◽  
Damaris Collado ◽  
Nadezna García ◽  
Saira Saborío ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Zika Virus ◽  
Clinical Manifestations ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Emerging Infections ◽  
Rt Pcr ◽  
Convalescent Phase ◽  
Reverse Transcription Pcr ◽  
Pcr Assays

ABSTRACTZika virus (ZIKV) is a mosquito-borne flavivirus that is responsible for recent explosive epidemics in the Americas. Notably, ZIKV infection during pregnancy has been found to cause congenital birth defects, including microcephaly, and ZIKV has been associated with Guillain-Barré syndrome in adults. Diagnosis and surveillance of Zika in the Americas have been challenging due to similar clinical manifestations and extensive antibody cross-reactivity with endemic flaviviral diseases, such as dengue. We evaluated four serological and two reverse transcription-PCR (RT-PCR) methods in acute-phase (mean day, 1.8), early-convalescent-phase (mean day, 16.7), and late-convalescent-phase (mean, ~7 months) samples from the same individuals in a long-term pediatric cohort study in Nicaragua. Well-characterized samples from 301 cases of Zika, dengue, or non-Zika, nondengue febrile illnesses were tested. Compared to a composite reference, an in-house IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the NIAID-Biodefense and Emerging Infections (BEI) MAC-ELISA measuring IgM yielded sensitivities of 94.5% and 70.1% and specificities of 85.6% and 82.8%, respectively. The NS1 blockade-of-binding ELISA measuring anti-ZIKV NS1 antibody levels yielded sensitivities of 85.0% and 96.5% and specificities of 91.4% and 92.6% at early and late convalescence, respectively. An inhibition ELISA detecting total anti-ZIKV antibodies had sensitivity and specificity values of 68.3% and 58.3% for diagnosis and 94.0% and 98.6% for measuring annual infection incidence. Finally, the ZCD and Trioplex real-time RT-PCR assays detecting Zika, chikungunya, and dengue viruses both yielded a sensitivity of 96.1% and specificity of 100%. Together, these assays resolve the urgent need for diagnostic and surveillance tools for countries affected by Zika virus infections.

scholarly journals Agile design and development of a high throughput cobas® SARS-CoV-2 RT-PCR diagnostic test

2021 ◽  
Author(s):  
Chitra Manohar ◽  
Jingtao Sun ◽  
Peter Schlag ◽  
Chris Santini ◽  
Marcel Fontecha ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Rapid Development ◽  
Diagnostic Testing ◽  
In Silico Analysis ◽  
Rt Pcr ◽  
Assay Sensitivity ◽  
Agile Design ◽  
Assay Design ◽  
Pcr Test ◽  
Dual Target

Diagnostic testing is essential for management of the COVID-19 pandemic. An agile assay design methodology, optimized for the cobas® 6800/8800 system, was used to develop a dual-target, qualitative SARS-CoV-2 RT-PCR test using commercially available reagents and existing sample processing and thermocycling profiles. The limit of detection was 0.004 to 0.007 TCID50/mL for USA-WA1/2020. Assay sensitivity was confirmed for SARS-CoV-2 variants Alpha, Beta, Gamma, Delta and Kappa. The coefficients of variation of the cycle threshold number (Ct) were between 1.1 and 2.2%. There was no difference in Ct using nasopharyngeal compared to oropharyngeal swabs in universal transport medium (UTM). A small increase in Ct was observed with specimens collected in cobas® PCR medium compared to UTM. In silico analysis indicated that the dual-target test is capable of detecting all >1,800,000 SARS-CoV-2 sequences in the GISAID database. Our agile assay design approach facilitated rapid development and deployment of this SARS-CoV-2 RT-PCR test.

scholarly journals Vertical transmission of zika virus in Aedes albopictus

2020 ◽  
Vol 14 (10) ◽  
pp. e0008776
Author(s):  
Zetian Lai ◽  
Tengfei Zhou ◽  
Jiayong Zhou ◽  
Shuang Liu ◽  
Ye Xu ◽  
...  
Keyword(s):  
Vertical Transmission ◽  
Aedes Albopictus ◽  
Reverse Transcription ◽  
Zika Virus ◽  
Transmission Rate ◽  
Horizontal Transmission ◽  
Infection Rates ◽  
Transmission Rates ◽  
Suckling Mice ◽  
Reverse Transcription Pcr

Background Zika virus (ZIKV) is an arthropod-borne flavivirus transmitted by Aedes mosquitoes. Aedes albopictus is an important vector of ZIKV worldwide. To date, most experiments have focused on the vertical transmission of ZIKV in Ae. aegypti, while studies on Ae. albopictus are very limited. To explore vertical transmission in Ae. albopictus, a series of laboratory studies were carried out. Methodology/Principal findings In this study, Ae. albopictus were blood-fed with ZIKV-infectious blood, and the ovaries and offspring viral infection rates were analyzed by reverse transcription PCR (RT-PCR), real-time reverse transcription PCR (RT-qPCR) and immunohistochemistry (IHC). ZIKV was detected in the ovaries and oviposited eggs in two gonotrophic cycles. The minimum filial egg infection rates in two gonotrophic cycles were 2.06% and 0.69%, and the effective population transmission rate was 1.87%. The hatching, pupation, and emergence rates of infected offspring were not significantly different from those of uninfected offspring, indicating that ZIKV did not prevent the offspring from completing the growth and development process. ZIKV was detected in three of thirteen C57BL/6 suckling mice bitten by ZIKV-positive F1 females, and the viremia persisted for at least seven days. Conclusions/Significance ZIKV can be vertically transmitted in Ae. albopictus via transovarial transmission. The vertical transmission rates in F1 eggs and adults were 2.06% and 1.87%, respectively. Even though the vertical transmission rates were low, the female mosquitoes infected via the congenital route horizontally transmitted ZIKV to suckling mice through bloodsucking. This is the first experimental evidence of offspring with vertically transmitted ZIKV initiating new horizontal transmission. The present study deepens the understanding of the vertical transmission of flaviviruses in Aedes mosquitoes and sheds light on the prevention and control of mosquito-borne diseases.

scholarly journals Zika Virus Testing Considerations: Lessons Learned from the First 80 Real-Time Reverse Transcription-PCR-Positive Cases Diagnosed in New York State

2016 ◽  
Vol 55 (2) ◽  
pp. 535-544 ◽  
Author(s):  
Kirsten St. George ◽  
Inderbir S. Sohi ◽  
Elizabeth M. Dufort ◽  
Amy B. Dean ◽  
Jennifer L. White ◽  
...  
Keyword(s):  
New York ◽  
Pregnant Women ◽  
Real Time ◽  
Molecular Diagnosis ◽  
Reverse Transcription ◽  
Zika Virus ◽  
New York State ◽  
Lessons Learned ◽  
York State ◽  
Reverse Transcription Pcr

ABSTRACTThe performance and interpretation of laboratory tests for Zika virus (ZKV) continue to be evaluated. Serology is cross-reactive, laborious, and frequently difficult to interpret, and serum was initially solely recommended for molecular diagnosis. ZKV testing was initiated in January 2016 in New York State for symptomatic patients, pregnant women, their infants, and patients with Guillain-Barré syndrome who had traveled to areas with ZKV transmission. Subsequently, eligibility was expanded to pregnant women with sexual partners with similar travel histories. Serum and urine collected within 4 weeks of symptom onset or within 6 weeks of travel were tested with real-time reverse transcription-PCR (RT-PCR) assays targeting the ZKV envelope and NS2B genes. In this review of lessons learned from the first 80 positive cases in NYS, ZKV RNA was detected in urine only in 50 patients, in serum only in 19 patients, and in both samples concurrently in 11 patients, with average viral loads in urine a log higher than those in serum. Among 93 positive samples from the 80 patients, 41 were positive on both gene assays, 52 were positive on the envelope only, and none were positive on the NS2B only. Of the 80 infected patients, test results for 74 (93%) would have defined their infection status as not detected or equivocal if the requirement for positive results from two assay targets (two-target-positive requirement) in the initial federal guidance to public health laboratories was enforced, if urine was not tested, or if the extended eligibility time for molecular testing was not implemented. These changes facilitated more extensive molecular diagnosis of ZKV, reducing reliance on time-consuming and potentially inconclusive serology.

scholarly journals Implementation of Antibody Rapid Diagnostic Testing versus Real-Time Reverse Transcription-PCR Sample Pooling in the Screening of COVID-19: a Case of Different Testing Strategies in Africa

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Tinashe K. Nyazika ◽  
Rabelani Kaela ◽  
Mathias Mugoni ◽  
Kudakwashe Musomekwa ◽  
Eric Kyei-Baafour ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
Disease Burden ◽  
Diagnostic Testing ◽  
Single Test ◽  
African Countries ◽  
Rapid Diagnostic Testing ◽  
Reverse Transcription Pcr ◽  
Testing Strategies ◽  
Sample Pooling

ABSTRACT Coronavirus disease 2019 (COVID-19) has wreaked havoc across the globe; although the number of cases in Africa remains lower than in other regions, it is on a gradual upward trajectory. To date, COVID-19 cases have been reported in 54 out of 55 African countries. However, due to limited severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) real-time reverse transcription-PCR (rRT-PCR) testing capacity and scarcity of testing reagents, it is probable that the total number of cases could far exceed published statistics. In this viewpoint, using Ghana, Malawi, South Africa, and Zimbabwe as examples of countries that have implemented different testing strategies, we argue that the implementation of sample pooling for rRT-PCR over antibody rapid diagnostic testing could have a greater impact in assessing disease burden. Sample pooling offers huge advantages compared to single test rRT-PCR, as it reduces diagnostic costs, personnel time, burnout, and analytical run times. Africa is already strained in terms of testing resources for COVID-19; hence, cheaper alternative ways need to be implemented to conserve resources, maximize mass testing, and reduce transmission in the wider population.

Sign in / Sign up

Export Citation Format

Share Document