Viral Transport Medium Research Articles

Effects of storage temperature on throat swabs preserved in different transport media for detection of SARS-CoV-2 by reverse transcriptase polymerase chain reaction

Objectives: The coronavirus disease 2019 (COVID-19) pandemic resulted in an increased need for molecular diagnostic testing. Delay in the specimen processing and storage of samples in laboratories leads to degradation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral RNA. Inactivation transport medium (ITM) contains chaotropic agents that inactivate the virus and stabilize SARS-CoV-2 RNA for a longer duration, even at room temperature. The effect of different temperatures and duration of storage of samples in viral transport media (VTM) and ITM for detection of SARS-CoV-2 RNA was assessed. Materials and Methods: Samples from COVID-19 patients were aliquoted in ITM and VTM and kept at ambient temperature, 37°C and 45°C. SARS-CoV-2 viral RNA was extracted. Multiplex real-time polymerase chain reaction was done on days 0, 1, 3, and 5, and cycle threshold (Ct) values were noted. Statistical Analysis: Data were analyzed using the Statistical Package for the Social Sciences version 26.0. Linear variables were summarized as mean and standard deviations. One-way analysis of variance test with post hoc Tukey honestly significant difference was used to compare mean value between different loops and for pair-wise comparison. P < 0.05 was taken as significant. Results: The mean Ct values of both the Orf and E genes of the samples in VTM and ITM were stable across all temperature conditions on day 1. On day 5, the increase in Ct values for both E and Orf genes were significantly higher for VTM than ITM at ambient temperature, 37°C and 45°C. Ribonuclease P failure was significantly higher for VTM than ITM at ambient temperature and 37°C on day 3 and at all temperatures on day 5. Conclusions: ITM is a valuable transport media that can preserve SARS-CoV-2 for up to 5 days at ambient temperature and 37°C. As it renders the samples non-infectious, thus reducing the potential of biohazard events, this transport medium can be used effectively for the collection and transportation of SARS-CoV-2 samples, especially from remote or isolated healthcare facilities.

Respiratory viral infections in bone marrow transplant patients: insights from a tertiary care hospital in Rawalpindi, Pakistan.

To determine the incidence of respiratory viral infections in bone marrow transplant patients. The prospective, descriptive, cross-sectional study was conducted at a tertiary care hospital in Rawalpindi, Pakistan, from September 2019 to August 2020, and comprised respiratory specimens from recipients of haematopoietic stem cell transplant. The specimens were collected in viral transport medium, and were then taken to the Department of Virology. Multiplex polymerase chain reaction was performed on the specimens to ascertain the incidence and prevalence of respiratory viruses. Data was analysed using SPSS 24. Of the 85 subjects, 53(62.35%) were males and 32(37.65%) were females. The overall median age was 20.0 years (interquartile range: 11.0-32.0 years). Respiratory viral infections were detected in 31(36.4%) specimens. Among them, human rhinovirus was detected in 12(38.7%) cases, respiratory syncytial virus in 5(16.1%), influenza A/H3 in 4(13%), human parainfluenza virus-1 in 3(9.7%), adenovirus in 2(6.4%), human parainfluenza virus-3 in 1(3.2%), human parainfluenza virus-4 in 1(3.2%) and human metapneumovirus in 1(3.2%) case. There were 2(6.4%) cases of co-infection. More than one-third recipients of haematopoietic stem cell transplant were found to have respiratory viral infections, highlighting the importance of employing multiplex respiratory polymerase chain reaction in early diagnosis and treatment of such infections.

Dry Swabs and Dried Saliva as Alternative Samples for SARS-CoV-2 Detection in Remote Areas in Lao PDR.

Surveillance of SARS-CoV-2 circulation is mainly based on real-time reverse transcription-polymerase chain reaction, which requires laboratory facilities and cold chain for sample transportation. This is difficult to achieve in remote rural areas of resource-limited settings. The use of dried blood spots shipped at room temperature has shown good efficiency for the detection of arboviral RNA. Using a similar approach, we conducted a study at 3 provincial hospitals in Laos to compare the detection of SARS-CoV-2 from neat and dried spot samples. Between January 2022 and March 2023, patients with respiratory symptoms were recruited. Nasopharyngeal/oropharyngeal swabs in virus transport medium (VTM), dry swabs, saliva, and dried saliva spotted on filter paper were collected. All samples were tested by SARS-CoV-2 real-time reverse transcription-polymerase chain reaction. In total, 479 participants were included. The VTM samples tested positive for 288 (60.1%). High positive percent agreements were observed for dry swab (84.8%; 95% CI, 80.2%-88.8%) and saliva (89.2%; 95% CI, 85.1%-92.6%) as compared with VTM. There was a loss of sensitivity when saliva was dried on filter paper (73.6%; 95% CI, 68.1%-78.6%) as compared with saliva. SARS-CoV-2 variant (Delta or Omicron) had no significant impact on the performance of the different sample types. Our findings suggest that dry swabs could be a good alternative for sample collection and permit easy shipping at ambient temperature for subsequent viral SARS-CoV-2 RNA purification and molecular investigation. This is a useful tool to consider for a rapid implementation of large-scale surveillance of SARS-CoV-2 in remote areas, which could be extrapolated to other respiratory targets during routine surveillance or in the case of a novel emerging pandemic.

COVID-19 pandemic – Cocktail of variants, a study from Northern India

ABSTRACT Context: The aim of the study was to identify and monitor the circulating strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the samples received at our center and update the existing national and international genomic surveillance data. Introduction: SARS-CoV-2 is no exception to the basic nature of the viruses ability to change and evolve. Since its first report in December 2019 from Wuhan, China, multiple variants of the virus have emerged and been reported. Five variants of concern have been recognized and reported by the Centers for Disease Control and Prevention, which are associated with variable degrees of transmissibility and mortality. Materials and Methods: Nasopharyngeal and oropharyngeal swabs received in viral transport medium at the Viral Research Diagnostic Laboratory were processed for reverse transcription-polymerase chain reaction for SARS-CoV-2. Whole genome sequencing (WGS) was performed for selective positive samples using Oxford Nanopore sequencing technology, using MinKNOW software for data acquisition. Statistical Analysis: The clades were assigned using Nextclade v2.4.1 software. The statistical analysis was calculated using OpenEpi version 3, an open-source calculator, and two by two. Results: Variants reported over the study period included Alpha, Kappa, Delta, and Omicron. Delta dominated in the year 2021, while Omicron was the dominant variant in 2022. In both the dominant variants, asymptomatics contributed to around 30–40% of positives. Intensive care unit admissions and mortality were higher in the Delta variant, while vaccination history and travel history were higher in the patients with Omicron variant. Conclusion: The trend tracking of these variants has been important in view of public health, enabling early interventions to control the spread of the disease and foresight in preparation for the situation.

Ammonium sulfate denatures transport medium less dependent on guanidinium isothiocyanate and enables SARS-CoV-2 RNA and antigen detection compatibility.

Rapid identification of infected individuals through viral RNA or antigen detection followed by effective personal isolation is usually the most effective way to prevent the spread of a newly emerging virus. Large-scale detection involves mass specimen collection and transportation. For biosafety reasons, denaturing viral transport medium has been extensively used during the SARS-CoV-2 pandemic. However, the high concentrations of guanidinium isothiocyanate (GITC) in such media have raised issues around sufficient GITC supply and laboratory safety. Moreover, there is a lack of denaturing transport media compatible with SARS-CoV-2 RNA and antigen detection. Here, we tested whether supplementing media containing low concentrations of GITC with ammonium sulfate (AS) would affect the throat-swab detection of SARS-CoV-2 or a viral inactivation assay targeting coronavirus and other enveloped and non-enveloped viruses. The effect of adding AS to the media on RNA stability and its compatibility with SARS-CoV-2 antigen detection were also tested. We found that adding AS to the denaturing transport media reduced the need for high levels of GITC, improved SARS-COV-2 RNA detection without compromising virus inactivation, and enabled the denaturing transport media compatible with SARS-CoV-2 antigen detection.

Common laboratory organic solvents are better medium for molecular detection of RNA viruses using PCR

PurposeThe unavailability of recommended viral transport medium during epidemics of respiratory viral infections is a substantial healthcare concern. It may prompt the use of alternatives, which may give rise to results with questionable validity. The present study was carried out to assess and validate the utility of commonly available solvents in the hospital/healthcare set-ups which may be used as ready and economical alternatives to commercial VTMs. MethodsTo evaluate the readily available solvents as an alternative to VTM, cell culture supernatant of pH1N1 2009 isolate with HA titres of 1:4 and extracted viral RNA of SARS-CoV-2 were spiked in a 1:10 ratio in ethanol, acetone, methanol and were compared to commercially available VTM for detection of influenza virus by real time RT-PCR (qRT-PCR). The tubes were kept at room temperature 24 h, 48 h and 72 h. Ct values of the various solvents at different time points were compared and statistical analysis was performed using Python. ResultsThe Ct values of the Influenza and SARS-CoV2 viral genes in each solvent were maintained for 3 days at room temperatures, suggesting viral samples were stably preserved in the solvent for 3 days. ConclusionMethanol was found to be the most promising solvent for increasing the stability of viral RNA thereby enhancing the molecular diagnosis of the concerned pathogen.

Optimisation and evaluation of viral genomic sequencing of SARS-CoV-2 rapid diagnostic tests: a laboratory and cohort-based study

Sequencing of SARS-CoV-2 from rapid diagnostic tests (RDTs) can bolster viral genomic surveillance efforts; however, approaches to maximise and standardise pathogen genome recovery from RDTs remain underdeveloped. We aimed to systematically optimise the elution of genetic material from RDT components and to evaluate the efficacy of RDT sequencing for outbreak investigation. In this laboratory and cohort-based study we seeded RDTs with inactivated SARS-CoV-2 to optimise the elution of genomic material from RDT lateral flow strips. We measured the effect of changes in buffer type, time in buffer, and rotation on PCR cycle threshold (Ct) value. We recruited individuals older than 18 years residing in the greater Boston area, MA, USA, from July 18 to Nov 5, 2022, via email advertising to students and staff at Harvard University, MA, USA,and via broad social media advertising. All individuals recruited were within 5days of a positive diagnostic test for SARS-CoV-2; no other relevant exclusion criteria were applied. Each individual completed two RDTs and one PCR swab. On Dec 29, 2022, we also collected RDTs from a convenience sample of individuals who were positive for SARS-CoV-2 and associated with an outbreak at a senior housing facility in MA, USA. We extracted all returned PCR swabs and RDT components (ie, swab, strip, or buffer); samples with a Ct of less than 40 were subject to amplicon sequencing. We compared the efficacy of elution and sequencing across RDT brands and components and used RDT-derived sequences to infer transmission links within the outbreak at the senior housing facility. We conducted metagenomic sequencing of negative RDTs from symptomatic individuals living in the senior housing facility. Neither elution duration of greater than 10 min nor rotation during elution impacted viral titres. Elution in Buffer AVL (Ct=31·4) and Tris-EDTA Buffer (Ct=30·8) were equivalent (p=0·34); AVL outperformed elution in lysis buffer and 50% lysis buffer (Ct=40·0, p=0·0029 for both) as well as Universal Viral Transport Medium (Ct=36·7, p=0·079). Performance of RDT strips was poorer than that of matched PCR swabs (mean Ct difference 10·2 [SD 4·3], p<0·0001); however, RDT swabs performed similarly to PCR swabs (mean Ct difference 4·1 [5·2], p=0·055). No RDT brand significantly outperformed another. Across sample types, viral load predicted the viral genome assembly length. We assembled greater than 80% complete genomes from 12 of 17 RDT-derived swabs, three of 18 strips, and four of 11 residual buffers. We generated outbreak-associated SARS-CoV-2 genomes using both amplicon and metagenomic sequencing and identified multiple introductions of the virus that resulted in downstream transmission. RDT-derived swabs are a reasonable alternative to PCR swabs for viral genomic surveillance and outbreakinvestigation. RDT-derived lateral flow strips yield accurate, but significantly fewer, viral reads than matched PCR swabs. Metagenomic sequencing of negative RDTs can identify viruses that might underlie patient symptoms. The National Science Foundation, the Hertz Foundation, the National Institute of General Medical Sciences, Harvard Medical School, the Howard Hughes Medical Institute, the US Centers for Disease Control and Prevention, the Broad Institute and the National Institute of Allergy and Infectious Diseases.

Comparative Analysis of Pooling Methods for SARS-CoV-2 Real-time Polymerase Chain Reaction Testing

Abstract Background: Wide spread coronavirus 2019 (COVID-19) infections in 2020 and 2021 and fewer real-time polymerase chain reaction (PCR) laboratories placed extraordinary demand on molecular diagnostics. To accommodate demand for increased testing volumes, the Indian Council of Medical Research had initially allowed pooling of five samples. This study aimed to conduct a comparative analysis of three sample pooling methods for SARS-CoV-2 testing to assess their effectiveness, sensitivity, and specificity. Methods: In this cross-sectional study, samples intended for SARS-CoV-2 testing were initially tested individually and then combined in a 1:4 positive-to-negative ratio. A total of 90 pools, comprising 450 samples, were analyzed using three distinct pooling methods: swab pooling, viral transport medium (VTM) pooling, and RNA pooling, all targeting the detection of the RdRp gene. PCR testing was conducted for all 90 pools comprising 450 samples in a uniform manner. Results: Swab pooling and RNA pooling methods correctly identified RdRp gene in all samples. VTM pooling method failed to identify RdRp gene in 4 samples. Analysis of cycle threshold (CT) value showed, loss of mean CT value of 2.80 ± 0.86 in swab pooling method with Z score of 6.03, VTM pooling method showed loss of mean CT value of 1.96 ± 0.76 with Z score of 3.22 and RNA pooling method showed loss of mean CT value of 1.73 ± 0.58 with Z score of 4.29 in. P value was statistically significant (&lt;0.001) in all three methods. Conclusion: This study concludes that the RNA pooling method is superior, with minimal sensitivity loss in CT values. Swab pooling is cost-effective for negative pools but impractical for positive ones, while the VTM pooling method offers greater cost-effectiveness compared to RNA pooling.

Mpox virus DNA detection in different clinical specimens: tertiary-level laboratory experience, Bosnia and Herzegovina, 2022

Mpox virus (MPXV) infection is difficult to distinguish from other (non-)infectious diseases. The etiology of rash can be differentiated by real-time polymerase chain reaction (rtPCR) on different types of samples. The study aims to provide experience with emerging MPXV diagnostics in a tertiary-level laboratory in Bosnia and Herzegovina. From July-December 2022, a total of 18 mpox suspected persons were tested. MPXV infection was confirmed by rtPCR in 10/18 (55.56 %) persons. The number of cases reached a peak in October 2022. The lowest median Crossing point (Cp) (x̄ = 29.76) was obtained from a swab of skin lesions in a viral transport medium (VTM). Evaluating the Cp values for the 7/9 mpox cases from whom paired swab samples from different anatomic sites were collected, higher positivity of skin lesion swabs in VTM was observed. In conclusion, our data highlighted the confirmatory role of rtPCR in the diagnosis of MPXV in skin lesion samples.

Comparison of seven commercial RT-PCR kits with the NIV kit for the diagnosis of Covid-19

Objectives Coronavirus disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spread across the globe in an unprecedented manner and was declared a pandemic on March 11, 2020 by the World Health Organization (WHO). This study was carried out with the aim to compare the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and agreement of the eight different RT-PCR kits for the diagnosis of COVID-19. Material and Methods This observational cross-sectional study was carried out in the Department of Microbiology of a tertiary care hospital in Central Delhi from July to October 2021. A total of 45 nasopharyngeal and/or oropharyngeal swabs in Viral Transport Medium (VTM) from suspected COVID-19 patients were received in the laboratory for RT-PCR. These samples were tested by eight different Indian Council of Medical Research (ICMR)-approved RT-PCR kits with different gene targets. The comparison was made with the National Institute of Virology (NIV), the Pune COVID-19 RT-PCR kit. Statistical analysis: sensitivity, specificity, PPV, and NPV were calculated for each kit and compared using the McNemar test. Agreement of different kits was evaluated using Kappa analysis. Results The results of the 45 samples of suspected COVID-19 cases were recorded as per the cycle threshold (Ct) provided in the kit insert. Of these, 15 samples detected both E and RdRp genes and 30 were negative for both the genes of SARS CoV-2 by NIV, the Pune COVID-19 RT-PCR kit. All kits showed 100% sensitivity and had 100% NPV when compared with the NIV kit. However, specificity, PPV, and agreement were variable as compared to the NIV kit. Conclusion The reporting should be carried out as per the manufacturer’s instructions. However, positive results with Ct values ≥ 36 showed variable results with different RT PCR kits and hence should be interpreted with caution.

Viral etiology of measles-like rash in Guinean children during the COVID epidemic in 2022.

Covid-19 in West Africa masked outbreaks of vaccine-preventable diseases such as the measles epidemic in children in Guinea in 2021-2022 characterized by a lack of confirmation of suspected clinical cases. During weeks 13-22 of 2022, saliva samples were collected from 213 children (3-60 months old) with measles-like symptoms within the St Gabriel dispensary in Conakry. Samples were processed in Virus Transport Medium (VTM) and tested on the same day by triplex reverse transcriptase -real-time polymerase chain reaction for Measles, Rubella and RNaseP. Samples were also tested for HHV6 and Parvovirus B19, viruses causing clinical signs similar to measles. We confirmed 146 (68.5%) measles cases, 27 (12.7%) rubella, 5 (2.3%) double-positive measles-rubella, 35 (16.4%) HHV-6 and 8 (3.75%) Parvovirus B19. To test the assay's robustness, 27 samples were kept at 26-30°C. Measles and rubella were still detected after 7 days at 26-30°C, and after 21 days measles and rubella were still detectable in all samples but one. Sequencing indicated the circulation of the B3 measles genotype, as expected in West Africa. This study highlights the robustness of the measles/rubella diagnostic test on saliva samples stored in VTM. The high level of rubella detection questioned the single valence measles vaccination strategy.

Epidemiology of Keratoconjunctivitis Across India from 2017 to 2019: A Multicentric Hospital-Based Study

ABSTRACT Purpose Conjunctivitis is one of the most common ocular conditions in clinical practice. Human adenoviruses have been the common causative agents known to cause epidemic kerato-conjunctivitis (EKC) in India from 1996 to 2019 with a positivity range of 13.8%–65.2%. The current study was initiated to throw light on the distribution of keratoconjunctivitis causing agents across India covering a span of 3 years. Methods A total of 709 swabs were collected from patients in viral transport medium (VTM), and real-time PCR was done to identify agents including Adenovirus (HAdV), Enterovirus, HSV, and Chlamydia. Results 47.8% of the samples were positive for HAdV followed by HSV (3.4%), Enterovirus (2.7%), and Chlamydia (0.6%). Overall, 386 people (54.4%) tested positive for one of these infections, with Chandigarh (88.4%) and Port Blair (71.7%) showing higher positivity rate. Pre-auricular lymphadenopathy and follicles were significantly associated with increased risk of conjunctivitis. Conclusion Epidemiology of keratoconjunctivitis in the current study revealed HAdV to be predominant causative agent. Knowledge gained in such epidemiological studies guide us in outbreak expectations, limit antibiotic over-prescription, and enhance disease prevention.

Efficacy of sample collection without virus transport medium in suspected enteroviral infections for molecular diagnosis.

Clinical swabs with suspected viral infection are usually transported in virus transport medium (VMT). During epidemics/pandemics, tampons without VTM would be more suitable for saving space and cost. This study was conducted to verify the applicability of throat swabs without VTM in the diagnosis/screening of enteroviral infections by polymerase chain reaction (PCR) in avolunteer study group. Three different swab types were used in 40 volunteers: swabs with two different tips (cotton- or synthetic-tipped) without VTM and standard synthetic tips with VTM. The swabs were processed immediately or after 12 days of storage at either -80°C or +4°C. The molecular analysis included viral RNA extraction, and combination of reverse transcriptase PCR and nested PCR. Enteroviral RNA was detected in 15% (6/40) of the studied volunteers. When processed immediately, the results for all three swab types were compatible. Swabs without VTM may be used for collection of clinical samples in the diagnosis of suspected enteroviral infections or as potential screening tools for enteroviruses (Tab. 2, Ref. 15). Keywords: enterovirus infection, swab, transport medium, PCR, molecular diagnostics.

Household Transmission of SARS-CoV-2 in the Third Wave of the Pandemic with Special Reference to Clinico-epidemiological Characteristics.

Coronavirus disease 2019 (COVID-19) pandemic began in India in 2020. Despite successful vaccination, cases again started increasing from mid-December 2021. Therefore, this study was undertaken to find out the clinico-epidemiological characteristics and effectiveness of vaccination in the household transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in and around Pune. All samples received from December 15, 2021, till February 15, 2022, were included in the study. Samples received in viral transport medium (VTM) were extracted by the MagMAX RNA Extraction Kit, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed by the CoviPath Kit as per kit guidelines. Values of nucleocapsid (N) gene and open reading frame (ORF) less than 37 were considered positive. Clinico-epidemiological data were analyzed from the sample referral form (SRF). A total of 712 of 1032 household contacts of 271 families were positive. When geographical areas were compared, it was found that rural areas were affected more (63.76%) as compared to urban areas (36.24%). Males were more affected than females. The most commonly affected age group was 41-50 years (26.54%). Small families were found to have more household transmission. Mild symptoms were present in 97.89%. Among 271 infected individuals, seven were admitted to hospital, of which one patient died due to pneumonia. Two doses of vaccination were completed in 93.95%, and 3.79% had taken booster dose. Data from this study showed that a high rate of transmission was observed in household contact despite two doses of vaccination. However, these vaccinated individuals had mild symptoms, maybe due to the effect of vaccination and infecting variant omicron.

Detection of Human Adenovirus from Clinical Samples of Conjunctivitis by Real-time PCR: A Cross-sectional Descriptive Study

Introduction: Human Adenoviruses (HAdV) have been implicated in a variety of infections, including conjunctivitis, respiratory tract infections, genitourinary infections and gastroenteritis. Epidemic Keratoconjunctivitis (EKC) is a severe ocular surface infection strongly associated with HAdV, known to occur in widespread outbreaks. HAdV species B, D and E are associated with ocular manifestations ranging from simple follicular conjunctivitis (types 3, 4, 7) and pharyngoconjunctival fever (types 3, 7, 14) to the more severe EKC (types 8, 19, 37, 53, 54, 56 and 64). Viral cell cultures of conjunctival specimens help confirm adenovirus infection through the characteristic Cytopathic Effect (CPE) and Polymerase Chain Reaction (PCR) is the best standard method to diagnose viral conjunctivitis due to its sensitivity, accuracy and rapidity. Aim: To diagnose HAdV in clinically suspected cases of viral conjunctivitis using real-time PCR. To isolate HAdV in viral cell culture and confirm it by observing its characteristic CPE and performing adenoviral real-time PCR. Materials and Methods: A cross-sectional descriptive study was conducted from July 2023 to September 2023 at the state-level Virus Research and Diagnostic Laboratory (VRDL) at Bangalore Medical College and Research Institute (BMCRI), Bengaluru, Karnataka, India. A total of 45 conjunctival swab samples from patients with suspected viral conjunctivitis, who attended the Ophthalmology Outpatient Department (OPD) or were admitted to the wards, were included in the study. Conjunctival swab samples collected in Viral Transport Medium (VTM) were centrifuged at 3000 rpm for five minutes at 4°C. Real-time PCR was performed and samples positive for HAdV by real-time PCR were taken up for viral cell culture. Confirmatory PCR was conducted for samples showing CPEs in the cell line. The data collected were analysed using descriptive statistics. Results: The majority of patients in the present study were in the age group of 18-45 years, comprising 25 (56%) of the total patients. Out of 45 conjunctival samples tested, 8 samples were positive in adenovirus real-time PCR. All eight PCR-positive samples showed a CPE in viral cell culture on the A549 cell line. The study found PCR positivity in 8 samples (17.7%), while adenoviral recovery from cell culture was observed in 6 samples (13.3%). Conclusion: Real-time PCR has become the standard diagnostic procedure for detecting adenovirus conjunctivitis. Rapid and accurate diagnosis is key to interrupting the contagious spread of adenoviral conjunctivitis, along with timely treatment.

Monkeypox Diagnosis in Clinical Settings: A Comprehensive Review of Best Laboratory Practices.

An outbreak of monkeypox (Mpox) was reported in more than 40 countries in early 2022. Accurate diagnosis of Mpox can be challenging, but history, clinical findings, and laboratory diagnosis can establish the diagnosis. The pre-analytic phase of testing includes collecting, storing, and transporting specimens. It is advised to swab the lesion site with virus transport medium (VTM) containing Dacron or polyester flock swabs from two different sites. Blood, urine, and semen samples may also be used. Timely sampling is necessary to obtain a sufficient amount of virus or antibodies. The analytical phase of infectious disease control involves diagnostic tools to determine the presence of the virus. While polymerase chain reaction (PCR) is the gold standard for detecting Mpox, genome sequencing is for identifying new or modified viruses. As a complement to these methods, isothermal amplification methods have been designed. ELISA assays are also available for the determination of antibodies. Electron microscopy is another effective diagnostic method for tissue identification of the virus. Wastewater fingerprinting provides some of the most effective diagnostic methods for virus identification at the community level. The advantages and disadvantages of these methods are further discussed. Post-analytic phase requires proper interpretation of test results and the preparation of accurate patient reports that include relevant medical history, clinical guidelines, and recommendations for follow-up testing or treatment.

A Retrospective Observational Study to Assess the Quality Management System in a Molecular Diagnostic Laboratory of a COVID-19 Dedicated Hospital in Delhi, India

Introduction: A molecular diagnostic laboratory is the cornerstone of Coronavirus Disease-2019 (COVID-19) disease diagnosis, as the patient’s treatment and management protocol depend on molecular results. Therefore, the laboratory conducting these tests must adhere to quality management process to increase the accuracy and validity of the generated reports. Rajiv Gandhi Super Speciality Hospital established its molecular diagnostic set-up at the beginning of the pandemic. Hence, this study aims to generate quality management data to help improve weak points. Aim: To assess the quality management system for COVID-19 diagnosis. Materials and Methods: This retrospective observational study was conducted at Rajiv Gandhi Super Speciality Hospital in Delhi, India. A total of 14,561 samples were collected over six months, from February 2021 to July 2021. Data from all samples received during this period for COVID-19 ReverseTranscriptase Polymerase Chain Reaction (RT-PCR) testing were included. Data were retrospectively collected from the electronic Laboratory Information Management System (LIMS). Quality variables were analysed over six months from July to December 2021 and classified into preanalytical, analytical, and postanalytical variables. Quality Indicators (QIs) were selected from a common model of QIs set by the International Federation of Clinical Chemistry and Laboratory Medicine. The results were presented in percentages, and descriptive statistics were analysed using Statistical Package for Social Sciences (SPSS) software. Results: During the six-month study period, the molecular laboratory received 14,561 samples. Among the preanalytical variables, sample leakage was the most common cause of sample rejection (134 samples, 0.92%), followed by the non generation of Specimen Referral Form (SRF) identification (76 samples, 0.52%), and non compliance with triple packaging (44 samples, 0.3%). Other preanalytical aspects assessed included incomplete patient identification (17 samples, 0.11%), insufficient sample quantity (12 samples, 0.08%), missing forms/samples (7 samples, 0.04%), samples in the wrong vials/ empty Viral Transport Media (VTM) tubes (5 samples, 0.03%), and incomplete LIMS entry (2 samples, 0.01%). Internal Quality Control (QC) was not obtained in 55 samples (0.37%), and two incidents of cross-contamination resulted in false-positive results. Among the postanalytical factors, 11 samples (0.07%) could not be dispatched within the stipulated time frame. Conclusion: The assessment of the quality management system revealed some areas for improvement, emphasising the importance of adhering to QC processes for the smooth operation of diagnostic laboratories, especially those involved in critical reporting. The assessment of QIs helped monitor laboratory parameters effectively.

Detection of Reverse Transcriptase LAMP-Amplified Nucleic Acid from Oropharyngeal Viral Swab Samples Using Biotinylated DNA Probes through a Lateral Flow Assay.

This study focuses on three key aspects: (a) crude throat swab samples in a viral transport medium (VTM) as templates for RT-LAMP reactions; (b) a biotinylated DNA probe with enhanced specificity for LFA readouts; and (c) a digital semi-quantification of LFA readouts. Throat swab samples from SARS-CoV-2 positive and negative patients were used in their crude (no cleaning or pre-treatment) forms for the RT-LAMP reaction. The samples were heat-inactivated but not treated for any kind of nucleic acid extraction or purification. The RT-LAMP (20 min processing time) product was read out by an LFA approach using two labels: FITC and biotin. FITC was enzymatically incorporated into the RT-LAMP amplicon with the LF-LAMP primer, and biotin was introduced using biotinylated DNA probes, specifically for the amplicon region after RT-LAMP amplification. This assay setup with biotinylated DNA probe-based LFA readouts of the RT-LAMP amplicon was 98.11% sensitive and 96.15% specific. The LFA result was further analysed by a smartphone-based IVD device, wherein the T-line intensity was recorded. The LFA T-line intensity was then correlated with the qRT-PCR Ct value of the positive swab samples. A digital semi-quantification of RT-LAMP-LFA was reported with a correlation coefficient of R2 = 0.702. The overall RT-LAMP-LFA assay time was recorded to be 35 min with a LoD of three RNA copies/µL (Ct-33). With these three advancements, the nucleic acid testing-point of care technique (NAT-POCT) is exemplified as a versatile biosensor platform with great potential and applicability for the detection of pathogens without the need for sample storage, transportation, or pre-processing.

Emerging Importance of Viral Transport Media in High-Throughput Sequencing Fidelity for Genomic Analysis

The impact of Viral Transport Media (VTM) components on the efficacy and accuracy of high-throughput Next-Generation Sequencing (NGS) techniques is a subject of paramount importance in the field of viral genomics and diagnostics. VTMs play a pivotal role in preserving viral samples, and their composition can profoundly influence the quality and reliability of NGS results. This study explores the intricate relationship between VTM components and NGS outcomes, with a focus on optimizing diagnostic precision and the efficiency of NGS in viral genomics. Through comprehensive investigation, this research sheds light on the critical implications of VTM composition for enhancing viral genomic analysis, streamlining diagnostic processes, and bolstering public health responses. The findings have far-reaching consequences, including the potential for personalized medicine, rapid detection of emerging viral threats, and the improvement of public health surveillance. Standardized protocols and ongoing technological advancements are essential in harnessing the full potential of NGS for genomics and metagenomics, marking a significant step toward more effective viral disease management and outbreak response.

Assessing the performance of regular surgical nose masks as a sampling method for SARS-CoV-2 detection in a cross-sectional study.

Nose masks are widely worn for protection against respiratory pathogens, including SARS-CoV-2. They have been reported as possible substrates for viral sampling and testing for COVID-19 but, evaluations have so far been purposive; involving individuals known to have the infection and using improved materials on the nose masks to trap the virus. We investigated the feasibility of using the regular 3-ply surgical masks and, voluntary coughing as a mode of particle expulsion for detecting SARS-CoV-2 infections in a cross-sectional study at Ghana's first COVID-19 testing reference laboratory, the Noguchi Memorial Institute for Medical Research, University of Ghana. Paired samples of naso-oropharyngeal swabs and nose masks already worn by 103 consenting adult participants (retro masks) were collected. Participants were also required to produce three strong coughs into a newly supplied sterile surgical nose mask. Pre-wetted swabs in Viral Transport Media (VTM) were used in swabbing the inner lining of each nose mask. The swabs used were then stored in VTM to maintain the integrity of the samples. PCR results of SARS-CoV-2 detection from the nose masks were compared to those from naso-oropharyngeal swabs ('gold-standard'). Out of the 103 participants tested with all three methods, 66 individuals sampled with naso-oropharyngeal swabs were detected as positive, and the retro and new masks matched 9 and 4, respectively. Only 3 individuals were positive across all three sampling methods accessed. The retro nose masks performed better in matching the gold-standard results than the new mask + coughing method, with 90% vs 80% sensitivity, positive predictive value of 13.6% vs 6%, and a weak but significant linear relationship (adj. R2 = 0.1; P = 0.0004). Importantly, we also show that the nose masks would work for sampling whether individuals are symptomatic or asymptomatic since gold-standard PCR cycling threshold (Ct) values for positive individuals did not differ between the two groups (P< 0.05). We recommend including features such as talking during participant engagement, use of a spontaneous cough inducer and increased coughing bouts > 3, to improve the performance of sterile nose masks for SARS-CoV-2 detection.