SwabExpress: An End-to-End Protocol for Extraction-Free COVID-19 Testing.

BACKGROUND: The urgent need for massively scaled clinical testing for SARS-CoV-2, along with global shortages of critical reagents and supplies, has necessitated development of streamlined laboratory testing protocols. Conventional nucleic acid testing for SARS-CoV-2 involves collection of a clinical specimen with a nasopharyngeal swab in transport medium, nucleic acid extraction, and quantitative reverse-transcription PCR (RT-qPCR). As testing has scaled across the world, the global supply chain has buckled, rendering testing reagents and materials scarce. To address shortages, we developed SwabExpress, an end-to-end protocol developed to employ mass produced anterior nares swabs and bypass the requirement for transport media and nucleic acid extraction. METHODS: We evaluated anterior nares swabs, transported dry and eluted in low-TE buffer as a direct-to-RT-qPCR alternative to extraction-dependent viral transport media. We validated our protocol of using heat treatment for viral inactivation and added a proteinase K digestion step to reduce amplification interference. We tested this protocol across archived and prospectively collected swab specimens to fine-tune test performance. RESULTS: After optimization, SwabExpress has a low limit of detection at 2-4 molecules/µL, 100% sensitivity, and 99.4% specificity when compared side by side with a traditional RT-qPCR protocol employing extraction. On real-world specimens, SwabExpress outperforms an automated extraction system while simultaneously reducing cost and hands-on time. CONCLUSION: SwabExpress is a simplified workflow that facilitates scaled testing for COVID-19 without sacrificing test performance. It may serve as a template for the simplification of PCR-based clinical laboratory tests, particularly in times of critical shortages during pandemics.

Evaluation of SARS-CoV-2 isolation in cell culture from nasal/nasopharyngeal swabs or saliva specimens of patients with COVID-19.

It has been revealed that SARS-CoV-2 can be efficiently isolated from clinical specimens such as nasal/nasopharyngeal swabs or saliva in cultured cells. In this study, we examined the efficiency of viral isolation including SARS-CoV-2 mutant strains between nasal/nasopharyngeal swab or saliva specimens. Furthermore, we also examined the comparison of viral isolation rates by sample species using simulated specimens for COVID-19. As a result, it was found that the isolation efficiency of SARS-CoV-2 in the saliva specimens was significantly lower than that in the nasal/nasopharyngeal swab specimens. In order to determine which component of saliva is responsible for the lower isolation rate of saliva specimens, we tested the abilities of lactoferrin, amylase, cathelicidin, and mucin, which are considered to be abundant in saliva, to inhibit the infection of SARS-CoV-2 pseudotyped viruses (SARS-CoV-2pv). Lactoferrin and amylase were found to inhibit SARS-CoV-2pv infection. In conclusion, even if the same number of viral genome copies was detected by the real-time RT-PCR test, infection of SARS-CoV-2 present in saliva is thought to be inhibited by inhibitory factors such as lactoferrin and amylase, compared to nasal/nasopharyngeal swab specimens.

Misdiagnosis of Clostridioides difficile Infections by Standard-of-Care Specimen Collection and Testing among Hospitalized Adults, Louisville, Kentucky, USA, 2019-20201.

Although Clostridioides difficile infection (CDI) incidence is high in the United States, standard-of-care (SOC) stool collection and testing practices might result in incidence overestimation or underestimation. We conducted diarrhea surveillance among inpatients >50 years of age in Louisville, Kentucky, USA, during October 14, 2019-October 13, 2020; concurrent SOC stool collection and CDI testing occurred independently. A study CDI case was nucleic acid amplification test‒/cytotoxicity neutralization assay‒positive or nucleic acid amplification test‒positive stool in a patient with pseudomembranous colitis. Study incidence was adjusted for hospitalization share and specimen collection rate and, in a sensitivity analysis, for diarrhea cases without study testing. SOC hospitalized CDI incidence was 121/100,000 population/year; study incidence was 154/100,000 population/year and, in sensitivity analysis, 202/100,000 population/year. Of 75 SOC CDI cases, 12 (16.0%) were not study diagnosed; of 109 study CDI cases, 44 (40.4%) were not SOC diagnosed. CDI incidence estimates based on SOC CDI testing are probably underestimated.

Perceived barriers to cervical cancer screening and motivators for at-home human papillomavirus self-sampling during the COVID-19 pandemic: Results from a telephone survey.

Background: Home-based self-sampling for human papillomavirus (HPV) testing may be an alternative for women not attending clinic-based cervical cancer screening. Methods: We assessed barriers to care and motivators to use at-home HPV self-sampling kits during the COVID-19 pandemic as part of a randomized controlled trial evaluating kit effectiveness. Participants were women aged 30-65 and under-screened for cervical cancer in a safety-net healthcare system. We conducted telephone surveys in English/Spanish among a subgroup of trial participants, assessed differences between groups, and determined statistical significance at p<0.05. Results: Over half of 233 survey participants reported that clinic-based screening (Pap) is uncomfortable (67.8%), embarrassing (52.4%), and discomfort seeing male providers (63.1%). The last two factors were significantly more prevalent among Spanish vs English speakers (66.4% vs 30% (p=0.000) and 69.9 vs 52.2% (p=0.006), respectively). Most women who completed the kit found Pap more embarrassing (69.3%), stressful (55.6%), and less convenient (55.6%) than the kit. The first factor was more prevalent among Spanish vs English speakers (79.6% vs 53.38%, p=0.001) and among patients with elementary education or below. Conclusions: The COVID-19 pandemic influenced most (59.5%) to participate in the trial due to fear of COVID, difficulty making appointments, and ease of using kits. HPV self-sampling kits may reduce barriers among under-screened women in a safety-net system. Funding: This study is supported by a grant from the National Institute for Minority Health and Health Disparitie s (NIMHD, R01MD013715, PI: JR Montealegre). Clinical trial number: NCT03898167.

SERS Signature of SARS-CoV-2 in Saliva and Nasopharyngeal Swabs: Towards Perspective COVID-19 Point-of-Care Diagnostics.

In this study, the intrinsic surface-enhanced Raman spectroscopy (SERS)-based approach coupled with chemometric analysis was adopted to establish the biochemical fingerprint of SARS-CoV-2 infected human fluids: saliva and nasopharyngeal swabs. The numerical methods, partial least squares discriminant analysis (PLS-DA) and support vector machine classification (SVMC), facilitated the spectroscopic identification of the viral-specific molecules, molecular changes, and distinct physiological signatures of pathetically altered fluids. Next, we developed the reliable classification model for fast identification and differentiation of negative CoV(-) and positive CoV(+) groups. The PLS-DA calibration model was described by a great statistical value-RMSEC and RMSECV below 0.3 and R2cal at the level of ~0.7 for both type of body fluids. The calculated diagnostic parameters for SVMC and PLS-DA at the stage of preparation of calibration model and classification of external samples simulating real diagnostic conditions evinced high accuracy, sensitivity, and specificity for saliva specimens. Here, we outlined the significant role of neopterin as the biomarker in the prediction of COVID-19 infection from nasopharyngeal swab. We also observed the increased content of nucleic acids of DNA/RNA and proteins such as ferritin as well as specific immunoglobulins. The developed SERS for SARS-CoV-2 approach allows: (i) fast, simple and non-invasive collection of analyzed specimens; (ii) fast response with the time of analysis below 15 min, and (iii) sensitive and reliable SERS-based screening of COVID-19 disease.

A Review of the Scope of Direct-to-Consumer Sexually Transmitted Infection Testing Services Offered on the Internet.

BACKGROUND: The prevalence of sexually transmitted infections (STIs) is at an all-time high. Direct-to-consumer STI testing services may help alleviate this undue health burden. These products are sold online and rarely require interaction with a health care professional (HCP). Vendors offer STI self-collection kits or prescriptions for HCP specimen collection. The objective was to understand the scope of direct-to-consumer STI testing services offered and provide recommendations for consumers and industry. METHODS: Seven volunteers searched for "STD tests" on Google from February 1 through March 31, 2021 and shared their top 3 results. The study team extracted data from consumer-facing information on each website. Descriptive statistics and thematic qualitative analyses were performed. RESULTS: Twenty vendors were identified. Most vendors (95%) used Clinical Laboratory Improvement Amendments (CLIA)-certified or College of American Pathologists (CAP) accredited laboratories. Analyses distinguished between STI self-collection kits (n = 9) using independent laboratories and HCP specimen collection (n = 10), which used commercial laboratories (n = 1 offered both). The STI self-collection kits were cheaper per test and bundle on average (eg, $79.00 vs. $106.50 for chlamydia/gonorrhea), and more closely aligned with clinical recommendations compared with the HCP specimen collection options. Websites often contained inaccurate or misleading information (n = 13), often promoting testing outside of the recommendations. CONCLUSIONS: Direct-to-consumer STI testing services are part of an emerging market lacking regulation. Consumers should select vendors offering prescriptions for HCP specimen collection at CAP accredited and CLIA-certified laboratories. Vendors should provide a screening tool to assess individual patient risk prior to test purchase.

Direct comparison of clinical diagnostic sensitivity of saliva from buccal swabs versus combined oro-/nasopharyngeal swabs in the detection of SARS-CoV-2 B.1.1.529 Omicron.

BACKGROUND/PURPOSE: While current guidelines recommend the use of respiratory tract specimens for the direct detection of SARS-CoV-2 infection, saliva has recently been suggested as preferred sample type for the sensitive detection of SARS-CoV-2 B.1.1.529 (Omicron). By comparing saliva collected using buccal swabs and oro-/nasopharyngeal swabs from patients hospitalized due to COVID-19, we aimed at identifying potential differences in virus detection sensitivity between these sample types. METHODS: We compare the clinical diagnostic sensitivity of paired buccal swabs and combined oro-/nasopharyngeal swabs from hospitalized, symptomatic COVID-19 patients collected at median six days after symptom onset by real-time polymerase chain reaction (PCR) and antigen test. RESULTS: Of the tested SARS-CoV-2 positive sample pairs, 55.8% were identified as SARS-CoV-2 Omicron BA.1 and 44.2% as Omicron BA.2. Real-time PCR from buccal swabs generated significantly higher quantification cycle (Cq) values compared to those from matched combined oro-/nasopharyngeal swabs and resulted in an increased number of false-negative PCR results. Reduced diagnostic sensitivity of buccal swabs by real-time PCR was observed already at day one after symptom onset. Similarly, antigen test detection rates were reduced in buccal swabs compared to combined oro-/nasopharyngeal swabs. CONCLUSION: Our results suggest reduced clinical diagnostic sensitivity of saliva collected using buccal swabs when compared to combined oro-/nasopharyngeal swabs in the detection of SARS-CoV-2 Omicron in symptomatic individuals.

A novel anterior nasal swab to detect respiratory viruses: a prospective study of diagnostic accuracy.

Detection of respiratory viruses requires testing of the upper respiratory tract to obtain specimens for analysis. However, nasal and throat swabs can cause discomfort and procedural anxiety in children. Respiratory sampling methods which are accurate and less invasive are needed. We aim to determine the positive and negative percentage agreement of a novel anterior nasal swab (ANS) compared with the combined throat and anterior nasal swab (CTN), the reference standard, for detection of respiratory viruses. Children 5 - 18 years of age presenting to a tertiary paediatric hospital with respiratory symptoms were tested with both swabs in randomised order. Respiratory samples were tested on a multiplex RT-PCR panel. Viral detections, RT-PCR cycle-threshold values and child/parent/clinician experience of the swab were recorded. There were 157 viral detections from 249 participant CTN swabs. In comparison with the CTN, the overall positive and negative percentage agreement of ANS for detection of respiratory viruses was 96.2% (95% CI, 91.8-98.3%) and 99.8% (95% CI, 99.6-99.9%), respectively. The ANS was "extremely comfortable", or only a "little uncomfortable" for 90% of children compared with 48% for CTN. 202 children (84%) rated the ANS as the preferred swab, and 208 (87%) indicated they would prefer ANS for future testing. The ANS required additional laboratory handling processes compared to the CTN. The ANS has high positive percentage agreement and is comparable to the current standard of care. The high acceptability from the less invasive ANS provides a more comfortable method for respiratory virus testing in children.Trial registrationClinicalTrials.gov ID NCT05043623.

Taking a step back from testing: Preanalytical considerations in molecular infectious disease diagnostics.

Recent studies evaluating the preanalytical factors that impact the outcome of nucleic-acid based methods for the confirmation of SARS-CoV-2 have illuminated the importance of identifying variables that promoted accurate testing, while using scarce resources efficiently. The majority of laboratory errors occur in the preanalytical phase. While there are many resources identifying and describing mechanisms for main laboratory testing on automated platforms, there are fewer comprehensive resources for understanding important preanalytical and environmental factors that affect accurate molecular diagnostic testing of infectious diseases. This review identifies evidence-based factors that have been documented to impact the outcome of nucleic acid-based molecular techniques for the diagnosis of infectious diseases.

Accuracy of saliva for SARS-CoV-2 detection in outpatients and their household contacts during the circulation of the Omicron variant of concern.

BACKGROUND: While nasopharyngeal (NP) swabs are considered the gold standard for severe acute respiratory coronavirus 2 (SARS-CoV-2) real-time reverse transcriptase-polymerase chain reaction (RT-PCR) detection, several studies have shown that saliva is an alternative specimen for COVID-19 diagnosis and screening. METHODS: To analyze the utility of saliva for the diagnosis of COVID-19 during the circulation of the Omicron variant, participants were enrolled in an ongoing cohort designed to assess the natural history of SARS-CoV-2 infection in adults and children. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Cohen's kappa coefficient were calculated to assess diagnostic performance. RESULTS: Overall, 818 samples were collected from 365 outpatients from January 3 to February 2, 2022. The median age was 32.8 years (range: 3-94 years). RT-PCR for SARS-CoV-2 was confirmed in 97/121 symptomatic patients (80.2%) and 62/244 (25.4%) asymptomatic patients. Substantial agreement between saliva and combined nasopharyngeal/oropharyngeal samples was observed with a Cohen's kappa value of 0.74 [95% confidence interval (CI): 0.67-0.81]. Sensitivity was 77% (95% CI: 70.9-82.2), specificity 95% (95% CI: 91.9-97), PPV 89.8% (95% CI: 83.1-94.4), NPV 87.9% (95% CI: 83.6-91.5), and accuracy 88.5% (95% CI: 85.0-91.4). Sensitivity was higher among samples collected from symptomatic children aged three years and older and adolescents [84% (95% CI: 70.5-92)] with a Cohen's kappa value of 0.63 (95% CI: 0.35-0.91). CONCLUSIONS: Saliva is a reliable fluid for detecting SARS-CoV-2, especially in symptomatic children and adolescents during the circulation of the Omicron variant.

Pooled RNA-extraction-free testing of saliva for the detection of SARS-CoV-2.

The key to limiting SARS-CoV-2 spread is to identify virus-infected individuals (both symptomatic and asymptomatic) and isolate them from the general population. Hence, routine weekly testing for SARS-CoV-2 in all asymptomatic (capturing both infected and non-infected) individuals is considered critical in situations where a large number of individuals co-congregate such as schools, prisons, aged care facilities and industrial workplaces. Such testing is hampered by operational issues such as cost, test availability, access to healthcare workers and throughput. We developed the SalivaDirect RT-qPCR assay to increase access to SARS-CoV-2 testing via a low-cost, streamlined protocol using self-collected saliva. To expand the single sample testing protocol, we explored multiple extraction-free pooled saliva testing workflows prior to testing with the SalivaDirect RT-qPCR assay. A pool size of five, with or without heat inactivation at 65 °C for 15 min prior to testing resulted in a positive agreement of 98% and 89%, respectively, and an increased Ct value shift of 1.37 and 1.99 as compared to individual testing of the positive clinical saliva specimens. Applying this shift in Ct value to 316 individual, sequentially collected, SARS-CoV-2 positive saliva specimen results reported from six clinical laboratories using the original SalivaDirect assay, 100% of the samples would have been detected (Ct value < 45) had they been tested in the 1:5 pool strategy. The availability of multiple pooled testing workflows for laboratories can increase test turnaround time, permitting results in a more actionable time frame while minimizing testing costs and changes to laboratory operational flow.

Underscoring the effect of swab type, workflow, and positive sample order on swab pooling for COVID-19 surveillance testing.

Sample pooling is a promising strategy to facilitate COVID-19 surveillance testing for a larger population in comparison to individual single testing due to resource and time constraints. Increased surveillance testing capacity will reduce the likelihood of outbreaks as the general population is returning to work, school, and other gatherings. We have analyzed the impact of three variables on the effectiveness of pooling test samples: swab type, workflow, and positive sample order. We investigated the performance of several commercially available swabs (Steripack polyester flocked, Puritan nylon flocked, Puritan foam) in comparison to a new injected molded design (Yukon). The bench-top performance of collection swab was conducted with a previously developed anterior nasal cavity tissue model, based on a silk-glycerol sponge to mimic soft tissue mechanics and saturated with a physiologically relevant synthetic nasal fluid spiked with heat-inactivated SARS-CoV-2. Overall, we demonstrated statistically significant differences in performance across the different swab types. A characterization of individual swab uptake (gravimetric analysis) and FITC microparticle release suggests that differences in absorbance and retention drive the observed differences in Ct of the pooled samples. We also proposed two distinct pooling workflows to encompass different community collection modes and analyzed the difference in resulting positive pools as an effect of workflow, swab type, and positive sample order. Overall, swab types with lower volume retention resulted in reduced false negative occurrence, also observed for collection workflows with limited incubation times. Concurrently, positive sample order did have a significant impact on pooling test outcome, particularly in the case of swab type with great volume retention. We demonstrated that the variables investigated here affect the results of pooled COVID-19 testing, and therefore should be considered while designing pooled surveillance testing.

Insights from a workplace SARS-CoV-2 specimen collection program, with genomes placed into global sequence phylogeny.

In 2020, the Department of Energy established the National Virtual Biotechnology Laboratory (NVBL) to address key challenges associated with COVID-19. As part of that effort, Pacific Northwest National Laboratory (PNNL) established a capability to collect and analyze specimens from employees who self-reported symptoms consistent with the disease. During the spring and fall of 2021, 688 specimens were screened for SARS-CoV-2, with 64 (9.3%) testing positive using reverse-transcriptase quantitative PCR (RT-qPCR). Of these, 36 samples were released for research. All 36 positive samples released for research were sequenced and genotyped. Here, the relationship between patient age and viral load as measured by Ct values was measured and determined to be only weakly significant. Consensus sequences for each sample were placed into a global phylogeny and transmission dynamics were investigated, revealing that the closest relative for many samples was from outside of Washington state, indicating mixing of viral pools within geographic regions.

Comparison of Nasal Swabs, Nasopharyngeal Swabs, and Saliva Samples for the Detection of SARS-CoV-2 and other Respiratory Virus Infections.

Background: Nasal swabs and saliva samples are being considered alternatives to nasopharyngeal swabs (NPSs) for detecting severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2); however, few studies have compared the usefulness of nasal swabs, NPSs, and saliva samples for detecting SARS-CoV-2 and other respiratory virus infections. We compared the positivity rates and concentrations of viruses detected in nasal swabs, NPSs, and saliva samples using cycle threshold (Ct) values from real-time PCR tests for respiratory viruses. Methods: In total, 236 samples (48 five-rub and 10 10-rub nasal swabs, 96 NPSs collected using two different products, 48 saliva swabs, and 34 undiluted saliva samples) from 48 patients (34 patients with SARS-CoV-2 and 14 with other respiratory virus infections) and 40 samples from eight healthy controls were obtained. The PCR positivity and Ct values were compared using Allplex Respiratory Panels 1/2/3 and Allplex SARS-CoV-2 real-time PCR. Results: NPSs showed the lowest Ct values (indicating the highest virus concentrations); however, nasal and saliva samples yielded positive results for SARS-CoV-2 and other respiratory viruses. The median Ct value for SARS-CoV-2 E gene PCR using nasal swab samples collected with 10 rubs was significantly different from that obtained using nasal swabs collected with five rubs (Ct=24.3 vs. 28.9; P=0.002), but not from that obtained using NPSs. Conclusions: Our results confirm that the NPS is the best sample type for detecting respiratory viruses, but nasal swabs and saliva samples can be alternatives to NPSs. Vigorously and sufficiently rubbed nasal swabs can provide SARS-CoV-2 concentrations similar to those obtained with NPSs.

A simplified nasopharyngeal swab collection procedure for minimizing patient discomfort while retaining sample quality.

A nasopharyngeal swab (NPS) is the most frequently collected sample type when molecular diagnosis of respiratory viruses, including SARS CoV-2, is required. An optimal collection technique would provide sufficient sample quality for the diagnostic process and would minimize the discomfort felt by the patient. This study compares a simplified NPS collection procedure with only one rotation of the swab to a more standard procedure with five rotations. Swabs were collected from 76 healthy volunteers by the same healthcare professional on 2 consecutive days at a similar hour to minimize variability. The number of Ubiquitin C copy number per sample was measured by real-time quantitative PCR and patient discomfort was assessed by questionnaire. No statistically significant difference (p = 0.15) was observed in the Ubiquitin C copy number per sample between a NPS collected with one rotation (5.2 ± 0.6 log UBC number copies/sample) or five rotations (5.3 ± 0.5 log UBC number copies/sample). However, a statistically significant difference was observed in discomfort between these two procedures, the second being much more uncomfortable. Additional analysis of the results showed a weak correlation between discomfort and the number of human cells recovered (Spearman's rho = 0.202) and greater discomfort in younger people. The results of this study show that a NPS collected with one slow rotation has the same quality as a NPS collected with five rotations. However, the collection time is shorter and, most importantly, less unpleasant for patients.

RECAST: Study protocol for an observational study for the understanding of the increased REsilience of Children compared to Adults in SARS-CoV-2 infecTion.

INTRODUCTION: The SARS-CoV-2 pandemic remains a threat to public health. Soon after its outbreak, it became apparent that children are less severely affected. Indeed, opposing clinical manifestations between children and adults are observed for other infections. The SARS-CoV-2 outbreak provides the unique opportunity to study the underlying mechanisms. This protocol describes the methods of an observational study that aims to characterise age dependent differences in immune responses to primary respiratory infections using SARS-CoV-2 as a model virus and to assess age differences in clinical outcomes including lung function. METHODS AND ANALYSIS: The study aims to recruit at least 120 children and 60 adults that are infected with SARS-CoV-2 and collect specimen for a multiomics analysis, including single cell RNA sequencing of nasal epithelial cells and peripheral blood mononuclear cells, mass cytometry of whole blood samples and nasal cells, mass spectrometry-based serum and plasma proteomics, nasal epithelial cultures with functional in vitro analyses, SARS-CoV-2 antibody testing, sequencing of the viral genome and lung function testing. Data obtained from this multiomics approach are correlated with medical history and clinical data. Recruitment started in October 2020 and is ongoing. ETHICS AND DISSEMINATION: The study was reviewed and approved by the Ethics Committee of Charité - Universitätsmedizin Berlin (EA2/066/20). All collected specimens are stored in the central biobank of Charité - Universitätsmedizin Berlin and are made available to all participating researchers and on request. TRIAL REGISTRATION NUMBER: DRKS00025715, pre-results publication.

Association between soluble angiotensin-converting enzyme 2 in saliva and SARS-CoV-2 infection: a cross-sectional study.

This study aimed to investigate the association between saliva soluble angiotensin-converting enzyme 2 (sACE2) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children and adults. We selected a convenience sample of adults with post-acute SARS-CoV-2 infection and their household children living in quarantined family households of the metropolitan Barcelona region (Spain) during the spring 2020 pandemic national lockdown. Participants were tested for saliva sACE2 quantification by western blot and nasopharyngeal SARS-CoV-2 RT-PCR detection. A total of 161 saliva samples [82 (50.9%) from children; 79 (49.1%) from females] yielded valid western blot and RT-PCR results. Saliva sACE2 was detected in 79 (96.3%) children and 76 (96.2%) convalescent adults. Twenty (24.4%) children and 20 (25.3%) convalescent adults were positive for SARS-CoV-2 in nasopharynx by RT-PCR. SARS-CoV-2 RT-PCR-negative children had a significantly higher mean proportional level of saliva sACE2 (0.540 × 10-3%) than RT-PCR-positive children (0.192 × 10-3%, p < 0.001) and convalescent adults (0.173 × 10-3%, p < 0.001). In conclusion, children negative for nasopharyngeal SARS-CoV-2 RT-PCR appear to exhibit a higher concentration of saliva sACE2 than SARS-CoV-2 RT-PCR-positive children and convalescent adults. Release of adequate levels of sACE2 in saliva could play a protective role against SARS-CoV-2.

The pre-analytical process management status and influencing factors of laboratory test before prescribing antimicrobial in developing country.

INTRODUCTION: The results of laboratory testing are crucial basis for clinicians to prescribe antimicrobial. Laboratory testing is a highly complex process, and increasing evidence suggests that errors and obstacles in the pre-analytical process (PP) will affect reasonable antimicrobial use. However, PP was an easily neglected link in hospital infection management and the current situation of it and the influencing factors of management are not clear. METHODS: A cross-sectional survey was conducted in the department of clinical, specimen collection, transportation, and inspection in 109 secondary and tertiary hospitals in Central China. The rate of antimicrobial susceptibility test request (AST) and related indexes of above departments were calculated to describe the situation. Management characteristics (frequency of training etc.) were described as proportions and fractional probit regression analysis was used to determine the influencing factors. RESULTS: The average rate of non restricted-use antimicrobial was 63%, the restricted-use was 86%, the special-use was 95%. The zero obstacle rate of specimen collection was 27.3%, of specimen transportation was 19.4% and of inspection feedback was 61.7%. There was a difference between the secondary and tertiary hospitals on non restricted-use (X2 = 22.968, P < 0.001); restricted-use (X2 = 29.466, P < 0.001); special-use (X2 = 27.317, P < 0.001). Taking non restricted-use as an example, training (OR = 0.312, 95%CI: 0.148,0.429), low-frequency appraisal (OR = 0.153, 95%CI: 0.082,0.224), guidance (OR = 0.32, 95%CI: 0.237,0.403) and information technology (OR = 0.104, 95%CI: 0.009,0.199) were positive factors. CONCLUSIONS: There were substantial differences in the rate of AST request in clinical department between secondary and tertiary hospitals. The zero obstacle rate in collection, transportation and inspection department were still low. In most departments, training and performance appraisal were positive factors, guidance and information technology were positive supporting factors.

COVID-19: Test, Test and Test.

A new virus was identified in late December 2019 when China reported the first cases of pneumonia in Wuhan, and a global COVID-19 pandemic followed. The world was not late to respond, with a number of sweeping measures ranging from social distancing protocols, stringent hygienic practices, and nation-wide lockdowns, as well as COVID-19 testing campaigns in an attempt to prevent the transmission of the disease and contain the pandemic. Currently, different types of diagnostic testing have been adopted globally, such as nucleic acid detection tests, immunological tests and imaging approaches; however, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) remains the "gold standard" for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-analytical factors, such as specimen selection and collection, are crucial for RT-PCR, and any suboptimal collection may contribute to false-negative results. Herein, we address some of the specimen types that have been used in molecular detection methods for COVID-19. However, the pandemic is still evolving, and information might change as more studies are conducted.

Pre-enriched saline gargle samples for detection of SARS-CoV-2.

A self­collected gargle sample, which avoids discomfort and largely reduces the dependency on medical resources, is emerging for detection of SARS­CoV­2. However, the incomplete usage of starting materials for both routine oropharyngeal swabs (OPS)/nasopharyngeal swabs (NPS) and saline gargle (SG) samples implies sensitivity can be further improved. Presented here is a bead­based strategy for pre­enrichment of SG samples, and results revealed that it acquired about 20 times the starting materials obtained from OPS samples for downstream detection of SARS­CoV­2. The sensitivity and specificity of this pre­enrichment strategy were validated in 100 paired pre­enriched saline gargle (PenSG) and OPS samples and 89 PenSG samples from healthy volunteers. In addition to detection of SARS­CoV­2, this pre­enrichment strategy may also be implemented in more clinical settings to optimize detection of other diseases.