Guide to Utilization of the Microbiology Laboratory for Diagnosis of Infectious Diseases: 2024 Update by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM).

The critical nature of the microbiology laboratory in infectious disease diagnosis calls for a close, positive working relationship between the physician and the microbiologists who provide enormous value to the health care team. This document, developed by experts in both adult and pediatric laboratory and clinical medicine, provides information on which tests are valuable and in which contexts, and on tests that add little or no value for diagnostic decisions. Sections are divided into anatomic systems, including Bloodstream Infections and Infections of the Cardiovascular System, Central Nervous System Infections, Ocular Infections, Soft Tissue Infections of the Head and Neck, Upper Respiratory Infections, Lower Respiratory Tract infections, Infections of the Gastrointestinal Tract, Intraabdominal Infections, Bone and Joint Infections, Urinary Tract Infections, Genital Infections, and Skin and Soft Tissue Infections; or into etiologic agent groups, including arboviral Infections, Viral Syndromes, and Blood and Tissue Parasite Infections. Each section contains introductory concepts, a summary of key points, and detailed tables that list suspected agents; the most reliable tests to order; the samples (and volumes) to collect in order of preference; specimen transport devices, procedures, times, and temperatures; and detailed notes on specific issues regarding the test methods, such as when tests are likely to require a specialized laboratory or have prolonged turnaround times. In addition, the pediatric needs of specimen management are also addressed. There is redundancy among the tables and sections, as many agents and assay choices overlap. The document is intended to serve as a reference to guide physicians in choosing tests that will aid them to diagnose infectious diseases in their patients.

Use of next-generation sequencing to detect mutations associated with antiviral drug resistance in cytomegalovirus.

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality among immunocompromised hosts, including transplant recipients. Antiviral prophylaxis or treatment is used to reduce the incidence of CMV disease in this patient population; however, there is concern about increasing antiviral resistance. Detection of antiviral resistance in CMV was traditionally accomplished using Sanger sequencing of UL54 and UL97 genes, in which specific mutations may result in reduced antiviral activity. In this study, a novel next-generation sequencing (NGS) method was developed and validated to detect mutations in UL54/UL97 associated with antiviral resistance. Plasma samples (n = 27) submitted for antiviral resistance testing by Sanger sequencing were also analyzed using the NGS method. When compared to Sanger sequencing, the NGS assay demonstrated 100% (27/27) overall agreement for determining antiviral resistance/susceptibility and 88% (22/25) agreement at the level of resistance-associated mutations. The limit of detection of the NGS method was determined to be 500 IU/mL, and the lower threshold for detecting mutations associated with resistance was established at 15%. The NGS assay represents a novel laboratory tool that assists healthcare providers in treating patients who are infected with CMV harboring resistance-associated mutations and who may benefit from tailored antiviral therapy.

Current regulatory landscape for viral point-of-care testing in the United States.

Historically, the diagnosis of viral infections has been accomplished using a combination of laboratory-based methods, including culture, serology, antigen-based tests, and molecular (e.g., real-time PCR) assays. Although these methods provide an accurate way to detect viral pathogens, testing in a centralized laboratory may delay results, which could impact patient diagnosis and management. Point-of-care tests, including antigen- and molecular-based assays, have been developed to assist with the timely diagnosis of several viral infections, such as influenza, respiratory syncytial virus, and COVID-19. Despite the ability of point-of-care tests to provide rapid results (i.e., <30 min), there are issues to consider prior to their routine use, including test performance and specific regulatory requirements. This review will provide a summary of the regulatory landscape of point-of-care tests for viral infections in the United States, and address important considerations such as site certification, training and inspection readiness.

Authorized SARS-CoV-2 molecular methods show wide variability in the limit of detection.

On February 29th, 2020, the U.S. Food and Drug Administration issued the first Emergency Use Authorization (EUA) for a SARS-CoV-2 assay outside of the U.S. Centers for Disease Control and Prevention. As of May 3rd, 2021, 289 total EUAs have been granted. Like influenza, there is no standard for defining limit of detection (LoD), but rather guidance that analytical sensitivity/LoD be established as the level that gives a 95% detection rate in at least 20 replicates. Here we compare the performance characteristics of SARS-CoV-2 tests receiving EUA by standardizing sensitivity to a common unit of measure and assess the variability in LoD between tests. Additionally, we looked at factors that may impact sensitivities due to lack of standardization of the test development process and compare results for a standardized reference panel for comparative analysis within a subset of EUA tests offered by the U.S. Food and Drug Administration.

Incidence of Respiratory Syncytial Virus Infection in Older Adults Before and During the COVID-19 Pandemic.

Importance: Little is known about the burden and outcomes of respiratory syncytial virus (RSV)-positive acute respiratory infection (ARI) in community-dwelling older adults. Objective: To assess the incidence of RSV-positive ARI before and during the COVID-19 pandemic, and to assess outcomes for RSV-positive ARI in older adults. Design, Setting, and Participants: This was a community-based cohort study of adults residing in southeast Minnesota that followed up with 2325 adults aged 50 years or older for 2 RSV seasons (2019-2021) to assess the incidence of RSV-positive ARI. The study assessed outcomes at 2 to 4 weeks, 6 to 7 months, and 12 to 13 months after RSV-positive ARI. Exposure: RSV-positive and -negative ARI. Main Outcomes and Measures: RSV status was the main study outcome. Incidence and attack rates of RSV-positive ARI were calculated during each RSV season, including before (October 2019 to April 2020) and during (October 2020 to April 2021) COVID-19 pandemic, and further calculated during non-RSV season (May to September 2021) for assessing impact of COVID-19. The self-reported quality of life (QOL) by Short-Form Health Survey-36 (SF-36) and physical functional measures (eg, 6-minute walk and spirometry) at each time point was assessed. Results: In this study of 2325 participants, the median (range) age of study participants was 67 (50-98) years, 1380 (59%) were female, and 2240 (96%) were non-Hispanic White individuals. The prepandemic incidence rate of RSV-positive ARI was 48.6 (95% CI, 36.9-62.9) per 1000 person-years with a 2.50% (95% CI, 1.90%-3.21%) attack rate. No RSV-positive ARI case was identified during the COVID-19 pandemic RSV season. Incidence of 10.2 (95% CI, 4.1-21.1) per 1000 person-years and attack rate of 0.42%; (95% CI, 0.17%-0.86%) were observed during the summer of 2021. Based on prepandemic RSV season results, participants with RSV-positive ARI (vs matched RSV-negative ARI) reported significantly lower QOL adjusted mean difference (limitations due to physical health, -16.7 [95% CI, -31.8 to -1.8]; fatigue, -8.4 [95% CI, -14.3 to -2.4]; and difficulty in social functioning, -11.9 [95% CI, -19.8 to -4.0] within 2 to 4 weeks after RSV-positive ARI [ie, short-term outcome]). Compared with participants with RSV-negative ARI, those with RSV-positive ARI also had lower QOL (fatigue: -4.0 [95% CI, -8.5 to -1.3]; difficulty in social functioning, -5.8 [95% CI, -10.3 to -1.3]; and limitation due to emotional problem, -7.0 [95% CI, -12.7 to -1.3] at 6 to 7 months after RSV-positive ARI [intermediate-term outcome]; fatigue, -4.4 [95% CI, -7.3 to -1.5]; difficulty in social functioning, -5.2 [95% CI, -8.7 to -1.7] and limitation due to emotional problem, -5.7 [95% CI, -10.7 to -0.6] at 12-13 months after RSV-positive ARI [ie, long-term outcomes]) independent of age, sex, race and/or ethnicity, socioeconomic status, and high-risk comorbidities. Conclusions and Relevance: In this cohort study, the burden of RSV-positive ARI in older adults during the pre-COVID-19 period was substantial. After a reduction of RSV-positive ARI incidence from October 2020 to April 2021, RSV-positive ARI re-emerged during the summer of 2021. RSV-positive ARI was associated with significant long-term lower QOL beyond the short-term lower QOL in older adults.

Monkeypox 2022: Gearing Up for Another Potential Public Health Crisis.

Monkeypox virus, a member of the Orthopoxvirus genus, was first identified as the etiology of monkeypox in 1970 in the Democratic Republic of Congo and remains endemic in regions of Central and West Africa. Following the most recent outbreak of monkeypox in multiple countries throughout Europe and North America, the infection has been declared a public health emergency by the Centers for Disease Control and Prevention. Within this report, we aim to provide clinicians with a focused overview of the epidemiology, clinical manifestation, diagnosis, and approaches to treat and prevent monkeypox infection amidst the global outbreak.

Analytic and Clinical Performance of Major Commercial Severe Acute Respiratory Syndrome Coronavirus 2 Molecular Assays in the United States.

The rapid development of commercially available molecular assays in response to the COVID-19 pandemic has been essential in identifying positive cases and guiding state and national response plans. With over 200 SARS-CoV-2 molecular tests having received emergency use authorization by the US Food and Drug Administration, numerous studies have been conducted to evaluate these methods and compare their analytical and clinical performance. By applying the lessons learned from the rapid development of molecular assays in response to the COVID-19 pandemic, the diagnostic industry will be better prepared to respond to future outbreaks of novel infectious diseases.

Utility of Follow-up Coronavirus Disease 2019 (COVID-19) Antigen Tests After Acute Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection Among Healthcare Personnel.

We report the utility of rapid antigen tests (RAgT) in a cohort of US healthcare personnel with coronavirus disease 2019 (COVID-19) infection who met symptom criteria to return to work at day 5 or later of isolation. In total, 11.9% of initial RAgT were negative. RAgT can be helpful to guide return to work decisions.

SARS-CoV-2 Testing Before International Airline Travel, December 2020 to May 2021.

Although there have been several case reports and simulation models of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission associated with air travel, there are limited data to guide testing strategy to minimize the risk of SARS-CoV-2 exposure and transmission onboard commercial aircraft. Among 9853 passengers with a negative SARS-CoV-2 polymerase chain reaction test performed within 72 hours of departure from December 2020 through May 2021, five (0.05%) passengers with active SARS-CoV-2 infection were identified with rapid antigen tests and confirmed with rapid molecular test performed before and after an international flight from the United States to Italy. This translates to a case detection rate of 1 per 1970 travelers during a time of high prevalence of active infection in the United States. A negative molecular test for SARS-CoV-2 within 72 hours of international airline departure results in a low probability of active infection identified on antigen testing during commercial airline flight.

Association Between SARS-CoV-2 Cycle Threshold Values and Clinical Outcomes in Patients With COVID-19: A Systematic Review and Meta-analysis.

Cycle threshold (CT) values are correlated with the amount of viral nucleic acid in a sample and may be obtained from some qualitative real-time polymerase chain reaction tests used for diagnosis of most patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, CT values cannot be directly compared across assays, and they must be interpreted with caution as they are influenced by sample type, timing of sample collection, and assay design. Presently, the correlation between CT values and clinical outcomes is not well understood. We conducted a systematic review and meta-analysis of published studies through April 19, 2021, that reported an association between CT values and hospitalization, disease severity, and mortality in patients ≥18 years old with SARS-CoV-2. A meta-analysis of 7 studies showed no significant difference in mean CT values between hospitalized and nonhospitalized patients. Among hospitalized patients, those with CT values <25 had a high risk of more severe disease and mortality than patients with CT values >30 (odds ratio [OR], 2.31; 95% CI, 1.70 to 3.13; and OR, 2.95; 95% CI, 2.19 to 3.96; respectively). The odds of increased disease severity and mortality were less pronounced in patients with CT values of 25-30 compared with >30.

Can Testing Predict SARS-CoV-2 Infectivity? The Potential for Certain Methods To Be Surrogates for Replication-Competent Virus.

Since the beginning of the COVID-19 pandemic, molecular methods (e.g., real-time PCR) have been the primary means of diagnosing the disease. It is now well established that molecular tests can continue to detect SARS-CoV-2 genomic RNA for weeks or months following the resolution of clinical illness. This has prompted public health agencies to recommend a symptom- and/or time-based strategy for discontinuation of isolation precautions, which, for hospitalized patients, results in significant use of personal protective equipment. Due to the inability of current molecular diagnostic assays to differentiate between the presence of remnant viral RNA (i.e., noninfectious) and replication-competent (i.e., infectious) virus, there has been interest in determining whether laboratory tests can be used to predict an individual's likelihood of transmitting the virus to others. This review will highlight what is currently known about the potential for existing assays, such as real-time PCR and antigen tests, to predict active viral infection. In addition, data on the performance of new methods, such as molecular tests targeting viral RNA intermediates (e.g., subgenomic RNA), will be discussed.

Performance of three polymerase chain reaction-based assays for detection of SARS-CoV-2 in different upper respiratory tract specimens.

To meet the testing demands and overcome supply chain issues during the SARS-CoV-2 pandemic, many clinical laboratories validated multiple SARS-CoV-2 molecular testing platforms. Here, we compare three different molecular assays for SARS-CoV-2 that received emergency use authorization (EUA) from the U.S. Food and Drug Administration. In order to determine the agreement among Roche cobas® SARS-CoV-2 Test (Cobas), Abbott RealTime SARS-CoV-2 assay (ART), and Mayo Clinic Laboratory SARS-CoV-2 Molecular Detection Assay (Mayo LDT), 100 each of anterior nares (AN), nasopharyngeal (NP), oropharyngeal (OP), and NP+OP swabs were tested on each platform. The consensus result was defined as agreement by 2 or more methods. Furthermore, 30 positive NP swabs from each molecular platform (n = 90 total) were tested on the three platforms to determine the PPA among positive samples. ART platform called more specimens positive than the other two platforms. All three assays performed with greater than 90% agreement for NP specimens throughout the study.

Evaluation of Self-Collected Midturbinate Nasal Swabs and Saliva for Detection of SARS-CoV-2 RNA.

Rapid and accurate diagnostic testing is essential to bring the ongoing COVID-19 pandemic to an end. As the demand for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing continues to increase amid supply shortages, many laboratories have investigated the use of sources other than nasopharyngeal (NP) swabs. Saliva and midturbinate (MT) nasal swabs are attractive alternatives, as they allow for self-collection and are well accepted by patients. Saliva also requires limited consumables. We compared the performance of health care provider-collected NP swabs, patient-collected MT swabs, and patient-collected saliva specimens for SARS-CoV-2 detection using a laboratory-developed PCR assay that had received Emergency Use Authorization by the FDA. Of 281 total evaluable samples, 33 (11.7%) NP swabs, 33 (11.7%) MT swabs, and 32 (11.4%) saliva specimens were positive for SARS-CoV-2 following resolution of discordant results. Compared to NP swabs, saliva exhibited a sensitivity of 90.9% (30/33) and specificity of 99.2% (246/248), while patient-collected MT swabs exhibited a sensitivity of 93.9% (31/33) and specificity of 99.2% (246/248). When comparing to the consensus standard, the sensitivity was found to be 100% (31/31) for both NP and MT swabs and 96.8% (30/31) for saliva specimens, while specificity was the same in both NP swabs and saliva specimens (98.8% [247/250]) and 99.2% (248/250) for MT swabs. Pretreatment of saliva with proteinase K and heating for 15 min prior to extraction reduced the invalid rate from 26.7% (52/195) to 0% (0/195). These data show that midturbinate nasal swabs and saliva are suitable sources for self-collection in individuals who require routine monitoring for SARS-CoV-2 infection.

Evaluation of high-risk human papillomavirus testing and anal cytology to detect high-grade anal intraepithelial neoplasia.

INTRODUCTION: Optimal screening for detection of anal precancer has not been established, and most studies involve very high-risk populations. We evaluated high-risk human papillomavirus (HPV) testing and anal cytology to detect high-grade anal intraepithelial neoplasia (≥AIN2) in a cohort with mostly moderate risk factors for AIN. METHODS: Patients ≥35 years old undergoing anal biopsy for various lesions received HPV testing by Roche cobas and a subset by Hologic APTIMA HPV assays with concurrent anal ThinPrep cytology. Biopsies were blindly reviewed by 3 authors, and consensus diagnosis was compared with HPV and cytology results. Sensitivity and specificity for ≥AIN2 detection by HPV testing and cytology (≥ASC-US) were calculated. RESULTS: Among 64 patients, 19 (29.7%) showed ≥AIN2 on biopsy. All patients were tested by cobas, and 35 (54.7%) were positive. A subset of 39 patients were also tested by APTIMA, and 18 (46.2%) were positive. Positive cytology (≥ASC-US) was present in 37 (57.8%) patients, with 27 (73.0%) of these positive by cobas. HPV testing alone yielded 75.0% and 84.2% sensitivity for APTIMA and cobas, respectively; specificity was 66.7% and 57.8%. Sensitivity and specificity of cytology alone was 78.9% and 51.1%. Combined HPV testing and cytology had a sensitivity and specificity of 91.7% and 37.0% for APTIMA and 94.7% and 40.0% for cobas. CONCLUSIONS: Combined HPV testing and cytology had the highest sensitivity for ≥AIN2 detection, with a performance comparable to cervical cancer screening tests, suggesting this strategy may represent a viable screening option in a population with moderate risk factors for AIN.

Adherence to Public Health Measures Mitigates the Risk of COVID-19 Infection in Older Adults: A Community-Based Study.

OBJECTIVE: To assess the prevalence and characteristics of coronavirus disease 2019 (COVID-19) cases during the reopening period in older adults, given that little is known about the prevalence of COVID-19 after the stay-at-home order was lifted in the United States, nor the actual effects of adherence to recommended public health measures (RPHM) on the risk of COVID-19. PATIENTS AND METHODS: This was a cross-sectional study nested in a parent prospective cohort study, which followed a population-based sample of 2325 adults 50 years and older residing in southeast Minnesota to assess the incidence of viral infections. Participants were instructed to self-collect both nasal and oropharyngeal swabs, which were tested by reverse transcription polymerase chain reaction-based severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay between May 8, 2020, and June, 30, 2020. We assessed the prevalence of COVID-19 cases and characteristics of study subjects. RESULTS: A total of 1505 eligible subjects participated in the study whose mean age was 68 years, with 885 (59%) women, 32 (2%) racial/ethnic minorities, and 906 (60%) with high-risk conditions for influenza. The prevalence of other Coronaviridae (human coronavirus [HCoV]-229E, HCoV-NL63, and HCoV-OC43) during the 2019 to 2020 flu season was 109 (7%), and none tested positive for SARS-CoV-2. Almost all participants reported adhering to the RPHM (1,488 [99%] for social distancing, 1,438 [96%] for wearing mask in a public space, 1,476 [98%] for hand hygiene, and 1,441 (96%) for staying home mostly). Eighty-six percent of participants resided in a single-family home. CONCLUSION: We did not identify SARS-COV-2 infection in our study cohort. The combination of participants' behavior in following the RPHM and their living environment may considerably mitigate the risk of COVID-19.

Digital Health Surveillance Strategies for Management of Coronavirus Disease 2019.

OBJECTIVE: To describe the design, implementation, and utilization of electronic health record (EHR)-based digital health surveillance strategies used to manage the coronavirus disease 2019 (COVID-19) pandemic and to ensure delivery of high-quality clinical care, such as case identification, remote monitoring, telemedicine services, and recruitment to clinical trials at Mayo Clinic. METHODS: The design and implementation work described in this report was performed at Mayo Clinic, a large multistate integrated health care system with more than 1.5 million annual patient visits that uses the Epic EHR system. Rule-based live registries were designed in the EHR system to classify patients who currently test positive for COVID-19, patients who test positive but have recovered from COVID-19, patients who are thought to have COVID-19 but do not yet meet clinical diagnostic criteria, patients who test negative for COVID-19, and patients who exceed a risk score for serious complications from COVID-19. RESULTS: By use of registries, custom dashboards and operational reports were developed to provide a daily high-level summary for clinical practice use and up-to-date information to manage individual patients affected by COVID-19, including support of case identification, contact isolation, and other care management tasks. CONCLUSION: We developed and implemented a systematic approach to the use of EHR patient registries to manage the COVID-19 pandemic that proved feasible and useful in a large multistate group clinical practice. The key to harnessing the potential of digital surveillance tools to promote patient-centered care during the COVID-19 pandemic was to use the registry data, reports, and dashboards as informatics tools to inform decision-making.

Evaluation of the Cue Health point-of-care COVID-19 (SARS-CoV-2 nucleic acid amplification) test at a community drive through collection center.

Point-of-care (POC) tests are in high demand in order to facilitate rapid care decisions for patients suspected of SARS-CoV-2. We conducted a clinical validation study of the Cue Health POC nucleic acid amplification test (NAAT) using the Cue lower nasal swab, compared to a reference NAAT using standard nasopharyngeal swab, in 292 symptomatic and asymptomatic outpatients for SARS-CoV-2 detection in a community drive through collection setting. Positive percent agreement between Cue COVID-19 and reference SARS-CoV-2 test was 91.7% (22 of 24); or 95.7% (22 of 23) when one patient with no tie-breaker method was excluded. Negative percent agreement was 98.4% (239 of 243), and there were 25 (8.6%) invalid or canceled results. The Cue COVID-19 test demonstrated very good positive and negative percent agreement with central laboratory tests and will be useful in settings where accurate POC testing is needed to facilitate management of patients suspected of COVID-19.