A Laboratory-Developed Assay for Clade II Human Mpox Virus on the Panther Fusion Open Access System.

This paper describes the methods for developing and optimizing a laboratory-developed assay (LDA) for detecting clade II human mpox virus using the automated Panther Fusion platform and Open Access software. Various concentrations of reagents in a primer-probe mix were tested to optimize the LDA. The LDA was validated using 10 previously characterized positive and 10 negative human mpox samples, resulting in 95% accuracy and 100% precision. The LDA resulted in 100% specificity among previously tested HSV1-, HSV2-, and VZV-positive human samples. Several spiked media extensions were also validated and achieved 98% accuracy and 100% precision across all collection media types. The assay's limit of detection was calculated to be 1.475 copies/reaction, and the polymerase chain reaction efficiency resulted in 89.87% (slope, -3.5911; R2 = 0.9947). The methods described here can be applied to the rapid optimization and development of LDAs for many possible pathogens of public health importance.

Limited Variation between SARS-CoV-2-Infected Individuals in Domain Specificity and Relative Potency of the Antibody Response against the Spike Glycoprotein.

The spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is arranged as a trimer on the virus surface, composed of three S1 and three S2 subunits. Infected and vaccinated individuals generate antibodies against spike, which can neutralize the virus. Most antibodies target the receptor-binding domain (RBD) and N-terminal domain (NTD) of S1; however, antibodies against other regions of spike have also been isolated. The interhost variability in domain specificity and relative neutralization efficacy of the antibodies is still poorly characterized. To this end, we tested serum and plasma samples collected from 85 coronavirus disease 2019 (COVID-19) convalescent subjects. Samples were analyzed using seven immunoassays that employ different domains, subunits, and oligomeric forms of spike to capture the antibodies. Samples were also tested for their neutralization of pseudovirus containing SARS-CoV-2 spike and of replication-competent SARS-CoV-2. While the total amount of anti-spike antibodies produced varied among convalescent subjects, we observed an unexpectedly fixed ratio of RBD- to NTD-targeting antibodies. The relative potency of the response (defined as the measured neutralization efficacy relative to the total level of spike-targeting antibodies) also exhibited limited variation between subjects and was not associated with the overall amount of antispike antibodies produced. These studies suggest that host-to-host variation in the polyclonal response elicited against SARS-CoV-2 spike in early pandemic subjects is primarily limited to the quantity of antibodies generated rather than their domain specificity or relative neutralization potency. IMPORTANCE Infection by SARS-CoV-2 elicits antibodies against various domains of the spike protein, including the RBD and NTD of subunit S1 and against subunit S2. The antibody responses of different infected individuals exhibit different efficacies to inactivate (neutralize) the virus. Here, we show that the observed variation in the neutralizing activity of the antibody responses in COVID-19 convalescent subjects is caused by differences in the amounts of antibodies rather than their recognition properties or the potency of their antiviral activity. These findings suggest that COVID-19 vaccine strategies that focus on enhancing the overall level of the antibodies will likely elicit a more uniformly efficacious protective response.

Clinical Laboratory Biosafety Gaps: Lessons Learned from Past Outbreaks Reveal a Path to a Safer Future.

Patient care and public health require timely, reliable laboratory testing. However, clinical laboratory professionals rarely know whether patient specimens contain infectious agents, making ensuring biosafety while performing testing procedures challenging. The importance of biosafety in clinical laboratories was highlighted during the 2014 Ebola outbreak, where concerns about biosafety resulted in delayed diagnoses and contributed to patient deaths. This review is a collaboration between subject matter experts from large and small laboratories and the federal government to evaluate the capability of clinical laboratories to manage biosafety risks and safely test patient specimens. We discuss the complexity of clinical laboratories, including anatomic pathology, and describe how applying current biosafety guidance may be difficult as these guidelines, largely based on practices in research laboratories, do not always correspond to the unique clinical laboratory environments and their specialized equipment and processes. We retrospectively describe the biosafety gaps and opportunities for improvement in the areas of risk assessment and management; automated and manual laboratory disciplines; specimen collection, processing, and storage; test utilization; equipment and instrumentation safety; disinfection practices; personal protective equipment; waste management; laboratory personnel training and competency assessment; accreditation processes; and ethical guidance. Also addressed are the unique biosafety challenges successfully handled by a Texas community hospital clinical laboratory that performed testing for patients with Ebola without a formal biocontainment unit. The gaps in knowledge and practices identified in previous and ongoing outbreaks demonstrate the need for collaborative, comprehensive solutions to improve clinical laboratory biosafety and to better combat future emerging infectious disease outbreaks.

Update on Biosafety and Emerging Infections for the Clinical Microbiology Laboratory.

Biosafety risks are prevalent in all areas of the clinical laboratories. Clinical laboratorians have become accustomed to accepting these risks. When an emerging pathogen appears, the concerns become elevated. Since the appearance of Ebola virus in the United States in 2014, biosafety practices have made progress. A recent Association of Public Health Laboratories survey shows that clinical laboratories are unprepared for current and emerging biosafety challenges. This article focuses on the biosafety program that clinical laboratory leaders should build to meet the needs of clinical laboratories; biosafety challenges of automated laboratory systems, facilities, personnel, and practices; and the relationship with occupational health.

Practical Guidance for Clinical Microbiology Laboratories: Implementing a Quality Management System in the Medical Microbiology Laboratory

This document outlines a comprehensive practical approach to a laboratory quality management system (QMS) by describing how to operationalize the management and technical requirements described in the ISO 15189 international standard. It provides a crosswalk of the ISO requirements for quality and competence for medical laboratories to the 12 quality system essentials delineated by the Clinical and Laboratory Standards Institute. The quality principles are organized under three main categories: quality infrastructure, laboratory operations, and quality assurance and continual improvement. The roles and responsibilities to establish and sustain a QMS are outlined for microbiology laboratory staff, laboratory management personnel, and the institution's leadership. Examples and forms are included to assist in the real-world implementation of this system and to allow the adaptation of the system for each laboratory's unique environment. Errors and nonconforming events are acknowledged and embraced as an opportunity to improve the quality of the laboratory, a culture shift from blaming individuals. An effective QMS encourages "systems thinking" by providing a process to think globally of the effects of any type of change. Ultimately, a successful QMS is achieved when its principles are adopted as part of daily practice throughout the total testing process continuum.

Use of the Abbott Architect HIV antigen/antibody assay in a low incidence population.

BACKGROUND: With the availability of 4th generation HIV diagnostic tests which are capable of detecting acute infection, Iowa evaluated the 3rd and 4th generation HIV test and compared the performance of these products in a low incidence population. OBJECTIVE: This study was conducted to evaluate the performance of an HIV antigen/antibody combination (4th generation) assay compared to an EIA 3rd generation assay. STUDY DESIGN: Over a 4 month period, 2037 specimens submitted for HIV screening were tested by Bio-Rad GS HIV-1/HIV-2 Plus O EIA and the Abbott Architect i1000SR HIV Ag/Ab Combo. The performance characteristics of sensitivity, specificity, positive predictive value and negative predictive value were determined. RESULTS: Of the 2037 specimens tested, there were 13 (0.64%) true positives detected. None of the positive specimens were from patients in the acute phase of infection. The Abbott antigen/antibody combo assay had a sensitivity, specificity, positive-predictive value and negative predictive value of 100%, 99.85%, 81.25%, and 100% respectively. The Bio-Rad EIA assay had a sensitivity, specificity, positive-predictive value and negative predictive value of 100%, 99.80%, 76.47% and 100%, respectively. The EIA had four false positive results which tested negative by the antigen/antibody assay and western blot. CONCLUSION: In a low-incidence state where early infections are less commonly encountered, the EIA assay and the antigen/antibody assay performed with near equivalency. The antigen/antibody assay had one less false positive result. While no patients were detected in the acute stage of infection, the use of the antigen/antibody assay presents the opportunity to detect an infected patient sooner and prevent transmission to others.

Guidelines for biosafety laboratory competency: CDC and the Association of Public Health Laboratories.

These guidelines for biosafety laboratory competency outline the essential skills, knowledge, and abilities required for working with biologic agents at the three highest biosafety levels (BSLs) (levels 2, 3, and 4). The competencies are tiered to a worker's experience at three levels: entry level, midlevel (experienced), and senior level (supervisory or managerial positions). These guidelines were developed on behalf of CDC and the Association of Public Health Laboratories (APHL) by an expert panel comprising 27 experts representing state and federal public health laboratories, private sector clinical and research laboratories, and academic centers. They were then reviewed by approximately 300 practitioners representing the relevant fields. The guidelines are intended for laboratorians working with hazardous biologic agents, obtained from either samples or specimens that are maintained and manipulated in clinical, environmental, public health, academic, and research laboratories.

Optimizing influenza sentinel surveillance at the state level.

Influenza-like illness data are collected via an Influenza Sentinel Provider Surveillance Network at the state level. Because participation is voluntary, locations of the sentinel providers may not reflect optimal geographic placement. The purpose of this study was to determine the "best" locations for sentinel providers in Iowa by using a maximal coverage model (MCM) and to compare the population coverage obtained with that of the current sentinel network. The authors used an MCM to maximize the Iowa population located within 20 miles (32.2 km) of 1-143 candidate sites and calculated the coverage provided by each additional site. The first MCM location covered 15% of the population; adding a second increased coverage to 25%. Additional locations provided more coverage but with diminishing marginal returns. In contrast, the existing 22 Iowa sentinel locations covered 56% of the population, the same coverage achieved with just 10 MCM sites. Using 22 MCM sites covered more than 75% of the population, an improvement over the current site placement, adding nearly 600,000 Iowa residents. Given scarce public health resources, MCMs can help surveillance efforts by prioritizing recruitment of sentinel locations.

The duration of mumps virus shedding after the onset of symptoms.

To determine how long people shed virus after the onset of mumps, we used logistic regression modeling to analyze data from the 2006 outbreak of mumps in Iowa. Our model establishes that the probability of mumps virus shedding decreases rapidly after the onset of symptoms. However, we estimate that 8%-15% of patients will still be shedding the virus 5 days after the onset of symptoms and, thus, may still be contagious during this period.