Explore the vast range of titles available.

Multiplex PCR methods are attractive to clinical laboratories wanting to broaden their detection of respiratory viral pathogens in clinical specimens. However, multiplexed assays must be well optimized to retain or improve upon the analytic sensitivity of their singleplex counterparts. In this experiment, the lower limit of detection (LOD) of singleplex real-time PCR assays targeting respiratory viruses is compared to an equivalent panel on a multiplex PCR platform, the GenMark eSensor RVP. LODs were measured for each singleplex real-time PCR assay and expressed as the lowest copy number detected 95-100% of the time, depending on the assay. The GenMark eSensor RVP LODs were obtained by converting the TCID50/mL concentrations reported in the package insert to copies/μL using qPCR. Analytical sensitivity between the two methods varied from 1.2-1280.8 copies/μL (0.08-3.11 log differences) for all 12 assays compared. Assays targeting influenza A/H3N2, influenza A/H1N1pdm09, influenza B, and human parainfluenza 1 and 2 were most comparable (1.2-8.4 copies/μL, <1 log difference). Largest differences in LOD were demonstrated for assays targeting adenovirus group E, respiratory syncytial virus subtype A, and a generic assay for all influenza A viruses regardless of subtype (319.4-1280.8 copies/μL, 2.50-3.11 log difference). The multiplex PCR platform, the GenMark eSensor RVP, demonstrated improved analytical sensitivity for detecting influenza A/H3 viruses, influenza B virus, human parainfluenza virus 2, and human rhinovirus (1.6-94.8 copies/μL, 0.20-1.98 logs). Broader detection of influenza A/H3 viruses was demonstrated by the GenMark eSensor RVP. The relationship between TCID50/mL concentrations and the corresponding copy number related to various ATCC cultures is also reported.

[This corrects the article DOI: 10.1371/journal.pone.0143164.].

Abstract Background Influenza outbreaks can occur among passengers and crews during the Alaska summertime cruise season. Ill travellers represent a potential source for introduction of novel or antigenically drifted influenza virus strains to the United States. From May to September 2013–2015, the Alaska Division of Public Health, the Centers for Disease Control and Prevention (CDC), and two cruise lines implemented a laboratory-based public health surveillance project to detect influenza and other respiratory viruses among ill crew members and passengers on select cruise ships in Alaska. Methods Cruise ship medical staff collected 2–3 nasopharyngeal swab specimens per week from passengers and crew members presenting to the ship infirmary with acute respiratory illness (ARI). Specimens were tested for respiratory viruses at the Alaska State Virology Laboratory (ASVL); a subset of specimens positive for influenza virus were sent to CDC for further antigenic characterization. Results Of 410 nasopharyngeal specimens, 83% tested positive for at least one respiratory virus; 71% tested positive for influenza A or B virus. Antigenic characterization of pilot project specimens identified strains matching predominant circulating seasonal influenza virus strains, which were included in the northern or southern hemisphere influenza vaccines during those years. Results were relatively consistent across age groups, recent travel history, and influenza vaccination status. Onset dates of illness relative to date of boarding differed between northbound (occurring later in the voyage) and southbound (occurring within the first days of the voyage) cruises. Conclusions The high yield of positive results indicated that influenza was common among passengers and crews sampled with ARI. This finding reinforces the need to bolster influenza prevention and control activities on cruise ships. Laboratory-based influenza surveillance on cruise ships may augment inland influenza surveillance and inform control activities. However, these benefits should be weighed against the costs and operational limitations of instituting laboratory-based surveillance programs on ships.

Background. Human infection by orthopoxviruses is being reported with increasing frequency, attributed in part to the cessation of smallpox vaccination and concomitant waning of population-level immunity. In July 2015, a female resident of interior Alaska presented to an urgent care clinic with a dermal lesion consistent with poxvirus infection. Laboratory testing of a virus isolated from the lesion confirmed infection by an Orthopoxvirus. Methods. The virus isolate was characterized by using electron microscopy and nucleic acid sequencing. An epidemiologic investigation that included patient interviews, contact tracing, and serum testing, as well as environmental and small-mammal sampling, was conducted to identify the infection source and possible additional cases. Results. Neither signs of active infection nor evidence of recent prior infection were observed in any of the 4 patient contacts identified. The patient's infection source was not definitively identified. Potential routes of exposure included imported fomites from Azerbaijan via the patient's cohabiting partner or wild small mammals in or around the patient's residence. Phylogenetic analyses demonstrated that the virus represents a distinct and previously undescribed genetic lineage of Orthopoxvirus, which is most closely related to the Old World orthopoxviruses. Conclusions. Investigation findings point to infection of the patient after exposure in or near Fairbanks. This conclusion raises questions about the geographic origins (Old World vs North American) of the genus Orthopoxvirus. Clinicians should remain vigilant for signs of poxvirus infection and alert public health officials when cases are suspected.

Multiplex PCR methods are attractive to clinical laboratories wanting to broaden their detection of respiratory viral pathogens in clinical specimens. However, multiplexed assays must be well optimized to retain or improve upon the analytic sensitivity of their singleplex counterparts. In this experiment, the lower limit of detection (LOD) of singleplex real-time PCR assays targeting respiratory viruses is compared to an equivalent panel on a multiplex PCR platform, the GenMark eSensor RVP. LODs were measured for each singleplex real-time PCR assay and expressed as the lowest copy number detected 95-100% of the time, depending on the assay. The GenMark eSensor RVP LODs were obtained by converting the TCID50/mL concentrations reported in the package insert to copies/ML using qPCR. Analytical sensitivity between the two methods varied from 1.2-1280.8 copies/ML (0.08-3.11 log differences) for all 12 assays compared. Assays targeting influenza A/H3N2, influenza A/H1N1pdm09, influenza B, and human parainfluenza 1 and 2 were most comparable (1.2-8.4 copies/ML, <1 log difference). Largest differences in LOD were demonstrated for assays targeting adenovirus group E, respiratory syncytial virus subtype A, and a generic assay for all influenza A viruses regardless of subtype (319.4-1280.8 copies/ML, 2.50-3.11 log difference). The multiplex PCR platform, the GenMark eSensor RVP, demonstrated improved analytical sensitivity for detecting influenza A/H3 viruses, influenza B virus, human parainfluenza virus 2, and human rhinovirus (1.6-94.8 copies/ML, 0.20-1.98 logs). Broader detection of influenza A/H3 viruses was demonstrated by the GenMark eSensor RVP. The relationship between TCID50/mL concentrations and the corresponding copy number related to various ATCC cultures is also reported.

The SARS-CoV-2 3CL protease is a critical drug target for small molecule COVID-19 therapy, given its likely druggability and essentiality in the viral maturation and replication cycle. Based on the conservation of 3CL protease substrate binding pockets across coronaviruses and using screening, we identified four structurally distinct lead compounds that inhibit SARS-CoV-2 3CL protease. After evaluation of their binding specificity, cellular antiviral potency, metabolic stability, and water solubility, we prioritized the GC376 scaffold as being optimal for optimization. We identified multiple drug-like compounds with <10 nM potency for inhibiting SARS-CoV-2 3CL and the ability to block SARS-CoV-2 replication in human cells, obtained co-crystal structures of the 3CL protease in complex with these compounds, and determined that they have pan-coronavirus activity. We selected one compound, termed coronastat, as an optimized lead and characterized it in pharmacokinetic and safety studies in vivo. Coronastat represents a new candidate for a small molecule protease inhibitor for the treatment of SARS-CoV-2 infection for eliminating pandemics involving coronaviruses. Small molecule drugs promise to remain a valuable tool in controlling the ongoing COVID-19 pandemic. Here the authors describe optimized drug-like small molecule inhibitors of the SARS-CoV-2 3CL protease for potential treatment of COVID-19.

Objectives To assess racial and ethnic minority parents’ perceptions about barriers to well-child visit attendance. Methods For this cross-sectional qualitative study, we recruited parents of pediatric primary care patients who were overdue for a well-child visit from the largest safety net healthcare organization in central Massachusetts to participate in semi-structured interviews. The interviews focused on understanding potential knowledge, structural, and experiential barriers for well-child visit attendance. Interview content was inductively coded and directed content analysis was performed to identify themes. Results Twenty-five racial and ethnic minority parents participated; 17 (68%) of whom identified Spanish as a primary language spoken at home. Nearly all participants identified the purpose, significance, and value of well-child visits. Structural barriers were most cited as challenges to attending well-child visits, including parking, transportation, language, appointment availability, and work/other competing priorities. While language emerged as a distinct barrier, it also exacerbated some of the structural barriers identified. Experiential barriers were cited less commonly than structural barriers and included interactions with office staff, racial/ethnic discrimination, appointment reminders, methods of communication, wait time, and interactions with providers. Conclusions Racial and ethnic minority parents recognize the value of well-child visits; however, they commonly encounter structural barriers that limit access to care. Furthermore, a non-English primary language compounds the impact of these structural barriers. Understanding these barriers is important to inform health system policies to enhance access and delivery of pediatric care with a lens toward reducing racial and ethnic-based inequities.

Paediatric COVID-19 vaccination programmes were initiated in response to the coronavirus pandemic declared by the World Health Organisation (WHO) in 2020. Ten COVID-19 vaccines received WHO Emergency Use Listing, however, only five were approved for use in children. ChAdOx1 nCoV-19 (AZD1222) was approved in adults in a two-dose regimen. We previously reported interim findings of a phase 2 study of ChAdOx1 nCoV-19 in children with immunogenicity, comparable with adults. Final results after 12 month follow-up are reported. Single-blind, randomised controlled trial across four UK centres, recruiting 261 children and adolescents (aged 6-17 years). Participants received either two doses of ChAdOx1 nCoV-19 or Bexsero vaccine (controls). The primary outcome was safety (adverse events for 28 days following vaccination and serious adverse events throughout), and secondary outcome was immunogenicity (measured by SARS-CoV-2 anti-spike enzyme-linked immunosorbent assay (ELISA) and enzyme-linked immunosorbent spot (ELISpot)). Five serious adverse events and four adverse events of special interest were reported. None were related to study vaccinations, and there were no deaths. Geometric mean titres (GMTs) from an anti-spike (Wuhan) ELISA in participants aged 6-11 years were 1 EU/ml (95% CI 1-2) at baseline versus 796 EU (95% CI 161-3948, n =4) at D364. In participants aged 12-17 years, GMTs were 1 EU/ml (95% CI 1-2, n=3) at baseline versus 1432 EU/ml (95% CI 2337-6083; n=6) at D364 (2 dose regimen at 112-day interval), compared to 3 EU/ml (95% CI 0-62) at baseline versus 392 EU/ml (95% CI 24, 6493; n=3) at D364 (2 dose regimen at a 28-day interval). A two-dose regimen of ChAdOx1 nCoV-19 was immunogenic and safe in the trial population. No vaccine-related serious adverse events were reported. Immune responses persisted to 12 months in participants who did not experience breakthrough infection, This trial was registered with ISRCTN, trial number 15638344. The study was funded by the Department of Health and Social Care, through the National Institute for Health Research, and AstraZeneca.