c Rapid identification of microorganisms causing bloodstream infections directly from a positive blood culture would decrease the time to directed antimicrobial therapy and greatly improve patient care. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) is a fast and reliable method for identifying microorganisms from positive culture. This study evaluates the performance of a novel filtration-based method for processing positive-blood-culture broth for immediate identification of microorganisms by MALDI-TOF with a Vitek MS research-use-only system (VMS). BacT/Alert non-charcoal-based blood culture bottles that were flagged positive by the BacT/Alert 3D system were included. An aliquot of positiveblood-culture broth was incubated with lysis buffer for 2 to 4 min at room temperature, the resulting lysate was filtered through a membrane, and harvested microorganisms were identified by VMS. Of the 259 bottles included in the study, VMS identified the organisms in 189 (73%) cultures to the species level and 51 (19.7%) gave no identification (ID), while 6 (2.3%) gave identifications that were considered incorrect. Among 131 monomicrobic isolates from positive-blood-culture bottles with one spot having a score of 99.9%, the IDs for 131 (100%) were correct to the species level. In 202 bottles where VMS was able to generate an ID, the IDs for 189 (93.6%) were correct to the species level, whereas the IDs provided for 7 isolates (3.5%) were incorrect. In conclusion, this method does not require centrifugation and produces a clean spectrum for VMS analysis in less than 15 min. This study demonstrates the effectiveness of the new lysis-filtration method for identifying microorganisms directly from positive-blood-culture bottles in a clinical setting. R ecently, new mass spectrometry (MS) technology has been introduced as a way to quickly and accurately identify bacteria. Compared to standard phenotypic identification, this technology is rapid, requires reagents that are inexpensive (after initial purchase of the instrument), and could provide accurate results comparable to those provided by 16S rRNA sequencing (1). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS has been shown to accurately identify bacteria grown on solid medium to the species level (2-4) and has the potential to serve as a fast and reliable method for identifying microorganisms directly from blood.Rapid identification of organisms causing bloodstream infections after a blood culture turns positive has the potential to improve patient care, and protocols have been developed for use with MALDI-TOF instrumentation. Previously published studies have explored a variety of approaches to accomplish this task, generally using a series of washes, centrifugations, protein extraction, and analysis using dedicated databases (e.g., BioTyper and SARAMIS) (1,3,(5)(6)(7)(8)(9)(10)(11).The Vitek MS research-use-only (RUO) system (VMS) with the SARAMIS database by bioMérieux (Durham, NC) is a research-us...

the CDC COVID-19 Response Team 1We evaluated the performance of self-collected anterior nasal swab (ANS) and saliva samples compared with healthcare worker-collected nasopharyngeal swab specimens used to test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We used the same PCR diagnostic panel to test all self-collected and healthcare worker-collected samples from participants at a public hospital in Atlanta, Georgia, USA. Among 1,076 participants, 51.9% were men, 57.1% were >50 years of age, 81.2% were Black (non-Hispanic), and 74.9% reported >1 chronic medical condition. In total, 8.0% tested positive for SARS-CoV-2. Compared with nasopharyngeal swab samples, ANS samples had a sensitivity of 59% and saliva samples a sensitivity of 68%. Among participants tested 3-7 days after symptom onset, ANS samples had a sensitivity of 80% and saliva samples a sensitivity of 85%. Sensitivity varied by specimen type and patient characteristics. These fi ndings can help physicians interpret PCR results for SARS-CoV-2. 1 Members are listed at the end of this article.

Mpox represents a diagnostic challenge due to varied clinical presentations and multiple mimics. A commercially available multiplex PCR panel accurately detects mpox virus as well as common mimics (HSV, VZV) in clinical specimens and could be used in routine clinical, surveillance, and outbreak settings.

Background The natural history and clinical progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can be better understood using combined serological and reverse transcription polymerase chain reaction (RT-PCR) testing. Methods Nasopharyngeal swabs and serum were collected at a single time-point from patients at an urban, public hospital August – November 2020 and tested for SARS-CoV-2 using RT-PCR, viral culture, and anti-Spike pan-Ig antibody testing. Participant demographics and symptoms were collected through interview. Chi-squared and Fisher’s exact tests were used to identify associations between RT-PCR and serology results with presence of viable virus and frequency of symptoms. Results Among 592 participants, 129 (21.8%) had evidence of SARS-CoV-2 infection by RT-PCR or serology. Presence of SARS-CoV-2 antibodies was strongly associated with lack of viable virus (p-value=0.016). COVID-19 symptom frequency was similar for patients testing RT-PCR positive/seronegative and patients testing RT-PCR positive/seropositive. Patients testing RT-PCR positive/seronegative reported headaches, fatigue, diarrhea and vomiting at rates not statistically significantly different from those testing RT-PCR negative/seropositive. Conclusions While patients testing SARS-CoV-2 seropositive were unlikely to test positive for viable virus and were therefore low-risk for forward transmission, COVID-19 symptoms were common. Paired SARS-CoV-2 RT-PCR and antibody testing provides more nuanced understanding of patients’ COVID-19 status.

We aimed to describe frequency of COVID-19 exposure risk factors among patients presenting for medical care at an urban, public hospital serving mostly uninsured/Medicare/Medicaid clients and risk factors associated with SARS-CoV-2 infection. Consenting, adult patients seeking care at a public hospital from August to November 2020 were enrolled in this cross-sectional investigation. Saliva, anterior nasal and nasopharyngeal swabs were collected and tested for SARS-CoV-2 using RT-PCR. Participant demographics, close contact, and activities ≤14 days prior to enrollment were collected through interview. Logistic regression was used to identify risk factors associated with testing positive for SARS-CoV-2. Among 1,078 participants, 51.8% were male, 57.0% were aged ≥50 years, 81.3% were non-Hispanic Black, and 7.6% had positive SARS-CoV-2 tests. Only 2.7% reported COVID-19 close contact ≤14 days before enrollment; this group had 6.79 adjusted odds of testing positive (95%CI = 2.78–16.62) than those without a reported exposure. Among participants who did not report COVID-19 close contact, working in proximity to ≥10 people (adjusted OR = 2.17; 95%CI = 1.03–4.55), choir practice (adjusted OR = 11.85; 95%CI = 1.44–97.91), traveling on a plane (adjusted OR = 5.78; 95%CI = 1.70–19.68), and not participating in an essential indoor activity (i.e., grocery shopping, public transit use, or visiting a healthcare facility; adjusted OR = 2.15; 95%CI = 1.07–4.30) were associated with increased odds of testing positive. Among this population of mostly Black, non-Hispanic participants seeking care at a public hospital, we found several activities associated with testing positive for SARS-CoV-2 infection in addition to close contact with a case. Understanding high-risk activities for SARS-CoV-2 infection among different communities is important for issuing awareness and prevention strategies.