Background SARS-CoV-2, the virus that causes COVID-19 disease, was first identified in Wuhan, China in December 2019, with subsequent worldwide spread. The first U.S. cases were identified in January 2020. Methods To determine if SARS-CoV-2 reactive antibodies were present in sera prior to the first identified case in the U.S. on January 19, 2020, residual archived samples from 7,389 routine blood donations collected by the American Red Cross from December 13, 2019 to January 17, 2020, from donors resident in nine states (California, Connecticut, Iowa, Massachusetts, Michigan, Oregon, Rhode Island, Washington, and Wisconsin) were tested at CDC for anti-SARS-CoV-2 antibodies. Specimens reactive by pan-immunoglobulin (pan Ig) enzyme linked immunosorbent assay (ELISA) against the full spike protein were tested by IgG and IgM ELISAs, microneutralization test, Ortho total Ig S1 ELISA, and receptor binding domain / Ace2 blocking activity assay. Results Of the 7,389 samples, 106 were reactive by pan Ig. Of these 106 specimens, 90 were available for further testing. Eighty four of 90 had neutralizing activity, 1 had S1 binding activity, and 1 had receptor binding domain / Ace2 blocking activity >50%, suggesting the presence of anti-SARS-CoV-2-reactive antibodies. Donations with reactivity occurred in all nine states. Conclusions These findings suggest that SARS-CoV-2 may have been introduced into the United States prior to January 19, 2020.

IMPORTANCEAs self-collected home antigen tests become widely available, a better understanding of their performance during the course of SARS-CoV-2 infection is needed. OBJECTIVE To evaluate the diagnostic performance of home antigen tests compared with reverse transcription-polymerase chain reaction (RT-PCR) and viral culture by days from illness onset, as well as user acceptability. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study was conducted from January to May 2021 in San Diego County, California, and metropolitan Denver, Colorado. The convenience sample included adults and children with RT-PCR-confirmed infection who used self-collected home antigen tests for 15 days and underwent at least 1 nasopharyngeal swab for RT-PCR, viral culture, and sequencing. EXPOSURES SARS-CoV-2 infection. MAIN OUTCOMES AND MEASURES The primary outcome was the daily sensitivity of home antigen tests to detect RT-PCR-confirmed cases. Secondary outcomes included the daily percentage of antigen test, RT-PCR, and viral culture results that were positive, and antigen test sensitivity compared with same-day RT-PCR and cultures. Antigen test use errors and acceptability were assessed for a subset of participants. RESULTS This study enrolled 225 persons with RT-PCR-confirmed infection (median [range] age, 29 [1-83] years; 117 female participants [52%]; 10 [4%] Asian, 6 [3%] Black or African American, 50 [22%] Hispanic or Latino, 3 [1%] Native Hawaiian or Other Pacific Islander, 145[64%] White, and 11 [5%] multiracial individuals) who completed 3044 antigen tests and 642 nasopharyngeal swabs. Antigen test sensitivity was 50% (95% CI, 45%-55%) during the infectious period, 64% (95% CI, 56%-70%) compared with same-day RT-PCR, and 84% (95% CI, 75%-90%) compared with same-day cultures. Antigen test sensitivity peaked 4 days after illness onset at 77% (95% CI, 69%-83%). Antigen test sensitivity improved with a second antigen test 1 to 2 days later, particularly early in the infection. Six days after illness onset, antigen test result positivity was 61% (95% CI, 53%-68%). Almost all (216 [96%]) surveyed individuals reported that they would be more likely to get tested for SARS-CoV-2 infection if home antigen tests were available over the counter. CONCLUSIONS AND RELEVANCEThe results of this cohort study of home antigen tests suggest that sensitivity for SARS-CoV-2 was moderate compared with RT-PCR and high compared with viral culture. The results also suggest that symptomatic individuals with an initial negative home antigen test result for SARS-CoV-2 infection should test again 1 to 2 days later because test sensitivity peaked several days after illness onset and improved with repeated testing.

During the past decade, extended-spectrum cephalosporin resistance has increased among human isolates of Salmonella enterica serovar Heidelberg, the fourth most common serotype in the United States. We therefore characterized 54 Heidelberg isolates with decreased susceptibility (minimum inhibitory concentrations >or=2 mg/L) to ceftriaxone or ceftiofur; 49 (90.7%) contained the CMY-type beta-lactamase (bla(CMY)) gene. The 49 bla(CMY)-positive human Heidelberg isolates demonstrated a high degree of relatedness; 4 clusters (25 isolates total) had indistinguishable XbaI and BlnI patterns by pulsed-field gel electrophoresis and were indistinguishable from 42 retail meat Heidelberg isolates. Further characterization of 15 of these isolates demonstrated that all of the bla genes were bla(CMY-2) and plasmid-encoded, and most (11/15) of the plasmids were approximately 100 kb in size and belong to the incompatibility group I1 (IncI1). All five IncI1 plasmids tested by plasmid multilocus sequence typing analysis were ST12. This report suggests that extended-spectrum cephalosporin resistance among human Heidelberg isolates is mediated by the spread of a common IncI1 bla(CMY-2) plasmid, which may have a preference for a particular genetic background.

Gordonia species are aerobic actinomycetes recently recognized as causing human disease, often in the setting of intravascular catheter-related infections. We describe a case of Gordonia bronchialis bacteremia and pleural space infection in the absence of an indwelling intravascular catheter and review the breadth of reported infections with this emerging pathogen. CASE REPORTA 52-year-old woman with a history of Hodgkin's lymphoma, prior splenectomy, and breast cancer was experiencing recurrent pleural effusions over several months prior to admission and presented with bloody drainage from an indwelling pleural catheter. The patient had been diagnosed with Hodgkin's lymphoma 35 years earlier and was treated with radiation therapy to the neck, chest, and abdomen at that time. She underwent a splenectomy for a splenic artery aneurysm 14 years prior to presentation. Five years prior to presentation, she had cardiac surgery for radiation-induced valvular disease, with placement of a St. Jude's mechanical prosthetic valve at the aortic position and repair of mitral and tricuspid valves with biological prosthetic material; a cardiac pacemaker for a heart block was placed. Four years prior to presentation, she had undergone bilateral mastectomies for breast cancer and was subsequently treated with tamoxifen and then anastrozole. Six months prior to presentation, she developed bilateral pleural effusions. The pleural fluid sampled on two occasions was consistent with exudative effusions, with slight lymphocyte predominance and negative Gram stains and cultures, including mycobacterial culture; cytology for malignant cells was negative. Based on these studies, the etiology of the pleural disease was unclear but was thought to be a late complication of her radiation therapy 35 years previously. Bilateral indwelling pleural catheters were placed, and the left-sided catheter was later removed when drainage ceased. In the weeks prior to the most recent presentation, the patient initiated systemic anticoagulation therapy for atrial fibrillation. She subsequently developed bloody drainage from the remaining right-sided indwelling pleural catheter, at which time she was admitted for further evaluation. She did not experience fever, chills, night sweats, cough, or other new symptoms.At the time of admission, the patient was afebrile. Blood cultures were drawn, and empirical therapy with vancomycin and ceftazidime was initiated. Anticoagulation therapy was discontinued. She subsequently developed rapid respiratory deterioration. On the fourth hospital day, video-assisted thorascopic surgery (VATS) was performed for drainage of a right-sided loculated pleural effusion, decortication, and placement of a right-sided chest tube (Fig. 1). She subsequently improved clinically, remaining afebrile on empirical antibacterial therapy. However, after 4 days of incubation, the aerobic blood culture bottle drawn on the day of admission grew Gram-positive rods, which also stained weakly acid fast (Fig. 2). All further blood cultures after in...