No abstract

In 2002, a sharp increase in outbreaks of norovirus-associated illness, both on cruise ships and on land, encouraged us to examine the molecular epidemiology of detected noroviruses, to identify a common strain or source. Of 14 laboratory-confirmed outbreaks on cruise ships, 12 (86%) were attributed to caliciviruses; among these 12, outbreak characteristics included continuation on successive cruises in 6 (50%), multiple modes of transmission in 7 (58%), and high (>10%) attack rates in 7 (58%). Eleven of the 12 calicivirus outbreaks were attributed to noroviruses, 7 (64%) of which were attributed to a previously unreported lineage, provisionally named "the Farmington Hills strain." From May 2002 to December 2002, 10 (45%) of 22 land-based outbreaks also were attributed to this strain. Nucleotide-sequence analysis provided insights into norovirus transmission, by documenting links among outbreaks, the introduction of strains onto ships, and viral persistence on board (despite cleaning). Control measures for outbreaks should address all routes of transmission. Better outbreak surveillance and collection of data on sequences will help to monitor norovirus strains and to identify common sources.

IMPORTANCE Preventive interventions are needed to protect residents and staff of skilled nursing and assisted living facilities from COVID-19 during outbreaks in their facilities. Bamlanivimab, a neutralizing monoclonal antibody against SARS-CoV-2, may confer rapid protection from SARS-CoV-2 infection and COVID-19.OBJECTIVE To determine the effect of bamlanivimab on the incidence of COVID-19 among residents and staff of skilled nursing and assisted living facilities. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind, single-dose, phase 3 trial that enrolled residents and staff of 74 skilled nursing and assisted living facilities in the United States with at least 1 confirmed SARS-CoV-2 index case. A total of 1175 participants enrolled in the study from August 2 to November 20, 2020. Database lock was triggered on January 13, 2021, when all participants reached study day 57.INTERVENTIONS Participants were randomized to receive a single intravenous infusion of bamlanivimab, 4200 mg (n = 588), or placebo (n = 587). MAIN OUTCOMES AND MEASURESThe primary outcome was incidence of COVID-19, defined as the detection of SARS-CoV-2 by reverse transcriptase-polymerase chain reaction and mild or worse disease severity within 21 days of detection, within 8 weeks of randomization. Key secondary outcomes included incidence of moderate or worse COVID-19 severity and incidence of SARS-CoV-2 infection. RESULTSThe prevention population comprised a total of 966 participants (666 staff and 300 residents) who were negative at baseline for SARS-CoV-2 infection and serology (mean age, 53.0 [range, 18-104] years; 722 [74.7%] women). Bamlanivimab significantly reduced the incidence of COVID-19 in the prevention population compared with placebo (8.5% vs 15.2%; odds ratio, 0.43 [95% CI, 0.28-0.68]; P < .001; absolute risk difference, −6.6 [95% CI, −10.7 to −2.6] percentage points). Five deaths attributed to COVID-19 were reported by day 57; all occurred in the placebo group. Among 1175 participants who received study product (safety population), the rate of participants with adverse events was 20.1% in the bamlanivimab group and 18.9% in the placebo group. The most common adverse events were urinary tract infection (reported by 12 participants [2%] who received bamlanivimab and 14 [2.4%] who received placebo) and hypertension (reported by 7 participants [1.2%] who received bamlanivimab and 10 [1.7%] who received placebo).CONCLUSIONS AND RELEVANCE Among residents and staff in skilled nursing and assisted living facilities, treatment during August-November 2020 with bamlanivimab monotherapy reduced the incidence of COVID-19 infection. Further research is needed to assess preventive efficacy with current patterns of viral strains with combination monoclonal antibody therapy.

Background Pre-exposure prophylaxis (PrEP) is the first biomedical intervention with proven efficacy to reduce human immunodeficiency virus (HIV) acquisition in men who have sex with men (MSM) and transgender women (TGW). Little is known about levels of interest and characteristics of individuals who elect to take PrEP in real-world clinical settings. Methods The US PrEP Demonstration Project is a prospective, open-label cohort study assessing PrEP delivery in municipal STD clinics in San Francisco and Miami and a community health center in Washington, DC. HIV-uninfected MSM and TGW seeking sexual health services at participating clinics were assessed for eligibility and offered up to 48 weeks of emtricitabine/tenofovir for PrEP. Predictors of enrollment were assessed using a multivariable Poisson regression model, and characteristics of enrolled participants are described. Results Of 1069 clients assessed for participation, 921 were potentially eligible and 557 (60.5%) enrolled. In multivariable analysis, participants from Miami (aRR 1.53; 95% CI 1.33-1.75) or DC (aRR 1.33; 95% CI 1.2-1.47), those who were self-referred (aRR 1.48; 95% CI 1.32-1.66), with prior PrEP awareness (aRR 1.56; 95% CI 1.05-2.33) and those reporting >1 episode of anal sex with an HIV-infected partner in the last 12 months (aRR 1.20; 95% CI 1.09-1.33) were more likely to enroll. Almost all (98%) of enrolled participants were MSM, and at baseline, 63.5% reported condomless receptive anal sex in the prior three months. Conclusions Interest in PrEP is high among a diverse population of MSM at risk for HIV infection when offered in STD and community health clinics.