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1.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22278274

RESUMO

BackgroundOver-the-counter rapid antigen tests for SARS-CoV-2 with an Emergency Use Authorization (EUA) in the United States generally include a condition of authorization to evaluate the tests performance in asymptomatic individuals when used serially. A goal of this study was to investigate the performance of SARS-CoV-2 antigen serial testing and generate data to support regulatory decisions. ObjectiveTo describe a novel study design to evaluate serial use of rapid antigen tests in detecting SARS-CoV-2 virus among asymptomatic individuals. DesignProspective cohort study using a decentralized approach. Eligible participants from across the U.S. could enroll and complete this study from their home environment through a study app. Participant enrollment was prioritized based on regional 7-day case rates, participants vaccination status, and sociodemographic characteristics prior to enrollment. Prioritization criteria were adjusted on a daily or weekly basis. Enrolled participants were mailed rapid antigen tests and molecular comparator collection kits and asked to test every 48 hours for 15 days. Three companies rapid antigen tests were used in the study; assignment of participant to a test was criteria-based and non-random, precluding head-to-head comparison between the tests. ParticipantsMainland United States residents over 2 years old with no reported COVID-19 symptoms in the 14 days prior to study enrollment. Main MeasuresParticipant demographics, COVID-19 vaccination status, and geographic distribution were used to understand the impact of the site-less recruitment and enrollment strategy. Key ResultsA total of 7,361 participants enrolled in the study between October 18, 2021 and February 15, 2022. Throughout the study, 369 participants tested positive for SARS-CoV-2, including 167 who were asymptomatic and tested negative on SARS-CoV-2 molecular assays to start the study. This exceeded the initial enrollment goals of 60 positive participants. We enrolled participants from 44 of the 48 mainland U.S. states, and geographic distribution of participants shifted in accordance with the changing COVID-19 prevalence nationwide. ConclusionsThe novel, digital site-less approach employed in the Test Us At Home study enabled rapid, efficient, and rigorous evaluation of rapid diagnostics for COVID-19, and can be adapted across research disciplines to optimize study enrollment and accessibility.

2.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22272727

RESUMO

ImportanceWide-spread distribution of diagnostics is an integral part of the United States COVID-19 strategy; however, few studies have assessed the effectiveness of this intervention at reducing transmission of community COVID-19. ObjectiveTo assess the impact of the Say Yes! Covid Test (SYCT!) Michigan program, a population-based program that distributed 20,000 free rapid antigen tests within Ann Arbor and Ypsilanti, Michigan in June-August 2021, on community prevalence of SARS-CoV-2. DesignThis ecological study analyzed cases of SARS-CoV-2 from March to October 2021 reported to the Washtenaw County Health Department. SettingWashtenaw County, Michigan ParticipantsAll residents of Washtenaw County InterventionsCommunity-wide distribution of 500,000 rapid antigen tests for SARS-CoV-2 to residents of Ann Arbor and Ypsilanti, Michigan. Each household was limited to one test kit containing 25 rapid antigen tests. Main Outcome and MeasuresCommunity prevalence of SARS-CoV-2, as measured through 7-day average cases, in Ann Arbor and Ypsilanti was compared to the rest of Washtenaw County. A generalized additive model was fitted with non-parametric trends for control and relative differences of trends in the pre-intervention, intervention, and post-intervention periods to compare intervention municipalities of Ann Arbor and Ypsilanti to the rest of Washtenaw County. Model results were used to calculate average cases prevented in the post-intervention period. ResultsIn the post-intervention period, there were significantly lower standardized average cases in the intervention communities of Ann Arbor/Ypsilanti compared to the rest of Washtenaw County (p<0.001). The estimated standardized relative difference between Ann Arbor/Ypsilanti and the rest of Washtenaw County was -0.016 cases per day (95% CI: -0.020 to -0.013), implying that the intervention prevented 40 average cases per day two months into the post-intervention period if trends were consistent. Conclusions and RelevanceMass distribution of rapid antigen tests may be a useful mitigation strategy to combat community transmission of SARS-CoV-2, especially given the recent relaxation of social distancing and masking requirements.

3.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22273242

RESUMO

ImportanceWide-spread distribution of rapid-antigen tests is integral to the United States strategy to address COVID-19; however, it is estimated that few rapid-antigen test results are reported to local departments of health. ObjectiveTo characterize how often individuals in six communities throughout the United States used a digital assistant to log rapid-antigen test results and report them to their local Department of Health. DesignThis prospective cohort study is based on anonymously collected data from the beneficiaries of The Say Yes! Covid Test program, which distributed 3,000,000 rapid antigen tests at no cost to residents of six communities between April and October 2021. We provide a descriptive evaluation of beneficiaries use of digital assistant for logging and reporting their rapid antigen test results. Main Outcome and MeasuresNumber and proportion of tests logged and reported to the Department of Health through the digital assistant ResultsA total of 178,785 test kits were ordered by the digital assistant, and 14,398 households used the digital assistant to log 41,465 test results. Overall, a small proportion of beneficiaries used the digital assistant (8%), but over 75% of those who used it reported their rapid antigen test results to their state public health department. The reporting behavior varied between communities and was significantly different for communities that were incentivized for reporting test results (p < 0.001). In all communities, positive tests were less reported than negative tests (60.4% vs 75.5%; p<0.001). Conclusions and RelevanceThese results indicate that app-based reporting with incentives may be an effective way to increase reporting of rapid tests for COVID-19; however, increasing the adoption of the digital assistant is a critical first step.

4.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22271090

RESUMO

BackgroundThere is a need to understand the performance of rapid antigen tests (Ag-RDT) for detection of the Delta (B.1.61.7; AY.X) and Omicron (B.1.1.529; BA1) SARS-CoV-2 variants. MethodsParticipants without any symptoms were enrolled from October 18, 2021 to January 24, 2022 and performed Ag-RDT and RT-PCR tests every 48 hours for 15 days. This study represents a non-pre-specified analysis in which we sought to determine if sensitivity of Ag-RDT differed in participants with Delta compared to Omicron variant. Participants who were positive on RT-PCR on the first day of the testing period were excluded. Delta and Omicron variants were defined based on sequencing and date of first RT-PCR positive result (RT-PCR+). Comparison of Ag-RDT performance between the variants was based on sensitivity, defined as proportion of participants with Ag-RDT+ results in relation to their first RT-PCR+ result, for different duration of testing with rapid Ag-RDT. Subsample analysis was performed based on the result of participants second RT-PCR test within 48 hours of the first RT-PCR+ test. ResultsFrom the 7,349 participants enrolled in the parent study, 5,506 met the eligibility criteria for this analysis. A total of 153 participants were RT-PCR+ (61 Delta, 92 Omicron); among this group, 36 (23.5%) tested Ag-RDT+ on the same day, and 84 (54.9%) tested Ag-RDT+ within 48 hours as first RT-PCR+. The differences in sensitivity between variants were not statistically significant (same-day: Delta 16.4% [95% CI: 8.2-28.1] vs Omicron 28.2% [95% CI: 19.4-38.6]; and 48-hours: Delta 45.9% [33.1-59.2] vs. Omicron 60.9% [50.1-70.9]). This trend continued among the 86 participants who had consecutive RT-PCR+ result (48-hour sensitivity: Delta 79.3% [60.3-92.1] vs. Omicron: 89.5% [78.5-96.0]). Conversely, the 38 participants who had an isolated RT-PCR+ remained consistently negative on Ag-RDT, regardless of the variant. ConclusionsThe performance of Ag-RDT is not inferior among individuals infected with the SARS-CoV-2 Omicron variant as compared to the Delta variant. The improvement in sensitivity of Ag-RDT noted with serial testing is consistent between Delta and Omicron variant. Performance of Ag-RDT varies based on duration of RT-PCR+ results and more studies are needed to understand the clinical and public health significance of individuals who are RT-PCR+ for less than 48 hours.

5.
Cancer Research and Clinic ; (6): 107-111, 2016.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-492079

RESUMO

Objective To investigate the prevalence and genotype distribution of human papilloma virus (HPV) infection among patients with cervical carcinoma or precancerous lesions in Xuzhou region. Methods 688 patients with cervical lesions confirmed by colposcopic biopsy were assigned to three groups:low-grade squamous intraepithelial lesion (LSIL) (187 cases), high-grade squamous intraepithelial lesion (HSIL) (359 cases) and cervical carcinoma (142 cases). The genotypes of HPV were determined by nucleic acid hybridization technique. The prevalence and genotype distribution of HPV were further analyzed. Results The infection rates of HPV in LSIL , HSIL and ICC group were 68.98 % (129/187), 94.99 % (341/359), 95.78 % (136/142), respectively. These rates were statistically significant different (P< 0.05). With the aggravation of cervical lesions, HR-HPV infection rate was gradually increased and LR-HPV infection rate was gradually decreased. The most common HPV types were listed below in order of decreasing prevalence. LSIL:HPV16, 52, 58, 18, 31; HSIL: HPV16, 58, 33, 31, 52; cervical carcinoma: HPV16, 31, 58, 18, 33. Based on the cumulative logistic regression model, confidence intervals of the relevance between the overall HPV prevalence and occurrence of cervical lesions were calculated: HPV16 (OR= 7.215, P< 0.05), HPV31 (OR=2.768, P<0.05), HPV33 (OR=1.846, P<0.05), HPV58 (OR=1.726, P<0.05) Conclusions The prevalence of HR-HPV infections increased with the aggravation of cervical carcinoma in Xuzhou region. In order of decreasing prevalence, the most prevalent of HPV types are HPV16, 31, 33, 58. The results indicate that HPV18 have strong tumorigenicity, but is not popular in Xuzhou region. By contrast HPV52 is more common in LSIL than that in cervical carcinoma.

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