Multisite Clinical Validation of Isothermal Amplification-Based SARS-CoV-2 Detection Assays Using Different Sampling Strategies.

Isothermal amplification-based tests have been introduced as rapid, low-cost, and simple alternatives to real-time reverse transcriptase PCR (RT-PCR) tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. The clinical performance of two isothermal amplification-based tests (Atila Biosystems iAMP coronavirus disease of 2019 [COVID-19] detection test and OptiGene COVID-19 direct plus RT-loop-mediated isothermal amplification [LAMP] test) was compared with that of clinical RT-PCR assays using different sampling strategies. A total of 1,378 participants were tested across 4 study sites. Compared with standard of care RT-PCR testing, the overall sensitivity and specificity of the Atila iAMP test for detection of SARS-CoV-2 were 76.2% and 94.9%, respectively, and increased to 88.8% and 89.5%, respectively, after exclusion of an outlier study site. Sensitivity varied based on the anatomic site from which the sample was collected. Sensitivity for nasopharyngeal sampling was 65.4% (range across study sites, 52.8% to 79.8%), for midturbinate was 88.2%, for saliva was 55.1% (range across study sites, 42.9% to 77.8%), and for anterior nares was 66.7% (range across study sites, 63.6% to 76.5%). The specificity for these anatomic collection sites ranged from 96.7% to 100%. Sensitivity improved in symptomatic patients (overall, 82.7%) and those with a higher viral load (overall, 92.4% for cycle threshold [CT] of ≤25). Sensitivity and specificity of the OptiGene direct plus RT-LAMP test, which was conducted at a single study site, were 25.5% and 100%, respectively. The Atila iAMP COVID test with midturbinate sampling is a rapid, low-cost assay for detecting SARS-CoV-2, especially in symptomatic patients and those with a high viral load, and could be used to reduce the risk of SARS-CoV-2 transmission in clinical settings. Variation of performance between study sites highlights the need for site-specific clinical validation of these assays before clinical adoption. IMPORTANCE Numerous SARS-CoV-2 detection assays have been developed and introduced into the market under emergency use authorizations (EUAs). EUAs are granted primarily based on small studies of analytic sensitivity and specificity with limited clinical validations. A thorough clinical performance evaluation of SARS-CoV-2 assays is important to understand the strengths, limitations, and specific applications of these assays. In this first large-scale multicentric study, we evaluated the clinical performance and operational characteristics of two isothermal amplification-based SARS-CoV-2 tests, namely, (i) iAMP COVID-19 detection test (Atila BioSystems, USA) and (ii) COVID-19 direct plus RT-LAMP test (OptiGene Ltd., UK), compared with those of clinical RT-PCR tests using different sampling strategies (i.e., nasopharyngeal, self-sampled anterior nares, self-sampled midturbinate, and saliva). An important specific use for these isothermal amplification-based, rapid, low-cost, and easy-to-perform SARS-CoV-2 assays is to allow for a safer return to preventive clinical encounters, such as cancer screening, particularly in low- and middle-income countries that have low SARS-CoV-2 vaccination rates.

Rethinking Cervical Cancer Screening in Brazil Post COVID-19: A Global Opportunity to Adopt Higher Impact Strategies.

The World Health Organization global call to eliminate cervical cancer encourages countries to consider introducing or improving cervical cancer screening programs. Brazil's Unified Health System (SUS) is among the world's largest public health systems offering free cytology testing, follow-up colposcopy, and treatment. Yet, health care networks across the country have unequal infrastructure, human resources, equipment, and supplies resulting in uneven program performance and large disparities in cervical cancer incidence and mortality. An effective screening program needs multiple strategies feasible for each community's reality, facilitating coverage and follow-up adherence. Prioritizing those at highest risk with tests that better stratify risk will limit inefficiencies, improving program impact across different resource settings. Highly sensitive human papillomavirus (HPV)-DNA testing performs better than cytology and, with self-collection closer to homes and workplaces, improves access, even in remote regions. Molecular triage strategies like HPV genotyping can identify from the same self-collected sample, those at highest risk requiring follow-up. If proven acceptable, affordable, cost-effective, and efficient in the Brazilian context, these strategies would increase coverage while removing the need for speculum exams for routine screening and reducing follow-up visits. SUS could implement a nationwide organized program that accommodates heterogenous settings across Brazil, informing a variety of screening programs worldwide.

Impact of COVID-19 on cervical cancer screening: Challenges and opportunities to improving resilience and reduce disparities.

The COVID-19 pandemic has a major impact on a wide range of health outcomes. Disruptions of elective health services related to cervical screening, management of abnormal screening test results, and treatment of precancers, may lead to increases in cervical cancer incidence and exacerbate existing health disparities. Modeling studies suggest that a short delay of cervical screening in subjects with previously negative HPV results has minor effects on cancer outcomes, while delay of management and treatment can lead to larger increases in cervical cancer. Several approaches can mitigate the effects of disruption of cervical screening and management. HPV-based screening has higher accuracy compared to cytology, and a negative HPV result provides longer reassurance against cervical cancer; further, HPV testing can be conducted from self-collected specimens. Self-collection expands the reach of screening to underserved populations who currently do not participate in screening. Self-collection and can also provide alternative screening approaches during the pandemic because testing can be supported by telehealth and specimens collected in the home, substantially reducing patient-provider contact and risk of COVID-19 exposure, and also expanding the reach of catch-up services to address backlogs of screening tests that accumulated during the pandemic. Risk-based management allows prioritizing management of patients at highest risk of cervical cancer while extending screening intervals for those at lowest risk. The pandemic provides important lessons for how to make cervical screening more resilient to disruptions and how to reduce cervical cancer disparities that may be exacerbated due to disruptions of health services.

Cervical Cancer Screening-Past, Present, and Future.

Cervical cancer screening has undergone a transformation in recent decades. Historically, programs were based on cervical cytology (i.e., "Pap smear"), which had to be repeated often because of its limited sensitivity and reproducibility. In more recent years, the discovery of human papillomavirus (HPV) as the necessary cause of virtually all cervical cancers has led to the introduction of HPV testing into clinical practice, first as a triage test for minor cytologic abnormalities, then in conjunction with cervical cytology (cotesting), and most recently, as a standalone screening test. Multiple randomized trials have shown that HPV-based screening has higher sensitivity compared with cytology, providing great reassurance against cervical precancer and cancer for women testing HPV-negative for many years. Analyses have also been conducted in support of the recent U.S. Preventive Services Task Force guidelines that show that primary HPV screening achieves the greatest balance of benefits and harms compared with other strategies. An added benefit of primary HPV testing is the ability to conduct it from self-collected samples, which is critical for extending coverage among hard-to-reach individuals and could provide a safe and effective alternative to in-person screening visits during the COVID-19 pandemic.See related article by Liang et al., p. 474.