A CLEIA Antigen Assay in Diagnosis and Follow-Up of SARS-CoV-2-Positive Subjects.

This study includes 259 consecutive nasopharyngeal swabs which tested positive for a molecular SARS-CoV-2 test and 77 subjects who were followed longitudinally, with nasopharyngeal swabs performed weekly until clinical recovery and a negative result for the molecular test were reached. All swabs were also tested with a Lumipulse SARS-CoV-2 chemiluminescence enzyme immunoassay (CLEIA) antigen assay. The antigen test was positive in 169 (65.3%) out of the 259 subjects, while no antigen was detected in 90 subjects (34.7%). In the antigen-positive subjects, clinical status moved slightly toward a more frequent presence of symptoms. Longitudinal follow-up shows how the time of negativization has a faster kinetic in the antigenic test than in the molecular test. Antigenic test result values, considered as a time-dependent covariate and log-transformed, were highly associated with the time to negative swab, with good prediction ability. Receiver operating characteristic (ROC) curve analysis showed a very good discrimination ability of antigenic tests in classifying negative swabs. The optimal cutoff which jointly maximized sensitivity and specificity was 1.55, resulting in an overall accuracy of 0.75, a sensitivity of 0.73, and a specificity of 0.83. After dichotomizing the antigenic test according to the previously determined cutoff value of 1.55, the time-dependent covariate Cox model again suggests a highly significant association of antigenic test values with the time to negative swab molecular: a subject with an antigenic test value lower than 1.55 had almost a 13-fold higher probability to also result negative in the molecular test compared to a subject with an antigenic test value higher than 1.55. IMPORTANCE Our work explores the possibility of using a sensible and reliable antigenic test in a wider range of SARS-CoV-2 diagnostic and clinical applications. Furthermore, this tool seems particularly promising in follow-up with infected subjects, because while the molecular test frequently yields the persistence of low positivities, raising yet unanswered questions, this antigenic test shows more uniform and faster negativization during the evolution of the infection, somehow paralleling the dynamics of infectivity. Although more data will be required to definitely prove it, we believe these findings might be of great interest.

An original logigramme to make safe discharge and community reintegration for COVID-19 patients.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the microorganism responsible for the aggressive Coronavirus Disease (COVID-19) pandemic. During the such pandemic, discharge and community reintegration of patients are critical phases in guaranteeing public health. A review of the international and Italian experiences that represent the best available evidence was carried out, mainly focusing on the precise allocation of tasks and related responsibilities. The report provides a proposal for a systematic management pathway dedicated to COVID-19 patients. The original result is a logigramme to guide health practitioners on discharge and community reintegration of COVID-19 patients. To standardize clinical attitudes helps in ensuring quality of care and patient safety, should be a core element even during a public health emergency. The logigramme suggests, after discharge, 14 days of further isolation with regular health monitoring and, finally, the execution of a nasopharyngeal swab for identification of SARS-CoV-2 viral RNA. Home-cared patients should be placed on 7 days of further isolation after at least 2 negative RT-PCR tests for respiratory tract samples (nasopharyngeal swab). The logigramme is already used in the Department of Prevention - Local Health Agency of Lecce (Apulia) but it will be updated according to the latest research findings.