RESUMO
Nasopharyngeal swabs (NPS) collected by trained healthcare professionals are the preferred specimen for SARS-CoV-2 testing. Self-collected specimens might decrease patient discomfort, conserve healthcare resources, and be preferred by patients. During August - November 2020, 1,806 adults undergoing SARS-CoV-2 testing in Denver, Colorado and Atlanta, Georgia, provided self-collected anterior nares swabs (ANS) and saliva specimens before NPS collection. Compared to NPS, sensitivity for SARS-CoV-2 detection by rRT-PCR appeared higher for saliva than for ANS (85% versus 80% in Denver; 67% versus 58% in Atlanta) and higher among participants reporting current symptoms (94% and 87% in Denver; 72% and 62% in Atlanta, for saliva and ANS, respectively) than among those reporting no symptoms (29% and 50% in Denver; 50% and 44% in Atlanta, for saliva and ANS, respectively). Compared to ANS, saliva was more challenging to collect and process. Self-collected saliva and ANS are less sensitive than NPS for SARS-CoV-2 detection; however, they offer practical advantages and might be most useful for currently symptomatic patients.
RESUMO
BackgroundCoronavirus disease 2019 (COVID-19), the respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China and has since become pandemic. As part of initial response activities in the United States, enhanced contact investigations were conducted to enable early identification and isolation of additional cases and to learn more about risk factors for transmission. MethodsClose contacts of nine early travel-related cases in the United States were identified. Close contacts meeting criteria for active monitoring were followed, and selected individuals were targeted for collection of additional exposure details and respiratory samples. Respiratory samples were tested for SARS-CoV-2 by real-time reverse transcription polymerase chain reaction (RT-PCR) at the Centers for Disease Control and Prevention. ResultsThere were 404 close contacts who underwent active monitoring in the response jurisdictions; 338 had at least basic exposure data, of whom 159 had [≥]1 set of respiratory samples collected and tested. Across all known close contacts under monitoring, two additional cases were identified; both secondary cases were in spouses of travel-associated case patients. The secondary attack rate among household members, all of whom had [≥]1 respiratory sample tested, was 13% (95% CI: 4 - 38%). ConclusionsThe enhanced contact tracing investigations undertaken around nine early travel-related cases of COVID-19 in the United States identified two cases of secondary transmission, both spouses. Rapid detection and isolation of the travel-associated case patients, enabled by public awareness of COVID-19 among travelers from China, may have mitigated transmission risk among close contacts of these cases.