Detailed virological, clinical and epidemiological characterisation of the first 12 patients with confirmed COVID-19 respiratory disease in the US has been reported. Additional studies involving larger sample sizes could further understanding of the clinical progression of the disease and help inform clinical management and public health strategies.
Claire Midgley and colleagues of the COVID-19 Investigation Team analysed the first 12 confirmed cases of COVID-19 in the US, from 20 January to 5 February 2020. The patients were identified in six states, ranged from 21 to 68 years of age, and comprised eight men and four women. Ten patients had recently travelled to China (nine to Wuhan City); the other two had close contact with a US patient with COVID-19.
The patients all experienced mild to moderate symptoms of COVID-19; eight experienced a cough and seven had a fever at the onset of the illness. Seven patients (including four with underlying medical conditions) were hospitalised and worsened during the second week of illness, which highlights the importance of monitoring into the second week of illness. Five hospitalised patients experienced difficulty breathing and four received oxygen, but none required mechanical ventilation and all recovered.
448 samples (from the nose and throat, sputum (mucus from the respiratory tract), serum, stool and urine) were collected from the patients throughout their illness. RNA from the causative coronavirus SARS-CoV-2 was detected in respiratory samples for approximately 2–3 weeks after illness onset. Highest viral levels in the upper respiratory tract were in the first week of illness. Symptoms lasted for 6–37 days, and SARS-CoV-2 RNA was detected after symptoms resolved in seven of the twelve patients, although infectiousness and transmissibility were not studied here.
Genome analysis of respiratory specimens from the 12 patients revealed a high degree of similarity, which suggests that the patients were all identified early in the outbreak.
The authors also report that three of the patients tolerated treatment with the antiviral remdesivir, which is currently undergoing clinical trials; it was not possible to assess its effectiveness or safety here, however.
Abstract
Data on the detailed clinical progression of COVID-19 in conjunction with epidemiological and virological characteristics are limited. In this case series, we describe the first 12 US patients confirmed to have COVID-19 from 20 January to 5 February 2020, including 4 patients described previously1,2,3. Respiratory, stool, serum and urine specimens were submitted for SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (rRT-PCR) testing, viral culture and whole genome sequencing. Median age was 53 years (range: 21–68); 8 patients were male. Common symptoms at illness onset were cough (n = 8) and fever (n = 7). Patients had mild to moderately severe illness; seven were hospitalized and demonstrated clinical or laboratory signs of worsening during the second week of illness. No patients required mechanical ventilation and all recovered. All had SARS-CoV-2 RNA detected in respiratory specimens, typically for 2–3 weeks after illness onset. Lowest real-time PCR with reverse transcription cycle threshold values in the upper respiratory tract were often detected in the first week and SARS-CoV-2 was cultured from early respiratory specimens. These data provide insight into the natural history of SARS-CoV-2. Although infectiousness is unclear, highest viral RNA levels were identified in the first week of illness. Clinicians should anticipate that some patients may worsen in the second week of illness.
Authors
The COVID-19 Investigation Team
[link url="https://www.nature.com/articles/s41591-020-0877-5"]Nature Medicine abstract[/link]