Research Press Release

Clinical and virologic characteristics of the first 12 patients with coronavirus disease 2019 (COVID-19) in the United States

Nature Medicine

April 24, 2020

Medical research: Clinical progression of first 12 confirmed US COVID-19 patients analysed Detailed virological, clinical and epidemiological characterization of the first 12 patients with confirmed COVID-19 respiratory disease in the USA is reported in Nature Medicine this week. 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 analysed the first 12 confirmed cases of COVID-19 in the USA, 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 hospitalized and worsened during the second week of illness, which highlights the importance of monitoring into the second week of illness. Five hospitalized 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.


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