Was that early on and he documented his progression ?
He documented his progression almost daily
https://www.dailymail.co.uk/news/article-8075633/First-British-victim-25-describes-coronavirus.html
The following were notes from a medical report regarding 2 patients.
“ A. The viruses isolated from a patient that lived in the United States (USA_2020/01/21.a, GISAID ID: EPI_ISL_404253) had the genotype Y (C or T) at both 8,782 and 28,144. The most likely explanation is that this patient was infected by both the L and S types. Note the reference is L type.
B. The viruses Australia_2020/01/28.a (GISAID ID:EPI_ISL_407894) identified from a patient in Australia had multiple degenerated nucleotides, and the best explanation is that this patient was infected by at least two different strains of SARS-CoV-2 viruses.