Oropharyngeal microbial composition and abundance among CCs, SCs, and Hs. A) Average compositions and relative abundance of the bacterial community in the three groups at the genus level. B) Heatmap of the relative abundances of differential OTUs for each sample in the three groups. The PCoA showed that there was no significant difference in the oropharyngeal microbiome distribution between CCs (n = 73) and SCs (n = 36) C) or between CCRs (n = 21) and SCRs (n = 36) D). E) Average compositions and relative abundance of the bacterial community in the four groups at the genus level. OTUs, operational taxonomic units; CCs, confirmed cases; CCRs, confirmed cases who recovered; SCs, suspected cases; SCRs suspected cases who recovered; Hs, healthy controls; PCoA, principal coordinate analysis.