Improve support for prolonged infection metadata

[dhoconno]

Longitudinal sequencing from individuals with prolonged SARS-CoV-2 has some different attributes than spot sequencing of individual cases. Can the metadata standards be updated to handle longitudinal sampling?

Some considerations:

• How should prolonged infections be differentiated from reinfections?
• For prolonged infections, could symptom_onset_date be elevated to required when a prolonged infection is suspected, so that sample timing relative to initial symptom onset can be computed?
• Can this information be mapped to Biosample submissions so that NCBI datasets from known prolonged infections can be readily identified?

Thanks!

dave