The Seattle Flu Study is a multi-institutional, community-wide surveillance project initially intended to track data from influenza that began testing nasal swabs for COVID-19 in any patient with respiratory symptoms. From January 1-March 9, they found that 1.1% of participants tested positive for COVID-19 in 30% of patients seeking clinical care.
In a retrospective analysis of over 3,000 COVID-19 patients, researchers found that RNA-based diagnostic testing methods lacked negative predictive value, though they were useful indicators for clinical course, pattern, and prognosis.
Convalescent plasma transfusion was found to be safe, clinically effective, and beneficial in reducing mortality in five studies of 27 COVID-19 patients.
Key laboratory tests recommended for COVID-19 patients are:
CBC with differential
Acute phase inflammatory biomarkers
Kidney, liver, and cardiac injury biomarkers
Indicators of improvement: CRP/procalcitonin
Prognostic biomarkers like D-dimer values
Sequential organ failure assessment.