| disease_stage_preferred | | | |
| Acute/Recent onset | A short-term infection or disease characterized by a dramatic onset and rapid recovery. Primary infections fall under this category. | | |
| Chronic | A long-term infection or illness and partial remission. | | |
| COVID-19 Disease Severity 0 | Patient is uninfected. There are no clinical or virological evidence of infection. | | |
| COVID-19 Disease Severity 1 | Patient is ambulatory without limitation of activities. | | |
| COVID-19 Disease Severity 2 | Patient is ambulatory but there is limitation of activities. | | |
| COVID-19 Disease Severity 3 | Patient is hospitalized with mild disease but does not require oxygen therapy. | | |
| COVID-19 Disease Severity 4 | Patient is hospitalized with mild disease but requires oxygen by mask or nasal prongs. | | |
| COVID-19 Disease Severity 5 | Patient is hospitalized with severe disease and requires non-invasive ventilation or high-flow oxygen. | | |
| COVID-19 Disease Severity 6 | Patient is hospitalized with severe disease and requires intubation and mechanical ventilation. | | |
| COVID-19 Disease Severity 7 | Patient is hospitalized with severe disease and requires ventilation plus additional organ support via vasopressor therapy, renal replacement therapy, or extracorporeal membrane oxygenation. | | |
| COVID-19 Disease Severity 8 | Patient is dead. | | |
| Critical COVID-19 | Defined by the criteria for acute respiratory distress syndrome (ARDS), sepsis, septic shock, or other conditions that would normally require the provision of life-sustaining therapies such as mechanical ventilation (invasive or non-invasive) or vasopressor therapy. | | |
| Non-severe COVID-19 | Defined as absence of any criteria for severe or critical COVID-19. | | |
| Other | Any disease stage that cannot be classified under the selections above will be classified under "other." Household contacts will be recorded as "other". | | |
| Post | Recovery from an illness, including latent (potentially existing but not presently evident or realized) and remission (a period during which symptoms of disease disappear [complete remission]). Note that partial remission will be recorded as "chronic". | | |
| SeroNet Covid-19 Disease Severity Death | Corresponds to WHO Severity Scale 8. Dead. | | |
| SeroNet Covid-19 Disease Severity Mild | Corresponds to WHO severity scale: (1) Ambulatory, asymptomatic or no limitation of activities or (2) ambulatory, limitation of activities. | | |
| SeroNet Covid-19 Disease Severity Moderate | Corresponds to WHO severity scale: (3) Hospitalized, no oxygen therapy or (4) hospitalized, oxygen by mask or nasal prongs. | | |
| SeroNet Covid-19 Disease Severity Severe | Corresponds to WHO severity scale: (5) Hospitalized with severe disease and non-invasive ventilation or high-flow oxygen, or (6) hospitalized with severe disease with intubation and mechanical ventilation, or (7) hospitalized with severe disease ventilation + additional organ support - pressors, RRT, ECMO | | |
| SeroNet Covid-19 Disease Severity Unknown | Covid-19 disease severity is not known. | | |
| Severe COVID-19 | Defined by any of: Oxygen saturation < 90% on room air. Respiratory rate > 30 breaths/min in adults and children > 5 years old; >= 60 breaths/min in children < 2 months old; >= 50 in children 2–11 months old; and >= 40 in children 1–5 years old. Signs of severe respiratory distress (accessory muscle use, inability to complete full sentences, and, in children, very severe chest wall indrawing, grunting, central cyanosis, or presence of any other general danger signs). | | |
| Unknown | Used when the disease stage is not clearly specified or known. | | |