Table 1.

Criteria for definition and classification of COVID-19 symptoms intensity among Belgrade University students

Grading and duration of COVID-19 symptoms	Fever	Other symptoms	Laboratory findings
Mild symptoms lasting for 1–3 days	No fever or fever ≤37.5°C lasting up to 3 days or fever >37.5°C lasting for 1 or 2 days	Nasal congestion, nasal discharge, and mild sore throat (having none, 1 or 2 out of 3 complaints)	Laboratory parameters are normal or deviate from reference values up to 5%
Moderate symptoms lasting for 4–7 days	Fever 37.6–38.5°C lasting 4–7 days and at least 2 symptoms/complaints listed in column “other symptoms”	Intense sore throat, loss of smell and taste, diarrhea, intense muscle aches, weakness, cough, and headache	Laboratory parameters deviate from reference values from od 6% to 20%
Severe symptoms lasting for 8 days or longer	Fever ≥38.6°C and at least 3 symptoms/ complaints listed in the column “other symptoms”	Chills and shivering, profuse sweating, intense and persistent headache, chest pain, persistent cough, breathing difficulties, nausea and vomiting, complete loss of smell and taste, and extreme exhaustion	Laboratory parameters deviate from reference values more than 20%