Early symptoms of delta virus and colds are distinguished by a different causative agent, nasal congestion and runny nose, altered olfactory and gustatory function, fever, and muscle aches and pains. 1. Different causative agents: The causative agent of delta virus is mainly a mutant strain of the new coronavirus, which is highly contagious; the causative agent of colds is mainly respiratory viruses, which are relatively less contagious. 2. Nasal congestion and runny nose: In the early stage of Delta infection, only a small number of patients will experience sneezing, nasal congestion, runny nose and other symptoms, while the majority of patients with colds will experience the above situation. 3. Altered sense of smell and taste: In the early stage of infection with delta virus, smell and taste dysfunction will occur in some patients, and a very small number of patients with colds will have such a situation. 4. Fever temperature: The fever temperature of delta virus is usually between 37.3 degrees Celsius and 38.5 degrees Celsius, which belongs to low-fever state, and seldom occurs higher than 38.5 degrees Celsius above the body temperature, but the patients with colds are prone to fluctuate to 38.5 degrees Celsius above. 5. Muscle aches and pains: Delta virus patients mainly show generalized aches and pains, weakness and fatigue, while only a small number of cold and flu patients will have muscle aches and pains, weakness and fatigue.