The Santa Clarita Valley three decades ago was serene. Running in early morning hours before sunrise smelled of country with the occasional sighting of coyotes and bobcats, and hearing the rustling of awakening native birds. We were an extension of urban life taking over their grounds.

One morning, it was pea-soup foggy as I thumped across an aged railroad trestle while the sun rose, casting stick-like tree shadows across my path. Momentarily entranced by the scene, I suddenly realized I was running through a swarm of small flies, inhaling some of them – causing a five-minute coughing spasm.

The coronavirus is likely inhaled from a cough or sneeze, with these viral particles invading the respiratory system of a human victim. If there is a swarm of the virus, the excessive exposure will make you very sick.

This may be why, in congregate work or living situations like in prisons, nursing homes or meat-packing plants, the higher concentration of the virus might intensify your illness.

We don’t know this for sure, but if someone coughs or sneezes in front of you, avoiding that cloud becomes your highest priority.

Flies did not make me sick. A swarm of coronavirus would.

Wear a mask.

Gene Uzawa Dorio, M.D., is a geriatric house-call physician who serves as president of the Los Angeles County Commission for Older Adults and Assemblyman to the California Senior Legislature. He has practiced in the Santa Clarita Valley for 32 years.