JEFFERSON, LA — In May, Ochsner began a study to determine the spread of the coronavirus in Jefferson and Orleans parishes. Thursday, researchers released the results.
In all, 2,640 people were tested from across both parishes. Researchers used a nasal swab to test for the virus and a blood draw to test for antibodies. By comparing the levels of each, they could determine whether people were in the early, intermediate or late stage of the virus running its course. They also expanded the numbers to determine an infection rate for the two parishes.
According to the study, 7.8% of the population either currently has or already recovered from Covid-19. Doctors say that statistic shows how much farther the area must go to reach any sort of herd immunity when most people are no longer at risk of contracting or spreading the virus.
Also, 75% of the people who were in the early stage of infection, a period when they’re most likely to spread the virus to other people, showed no symptoms. So they would have no way to know that they’re at risk of making others sick.
Ochsner doctors say that the results underscore the need for people to take precautions like social distancing, washing hands and wearing masks to reduce the risk of spreading the virus.
The study also measured common symptoms like fever, headache and fatigue. The most common symptom was anosmia, or the lost of the sense of smell. Of the people studied, those with anosmia were 17 times more likely to be infected.
The test did not measure how long antibodies remain in the body which would indicate whether people can get the virus more than once and how long a vaccine might be effective.
Given the CDC statistics on deaths, Ochsner doctors say that Covid-19 is about ten times more deadly than the seasonal flu. So reaching herd immunity simply through exposure — without a vaccine — would lead to thousands of more people dying.
The study also did not follow up to see how many of the people tested went on to require hospitalization.