viral load determines covid spread, study says

as of february 4, 793,734 cases of covid-19 have been recorded in canada, and as the number continues to rise, so do questions about what it is that makes the virus so contagious.

and while you may think that simply a cough is the most effective way to spread the deadly disease, a study published in the the lancet shows that spreadability actually also depends on the amount of virus in a person. those with the highest viral load are considered “superspreaders.”

michael marks from the london school of hygiene & tropical medicine studied 282 patients — “index cases” —  who had developed mild symptoms of covid-19 and 753 people who were their close contacts — members of the same household and caregivers. participants were included in the randomized control trial conducted between march 17 and april 28, 2020.

the study showed that o nly one-third of the index cases passed the virus to a close contact. in fact, participants with a relatively high viral load were much more likely to pass on the virus than those with a low viral load. and interestingly, those with a cough were no more likely to transmit the virus than those without one.

the findings help to highlight the importance of masks and social distancing, measures that not only reduce the likelihood of exposure to the deadly virus, but also put us into contact with less of it. and if that’s not enough to convince you of the importance of following public health guidelines, consider another recent study that concluded that the more virus in someone’s body, the greater chance there was of death.