There has been a steep rise in coronavirus cases reported in Orange County following the large crowds on the beaches on April 25-26.
In the week of April 20-26, there were 438 cases in Orange County. The week after that, 669 cases were reported, and the week after that, 759 cases. Further investigation is needed to determine whether the beaches were a source of spread for an outbreak or if the increase could be explained simply by other factors, such as increased testing.
“But you know, just us looking at it, there was a big jump in Orange County that was temporally consistent with possible transmission from that crowd event,” [Dr. George Rutherford, a former epidemic intelligence service officer with the U.S. Centers for Disease Control and Prevention] said.
Speech droplets generated by asymptomatic carriers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasingly considered to be a likely mode of disease transmission. Highly sensitive laser light scattering observations have revealed that loud speech can emit thousands of oral fluid droplets per second. In a closed, stagnant air environment, they disappear from the window of view with time constants in the range of 8 to 14 min, which corresponds to droplet nuclei of ca. 4 μm diameter, or 12- to 21-μm droplets prior to dehydration. These observations confirm that there is a substantial probability that normal speaking causes airborne virus transmission in confined environments.