Ups and downs in COVID-19 data may be caused by data reporting practices

As data accumulates on COVID-19 cases and deaths, researchers have observed patterns of peaks and valleys that repeat on a near-weekly basis. A new study reports that those oscillations arise from variations in testing practices and data reporting, rather than from societal practices around how people are infected or treated.

source https://www.sciencedaily.com/releases/2020/07/200714132741.htm