Delta variant makes contact tracing so much harder

The Greater Sydney lockdown began on June 26 and almost a month later, New South Wales is recording around 100 new COVID cases a day. We are also seeing the virus spread well beyond the initial eastern suburbs cluster. The virus then spread from NSW to Victoria resulting in a lockdown there too, followed by South Australia.

source https://medicalxpress.com/news/2021-07-delta-variant-contact-harder.html