There are minor genetic variations that can be used to trace whether infections came directly from Wuhan or through Italy or wherever. These variations do not

There are minor genetic variations that can be used to trace whether infections came directly from Wuhan or through Italy or wherever. These variations do not vary the function of the virus or its infectiousness or reproduction in any known way, but do enable some methods for tracing the spread. California has an aggressive ongoing effort to sequence the genes of all COVID-19 cases which has contributed to this.