...It was never zero, & no contact tracing... whoever spread it before, still spreading it... asymptomic folks...
We brought SARS -Classic to its heels isolating sick ppl... SARS mark II is smarter... lotsa "Typhoid Mary" types for COVID-19 spreading virus w no symptoms... why we all need 2 wear masks
... 1 infects 2 infects 4 infects 16... becomes 1024 pretty fast...