From the Guardian: China says Sars outbreak is 10 times worse than admitted
The behavior of Chinese officials in trying to cover up the extent of the outbreak is confusing. By understating the number of cases tenfold, they make it seem like the problem is much worse than they are willing to admit. But a tenfold increase in number of cases from 37 to 339, out of a country of billions of people, is still incredibly insignificant.
They should have just owned up to the outbreak earlier, and avoided creating this perception that China is overrun with cases.