This is the type of story that makes me think we're seeing the tip of the iceberg with this virus http://www.asahi.com/ajw/articles/13156296 (emphasis added):

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CHIBA--A teacher in her 60s at a junior high school here was found to be infected with the new coronavirus, prompting authorities to cancel classes for two days following the three-day holiday weekend that ends Feb. 24.

The Chiba prefectural and municipal governments jointly made the announcement on Feb. 22.

The teacher visited a medical institution on Feb. 12 after feeling nauseous and she was diagnosed with a cold.

She continued to teach, but was hospitalized on Feb. 19 after her condition worsened. She tested positive for the coronavirus on Feb. 21.

The Chiba municipal board of education decided to close the school as a precaution. The school will be disinfected. The health of all 580 or so students as well as all teachers at Chiba municipal schools will also be monitored for symptoms such as fevers.

The woman lived in western Chiba Prefecture and commuted by train to the school in Chiba city. She began wearing a face mask during the commute from Feb. 13. It remains unclear how she became infected since she had not been overseas in the two weeks before showing symptoms and no confirmation has been made of the woman coming in close contact with anyone with pneumonia.

Authorities in the main northernmost main island of Hokkaido said meantime that eight new cases of coronavirus had been confirmed. The eight, three males and five females, range in age between 10 and 90. They are all Japanese.

The latest announcement doubled the number of coronavirus cases in Hokkaido to 16. Local authorities are still trying to determine how they were infected because they reside in various parts of the island.[/color]