A new flu, H7N9, has killed 36 people since it was first found in China two months ago. A new virus from the SARS family has killed 22 people since it was found on the Arabian Peninsula last summer.
In past years, this might have been occasion for panic. Yet chicken and pork sales have not plummeted, as they did during flus linked to swine and birds. Travel to Shanghai or Mecca has not been curtailed, nor have there been alarmist calls to close national borders.
Is this relatively calm response in order? Or does the simultaneous emergence of two new diseases suggest something more dire?
Actually, experts say, the answer to both questions may well be yes.