Pneumonia Alert: The mysterious pneumonia that has been going around Asia has now touched North America and Europe, thanks to air travel. The WHO has issued a global disease alert, and the CDC is tracking contacts of a doctor from Singapore who fell ill shortly after visiting the US. Canada reports nine infections and two deaths. No one’s sure what the infecting organism is - viral or bacterial - but it seems to be highly contagious among close contacts and to cause serious, life-threatening complications. It has an incubation period between two and seven days.

The CDC’s press release is here, and recommendations for healthcare providers can be found here.

Don’t panic, though. Not every fever or cough is likely to be this virulent pneumonia. Only 150 cases have been identified world wide. The advisory is an attempt to stop the spread from continent to continent. However, if you’ve been to Asia recently, or on an airplane, or in close contact with someone who has been ill and been to Asia or on a flight, you might want to get that cough checked out.

CLARIFICATION: The illness usually begins with a high fever and cold symptoms, not just a cough. Like the flu.

UPDATE: Officials in Hong Kong say it's probably a strain of influenza:

They have so far revealed that it is a "B" strain version of flu. He said: "The rate of infection is very high. At first it's a respiratory illness and it deteriorates into pneumonia. There is a possibility it can mutate or it may be a virus that is known to us."

But Hong Kong Government officials said the illness was not related to a strain of "bird-flu" that killed a man in February.