Several regions of Russia have experienced minor outbreaks of an unknown illness with early symptoms in humans appearing to be similar to those of pneumonia.

Finland's Helsinki Times reported Russian physicians and patients report a list of symptoms such as high fever and coughing. But so far, there is no confirmation from Russian authorities about the specifics of the illness and whether it is caused by a bacterial infection or a virus.

Physicians have, at least in some cases, been recording the illness with a classification of "acute upper respiratory tract infection, unspecified" (ARVI), the Times reported.

Patients with initial symptoms matching the illness have reported weakness and body aches similar to those of the flu. But after several days, some have reported a worsening of their condition with a fever up to 102 Fahrenheit. A small number reported developing a cough and sometimes coughing up blood.

The Times reported that some physicians have speculated the illness appears similar to a bacterial infection that affected many Russians last fall. But no connection has been determined.

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