"They have not been isolated because they are not presenting with any symptoms," Alessandro Bartoloni of the Infectious Diseases clinic at Careggi hospital in Florence was quoted as saying.
Samples of their blood have been sent to the Superior Health Institute in Rome for confirmation, he added.
"There was a firm belief, according to the World Health Organisation, that the virus was not easily spread but was rather aggressive (in those infected). What we are seeing now seems, however, to be the exact opposite," he added.
Bartoloni said the clinic would continue to collect samples to see how widely the virus has spread.
The Middle East Respiratory Syndrome coronavirus (MERS-CoV) -- termed "New SARS" in Italy -- is believed to have killed around 30 people globally.