After the woman began suffering from fever, she and her husband were quarantined in the hospital wing of the ship and were tested for coronavirus. Neither they, nor anyone else on board will be released until their results come back negative; results were expected on Thursday afternoon.
"As soon as the suspected case was detected, the medical team on board immediately activated all the relevant health procedures to promptly isolate and manage clinical conditions," a spokesperson for the company said.
"The local health authority was immediately notified and is now on board to conduct all the pertinent measures."
"It is our utmost priority to ensure the health and safety of passengers and crew," they added. "The Company is at complete disposal of the health authority and their indication will be strictly applied. Costa Cruises continues to apply relevant national policies and epidemic protocols, as per World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) indications."
The couple are understood to have flown to Milan from the Macao region of China, which itself is a five hour flight south from the virus epicenter of Wuhan.
So far, more than 7,700 cases of the virus have been confirmed in China, while confirmed cases have been reported in at least 20 other countries, including the US, Canada, Australia, India, Germany, Finland, and France.
More than 170 people have died, mostly older people suffering from existing chronic conditions, although one 62-year-old doctor treating patients reportedly succumbed. There have been no reported deaths yet outside China.
On Thursday, the first person-to-person case in the US was confirmed, after a Chicago man tested positive for the virus he contracted from his wife, who had returned from a trip to Wuhan.
Shortly afterward, the World Health Organization finally declared the new coronavirus threat a global health emergency.
While coronaviruses are common — some cause mild respiratory issues like a runny nose or cough — the latest outbreak is a completely new strain known as novel coronavirus (nCoV) that has never been detected in humans before.
Symptoms include fever followed by a dry cough and shortness of breath; in severe cases it can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death.
Researchers are racing to create a vaccine from scratch, but human trials will not be ready until June at the earliest.