The death of the woman in a hospital in the small city of Crema in Lombardy, the centre of Italy's coronavirus scare, followed that of a 77-year-old woman on Saturday and a 78-year-old man on Friday, the first European victim of coronavirus.
Prime Minister Giuseppe Conte urged people “not to give in to panic and follow the advice of health authorities”.
“We should not be afraid because of the rising numbers,” he told public radio station Rai Uno, adding in another interview that cases were being discovered “because we are carrying out thousands of checks”.
The head of Italy's civil protection department, Angelo Borrelli, told a news conference that 152 people had now tested positive for the virus in the country, including the three deceased.
The cancer patient had been hospitalised for a few days, said Lombardy's health chief, Giulio Gallera. “She'd been tested and they already knew she had the coronavirus,” Gallera said, adding that it was too early to know whether the virus was the actual cause of death.
The deaths, and steadily rising number of cases of infected people, have prompted a series of security measures to try to check the spread of the contagion.
Eleven towns — 10 in Lombardy and one in neighbouring Veneto — are under lockdown, with some 50,000 residents prohibited from leaving.
Police checkpoints in Codogna, Lombardy. Photo: Miguel Medina/AFP
Regional authorities have ordered gathering spots, such as bars, restaurants and discos to close. Schools throughout the affected areas are to remain closed.
An Austrian train from Venice bound for Munich was stopped on Sunday on the Italian side of the Brenner Pass border crossing with Austria because of two possible cases, the Austrian interior ministry said.
It later announced that the passengers had tested negative and train services resumed.
The spread of the virus has disrupted high-profile events including Milan Fashion Week and the Venice Carnival while Serie A football matches were postponed. Operas have also had to be cancelled at Milan's famed La Scala.
Most of the cases in Italy are in Lombardy, a prosperous region in the country's north, and can be traced back to a 38-year-old man whom authorities have called “patient one”.
The man, who is intensive care, dined last month with another man who had visited China in January. He exhibited flu-like symptoms at the time of the dinner, but has since tested negative for the virus, media reports said.
Health officials are still puzzled over certain cases with no obvious links with infected persons.
— Giuseppe Conte (@GiuseppeConteIT) February 24, 2020
“The rapid increase in reported cases in Italy over the past two days is of concern,” World Health Organization (WHO) spokesperson Tarik Jasarevic said on Sunday.
“What is also worrying is that not all reported cases seem to have clear epidemiological links, such as travel history to China or contact with a confirmed case,” he added.
Experts from WHO and the European Centre for Disease Prevention and Control plan to arrive in Italy on Tuesday, he said.
Conte's government moved on Saturday to set up checkpoints in the region affected to ensure that nobody leaves the contaminated zone without special permission. Sunday saw police checking all vehicles travelling in and out of the area
along Codogno's main highway.
One police officer told AFP that “we're going to quickly enforce a total blockade” and that those who had made it into the area in recent days would be unable to leave.
Conte has said that residents could face weeks of lockdown, enough time for any potential infection to incubate.