Zaia told reporters that events scheduled for Sunday in the lagoon city would continue as planned. Some regions have banned public events.
Italian Prime Minister Giuseppe Conte said "everything is under control", and stressed the government was maintaining "an extremely high level of precaution". Malago said the idea of Inter playing their match behind closed doors at San Siro had been considered but "there were problems connected to 70,000 people who have already bought tickets and potential public order problems if some still made a decision to go to the stadium".
"The ordinance is immediately operative and will go into effect at midnight", said Mr Zaia, whose area includes Venice, where thousands packed St Mark's Square.
That man has since tested negative for the disease, but doctors were investigating whether he carried the virus and subsequently recovered without showing any symptoms, said Lombardy regional councillor Giulio Gallera.
Iran ordered the closure of schools, universities and cultural centres across 14 provinces from Sunday following five deaths in the Islamic Republic - the most outside East Asia and the first in the Middle East.
The government passed stringent emergency measures late on Saturday after the first two deaths from the disease were recorded in the wealthy northern regions of Lombardy and Veneto.
"We are asking basically that everyone who has come from areas stricken by the epidemic to remain under a mandatory house stay", Speranza said at a Saturday press conference.
In hard-hit Codogno, where the first patient of the northern cluster to fall ill was in critical condition, main street was practically a ghost town Saturday, with supermarkets, restaurants and businesses closed.
The Ministry of Education said schools in the affected areas will remain closed until February 29, while four Serie A football matches have been suspended.
Italy was the first euro zone country to suspend all direct flights to and from China, after two Chinese tourists from the badly hit city of Wuhan tested positive in Rome in late January.
The sudden spread since a man sought treatment on Feb 18 has left Italy with more than 130 cases, the most in Europe.
Italy's health minister said the man who died on Friday, Adriano Trevisan, had been admitted to hospital 10 days earlier for an unrelated health issue. In an interview published Sunday in French newspaper Le Parisien, he said he was closely monitoring the "very serious" situation, including in neighboring Italy.