A nurse on the frontline of Italy’s coronavirus outbreak has described the experience as “war-like”.

Doctors and nurses are working around the clock as the country tries to halt the spread of a virus that has so far claimed over 1,000 Italian lives.

Among the dead was a 59-year-old doctor and close friend of Roberta Re, a nurse at Piacenza hospital in Emilia-Romagna, the region with the second highest number of cases.

“It’s an experience I would compare to a world war,” Re told the Guardian. “But it’s a war that isn’t fightable with traditional arms – as we don’t yet know who the enemy is and so it’s difficult to fight. The only weapon we do have to avoid things getting even worse is to stay at home and to respect the rules, to do what they did in China, as this is paying off.”

Italy, which has had the worst coronavirus outbreak outside of China, tightened quarantine restrictions on Thursday after the death toll leapt. The total number of people infected since the epidemic began, including the deaths and those who have recovered, reached over 15,000 on Thursday.

“I’m usually a happy person, chatting and joking with everyone … but now there are days when I have cried and been depressed,” added Re.

Other medics at the centre of the outbreak have made harrowing pleas over social media, and have shared images of exhausted staff as their hospitals buckle under the pressure. Andrea Vercelli, who works in the emergency unit at Piacenza hospital, said in a Facebook video: “What we are experiencing is not a normal flu, we are getting 40 cases a day of pneumonia in the emergency room.”

Daniele Macchini, a doctor at Humanitas Gavazzeni hospital in the badly-affected province of Bergamo in the Lombardy region, wrote on Facebook a few days before the entire country was quarantined: “The situation is nothing short of dramatic. The war has literally exploded and the battle is uninterrupted, day and night.”

The city and provincial capital of Bergamo, in the Lombardy region of northern Italy, is said to be almost deserted as quarantine regulations are imposed. Photograph: Filippo Venezia/EPA

Meanwhile, Codacons, Italy’s main consumer association, has asked prosecutors in Bergamo to investigate after an anaesthetist in the intensive care unit at the Papa Giovanni XXIII hospital told the newspaper Corriere della Sera that the pressure was so immense that saving a life “is decided by age and health conditions … as in situations of war”.

“In no case can age be a discriminating factor when it comes to public health, and it certainly cannot be a criteria to decide who to treat and who not to treat,” Carlo Rienzi, the president of Codacons, said in a statement. “A shortage of beds must not lead to choices like those described by the doctor.”

The virus has infected many doctors and nurses as they worked. Roberto Stella, the president of the order of doctors in Varese, Lombardy, died on Wednesday. The 67-year-old was tending to patients until he started to suffer symptoms and went into intensive care himself last Friday.

“He died a hero, like other colleagues who have died in recent days,” Saverio Chiaravalle, vice-president of the Varese doctors order, told Corriere della Sera.

Prime minister Giuseppe Conte repeated his call for Italians to “stay at home” as he announced the closure of shops, bars and restaurants across the country on Wednesday in an additional step to try and contain the virus.

“People need to understand that the situation is very serious,” said Re. “The fundamental thing is to close everything, as well as to educate adolescents to have a concept of how serious this is.”