ROME (Reuters) - Coronavirus infections in Italy have yet to reach their peak, the head of the country's national health institute said on Friday, as officials warned that lockdown restrictions would have to be extended beyond April 3.

Italy has reported 8,215 deaths from the illness, more than anywhere else in the world, while confirmed cases total 80,539, with latest data from Thursday showing no let up in new infections, stifling hopes of a possible turnaround.  "We haven't reached the peak and we haven't passed it," the chief of the Superior Health Institute, Silvio Brusaferro, told reporters, adding that there were however "signs of a slowdown" in the numbers of people becoming infected.  "When the descent begins, how steep it is will depend on our behaviour," Brusaferro said, referring to how strictly Italians will continue to respect a government-imposed lockdown.

Italy was the first Western country to introduce swingeing restrictions on movement after uncovering the outbreak five weeks ago. It has progressively tightened the curbs, banning all non-essential activities until at least next Friday.  However, Franco Locatelli, who heads the council which advises the government on health matters, told reporters this deadline would need extending.  "If I had to decide using today's data, I believe it is inevitable these measures will be prolonged," he said.

Schools and universities were amongst the first places to be shut down, closing their doors nationwide on March 5. Education Minister Lucia Azzolina said on Friday that the current date for the order to be lifted, April 3, would have to be extended.  "Our aim is to ensure that students return to school only when we are completely sure that it is safe. Health is the priority," she told state broadcaster RAI.

The northern region of Lombardy, centred on the Italian financial capital Milan, has been the hardest hit, accounting for 43% of all known cases and 60% of all deaths.  The region saw a jump in new cases on Thursday that confounded previous signs of a downturn there, but the local governor, Attilio Fontana, said the increase was the result of greater testing and predicted more encouraging data for Friday.  "Today there is a reduction in the number of infections, which is good news," he said, adding that to spot definite trends you needed to view the data over a five-day period.

"The infection rate is not growing and I think it is about to fall," he said in his daily briefing.  Underscoring the virulence of the contagion, the national federation of doctors, surgeons and orthodontists said on Friday that 46 colleagues had so far died, six more than a day ago - many of them general practitioners in northern towns and cities.  In a open letter published on Friday, more than 300 doctors and scientists called on the government to let them use their own laboratories to ramp up testing and identify mild and asymptomatic cases that are currently going undetected.

At present, only a few, specialist labs are checking swabs, severely restricting the number of patients who can be tested, meaning the true extent of the illness is not being tracked.  "In Italy there is an extraordinary community of researchers who could contribute immediately and very significantly and at zero cost to the current emergency situation," they said.  There was no immediate response from the Health Ministry.