NEW cases of coronavirus in Lombardy appear to have peaked and Italian intensive care admissions will flatten out in early April as long as the public stick to strict quarantine rules, a new study predicts.

The analysis of how Covid-19 unfolded in Italy up until March 18 found that it took 19 days to reach the "maximum speed of increase" in the northern region of Lombardy, where the outbreak began.

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The author, Davide Manca, a professor of process systems engineering at Milan's Politecnico di Milano, warned other countries that their healthcare systems would be overwhelmed without tough lockdown measures.

He said: "If other countries want to have enough intensive care beds to treat all the Covid-19 patients that are going to be arriving in their hospitals, they have to decrease the peak of the tsunami of cases that are coming.

"The most effective way to do this is to follow and enforce Italy's very strict quarantine and social distancing measures, and make sure they are implemented."

Prof Manca's research, carried out for the European Society of Anaesthesiology (ESA), also found that high percentage of the critically ill coronavirus patients in one hospital were people who were overweight and obese.

In addition, he found evidence that breathing devices for treating sleep apnoea can be used as an alternative to ventilators in cases that are "serious but not critical, and when intensive care beds are not available".

Where protective masks in hospitals are running out, Prof Manca said it was possible to reuse them after proper sterilisation.

"Better than nothing but not recommended if it can be avoided," said Prof Manca.

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The study comes as the number of deaths from coronavirus in Italy - 3,405 - overtook China for the first time.

The first known cases of Covid-19 in Italy were reported on January 31 in two Chinese tourists holidaying in Rome.

Three weeks later the first cluster of cases was detected when 16 Italians were diagnosed with the virus in Lombardy on February 21.

Prof Manca analysed the trajectory of the disease from that point, in terms of the numbers of patients admitted to intensive care units (ICU).

He found that there had been an exponential growth initially "with numbers doubling over two- to four-day intervals, with this explosion observed for a long period, approximately until day 16 to 18".

This was followed by a period of three to four days where the "maximum speed of increase is continued". This is called the inflection point.

Prof Manca's found that this inflection point was reached by day 19 in Lombardy - March 11 - and March 14 for Italy as a whole.

He projects that there will now be a slowdown in new cases until eventually there is no further increase in patients entering intensive care.

Lombardy started out with 500 public and 140 private ICU beds. The region, one of the wealthiest in Italy, now has more than 900.

Other regions in central and Southern Italy are estimated to be 10 to 12 days behind the position in Lombardy, and these regions are scrambling to increase their capacity, for example by converting other wards to intensive care use.

Prof Manca said: "The difference between Lombardy and Italy was only due to the restrictive measures to movement and contacts among people adopted first in Lombardy and then all over Italy.

"Every day counts. After the inflection point, the rate of increase slows although overall numbers still increase steadily.

"However, the rate of increase slows down progressively until it flattens, with no further increase in the rate of people entering intensive care. The best estimate of when this will occur in Italy on this data is between days 38 and 40, which is to say in the first few days of April."

However, he cautions that this "will depend on how effective Italy's quarantine measures are in these next two week".

He added: "As various reports are showing, many people in Italy are not respecting the quarantine and social distancing rules."