Italy passes Peak Corona Patients

What changed in a week since my earlier Corona virus situation report?

• Total pandemic cases lowered from 200.000 190.000.
• Total pandemic deaths reduced from 28.000 to 27.000.
• Peak Patients raised from 100.000 to 110.000.
• Last new case and death pulled forward from June 20 to May 24.
• Last patient dismissed from treatment pulled forward from June 22 to June 2

The above last point contrasts with the outlook of the Italian Institute of Public Health which today suggested that we would continue seeing new cases through to the end of June - more in line with our forecast from one week ago. This is perfectly within the forecast error of our model, especially because we are looking at the national aggregate figures, while it will be the last regional and local city or town cases that will linger on in some random fashion.

New cases

Today we saw a second day of acceleration in the fall of the virus effective reproduction number. We saw 5 days of this falling at a daily pace half of the April 13 reduction, and then coming back to April 13 levels yesterday. We had expected to see new cases at 1.900 today, but we remain at just under 2.300 new cases. We see this falling to 1.900 already tomorrow and to 830 cases reported one week out. In our model we had expected to see the interaction between the incubation time and virus reproduction being a little more pronounced also on the way to virus extinction, and in the last week this became much more pronounced than one week back. This nonlinear element is what is driving the timeline to end of pandemic, It may seem we had a slowdown as we did not hit forecast on new cases over the last week, but the virus reproduction is accelerating towards zero.

Deaths

The rate of deaths as a proportion of prior five day average new cases has increased from 14% to 15% over the last week, and so resulting in the higher 450 deaths compared to an expected daily 360 victims. A higher than expected number of new cases - 3.300 rather than 2.300 - is the main reason for the higher absolute number, while the higher death rate is likely related to triage conditions in Lombardia as we reached Peak Patients 4 days later than expected a week ago. Uncomfortably high rates of contagion in nursing homes may have contributed. The higher death rate does not compensate for the impact of a lower total cases, and so the end result is still a reduction of one thousand victims in total. We project 470 deaths tomorrow, April 21, and 190 cases a week out.

Healed patients

Over the last week, we saw patients on average remaining in treatment 38 days, an increase over the prior week's 30 days. This lead to our forecast missing by 3.000 on total patients leaving treatment at home or in hospitals - at 49.000 actual compared to the expected 52.000. When we look forward, we still see the rate of healing accelerate to 28 days, down from the 30 days implied in our outlook from Monday, April 13. We model this looking at trends relative to active cases remaining. Given that today's single day figure implied a time to dismissal of 45 days, and since Day 31 the single day figures have varied between 15 and 73 days, we can appreciate that timelines are highly uncertain. The weekly average increased from 32 days to 42 days over the past week, so our call for a contrarian trend looks brave, maybe imprudent. In a highly volatile data set, we stick with iterative math and what we perceive as the stable equilibrium rate of healing. We should see 1.900 patients dismissed tomorrow, and 3.300 on April 27.

Peak Patients

Last week we foresaw a 100.000 patients plateau lasting from April 8 - 24 with April 15 the peak at 104.000 cases. Due to the combination of higher number of new cases, lower healing rates, slightly tempered by increasing death rates, the peak plateau raised to 110.000 in the period April 15 - 22, with a peak yesterday, April 19. For the first time, we saw a fall today of a few hundred patients. This means that the pressure is coming off the health system in a gradual manner. We should be at 94.000 active cases in a week.

The Situation on May 3

As we noted last week, the curfew was extended to May 3, and therefore this date is an important milestone for the so called Phase 2, and the speed with which the economy is opening for business.

Whereas we last week expected new cases to be at 710 per day on May 3, we now see this improving to 280 cases. Deaths are likely about 70 per day, down from the 130 projected on April 13. We continue to project 75.000 patients with Corona virus under treatment. In my view, this will be too many cases still in management to be accepted for general return to a normalized situation.