COVID-19: When more might be less.

During the “first wave” of the COVID-19 pandemic the primary and community care model of the Veneto region markedly limited the diffusion of SARS-CoV-2 infection in this area compared to the rest of Italy [1]. Afterwards, in all country, the cases progressively decreased, with the minimum daily increase by August 3rd (159 new cases) [2]. Then, daily positive cases began to grow slowly until the end of October 2020, when a sharp increase of COVID-19 cases occurred (the so-called “second wave”) (see Fig. 1 ).

Figure 1

The trend of CoSS index in Lombardy, Piedmont, Valle d’Aosta and Veneto in the time frame between October 1st and December 24th. As the picture shows, the index had a significant fall after the severe restrictions applied in Lombardy, Piedmont and Valle d’Aosta. The Veneto regions show a flat curve of CoSS index.

In September 2020, COVID-19 pandemic was under control, both in Italy and in Veneto. Here, the daily increase of cases was reduced to about 100 cases/day, lowering the pressure on the health care system: on September 1st, COVID-19 patients occupied 69 hospital beds, 9 in Intensive Care Units (ICUs). Conversely, by October 1st, the positive cases progressively started to climb (445/day), but patients requiring hospitalization were still few (180 hospital beds, 24 ICUs).

In the following weeks, the second wave of pandemic developed: by mid-November daily new cases were 40.902 in Italy and 3.605 in Veneto with 30.914 (3230 ICUs) and 1.831 (219 ICUs) hospital beds occupied by COVID-19 patients, respectively.

Then, SARS-CoV-2 infected patients gradually and continuously decreased in Italy. By contrast and differently from all the other regions, the remarkable rise of cases of mid-November did not slow down in Veneto, but the incident curve flattened on a constant, high level of new daily cases: on December 7th, for example, 2.550 more cases occurred than the day before with a plus of 51 deaths while 2.529 hospital beds were occupied by COVID-19 patients, with 317 admitted in ICUs (Table 1 ). On December 25th, the new daily cases in Veneto accounted for more than a quarter of all new daily cases in Italy (5.010 out of 19.037 in the whole country). Furthermore, according to the records of the Veneto Regional Health System [3], the rate of positive cases per swab resulted 36.4% in Veneto compared to 12.5% in the remaining Italian regions.

Table 1

New daily cases, hospital and ICU beds occupied by COVID-19 patients in the time frame of the second wave of the pandemic.

		1 Sept 2020		1 Oct 2020		13 Nov 2020		7 Dec 2020		25 Dec 2020
		Italy	Veneto	Italy	Veneto	Italy	Veneto	Italy	Veneto	Italy	Veneto
New cases	Total	978	97	2.548	445	40.902	3.605	13.720	2.550	19.037	5.010
	per 100.000 inhabitants	1,62	1,98	4,22	9,06	67,76	73,42	22,73	51,93	31,54	102,04
Hospital beds		1.380	69	3.097	180	30.914	1.831	30.524	2.529	23.402	2.582
ICU bedsa		107	9	291	24	3.230	219	3.382	317	2.584	346
ICU occupation rateb		1,5	1,0	4,1	2,9	45,5	26,5	47,6	38,4	36,4	41,9

As November 30th the available ICU beds were 7.092 in Italy and 825 in the Veneto region.

According to the Italian Minister of Health the alarm threshold is when the ICU occupation rate by COVID-19 patients is above 30%.

Which are the reasons concurring to the apparent worse scenario of the Veneto region compared to the rest of Italy? For sure, the higher percentage of positive cases/swab was the result of a misleading computation of the performed tests, which considered only the “molecular” swabs as denominator and not the sum of all diagnostic swabs (i.e. the antigenic ones) [4]. Furthermore, Veneto region performed the highest number of swabs per inhabitant, increasing significantly the chance to identify positive cases. For example, on December 26th the swabs completed in Veneto were 17.720 (0.36% per population) compared to the national amount of 81.285 (0.15%) [2]. Finally, as suggested [4], new mutations of the viral genome found in Veneto as well as in other countries might have made it more contagious and spreadable.

Still, Veneto was undoubtedly hit more severely by SARS-CoV-2 infection compared to other Italian regions, overturning the scenario of the first wave of the pandemic. The most probable explanation of the differences between Veneto and the rest of the country was the diverse regimen of restrictions applied.

The CoSS (COVID-19 Spread and Severity) Index [5] accurately defines the risk of COVID-19 spread and severity at any given time, in a specific geographic area (low risk <5, intermediate 5–10, high >10) as the ratio between total deaths and number of recovered patients multiplied by the incidence of new regional cases/total regional inhabitants in the last 2 weeks. As the Fig. 1 shows, on October 20th the CoSS index was 13.3 in Lombardy, 9.7 in Piedmont and 21.1 in Valle d’Aosta, while Veneto showed a lower value (4.6). At that time, the Italian Ministry of Health stratified all Italian regions in 3 different thresholds according to the risk of spreading of the SARS-CoV-2 infection (yellow: low, orange: intermediate, red: high). The color categorization defined different degrees of restrictions (the highest, the red areas; the mildest, the yellow ones) and was weekly updated, applying an algorithm built by 21 specific items. These indicators included clinical and/or epidemiological measures such as the Rt index and the daily new cases, the COVID 19-related admissions to Emergency Room and the number of new outbreaks in a specific area. Furthermore, the calculation kept into account the performance to efficiently manage the pandemic, by measuring the availability of ICUs and hospital beds and the readiness of human, instrumental and organizational resources to guarantee contact tracing and surveillance.

Since November 6th, four regions (Lombardy, Piedmont, Calabria and Valle d’Aosta) were labelled as “red”. On November 15th, Tuscany and Campania switched to the red level of risk, joined by Abruzzo on November 21st. Other regions, including Emilia-Romagna, Puglia, Friuli Venezia-Giulia, Marche and Sicily, were classified as “orange” with an intermediate degree of restrictions. By contrast, due to its good performance in the pandemic management and the wide availability of hospital/ICU beds, Veneto was always labelled as “yellow area” by the central Government and the Ministry of Health and left in the lowest degree of restrictions with very few limitations for most of the commercial and economic activities. Indeed, Veneto was very well prepared for the second wave of pandemic. Already in October, the regional authorities developed a specific anti “second wave” plan, built in five levels according to the severity and spreading of the infection. To each stage corresponds a different hospital organization, with a gradual increase of ICU beds and new opening of dedicated COVID-19 hospitals and facilities. In the meantime, “territorial” monitoring and contact tracing were implemented, by boosting the use of rapid “molecular” and “non-molecular” tests and by setting up 24-h swab facilities in all the region.

After the restrictions were applied, the CoSS index drastically collapsed in the so-called red area: Lombardy 6.3, Piedmont 4.1 and Valle d’Aosta 4.6. On the contrary, the Veneto Region showed a “plateau” with a peak up to 23.1 and a subsequent flattening of the curve around a value of 16.2.

Therefore, while the other Italian regions, especially those labelled as “red”, showed a gradual and consistent decrease of the new daily cases, Veneto continued to struggle with the spreading of SARS-CoV-2 infection, despite the increase of diagnostic tests and the progressive opening of new hospital facilities and dedicated wards for COVID-19 patients.

In fighting the COVID-19, it is crucial and mandatory to be prepared and well organized in term of human resources and hospital facilities as well as adopting a preventive medicine approach and implementing the contact tracing. However, these measures may be not enough when new infection waves occur. In these situations, to effectively slow down, already in the early phases, the spreading of SARS-CoV-2 infection requires social distancing, wearing masks and, above all, a targeted and a balanced “lockdown” preventive strategy. As physicians, we know that the prevention is the keystone for controlling cardiovascular atherosclerotic burden in the general population. Similarly, social and behavioral measures of prevention of the SARS-CoV-2 contagion are crucial to limit the spreading of the infection while waiting for the effect of the worldwide vaccination against the virus.

Funding

None.

Declaration of competing interest

The authors declare that they have no conflict of interest.