Analysis of the time evolution of COVID-19 lethality during the first epidemic wave in Italy

Main Article Content

Nicole Balasco
Vincenzo d’Alessandro
Pietro Ferrara
Giovanni Smaldone
Luigi Vitagliano

Keywords

COVID-19; Italy; lethality rate; mortality burden; SARS-CoV-2; weekly lethality rate

Abstract

Background and aim: While the entire world is still experiencing the dramatic emergency due to SARS-CoV-2, Italy has a prominent position since it has been the locus of the first major outbreak among Western countries. The aim of this study is the evaluation of temporal connection between SARS-CoV-2 positive tests (cases) and deaths in Italy in the first wave of the epidemic.


Methods: A temporal link between cases and deaths was determined by comparing their daily/weekly trends using surveillance data of the period March 2–June 2020.


Results: The monitoring of the cases/deaths evolution during the first wave of the outbreak highlights a striking correlation between infections of a certain week and deaths of the following one. We defined a weekly lethality rate that is virtually unchanged over the entire months of April and May until the first week of June (≈13.6%). Due to the rather low number of cases/deaths, this parameter starts to fluctuate in the following three weeks.


Conclusions: The analysis indicates that the weekly lethality rate is virtually unchanged over the entire first wave of the epidemic, despite the progressive increase of the testing. As observed for the overall lethality, this parameter uniformly presents rather high values. The definition of a temporal link between cases and deaths will likely represent a useful tool for highlighting analogies and differences between the first and the second wave of the pandemic and for evaluating the effectiveness, even if partial, of the strategies applied during the ongoing outbreak. (www.actabiomedica.it)

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References

1. World Health Organization. WHO Coronavirus Disease (COVID-19) Dashboard. Available online: https://covid19.who.int (Last accessed on December 21st, 2020).
2. COVID-19 coronavirus pandemic. Available online: https://www.worldometers.info/coronavirus/italy (Last accessed on December 21st, 2020).
3. Ferrara P, Albano L. COVID-19 and healthcare systems: what should we do next? Public Health 2020; 185: 1–2.
4. Anelli F, Leoni G, Monaco, R., et al. Italian doctors call for protecting healthcare workers and boosting community surveillance during COVID-19 outbreak. BMJ 2020; 368: m1254.
5. Conti S, Ferrara P, Fornari C, et al. Estimates of the initial impact of COVID-19 epidemic on overall mortality: evidence from Italy. ERJ Open Res 2020; 6: 00179-2020.
6. Dipartimento della Protezione Civile. COVID-19 Italia – Monitoraggio della situazione. Available online: www.opendatadpc.maps.arcgis.com/apps/opsdashboard/index.html#/b0c68bce2cce478eaac82fe38d4138b1 (Last accessed on December 21st, 2020).
7. Istituto Superiore di Sanità. COVID-19 integrated surveillance data in Italy. Available online: https://www.epicentro.iss.it/en/coronavirus/sars-cov-2-dashboard (Last accessed on December 21st, 2020).
8. Istituto Superiore di Sanità. Characteristics of SARS-CoV-2 patients dying in Italy. Available online: https://www.epicentro.iss.it/en/coronavirus/bollettino/Report-COVID-2019_7_september_2020.pdf (Last accessed on December 21st, 2020).
9. Ghani AC. Donnelly CA, Cox DR, et al. Methods for estimating the case fatality ratio for a novel, emerging infectious disease. Am J Epidemiol 2005; 162: 479–486.
10. Conti S, Ferrara P, Mazzaglia G, et al. Magnitude and time-course of excess mortality during COVID-19 outbreak: population-based empirical evidence from highly impacted provinces in northern Italy. ERJ Open Res 2020; 6: 00458-2020.
11. Ghayda RA, Lee KH, HanYJ, et al. Estimation of global case fatality rate of coronavirus disease 2019 (COVID-19) using meta-analyses: Comparison between calendar date and days since the outbreak of the first confirmed case. Int J Infect Dis 2020; 100:302-8
12. Oke J, Heneghan C. Global COVID-19 case fatality rates. CEBM Research, April 6, 2020. Available online: https://www.cebm.net/global-covid- 19-case-fatality-rates/ (Last accessed on December 21st, 2020).
13. Verity R, Okell LC, Dorigatti I, et al. Estimates of the severity of coronavirus disease 2019: a model-based analysis. Lancet Inf. Dis. 2020; 20(6): 669–677.
14. Wilson N, Kvalsvig A, Barnard L, Baker MG. Case-fatality risk estimates for COVID-19 calculated by using a lag time for fatality. Emerging Infectious Diseases 2020; 26(6): 1339–1441.
15. International Agency for Research on Cancer (IARC). Cancer Registration: Principles and Methods; IARC Scientific Publications: Lyon, France, 1991.
16. MATLAB R2014b, September 2014, MathWorks, Inc., Natick, Massachusetts, USA.
17. R Foundation for Statistical Computing. The R Foundation: Vienna, Austria. Available online: www.R-project.org
18. Istituto Superiore di Sanità. Characteristics of SARS-CoV-2 patients dying in Italy. Available online: https://www.epicentro.iss.it/en/coronavirus/bollettino/Report-COVID-2019_28_may_2020.pdf (Last accessed on December 21st, 2020).
19. Michelozzi P, de’Donato P, Scortichini M, et al. Temporal dynamics in total excess mortality and COVID-19 deaths in Italian cities. BMC Public Health 2020; 20: 1238.
20. Di Giambenedetto S, Ciccullo A, Borghetti A, et al. Off-label use of Tocilizumab in patients with SARS-CoV-2 infection. Journal of Medical Virology 2020;92(10):1787-1788.
21. Clementi N, Ferrarese R, Tonelli M, et al. Lower nasopharyngeal viral load during the latest phase of COVID-19 pandemic in a Northern Italy University Hospital. Clin Chem Lab Med. 2020; 58(9): 1573–1577.
22. Tang X, Wu C, Li X, et al. On the origin and continuing evolution of SARS-CoV-2. National Science Review 2020; nwaa036.
23. Veronesi L, Colucci ME, Pasquarella C, et al. Virological surveillance of SARS-CoV-2 in an Italian northern area: comparison of Real Time RT PCR cycle threshold (Ct) values in three epidemic periods. Acta Biomed. 2020; 91(S9): 19-21
24. Odone A, Vitale M, Signorelli C. The identity of public health in COVID-19 times. Acta Biomed. 2020; 91(S9): 5-6
25. Bertuzzo E, Mari L, Pasetto D, et al. The geography of COVID-19 spread in Italy and implications for the relaxation of confinement measures. Nature Communications 2020; 11: 4264.
26. Gandhi M, Rutherford GW. Facial Masking for Covid-19 — Potential for “Variolation” as We Await a Vaccine. N Engl J Med. 2020: 383: e101.
27. European Observatory on Health Systems and Policies. COVID-19 health system response monitor. Available online: www.covid19healthsystem.org/countries/italy/countrypage.aspx (Last accessed on December 21st, 2020).
28. Grasselli G, Zangrillo A, Zanella A, et al. Baseline characteristics and outcomes of 1591 patients infected with SARS-CoV-2 admitted to ICUs of the Lombardy region, Italy. JAMA 2020; 323: 1574–1581.
29. Esposito S, Gnocchi M, Gagliardi M; et al. Therapeutic strategies against COVID-19. Acta Biomed. 2020; 91(3): e2020038.