ISS
Epidemiology for public health
Istituto Superiore di Sanità

 

Epidemiology for public health - ISS

COVID-19 integrated surveillance: key national data

Infographics and extended reports for the COVID-19 integrated surveillance are regularly published on EpiCentro.

 

 

Extended document

 

ISS-ISTAT Report

 

Please note: consolidation of the collected data is an ongoing process and, as would be expected in an emergency situation, some information may be incomplete or subject to change on a daily basis. In addition, especially in the Regions/APs where sustained community transmission of the virus has occurred or is still occurring, there might be a few days’ delay between a diagnostic swab test being carried out and the case being reported on the dedicated platform.

 

How to interpret the data

The data published by the ISS come from the COVID-19 integrated surveillance system established in Italy, and are processed by the ISS integrating the microbiological and epidemiological data provided by all regions and Autonomous Provinces (APs) and by the ISS SARS-CoV-2 national reference laboratory.

  • For more information on how the COVID-19 integrated surveillance works, visit the dedicated page.

Data on laboratory-confirmed SARS-CoV-2 infections are provided on a daily basis to the ISS by all Regions/APs. The ISS has created a dedicated IT platform which allows data to be either collected through a web interface linked to the platform or sent directly as datasets.

 

All COVID-19 cases diagnosed by the regional reference laboratories, and other laboratories that officially joined the diagnostic network more recently, fall within the scope of the surveillance. It should be noted that, according to international case definitions, adopted also by the ISS, a confirmed case is a person with laboratory confirmation of the virus causing COVID-19 infection, irrespective of clinical signs and symptoms.

 

Individual data are updated by each Region/AP on a daily basis and have the peculiarity of providing a higher level of detail compared to other data flows (e.g. from the Civil Protection or the Ministry of Health). They often include information on pre-existing diseases and patients’ clinical conditions when their details were entered into the platform.

 

As would be expected in an emergency situation, some information may be temporarily incomplete. This is what is meant when information is described as “being consolidated”. In particular, especially in Regions/APs with a high number of infections, diagnosed and hospitalized cases, there might be a few days’ delay between a diagnostic swab test being carried out and the case being reported on the dedicated platform.

 

Interpretation of more recent data requires particular caution, and possible delays in reporting new cases should be taken into account when monitoring the evolution of the epidemic. Further information in this regard can be found on the page dedicated to the COVID-19 integrated surveillance.

 

Terminology

Case definitions

According to circular n. 0007922 of 9 March 2020, issued by the Ministry of Health, case definitions are based on currently available information and therefore may be revised based on the evolution of the epidemiological situation and the available scientific knowledge [3].

 

Suspect COVID-19 case requiring diagnostic testing

  1. A person with acute respiratory infection (sudden onset of at least one of the following signs and symptoms: fever, cough and shortness of breath)
    and
    in the absence of an alternative diagnosis that fully explains the clinical presentation
    and
    a history of travel to, or residence in, a country/area reporting community transmission (according to WHO classification) during the 14 days prior to symptom onset
    or
  2. A person with any acute respiratory infection
    and
    having been in close contact with a confirmed or probable COVID-19 case in the last 14 days prior to symptom onset
    or
  3. A person with severe acute respiratory infection (fever and at least one sign/symptom of respiratory disease - e.g. cough, shortness of breath)
    and
    requiring hospitalization (SARI)
    and
    in the absence of an alternative diagnosis that fully explains the clinical presentation. In primary care and hospital emergency departments, all patients with symptoms of acute respiratory infection must be considered as suspect cases if community transmission has been reported in their country or area.

Probable case: A suspect case for whom testing for SARS-CoV-2 is uncertain or inconclusive when using real-time PCR protocols for specific detection of SARS-CoV-2 at the regional reference laboratories, or is positive when using a pan-coronavirus assay.

 

Confirmed case: A case of SARS-CoV-2 infection, irrespective of clinical signs and symptoms, confirmed by the ISS national reference laboratory or regional reference laboratories fulfilling the criteria set out in Annex 3 to the Ministerial Circular.

 

Definition for deaths: For surveillance purposes, the WHO defines a death due to COVID-19 as a death resulting from a clinically compatible illness in a probable or confirmed COVID-19 case, unless there is a clear alternative cause of death that cannot be related to COVID-19 (e.g. trauma). There should be no period of complete recovery between illness and death.

 

Median age/Mean age: The median and the mean are two statistical measures used in epidemiology to summarize information about a variable (in this case, age). Mean age is calculated by adding up the ages of all individuals and then dividing the sum by the number of individuals. Median age is the age that divides a dataset into two equal halves, where half the ages are below this value and half are above it. Since in this epidemic the age distribution of COVID-19 cases is asymmetric, the median is better suited than the mean to describing the variable.

 

Number of deaths/case fatality rate: Case fatality rate is the number of deaths from a disease divided by the total number of people diagnosed with that disease. It is different from mortality rate, which is the number of deaths from the disease divided by the total population.

 

Asymptomatic: A person who tested positive for SARS-CoV-2, with no visible signs or symptoms of disease.

 

Paucisymptomatic: A person who tested positive for SARS-CoV-2, with only mild symptoms (e.g. general feeling of being unwell, slightly raised body temperature, fatigue).

 

Mild: A person who tested positive for SARS-CoV-2, with clear signs and symptoms of disease (respiratory disease) which are not severe enough to require hospitalization.

 

Severe: A person who tested positive for SARS-CoV-2, with clear signs and symptoms of disease (respiratory disease) which are severe enough to require hospitalization.

 

Critical: A person who tested positive for SARS-CoV-2, with clear signs and symptoms of disease (for example, a respiratory disease) which are severe enough to require intensive care.

 

 

Page last reviewed: 25 July 2020

Publication date:11 March 2020

Authors: Flavia Riccardo, Xanthi Andrianou, Antonino Bella, Martina Del Manso, Alberto Mateo Urdiales, Massimo Fabiani, Stefania Bellino, Stefano Boros, Fortunato (Paolo) D'Ancona, Maria Cristina Rota, Antonietta Filia, Ornella Punzo, Andrea Siddu, Maria Fenicia Vescio, Corrado Di Benedetto, Marco Tallon, Alessandra Ciervo, Patrizio Pezzotti, Paola Stefanelli - ISS