The case definition used in Portugal is based on the WHO case definition. Initially (25 January 2020), a suspected case was defined as any person with severe acute respiratory infection without any known aetiology and recent (within 14 days) travel or residence in China, or any person with acute respiratory illness and contact with a confirmed or probable case of infection by SARS-CoV-2 within the previous 14 days (https://covid19.min-saude.pt/wp-content/uploads/2020/03/Orientac%CC%A7a%CC%83o-002.pdf). A probable case was defined as a suspected case with inconclusive test for COVID-19 or positive test for pan-coronavirus, and without laboratory evidence for other agents. A confirmed case was defined as a case with laboratory confirmation for SARS-CoV-2, irrespective of clinical criteria.
Following the revision of the WHO case definition, the case definition used in Portugal was updated on 4 March (https://covid19.min-saude.pt/wp-content/uploads/2020/03/Orientac%CC%A7a%CC%83o-002A.pdf). A suspected case was defined as follows:
• A patient with acute respiratory infection, without any known aetiology and recent travel (within 14 days) or residence in any area with active community transmission; or
• A patient with acute respiratory infection and contact with a confirmed or probable case of infection by SARS-CoV-2, within the previous 14 days; or
• A patient with severe acute respiratory infection, without other aetiology, requiring hospitalization.
Currently, a suspected case is defined as any person who develops acute respiratory infection with cough (persistent or worsening of normal cough), or fever (temperature ≥ 38.0ºC) or dyspnea/difficulty in breathing (https://www.dgs.pt/directrizes-da-dgs/normas-e-circulares-normativas/norma-n-0042020-de-23032020-pdf.aspx). The definition for probable and confirmed cases has not been changed.
A close contact of a confirmed case of COVID-19 is defined as any person currently without symptoms but who had or may have had contact with a confirmed case of COVID-19. The exposure of the close contact will determine the kind of surveillance (https://www.dgs.pt/directrizes-da-dgs/normas-e-circulares-normativas/norma-n-0042020-de-23032020-pdf.aspx).
Since the latest update on April 25, and for those recovering at home, 1 negative test is enough to consider the patient cured, while 2 negative tests are still demanded if the patient is at the hospital. A recovered person is defined as a person with symptomatic recover and absence of the virus in the respiratory tract (negative test).
Public health units undertake contact tracing when a confirmed COVID-19 case is identified. All close contacts are evaluated according to their level of exposure. For those with a high risk exposure, the following procedures apply: isolation at home, active monitoring by the health authorities during the 14 days after the last exposure, and daily self-monitoring COVID-19 symptoms (including fever, cough or difficulty in breathing). Testing for contacts with high risk exposure can be determined by health authorities upon evaluation of the risk, particularly in a context of an outbreak or cluster (https://www.dgs.pt/directrizes-da-dgs/normas-e-circulares-normativas/norma-n-0152020-de-24072020-pdf.aspx). Those with low risk exposure are advised to self-monitor for COVID-19 symptoms on a daily basis.
Until July, Portugal was not prioritizing the mandatory use of mobile apps for contact tracing, as the use of these technologies may collide with the Constitution and the individual rights of citizens. Public health capacity has been strengthened by significantly expanding lab capacity and testing, particularly in vulnerable groups of the population such as the older people in residential facilities. New technological tools were developed in order to improve monitoring of confirmed cases and their contacts who are isolated at home.
As the epidemic evolved, thousands of people were traced and actively monitored by health authorities.
Since 2014, Portugal has operated an electronic system for epidemiological surveillance (SINAVE), which, since 2017, also includes laboratory notification. Hence, suspected cases are mandatorily notified by doctors using this electronic system, which issues an e-mail alert to local, regional and national health authorities. Likewise, when a laboratory tests a sample of a suspected case, it should also notify the results using the electronic system. Although, SINAVE is a very important tool for regular epidemiological surveillance, the system is not entirely suitable for outbreaks. However, Portugal also has a fully electronic system for death certificates (SICO), making it possible to identify variations in all-cause mortality, and other hospital-based systems which are useful for capturing changes in hospital activity.
Monitoring and surveillance of cases include long-term care facilities and home care. Following the identification of confirmed cases in residential facilities for the older people, the Ministry of Labour, Solidarity and Social Security in cooperation with the Ministry of Health, Universities and municipalities planned a country-wide COVID-19 testing targeting residents and workers on home care facilities. Likewise, all deaths occurring during the pandemic in facilities where suspected or confirmed cases have been identified should be tested for SARS-CoV-2 (https://www.dgs.pt/directrizes-da-dgs/orientacoes-e-circulares-informativas/orientacao-n-0092020-de-11032020-pdf.aspx).
By the end of August, the app StayAway COVID (https://www.sns.gov.pt/apps/stayaway-covid/) was launched. The app is available in digital stores and aims to identify potential exposition to COVID-19 cases. The use of the app in voluntary, free and anonymous. The app was developed in cooperation with the PORTO Engineering School.
If a user tests positive for COVID-19, a code must be inserted in the app and, after validation, the app will warn all those who were physically close to the confirmed case (less than 2 meters for more than 15 minutes).
In the beginning of October, the electronic version of the Passenger Locator Card (PLC) was launched in all flights with Portugal as destination (https://www.sns.gov.pt/noticias/2020/09/28/cartao-de-localizacao-de-passageiros-eletronico/). The electronic PLC collects data from passengers coming to Portugal in order to facilitate the work of health authorities if a confirmed case is identified on a flight.