Population-Based Assessment of Contact Tracing Operations for Coronavirus Disease 2019 in Pirkanmaa Hospital District, Finland
Rannikko, Juha; Viskari, Hanna; Sirkeoja, Simo; Tamminen, Pekka; Kaila, Ville; Ala-Mursula, Anni; Huttunen, Reetta; Laine, Janne; Syrjänen, Jaana; Nuorti, Pekka (2022-04-21)
Rannikko, Juha
Viskari, Hanna
Sirkeoja, Simo
Tamminen, Pekka
Kaila, Ville
Ala-Mursula, Anni
Huttunen, Reetta
Laine, Janne
Syrjänen, Jaana
Nuorti, Pekka
21.04.2022
ofac214
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202209157099
https://urn.fi/URN:NBN:fi:tuni-202209157099
Kuvaus
Peer reviewed
Tiivistelmä
Background: The coronavirus disease 2019 (COVID-19) epidemic overwhelmed local contact tracing (CT) efforts in many countries. In Finland, severe acute respiratory syndrome coronavirus 2 incidence and mortality were among the lowest in Europe during 2020-2021. We evaluated CT efficiency, effectiveness, and transmission settings. Methods: Polymerase chain reaction (PCR) test-positive COVID-19 cases and high-risk contacts in the population-based CT database of Pirkanmaa Hospital District (population 540 000) during June 2020-May 2021 were interviewed. Results: Altogether 353 926 PCR tests yielded 4739 (1.3%) confirmed cases (average 14-day case notification rate, 34 per 100 000 population); about 99% of confirmed cases and high-risk contacts were reached by a CT team. Of 26 881 high-risk contacts who were placed in quarantine, 2275 subsequently tested positive (48% of new cases), 825 (17%) had been in quarantine ≥48 hours before symptoms, and 3469 (77%) of locally acquired cases were part of transmission chains with an identified setting. The highest secondary attack rates were seen in households (31%), healthcare patients (18%), and private functions (10%). Among the 311 hospitalized patients, COVID-19 diagnosis or exposure was known in 273 (88%) before emergency room admission (identified patients). Healthcare workers had the highest proportion of work-related infections (159 cases [35%]). The source of infection was classifiable in 65% and was most commonly a coworker (64 cases [62%]). Conclusions: Our data demonstrate the role of effective testing and CT implementation during the cluster phase of COVID-19 spread. Although half of newly diagnosed cases were already in quarantine, targeted public health measures were needed to control transmission. CT effectiveness during widespread community transmission should be assessed.
Kokoelmat
- TUNICRIS-julkaisut [16726]