key: cord-0985118-gzysuusk
authors: Piapan, Linda; De Michieli, Paola; Ronchese, Federico; Rui, Francesca; Mauro, Marcella; Peresson, Maria; Segat, Ludovica; D’Agaro, Pierlanfranco; Negro, Corrado; Bovenzi, Massimo; Filon, Francesca Larese
title: COVID-19 outbreak in healthcare workers in Trieste hospitals (North-Eastern Italy)
date: 2020-08-14
journal: Journal of Hospital Infection
DOI: 10.1016/j.jhin.2020.08.012
sha: 89b53257db69276c44877b3ed89cc2737c69bb5f
doc_id: 985118
cord_uid: gzysuusk

nan

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), first reported in Wuhan, China, on December 2019 has rapidly become an increasing health concern worldwide [1]. During a pandemic, healthcare workers (HCWs) are at the frontline [2] , they are at high risk of infection providing care for patients [3] , and they are subjected to long working hours, psychological distress and fatigue. In Trieste, a north-eastern Italian province with 234 493 inhabitants, 903 of 4,216 HCWs in public hospitals reported contact with COVID-19 patients between March 1 and April 6, 2020, and were followed up to verify symptom onset. Their characteristics are reported in Table I . Contacts were interviewed daily to verify their health status, they had to monitor and report the body temperature twice a day and they were tested using RT-PCR virus detection in nasopharyngeal and oropharyngeal swabs every 3 days after close contact and after 13 days for causal contact. In case of symptom onset, HCWs were immediately tested, they stopped working, and remained at home with active daily monitoring by phone call.

Nasopharyngeal and oropharyngeal swabs were tested by rRT-PCR targeting the E, N and RdRp gene of SARS-CoV-2 according to the CDC and Charité laboratory protocols [4] . The cycle threshold values of rRT-PCR were used as qualitative indicators of viral load of SARS-CoV-2 RNA in specimens, with lower cycle threshold values corresponding to higher viral copy numbers. A cycle threshold value less than 40 was interpreted as positive for SARS-CoV-2 RNA. Data analysis was performed with the software STATA™ v.

14.0 (Stata Corp., LP, College Station, TX, USA). A p-value of <0.05 was established as the limit of statistical significance.

The vast majority of COVID-19 HCWs were employed in medical wards, with a significantly increased prevalence in Geriatric and Infectious Diseases (42.6%) (OR 67.9; CI 34.7-133) and Internal Medicine I and II (29.6%) (OR 9.6; CI 5.6-16.5). As regards the exposure history, most affected subjects had contact with an infected patient (51.3%), 27 reported to have been exposed only to colleagues (23.5%) and 29 to both patients and colleagues (25.2%) showing in this latter case a significant difference compared with J o u r n a l P r e -p r o o f the negative contacts (OR 7.0; CI 3.7-13.3). Most cases reported using personal protective equipment (PPE) during working hours (71.3%). However, following checks, it was found that the use of PPE was not appropriate during HCW meetings, thus contributing to COVID-19 spread among colleagues.

The COVID-19 spread in different wards and the time trend analysis of contact and case onset showed 4 major cluster outbreaks. The first cluster of contacts occurred on March 6, 2020, in Geriatric ward where an index patient without respiratory symptoms (one of the first cases documented in Trieste) was admitted: 72% of HCWs in the division were infected. Another two clusters of exposure occurred on March 10 and 11, 2020, in Internal Medicine I and II, due to the hospitalization of 2 patients not suspected to be COVID-19 positive at first (26% and 39% of HCWs infected). The fourth cluster was in the Infectious Diseases ward and began with a HCW who had acquired the infection in community and infected the 87% of co-workers. In the remaining hospital departments COVID-19 spread was much more contained, with some sporadic cases in other medical wards and none in surgical ones.

In the study period, infected HCWs accounted for 16.2% of all COVID-19 cases in the province of Trieste [5] . This percentage is higher than that reported in China (3.8%) [6] and similar to that observed in the 

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