Transmission Dynamics of SARS-CoV-2 during an Outbreak in a Roma Community in Thessaly, Greece—Control Measures and Lessons Learned
Michalis Koureas, Matthaios Speletas, Zacharoula Bogogiannidou, Dimitris Babalis, Vassilios Pinakas, Ουρανία Πινακά, A. Komnos, Stella Tsoutsa, Georgia Papadamou, Maria Kyritsi, Alexandros Vontas, Vasileios Nakoulas, Spyros Sapounas, Nikolaos Kanellopoulos, Dimitrios Kalompatsios, Vassiliki Papadouli, Katerina Dadouli, Soteris Soteriades, Paraskevi Mina, Varvara Α. Mouchtouri, Lemonia Anagnostopoulos, Kostantinos A. Stamoulis, Kostantinos Agorastos, Efthimia Petinaki, Panagiotis Prezerakos, Sotirios Tsiodras, Christos Hadjichristodoulou
Abstract
A COVID-19 outbreak occurred among residents of a Roma settlement in Greece (8 April-4 June 2020). The aim of this study was to identify factors associated with an increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to evaluate the effectiveness of control measures implemented. Data were analyzed from individuals that were tested for SARS-CoV-2 during contact tracing, population screening or hospital visits. RT-PCR was used for the detection of SARS-CoV-2 in oropharyngeal samples. Risk factors for household secondary attack rates (SAR) and hospitalization with COVID-19 were examined using chi-square tests, Fisher's exact tests and logistic regression analyses. During the outbreak, 142 cases, 20 hospitalizations and 1 death were recorded, with a total of 2273 individuals tested. The risk of hospitalization was associated with age (OR: 1.04, 95% CI: 1.02-1.07) and Cycle threshold (Ct) values (OR for a decrease in Ct values by 1: 1.18, 95% CI: 1.07-1.31). Household SAR was estimated at 38.62% (95% CI: 32.50-45.01%). After the designation of an isolation facility for cases, household SAR declined from 74.42% to 31.03%. Household size was associated with the risk of infection (OR: 2.65, 95% CI: 1.00-7.07). The presence of COVID-19 symptoms among index cases was correlated with higher transmission (OR: 23.68, 95% CI 2.21-253.74) in multivariate analysis, while age was found to be associated with SAR only in univariate analysis. Roma communities can be particularly vulnerable to the spread of SARS-CoV-2. In similar settings, symptomatic cases are more important transmitters of SARS-CoV-2. Within these communities, immediate measures should be implemented to mitigate disease spread.