Open Access“Mass gathering events and COVID-19 transmission in Borriana (Spain): A retrospective cohort study”
Author(s) -
Salvador Domènech-Montoliu,
María Rosario Pac-Sa,
Paula Vidal-Utrillas,
Marta Latorre-Poveda,
Alba Del Rio-González,
Sara Ferrando-Rubert,
Gema Ferrer-Abad,
Manuel Sánchez-Urbano,
Laura Aparisi-Esteve,
Gema Badenes-Marques,
Belén Cervera-Ferrer,
Ursula Clerig-Arnau,
Claudia Dols-Bernad,
María Fontal-Carcel,
Lorna Gómez-Lanas,
David Jovani-Sales,
Maria Carmen León-Domingo,
Maria Dolores Llopico-Vilanova,
Mercedes Moros-Blasco,
Cristiotari-Rodríguez,
Raquel Ruíz-Puig,
Sonia Valls-López,
Alberto Arnedo-Pena
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0256747
Subject(s) - covid-19 , retrospective cohort study , transmission (telecommunications) , pandemic , mass gathering , medicine , betacoronavirus , coronavirus infections , cohort study , virology , geography , outbreak , computer science , disease , telecommunications , public health , pathology , infectious disease (medical specialty)
Objective Mass gathering events (MGEs) are associated with the transmission of COVID-19. Between 6 and 10 March 2020, several MGEs related to the Falles festival took place in Borriana, a municipality in the province of Castellon (Spain). The aim of this study was to estimate the incidence of COVID-19 and its association with these MGEs, and to quantify the potential risk factors of its occurrence. Methods During May and June 2020, a population-based retrospective cohort study was carried out by the Public Health Center of Castelló and the Hospital de la Plana in Vila-real. Participants were obtained from a representative sample of 1663 people with potential exposure at six MGEs. A questionnaire survey was carried out to obtain information about attendance at MGEs and COVID-19 disease. In addition, a serologic survey of antibodies against SARS-Cov-2 was implemented. Inverse probability weighted regression was used in the statistical analysis. Results A total of 1338 subjects participated in the questionnaire survey (80.5%), 997 of whom undertook the serologic survey. Five hundred and seventy cases were observed with an attack rate (AR) of 42.6%; average age was 36 years, 62.3% were female, 536 cases were confirmed by laboratory tests, and 514 cases were found with SARS-CoV-2 total antibodies. Considering MGE exposure, AR was 39.2% (496/1264). A dose-response relationship was found between MGE attendance and the disease, (adjusted relative risk [aRR] = 4.11 95% confidence interval [CI]3.25–5.19). Two MGEs with a dinner and dance in the same building had higher risks. Associated risk factors with the incidence were older age, obesity, and upper and middle class versus lower class; current smoking was protective. Conclusions The study suggests the significance of MGEs in the COVID-19 transmission that could explain the subsequent outbreak in Borriana.