Household Severe Acute Respiratory Syndrome Coronavirus 2 Transmission and Children: A Network Prospective Study
Authors: Soriano-Arandes Antoni , Gatell Anna , Serrano Pepe , Biosca Mireia , Campillo Ferran , Capdevila Ramon , Fàbrega Anna , Lobato Zulema , López Núria , Moreno Ana Mª , Poblet Miriam , Riera-Bosch Maria Teresa , Rius Neus , Ruiz Montserrat , Sánchez Almudena , Valldepérez Cinta , Vilà Mònica , Pineda Valentí , Lazcano Uxue , Díaz Yesika , Reyes-Urueña Juliana , Soler-Palacín Pere ,   COVID-19 Pediatric Disease in Catalonia Research Group, García-Lorenzo Marc , Braviz Lorena , Naranjo Àngels , Salvadó Olga , Burgaya Silvia , Aulet Lidia , Cantero Javier , Ruiz Gloria , Fenoy Marina , Martínez-Mejías Abel , González Iris , Foguet Anton , Bayona Imma , García Guillermo , Solé Laia , Calbet Clara , Carulla Mireia , Piquè Neus , Llobet Pilar , Pujol Berta , Díaz-Conradi Álvaro , Esteller Maria , Rosich Blanca , Gómez Arantxa , Ristol Anna Mª , Guarch Borja , Ripoll Francesc , Chiné Maria , Losana Carlos , Conti Romina , Zambudio Isabel , Escuer Mercè , Manuel Torres Joan , Perez-Porcuna Tomas , Mora Emiliano , García-Puig Roger , Prado Silvia , Gros Daniel , Giribet Mercè , Villalobos Pili , Canadell Dolors , Bruna Xavier , Martínez-Carbonell Elisenda , Bordas Anna , Sentis Alexis , Aceiton Jordi , Casabona Jordi , Herrero Carlos , Casas Isabel , Joaqui Nathalia , Laveglia Vanessa , Vilagrasa Grisel , Méndez Maria , Minguell Laura , Visa Núria , Paredes Fernando , Vidal-Moreso Anna , Díez Rosario , Moreira Ana , Berbel Evelyn , Schneider Stephan , Milà Maria , Maldonado Ana , Caubet Imma , Campins Magda , Esperalba Juliana , Anton Andrés , Gómez i Prat Jordi , Morales Raisa , Santos José , Gussinyé Pilar , Fenollosa Teresa , Moreno Coral , Azemar Joan , Duran Xavier , Terrer Gemma , Galdeano Evaristo , Plasencia Raquel , Oglesby Rebecca , Vives-Oñós Isabel , Sabaté Silvia , Fernandez Vanessa , Ago Cintia , Castan Anna , Fornaguera Francesc , Panadés Dolors , Mónaco Ernesto , Ricós Gemma , Catasús Gina , Mendoza Maria , Busquets Lidia , Macià Esperança , Segura Sandra , Martín Ramona , Sandra López Verónica 
Published: March 2021

Abstract

Background
The role of children in household transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear. We describe the epidemiological and clinical characteristics of children with coronavirus disease 2019 (COVID-19) in Catalonia, Spain, and investigate the household transmission dynamics.

Methods
A prospective, observational, multicenter study was performed during summer and school periods (1 July 2020–31 October 2020) to analyze epidemiological and clinical features and viral household transmission dynamics in COVID-19 patients aged &lt;16 years. A pediatric index case was established when a child was the first individual infected. Secondary cases were defined when another household member tested positive for SARS-CoV-2 before the child. The secondary attack rate (SAR) was calculated, and logistic regression was used to assess associations between transmission risk factors and SARS-CoV-2 infection.

Results
The study included 1040 COVID-19 patients. Almost half (47.2%) were asymptomatic, 10.8% had comorbidities, and 2.6% required hospitalization. No deaths were reported. Viral transmission was common among household members (62.3%). More than 70% (756/1040) of pediatric cases were secondary to an adult, whereas 7.7% (80/1040) were index cases. The SAR was significantly lower in households with COVID-19 pediatric index cases during the school period relative to summer (P = .02) and compared to adults (P = .006). No individual or environmental risk factors associated with the SAR.

Conclusions
Children are unlikely to cause household COVID-19 clusters or be major drivers of the pandemic, even if attending school. Interventions aimed at children are expected to have a small impact on reducing SARS-CoV-2 transmission.