Nicolás Rosillo1,2, Javier Del-Águila-Mejía2,3, Ayelén Rojas-Benedicto2,4, María Guerrero-Vadillo2, Marina Peñuelas2, Clara Mazagatos2,4, Jordi Segú-Tell2,4, Rebeca Ramis5,6, Diana Gómez-Barroso2,4. 1. Servicio de Medicina Preventiva. Centro de Actividades Ambulatorias, 6ª planta, Bloque C, Hospital Universitario 12 de Octubre. Avenida de Córdoba, s/n, 28041, Madrid, Spain. 2. Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029, Madrid, Spain. 3. Servicio de Medicina Preventiva, Hospital Universitario de Móstoles, Calle Río Júcar, s/n, 28935, Móstoles, Spain. 4. Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Calle Monforte de Lemos 3-5, 28029, Madrid, Spain. 5. Centro Nacional de Epidemiología, Instituto de Salud Carlos IIII, Calle de Melchor Fernández Almagro 5, 28029, Madrid, Spain. rramis@isciii.es. 6. Consorcio de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP), Instituto de Salud Carlos III, Calle Monforte de Lemos 3-5, 28029, Madrid, Spain. rramis@isciii.es.
Abstract
BACKGROUND: On June 21st de-escalation measures and state-of-alarm ended in Spain after the COVID-19 first wave. New surveillance and control strategy was set up to detect emerging outbreaks. AIM: To detect and describe the evolution of COVID-19 clusters and cases during the 2020 summer in Spain. METHODS: A near-real time surveillance system to detect active clusters of COVID-19 was developed based on Kulldorf's prospective space-time scan statistic (STSS) to detect daily emerging active clusters. RESULTS: Analyses were performed daily during the summer 2020 (June 21st - August 31st) in Spain, showing an increase of active clusters and municipalities affected. Spread happened in the study period from a few, low-cases, regional-located clusters in June to a nationwide distribution of bigger clusters encompassing a higher average number of municipalities and total cases by end-August. CONCLUSION: STSS-based surveillance of COVID-19 can be of utility in a low-incidence scenario to help tackle emerging outbreaks that could potentially drive a widespread transmission. If that happens, spatial trends and disease distribution can be followed with this method. Finally, cluster aggregation in space and time, as observed in our results, could suggest the occurrence of community transmission.
BACKGROUND: On June 21st de-escalation measures and state-of-alarm ended in Spain after the COVID-19 first wave. New surveillance and control strategy was set up to detect emerging outbreaks. AIM: To detect and describe the evolution of COVID-19 clusters and cases during the 2020 summer in Spain. METHODS: A near-real time surveillance system to detect active clusters of COVID-19 was developed based on Kulldorf's prospective space-time scan statistic (STSS) to detect daily emerging active clusters. RESULTS: Analyses were performed daily during the summer 2020 (June 21st - August 31st) in Spain, showing an increase of active clusters and municipalities affected. Spread happened in the study period from a few, low-cases, regional-located clusters in June to a nationwide distribution of bigger clusters encompassing a higher average number of municipalities and total cases by end-August. CONCLUSION: STSS-based surveillance of COVID-19 can be of utility in a low-incidence scenario to help tackle emerging outbreaks that could potentially drive a widespread transmission. If that happens, spatial trends and disease distribution can be followed with this method. Finally, cluster aggregation in space and time, as observed in our results, could suggest the occurrence of community transmission.
Authors: Nushrat Nazia; Zahid Ahmad Butt; Melanie Lyn Bedard; Wang-Choi Tang; Hibah Sehar; Jane Law Journal: Int J Environ Res Public Health Date: 2022-07-06 Impact factor: 4.614