Contact Tracing contact examination 7 human 7 Humans 6 COVID-19 5 Article 4 SARS-CoV-2 4 computer simulation 3 coronavirus disease 2019 3 disease transmission 3 epidemic 3 epidemiology 3 pandemic 3 Adolescent 2 Adult 2 Aged 2 Computer Simulation 2 Contact tracing 2 Coronavirus 2 Epidemics 2 Human immunodeficiency virus infection 2 Middle Aged 2 Models, Biological 2 Public Health 2 Young Adult 2 adolescent 2 adult 2 aged 2 basic reproduction number 2 biological model 2