Reproduction number for an age of infection structured model

We study the basic reproduction number ( R 0 ) in an epidemic model where infected individuals are initially asymptomatic and structured by time since infection. At beginning of outbreak computation relies on limited data based mostly symptomatic cases, not detected surveillance system. has been widely used as indicator to assess dissemination infectious diseases. Asymptomatic assumed either become after a fixed period or they removed (recovery disease-related death). determine understood expected secondary cases produced primary case through chain infections. is computed directly interpreting ingredients also using more systematic approach next-generation operator. Reported Covid-19 during first wave pandemic Spain fit obtain both values before severe lockdown imposed March 2020. The results confirm that SARS-CoV-2 was expanding within population whereas virus spreading controlled two weeks lockdown. In memoriam Carles Perelló, emeritus professor at UAB, recently deceased scientific father/grandfather authors.