Household transmission of SARS-CoV-2: a prospective observational study in Bosnia and Herzegovina, August–December 2020

•The overall severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) secondary attack rate in this study was 17%.•Adults were more likely to be secondary cases than children.•Particular care should be taken if primary cases present with cough and rhinorrhoea.•Kissing a SARS-CoV-2 case or sharing a meal with a SARS-CoV-2 case increased the risk of infection.•Reducing contact in the household immediately is key to prevent onward transmission.