We report mean severe acute respiratory syndrome coronavirus 2 serial intervals for Montana, USA, from 583 transmission pairs; infectors' symptom onset dates occurred during March 1-July 31, 2020. Our estimate was 5.68 (95% CI 5.27-6.08) days, SD 4.77 (95% CI 4.33-5.19) days. Subperiod estimates varied temporally by nonpharmaceutical intervention type and fluctuating incidence.
Keywords: 2019 novel coronavirus disease; COVID-19; Montana; SARS-CoV-2; basic reproduction number; communicable disease control; coronavirus; coronavirus disease; epidemics; epidemiology; infectious disease transmission; mathematical model; rural population; severe acute respiratory syndrome coronavirus 2; viruses; zoonoses.