Estimating the incubation period of monkeypox virus during the 2022 multi-national outbreak

Abstract

Abstract Monkeypox is a zoonotic disease endemic in Central and West Africa. In May 2022, an outbreak of monkeypox characterized by human-to-human transmission was detected in multiple non-endemic countries. We estimated the incubation period for monkeypox using information from 22 probable (N = 1) and confirmed (N = 21) monkeypox cases in patients reported in the United States through June 6, 2022. We pooled U.S. patient data with the data from 18 confirmed cases in patients reported from the Netherlands through May 31, 2022. The mean incubation period from exposure to first symptom onset was 7.6 days (95% credible interval: 6.2 – 9.7), and the 95th percentile was 17.1 days (95% CrI: 12.7–24.3). These findings align with current CDC recommendations for monitoring close contacts of people with monkeypox for 21 days after their last exposure.