The dynamics of monkeypox transmission

Abstract

Pre-exposure vaccination and vaccine equity are urgently needed worldwide After a surge of monkeypox infections starting in May 2022, with more than 70 000 cases globally—including 99% from countries without previous known endemic spread—by the end of August 2022, new infections started to trend downward.12 Whether this marks the end of the outbreak or whether intermittent surges will continue is not yet clear. Understanding the underlying transmission dynamics is key to shedding light on this, as well as informing future interventions. In a linked paper, Ward and colleagues (doi:10.1136/bmj-2022-073153) used routine case questionnaires and contact tracing data to estimate two important characteristics of the monkeypox outbreak in the UK: the serial interval and incubation period.3 They found that shorter serial intervals are more common than shorter incubation periods. One explanation the authors provided is that considerable transmission is occurring before the appearance or detection of symptoms; otherwise, the serial interval should at a minimum equal the incubation period. This study had a relatively large sample size and appropriate statistical adjustments to account for key biases in the data. The researchers used paired case-contact data to validate their model based conclusions. …