United States: An international team of researchers approximated that the average incubation duration from infection to symptom experienced during the worldwide mpox epidemic of 2022 mirrored that of preceding outbreaks.
However, the time from the onset of symptoms to the next was approximately five (5) days shorter in 2022. This period, known as the serial interval, delineates the span between the initial appearance of symptoms in an index case and those in subsequent cases resulting from transmission, according to CIDRAP News.
These conclusions, delineated in Emerging Infectious Diseases, could imply that the prevalence of sexually linked transmission modalities in 2022 potentially impacted the serial interval, alongside heightened public health vigilance and monitoring amid the global epidemic.
Historically, mpox epidemics dating back to the 1950s have been characterized by intra-household transmission dynamics and modest case tallies. Nonetheless, the 2022 outbreak witnessed a shift, with the virus primarily disseminated through sexual encounters, particularly among men who engage in same-sex relations, as outlined by CIDRAP.
The study conducted comparisons between transmission and onset data from 15 studies comprising 42 case profiles from pre-2022 mpox outbreaks and corresponding data from 42 pertinent investigations conducted during the 2022 epidemic.
Results revealed an incubation period of 8.1 days in 2022, slightly lower than the 8.2 days recorded in earlier outbreaks. Conversely, the serial interval was notably shorter in 2022, at 8.7 days, compared to the 14.2 days observed in previous years.
“Our research underscores the necessity of vigilantly tracking temporal shifts in transmission dynamics and disease progression,” remarked the experts, CIDRAP highlighted.
In conclusion, the authors asserted, “Given that estimates of epidemiological parameters frequently inform interventions against a spectrum of pathogens, our study underscores the criticality of monitoring temporal fluctuations in transmission and disease evolution.”