Superspreading and heterogeneity in transmission of SARS, MERS, and COVID-19: A systematic review

Abstract

Background Severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and coronavirus disease 2019 (COVID-19) have caused substantial public health burdens and global health threats. Understanding the superspreading potential of a virus is important for characterizing transmission patterns and informing strategic decision-making in disease control. This systematic review aimed to summarize the existing evidence on superspreading features and to compare the heterogeneity in transmission within and among various coronavirus epidemics of SARS, MERS and COVID-19. Methods PubMed, Medline, and Embase databases were extensively searched for original studies on the transmission heterogeneity of SARS, MERS, and COVID-19 published in English between January 1, 2003, and February 10, 2021. After screening the articles, we extracted data pertaining to the estimated dispersion parameter ( k ) which has been a commonly-used measurement for transmission heterogeneity and superspreading potential. Findings We included a total of 60 estimates of transmission heterogeneity from 26 studies on outbreaks in 22 regions. The majority (90%) of the k estimates were small, with values less than 1, indicating an over-dispersed transmission pattern. The point estimates of k for SARS and MERS ranged from 0.12 to 0.20 and from 0.06 to 2.94, respectively. Among 45 estimates of individual-level transmission heterogeneity for COVID-19 from 17 articles, 91% were derived from Asian regions. The point estimates of k for COVID-19 ranged between 0.1 and 5.0. Conclusions We detected a substantial over-dispersed transmission pattern in all three coronaviruses, while the k estimates varied by differences in study design and public health capacity. Our findings suggested that even with a reduced R value, the epidemic still has a high resurgence potential due to transmission heterogeneity.

Superspreading potential of infection seeded by the SARS-CoV-2 Omicron BA.1 variant in South Korea

“…Our findings suggest that the transmission of the BA.1 variant had high potential of superspreading, which is higher than the Delta variants 6 , and other historical SARS-CoV-2 strains 7 . The BA.1 variant appeared more transmissible with a higher risk of superspreading within community settings than in household and school settings.…”

Systematic review and meta‐analyses of superspreading of SARS‐CoV‐2 infections

“…For SARS and MERS, most infections are caused by a small proportion of cases, with the dispersion parameter ranging from 0.06 to 2.94 (Wang et al., 2021 ). However, a comprehensive review and comparison of the superspreading potential of COVID‐19 and its uncertainty over countries is still lacking.…”

Monitoring real-time transmission heterogeneity from Incidence data

“…This merit of our model could allow for fast and timely epidemiological surveillance, possibly even for the new SARS-CoV-2 variant of Omicron, which has been spreading wildly across the world since its first detection in November 2021 in Gauteng Province, South Africa. We estimated the heterogeneity (in terms of dispersion number k ) was K ≈ 3.43 * 10 − 4 in December 2021 in South Africa, which was more significant than that of the Delta wave (i.e., k ≈ 10 − 3 ) [42]. The more significant heterogeneity of Omicron, together with its higher reproduction number, might be able to explain its unprecedentedly fast spreading.…”