Identifying and Interrupting Superspreading Events

Implications for Control of Severe Acute Respiratory Syndrome Coronavirus 2

Thomas R. Frieden; Christopher T. Lee


Emerging Infectious Diseases. 2020;26(6):1059-1066. 

In This Article


COVID-19 has already killed more persons than SARS and MERS combined. Both of these coronavirus infections were fueled by SSEs. Understanding transmission dynamics associated with SSEs and their control during other coronavirus outbreaks can help inform current public health approaches to SARS-CoV-2. Anticipated heterogeneity in transmission should be used to plan disease control programs and risk-stratify populations for public health interventions. Countries should develop and implement protocols for implementation of rapid identification, diagnosis, and isolation of patients; effective infection prevention and control practices in healthcare facilities; and timely and relevant risk communication. Such measures can mitigate the impact of SSEs, which have been major drivers of recent epidemics.

Because delay in diagnosis and failure to rapidly implement isolation and response measures have fueled previous SSEs, countries should have plans and operational capacities in place during the containment phase of the response for immediate investigation and implementation of control measures. During the later mitigation phase, when surveillance and laboratory resources are limited, surveillance and focused response efforts should prioritize environments and settings at high risk for SSEs, including closed environments such as healthcare facilities, nursing homes, prisons, homeless shelters, schools, and sites of mass gatherings while community-wide NPIs are implemented more broadly.

Targeted and rapidly implemented public health interventions to prevent and mitigate SSEs are critical for early interruption of transmission during the containment phase and to reduce the effect on the disruption of healthcare services and society during the mitigation phase. Because of the societal and cultural underpinnings of behavioral and environmental factors including the local acceptability of adoption of NPIs, early engagement of communities, including an in-depth understanding of knowledge, attitudes, and practices relevant to the pandemic will be critical to response efforts during all phases.