The impact of COVID-19 non-pharmaceutical interventions on future respiratory syncytial virus transmission in South Africa

Abstract

The COVID-19 pandemic has had far-reaching impacts around the world, infecting 500 million people and causing over 6 million deaths since its emergence in December of 2019. In order to prevent widespread transmission of COVID-19, large-scale nonpharmaceutical interventions (NPIs) such as lockdowns, travel bans, and social distancing were implemented around the world. The implementation of these control measures on a global scale has been crucial to mitigating disease transmission and limiting healthcare system strain. While NPIs have been useful in the control of the COVID-19 pandemic, these public health measures have also functioned in slowing the spread of other endemic respiratory pathogens. Surveillance data from South Africa indicates low circulation of respiratory syncytial virus (RSV) throughout the 2020-2021 seasons. Here we fit an age-structured epidemiological model to South African national surveillance data to predict the timing, magnitude, and age structure of the 2022 RSV outbreak following two suppressed seasons. We project a 32% increase in the peak number of monthly RSV-related hospitalizations among infants ≤ 2 years, with older infants (6-23-month olds) experiencing a larger portion of severe disease burden than typical. The work contained in this thesis report is the first age-structured analysis on the impact of COVID-19 on RSV in a lower middle-income country (LMIC) and has been published in medRxiv* and disseminated by the National Institute for Communicable Diseases of South Africa to the Facility Readiness Group in order to prepare the healthcare system for the impending outbreak. The following report will describe the mathematical process used to formulate these epidemiological predictions, the results, and their public health implications in South Africa.