Epidemic dynamics of respiratory syncytial virus in current and future climates

Abstract

A key question for infectious disease dynamics is the impact of the climate on future burden. Here, we evaluate the climate drivers of respiratory syncytial virus (RSV), an important determinant of disease in young children. We combine a dataset of county-level observations from the US with state-level observations from Mexico, spanning much of the global range of climatological conditions. Using a combination of nonlinear epidemic models with statistical techniques, we find consistent patterns of climate drivers at a continental scale explaining latitudinal differences in the dynamics and timing of local epidemics. Strikingly, estimated effects of precipitation and humidity on transmission mirror prior results for influenza. We couple our model with projections for future climate, to show that temperature-driven increases to humidity may lead to a northward shift in the dynamic patterns observed and that the likelihood of severe outbreaks of RSV hinges on projections for extreme rainfall.

Prospects for SARS-CoV-2 diagnostics, therapeutics and vaccines in Africa

“…as with many respiratory pathogens, both Middle east respiratory syndrome (Mers-Cov) and sars-Cov exhibit decreased viability in the laboratory following exposure to increasing temperature and humidity 137,138 . similar observations have also been reported for influenza virus and respiratory syncytial virus, for which the incidence of infection is highest under cold and dry conditions, which results in seasonal cycles of infection 139,140 . a similar seasonality has also been observed for other endemic human coronaviruses, which led to the speculation that sars-Cov-2 may also conform to a seasonal cycle of infection 136 .…”

Susceptible supply limits the role of climate in the early SARS-CoV-2 pandemic

“…Specific humidity (the mass of water vapor in a unit mass of moist air) has been shown to be important for influenza transmission in both laboratory settings (9)(10)(11), and in population-level studies (12). Respiratory syncytial virus (RSV), a childhood pathogen, has also been found to be dependent on specific humidity (13) and exhibits latitudinal correlations with climate (14). For both influenza and RSV, low specific humidity increases transmission and epidemics tend to peak in the wintertime in northern latitudes.…”

“…Motivated by the climate-dependence of influenza and RSV, we posit that transmission depends on specific humidity: we use population-weighted average climatology of specific humidity over 2014-2020 taken from the ERA5 reanalysis dataset (20), with population data from (21). We note that specific humidity is dependent on temperature via the Clausius-Clapeyron relation and results using both variables have been found to be equivalent for other diseases (13). After fitting the model parameters, we run simulations of the SARS-CoV-2 pandemic under three scenarios.…”

“…Strong seasonal forcing has been linked to biennial outbreaks, as observed for HKU1 ( fig. S2), in other respiratory pathogens (13) and implies endemic dynamics driven by herd immunity; however this inference may be complicated by cross-protection from other circulating strains (18). While there is some uncertainty in our estimates, simulating a pandemic outbreak using a range of climate-transmission dependencies allows us to explore a wide plausible range of potential climate effects.…”

Editorial JTH 16 –The Coronavirus Disease COVID-19 and implications for transport and health

“…To mitigate these negative effects, robust disease control and prevention planning is becoming more important than ever as globalisation and climate change will make the occurrence of new disease more common in the future (e.g. Cho, 2014;Baker et al, 2019). Further, desperately needed are more robust, evidence-driven transport-based interventions, based on understanding the effectiveness of each.…”