Attention:The NSF Public Access Repository (PAR) system and access will be unavailable from 5:00 PM ET until 8:00 PM ET on Friday, September 11 due to maintenance. We apologize for the inconvenience.


Title: Disentangling local and global climate drivers in the population dynamics of mosquito-borne infections
Identifying climate drivers is essential to understand and predict epidemics of mosquito-borne infections whose population dynamics typically exhibit seasonality and multiannual cycles. Which climate covariates to consider varies across studies, from local factors such as temperature to remote drivers such as the El Niño–Southern Oscillation. With partial wavelet coherence, we present a systematic investigation of nonstationary associations between mosquito-borne disease incidence and a given climate factor while controlling for another. Analysis of almost 200 time series of dengue and malaria around the globe at different geographical scales shows a systematic effect of global climate drivers on interannual variability and of local ones on seasonality. This clear separation of time scales of action enhances detection of climate drivers and indicates those best suited for building early-warning systems.  more » « less
Award ID(s):
2414688
PAR ID:
10512382
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
the American Association for the Advancement of Science
Date Published:
Journal Name:
Science Advances
Volume:
9
Issue:
39
ISSN:
2375-2548
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Campbell, Corey; Brenner, David (Ed.)
    Abstract There is mounting concern surrounding climate change effects on human health. Vector-borne diseases—transmitted by ectotherms like mosquitos—are sensitive to abiotic conditions, and there is a significant interest in modeling their response to future climate change. However, changing climate also contributes to increasing variability and frequency of extreme weather, including “climate whiplash” events, when weather conditions abruptly shift between extremes. These events may have more immediate effects on vector-borne diseases, though they have received less attention. Here, we use the series of extreme atmospheric rivers of 2022/2023 in California, following years of extreme drought, as a natural experiment to assess the effect of climate whiplash on vector-borne disease risk. Using high spatiotemporal resolution standing water remote sensing, mosquito and viral surveillance, and community science observations of key reservoir hosts, we estimate mosquito species- and virus-specific responses to flooding following atmospheric rivers using panel regression models. We find significant positive effects of flooding on abundance of the rural West Nile virus (WNV) vector in California's Central Valley, with the largest effects at landscape scales. We find no significant effects for the urban WNV vector, or globally invasive yellow fever mosquito. Finally, we find similarly divergent effects on WNV and Saint Louis Encephalitis virus (SLEV) infection: WNV rates decline significantly in the urban vector and SLEV increases significantly in the rural vector. These results reveal species-specific responses to climate whiplash that are predictable by mosquito ecology, relevant to globally important mosquito vectors and diseases, and inform public health response to future extreme events. 
    more » « less
  2. Variability of climatic conditions can impact numerous important public health outcomes, including the prevalence of mosquito-borne diseases such as West Nile virus (WNV). 2002 and 2003 were epidemic years for WNV in the United States, with 685 cases of the novel virus reported from Chicago, IL alone. WNV’s prevalence is most noted in urban areas due to juvenile mosquito habitats provided by subterranean stormwater drainage systems. Transmission in urban environments is favored by suitable weather conditions that stimulate and sustain mosquito reproduction and growth of vector species. Field and laboratory studies indicate that temperature is a crucial factor for suitable conditions for juvenile development, while precipitation plays a dual role: it can provide moisture necessary for aquatic habitats to persist, yet high rain rates lead to flushing of larvae out of subterranean stormwater habitats. The duration of these conditions, and locational features (i.e. topography, elevation and depth below ground), matter too. This study addresses two significant questions: 1) What is the seasonality of suitable juvenile habitat conditions across different human land-use types that employ a mixture of subterranean and surface stormwater infrastructure, and 2) Whether the seasonality of these climatic conditions for mosquito reproduction have shifted over time, which in turn affects the timing and severity of mosquito-borne disease transmission. In our study, we consider over 20 years of multi-scale observations and fine resolution spatiotemporal reanalysis data during the 7-month warm season (April-November) for five small and midsize cities in north-central Illinois. We use weather station data from Illinois State Water Survey and NCEP/EMC 4 KM Gridded Stage IV Data to track the intersection of necessary temperature and precipitation thresholds known to support mosquito reproduction in subterranean and surface stormwater systems. Our analysis will thus identify when and where risk of WNV transmission is more prevalent across the urban-to-rural land-use gradient. Such results will be helpful in identifying the timing of mosquito-borne disease risk and inform policies to curb transmission. 
    more » « less
  3. The role of climate factors on transmission of mosquito-borne infections within urban landscapes must be considered in the context of the pronounced spatial heterogeneity of such environments. Socio-demographic and environmental variation challenge control efforts for emergent arboviruses transmitted via the urban mosquitoAedes aegypti. We address at high resolution, the spatial heterogeneity of dengue transmission risk in the megacity of Delhi, India, as a function of both temperature and the carrying-capacity of the human environment for the mosquito. Based on previous results predicting maximum mosquitoes per human for different socio-economic typologies, and on remote sensing temperature data, we produce a map of the reproductive number of dengue at a resolution of 250m by 250m. We focus on dengue risk hotspots during inter-epidemic periods, places where chains of transmission can persist for longer. We assess the resulting high-resolution risk map of dengue with reported cases for three consecutive boreal winters. We find that both temperature and vector carrying-capacity per human co-vary in space because of their respective dependence on population density. The synergistic action of these two factors results in larger variation of dengue’s reproductive number than when considered separately, with poor and dense locations experiencing the warmest conditions and becoming the most likely reservoirs off-season. The location of observed winter cases is accurately predicted for different risk threshold criteria. Results underscore the inequity of risk across a complex urban landscape, whereby individuals in dense poor neighborhoods face the compounded effect of higher temperatures and mosquito carrying capacity. Targeting chains of transmission in inter-epidemic periods at these locations should be a priority of control efforts. A better mapping is needed of the interplay between climate factors that are dominant determinants of the seasonality of vector-borne infections and the socio-economic conditions behind unequal exposure. 
    more » « less
  4. Abstract Mosquito-borne diseases are a major public health issue. The USA has experienced mosquito-borne disease outbreaks, including West Nile virus, Zika, dengue, and malaria, highlighting widespread risk across the country. In the USA, exposure to mosquito vectors primarily occurs outdoors. Individuals experiencing unsheltered homelessness are particularly vulnerable to mosquito-borne diseases due to their increased exposure to mosquito vectors, limited access to healthcare, and high prevalence of underlying conditions. This review aims to examine the literature on mosquito-borne disease infections among individuals experiencing homelessness in the USA between 1999 and 2024. Our search strategy used Boolean methods on PubMed, Scopus, and Web of Science to select relevant publications. Two queries were used: the first query focused on individuals experiencing homelessness and mosquito-borne diseases, and the second one focused on epidemiological analyses of mosquito-borne disease outbreaks in the USA. Only studies reporting at least one infection among individuals experiencing homelessness were included. Our search resulted in the identification of 347 studies. After screening them, eight were ultimately included in this review. Half of the studies identified West Nile virus among individuals experiencing homelessness, and the other half reported cases of malaria. These studies show that individuals who spend more time outdoors, including individuals experiencing homelessness, may be at a greater risk of MBDs compared to the general population. However, the full extent of mosquito-borne disease exposure among individuals experiencing homelessness remains unclear. With climate change and globalization, there is a consensus in the literature showing an increasing risk of mosquito-borne disease transmission in the next decades, and we have already started to witness this increasing trend. Moreover, the USA is experiencing a steep increase in the overall nationwide homeless population. Therefore, we argue that developing policies aimed at providing homeless populations with housing during mosquito-borne disease outbreaks could be instrumental in protecting this segment of the population and promoting health equity. 
    more » « less
  5. Experiments and models suggest that climate affects mosquito-borne disease transmission. However, disease transmission involves complex nonlinear interactions between climate and population dynamics, which makes detecting climate drivers at the population level challenging. By analysing incidence data, estimated susceptible population size, and climate data with methods based on nonlinear time series analysis (collectively referred to as empirical dynamic modelling), we identified drivers and their interactive effects on dengue dynamics in San Juan, Puerto Rico. Climatic forcing arose only when susceptible availability was high: temperature and rainfall had net positive and negative effects respectively. By capturing mechanistic, nonlinear and context-dependent effects of population susceptibility, temperature and rainfall on dengue transmission empirically, our model improves forecast skill over recent, state-of-the-art models for dengue incidence. Together, these results provide empirical evidence that the interdependence of host population susceptibility and climate drives dengue dynamics in a nonlinear and complex, yet predictable way. 
    more » « less