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Biology subjects

Nova, N.

Publications and source records attributed to Nova, N..

4 recordsLinked to original sources

Persistent, Multi-Species Outbreaks and Long-Range Transmissions of a Measles-Like Virus

Canine distemper--a measles-like disease with high mortality and presently without a cure--poses a major threat to wild and domestic carnivores globally. Domestic dogs are generally considered to be the main reservoir and long-range transmitter of the disease, but the role of wildlife is likely underestimated and the long-term persistence of CDV in wildlife has never been assessed. We sequenced canine distemper virus (CDV) full and partial genomes that were sampled over a decade (2012-2021) from Arctic foxes and other canids in Alaska and Yellowstone, and compiled a dataset of all published CDV genomes sampled across 32 species globally. We show the first ever evidence of persistence of CDV in wildlife (for almost a decade) with explosive transmission dynamics crossing host species barriers. Strains sampled from the Arctic for the first time connect North America to Eurasia, and are distinct from the Yellowstone strain and other known North American lineages. This suggests that separate wildlife outbreaks occur concurrently in North America, with possible introductions from Eurasia. The long-term persistence, long-range movement and explosive spread of this devastating panzootic virus that we document within wildlife is alarming and highlights the need for increased monitoring efforts to better protect wildlife populations globally.

genomics↗

Empirical dynamic modeling reveals ecological drivers of dengue dynamics

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 analyzing incidence data, estimated susceptible population size, and climate data with methods based on nonlinear time series analysis (collectively referred to as empirical dynamic modeling), 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 drive dengue dynamics in a nonlinear and complex, yet predictable way.

ecology↗

Return of an apex predator to a suburban preserve triggers a rapid trophic cascade

Absence of apex predators simplifies food chains, leading to trophic degradation of ecosystems and diminution of the services they provide1. However, most predators do not coexist well with humans, which has resulted in a decline of carnivores and functional ecosystems worldwide2. In some instances, cryptic carnivores manage to survive amidst human settlements, finding refuge in small biological islands surrounded by urban landscapes. In such a system, we used two non-invasive data collection methods (camera trapping and fecal sampling) to investigate the multiannual relationship between predators and prey, and between competitors, through analysis of: (1) relative abundance and detection probability of species over time, (2) causal interactions via empirical dynamic modeling, (3) diet, and (4) diel activity patterns. All approaches show concordance in the results: the natural return of an apex predator, the puma (Puma concolor), triggered a trophic cascade, affecting the abundance and behavior of its main prey, subordinate predators and other prey in the studied system. Our study demonstrates that trophic recovery can occur rapidly following the return of a top predator, even in small protected areas in increasingly urbanized landscapes.

ecology↗

Mosquito and primate ecology predict human risk of yellow fever virus spillover in Brazil

Many (re)emerging infectious diseases in humans arise from pathogen spillover from wildlife or livestock, and accurately predicting pathogen spillover is an important public health goal. In the Americas, yellow fever in humans primarily occurs following spillover from non-human primates via mosquitoes. Predicting yellow fever spillover can improve public health responses through vector control and mass vaccination. Here, we develop and test a mechanistic model of pathogen spillover to predict human risk for yellow fever in Brazil. Our environmental risk model, based on the ecology of mosquito vectors and non-human primate hosts, distinguished municipality-months with yellow fever spillover from 2001 to 2016 with high accuracy (AUC = 0.71). Incorporating hypothesized cyclical dynamics of infected primates improved accuracy (AUC = 0.79). Using boosted regression trees to identify gaps in the mechanistic model, we found that important predictors include current and lagged (mechanistic) environmental risk, vaccine coverage, population density, temperature, and precipitation. More broadly, we show that for a widespread human viral pathogen, the ecological interactions between environment, vectors, reservoir hosts, and humans can predict spillover with surprising accuracy, suggesting the potential to improve preventative action to reduce yellow fever spillover and prevent onward epidemics in humans.

ecology↗