Publications by authors named "Cara E Brook"

Kobuviruses (family , genus ) are enteric viruses that infect a wide range of both human and animal hosts. Much of the evolutionary history of kobuviruses remains elusive, largely due to limited screening in wildlife. Bats have been implicated as major sources of virulent zoonoses, including coronaviruses, henipaviruses, and filoviruses, though much of the bat virome still remains uncharacterized.

View Article and Find Full Text PDF

Bats (order Chiroptera) are hosts for highly virulent zoonotic pathogens. Many bats demonstrate seasonally varying antiviral responses, including antibody responses which have been observed to peak during the nutritionally depleted dry-season and female gestation periods, suggesting some impact of resource deficits on bat virus immunity. Given the frequent overlap in these energetically demanding periods, it is likely that endocrinological changes associated with pregnancy might partially explain the aforementioned pattern in antibody dynamics.

View Article and Find Full Text PDF

Flying birds and bats have simplified gastrointestinal tracts (GITs) and low intestinal mass to facilitate flight. Previous work showed reduced GIT transit times in birds relative to other vertebrates-but GIT transit has never been collectively quantified for bats. Unique among mammals, bat GIT microbiomes are dominated by Pseudomonadota bacteria (previously Proteobacteria), which also dominate the microbiomes of flying birds - we hypothesized this convergence to result from rapid GIT transit times for both volant taxa.

View Article and Find Full Text PDF

The incidence of dengue virus disease has increased globally across the past half-century, with highest number of cases ever reported in 2019 and again in 2023. We analyzed climatological, epidemiological, and phylogenomic data to investigate drivers of two decades of dengue in Cambodia, an understudied endemic setting. Using epidemiological models fit to a 19-y dataset, we first demonstrate that climate-driven transmission alone is insufficient to explain three epidemics across the time series.

View Article and Find Full Text PDF
Article Synopsis
  • * Astroviruses, which are often overlooked, have been found in bats with significant prevalence, indicating that bats might play a key role in their transmission to other species.
  • * This study used advanced metagenomic Next Generation Sequencing to identify astroviruses in Madagascar fruit bats, revealing important insights into the evolutionary history of these viruses and reinforcing the significance of bats as astrovirus hosts.
View Article and Find Full Text PDF
Article Synopsis
  • * Astroviruses, which have shown potential for zoonotic transfer, are an under-researched group with significant diversity detected in bats.
  • * This study utilizes metagenomic Next Generation Sequencing to find astroviruses in Madagascar fruit bats, providing insights into their evolutionary history and highlighting bats as key hosts for these viruses in the Southwest Indian Ocean.
View Article and Find Full Text PDF

Introduction: Bats are important providers of ecosystem services such as pollination, seed dispersal, and insect control but also act as natural reservoirs for virulent zoonotic viruses. Bats host multiple viruses that cause life-threatening pathology in other animals and humans but, themselves, experience limited pathological disease from infection. Despite bats' importance as reservoirs for several zoonotic viruses, we know little about the broader viral diversity that they host.

View Article and Find Full Text PDF

The management of future pandemic risk requires a better understanding of the mechanisms that determine the virulence of emerging zoonotic viruses. Meta-analyses suggest that the virulence of emerging zoonoses is correlated with but not completely predictable from reservoir host phylogeny, indicating that specific characteristics of reservoir host immunology and life history may drive the evolution of viral traits responsible for cross-species virulence. In particular, bats host viruses that cause higher case fatality rates upon spillover to humans than those derived from any other mammal, a phenomenon that cannot be explained by phylogenetic distance alone.

View Article and Find Full Text PDF

Global dengue incidence has increased dramatically over the past few decades from approximately 500 000 reported cases in 2000 to over 5 million in 2019. This trend has been attributed to population growth in endemic areas, rapid unplanned urbanization, increasing global connectivity, and climate change expanding the geographic range of the . mosquito, among other factors.

View Article and Find Full Text PDF

Objective: Data from 19 years of national dengue surveillance in Cambodia (2002-2020) were analyzed to describe trends in dengue case characteristics and incidence.

Methods: Generalized additive models were fitted to dengue case incidence and characteristics (mean age, case phenotype, fatality) over time. Dengue incidence in a pediatric cohort study (2018-2020) was compared to national data during the same period to evaluate disease under-estimation by national surveillance.

View Article and Find Full Text PDF

The island nation of Madagascar is home to three endemic species of Old World fruit bat in the family Pteropodidae: , , and , all three of which are IUCN Red Listed under some category of threat. Delineation of seasonal limits in the reproductive calendar for threatened mammals can inform conservation efforts by clarifying parameters used in population viability models, as well as elucidate understanding of the mechanisms underpinning pathogen persistence in host populations. Here, we define the seasonal limits of a staggered annual birth pulse across the three species of endemic Madagascar fruit bat, known reservoirs for viruses of high zoonotic potential.

View Article and Find Full Text PDF

The genus (family ) currently comprises seven viruses, four of which have demonstrated prior evidence of zoonotic capacity. These include the biosafety level 4 agents Hendra (HeV) and Nipah (NiV) viruses, which circulate naturally in pteropodid fruit bats. Here, we describe and characterize Angavokely virus (AngV), a divergent henipavirus identified in urine samples from wild, Madagascar fruit bats.

View Article and Find Full Text PDF

SignificanceThe clear need to mitigate zoonotic risk has fueled increased viral discovery in specific reservoir host taxa. We show that a combination of viral and reservoir traits can predict zoonotic virus virulence and transmissibility in humans, supporting the hypothesis that bats harbor exceptionally virulent zoonoses. However, pandemic prevention requires thinking beyond zoonotic capacity, virulence, and transmissibility to consider collective "burden" on human health.

View Article and Find Full Text PDF
Article Synopsis
  • Bats are key reservoirs for zoonotic coronaviruses, with significant research focused in Asia, yet these viruses are found globally, including Africa and Europe.
  • A long-term study in Madagascar on local fruit bats revealed the presence of novel coronaviruses, with full genome sequences identified that show distinct evolutionary branches.
  • This research highlights Madagascar's unique position for viral diversity and mixing, stressing the importance of monitoring bat coronaviruses to prevent future zoonotic outbreaks as bats are commonly consumed in the region.
View Article and Find Full Text PDF

Bats are reservoirs for zoonotic viruses, which they tolerate without experiencing disease. Research focused on deciphering mechanisms of virus tolerance in bats has rarely considered the influence of their gastrointestinal tract (GIT) microbiome. In mammals, GIT microbiomes influence infections through their effect on host physiology, immunity, nutrition, and behavior.

View Article and Find Full Text PDF

As the national reference laboratory for febrile illness in Madagascar, we processed samples from the first epidemic wave of COVID-19, between March and September 2020. We fit generalized additive models to cycle threshold (C) value data from our RT-qPCR platform, demonstrating a peak in high viral load, low-C value infections temporally coincident with peak epidemic growth rates estimated in real time from publicly-reported incidence data and retrospectively from our own laboratory testing data across three administrative regions. We additionally demonstrate a statistically significant effect of duration of time since infection onset on C value, suggesting that C value can be used as a biomarker of the stage at which an individual is sampled in the course of an infection trajectory.

View Article and Find Full Text PDF
Article Synopsis
  • Better prediction and prevention methods for zoonotic viruses can help reduce future epidemic risks.
  • A network science framework is suggested to understand and predict how humans and animals are susceptible to viral infections.
  • The article discusses improving modeling accuracy and actionable outcomes, while addressing barriers to applying viral ecology research to public health policies.
View Article and Find Full Text PDF

The high proportion of transmission events derived from asymptomatic or presymptomatic infections make SARS-CoV-2, the causative agent in COVID-19, difficult to control through the traditional non-pharmaceutical interventions (NPIs) of symptom-based isolation and contact tracing. As a consequence, many US universities developed asymptomatic surveillance testing labs, to augment NPIs and control outbreaks on campus throughout the 2020-2021 academic year (AY); several of those labs continue to support asymptomatic surveillance efforts on campus in AY2021-2022. At the height of the pandemic, we built a stochastic branching process model of COVID-19 dynamics at UC Berkeley to advise optimal control strategies in a university environment.

View Article and Find Full Text PDF

In the past two decades, three coronaviruses with ancestral origins in bats have emerged and caused widespread outbreaks in humans, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first SARS epidemic in 2002-2003, the appreciation of bats as key hosts of zoonotic coronaviruses has advanced rapidly. More than 4,000 coronavirus sequences from 14 bat families have been identified, yet the true diversity of bat coronaviruses is probably much greater.

View Article and Find Full Text PDF

As the national reference laboratory for febrile illness in Madagascar, we processed samples from the first epidemic wave of COVID-19, between March and September 2020. We fit generalized additive models to cycle threshold (C ) value data from our RT-qPCR platform, demonstrating a peak in high viral load, low-C value infections temporally coincident with peak epidemic growth rates estimated in real time from publicly-reported incidence data and retrospectively from our own laboratory testing data across three administrative regions. We additionally demonstrate a statistically significant effect of duration of time since infection onset on C value, suggesting that C value can be used as a biomarker of the stage at which an individual is sampled in the course of an infection trajectory.

View Article and Find Full Text PDF
Article Synopsis
  • Regular surveillance testing of asymptomatic individuals for SARS-CoV-2 was key to preventing outbreaks on college campuses, notably at UC Berkeley in 2020.
  • The university implemented a voluntary saliva testing program as part of a research study, allowing for improvement of testing methods before wider clinical use.
  • The success of the program highlighted effective strategies for promoting participation and fostering a sense of community responsibility among students.
View Article and Find Full Text PDF

Background: Following the first detection of SARS-CoV-2 in passengers arriving from Europe on 19 March 2020, Madagascar took several mitigation measures to limit the spread of the virus in the country.

Methods: Nasopharyngeal and/or oropharyngeal swabs were collected from travellers to Madagascar, suspected SARS-CoV-2 cases and contact of confirmed cases. Swabs were tested at the national reference laboratory using real-time RT-PCR.

View Article and Find Full Text PDF

The high proportion of transmission events derived from asymptomatic or presymptomatic infections make SARS-CoV-2, the causative agent in COVID-19, difficult to control through the traditional non-pharmaceutical interventions (NPIs) of symptom-based isolation and contact tracing. As a consequence, many US universities developed asymptomatic surveillance testing labs, to augment NPIs and control outbreaks on campus throughout the 2020-2021 academic year (AY); several of those labs continue to support asymptomatic surveillance efforts on campus in AY2021-2022. At the height of the pandemic, we built a stochastic branching process model of COVID-19 dynamics at UC Berkeley to advise optimal control strategies in a university environment.

View Article and Find Full Text PDF