Last data update: Sep 23, 2024. (Total: 47723 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Hoover CM [original query] |
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Mitigating outbreaks in congregate settings by decreasing the size of the susceptible population (preprint)
Blumberg S , Lu P , Hoover CM , Lloyd-Smith JO , Kwan AT , Sears D , Bertozzi SM , Worden L . medRxiv 2021 While many transmission models have been developed for community spread of respiratory pathogens, less attention has been given to modeling the interdependence of disease introduction and spread seen in congregate settings, such as prisons or nursing homes. As demonstrated by the explosive outbreaks of COVID-19 seen in congregate settings, the need for effective outbreak prevention and mitigation strategies for these settings is critical. Here we consider how interventions that decrease the size of the susceptible populations, such as vaccination or depopulation, impact the expected number of infections due to outbreaks. Introduction of disease into the resident population from the community is modeled as a branching process, while spread between residents is modeled via a compartmental model. Control is modeled as a proportional decrease in both the number of susceptible residents and the reproduction number. We find that vaccination or depopulation can have a greater than linear effect on anticipated infections. For example, assuming a reproduction number of 3.0 for density-dependent COVID-19 transmission, we find that reducing the size of the susceptible population by 20% reduced overall disease burden by 47%. We highlight the California state prison system as an example for how these findings provide a quantitative framework for implementing infection control in congregate settings. Additional applications of our modeling framework include optimizing the distribution of residents into independent residential units, and comparison of preemptive versus reactive vaccination strategies. |
Aligning staff schedules, testing, and isolation reduces the risk of COVID-19 outbreaks in carceral and other congregate settings: A simulation study
Hoover CM , Skaff NK , Blumberg S , Fukunaga R . PLOS Glob Public Health 2023 3 (1) e0001302 COVID-19 outbreaks in congregate settings remain a serious threat to the health of disproportionately affected populations such as people experiencing incarceration or homelessness, the elderly, and essential workers. An individual-based model accounting for individual infectiousness over time, staff work schedules, and testing and isolation schedules was developed to simulate community transmission of SARS-CoV-2 to staff in a congregate facility and subsequent transmission within the facility that could cause an outbreak. Systematic testing strategies in which staff are tested on the first day of their workweek were found to prevent up to 16% more infections than testing strategies unrelated to staff schedules. Testing staff at the beginning of their workweek, implementing timely isolation following testing, limiting test turnaround time, and increasing test frequency in high transmission scenarios can supplement additional mitigation measures to aid outbreak prevention in congregate settings. |
Modeling scenarios for mitigating outbreaks in congregate settings.
Blumberg S , Lu P , Kwan AT , Hoover CM , Lloyd-Smith JO , Sears D , Bertozzi SM , Worden L . PLoS Comput Biol 2022 18 (7) e1010308 The explosive outbreaks of COVID-19 seen in congregate settings such as prisons and nursing homes, has highlighted a critical need for effective outbreak prevention and mitigation strategies for these settings. Here we consider how different types of control interventions impact the expected number of symptomatic infections due to outbreaks. Introduction of disease into the resident population from the community is modeled as a stochastic point process coupled to a branching process, while spread between residents is modeled via a deterministic compartmental model that accounts for depletion of susceptible individuals. Control is modeled as a proportional decrease in the number of susceptible residents, the reproduction number, and/or the proportion of symptomatic infections. This permits a range of assumptions about the density dependence of transmission and modes of protection by vaccination, depopulation and other types of control. We find that vaccination or depopulation can have a greater than linear effect on the expected number of cases. For example, assuming a reproduction number of 3.0 with density-dependent transmission, we find that preemptively reducing the size of the susceptible population by 20% reduced overall disease burden by 47%. In some circumstances, it may be possible to reduce the risk and burden of disease outbreaks by optimizing the way a group of residents are apportioned into distinct residential units. The optimal apportionment may be different depending on whether the goal is to reduce the probability of an outbreak occurring, or the expected number of cases from outbreak dynamics. In other circumstances there may be an opportunity to implement reactive disease control measures in which the number of susceptible individuals is rapidly reduced once an outbreak has been detected to occur. Reactive control is most effective when the reproduction number is not too high, and there is minimal delay in implementing control. We highlight the California state prison system as an example for how these findings provide a quantitative framework for understanding disease transmission in congregate settings. Our approach and accompanying interactive website (https://phoebelu.shinyapps.io/DepopulationModels/) provides a quantitative framework to evaluate the potential impact of policy decisions governing infection control in outbreak settings. |
Feeding success and host selection by Culex quinquefasciatus say mosquitoes in experimental trials
McMillan JR , Marcet PL , Hoover CM , Mead D , Kitron U , Vazquez-Prokopec GM . Vector Borne Zoonotic Dis 2019 19 (7) 540-548 Arthropod vector feeding preferences are defined as an overutilization of a particular host species given its abundance in relationship to other species in the community. Numerous methods exist to quantify vector feeding preferences; however, controlled host choice experiments are generally an underutilized approach. In this report, we present results from controlled vector host choice experiments using Culex quinquefasciatus Say (Diptera: Culicidae) mosquitoes and wild avian hosts identified as important contributors to West Nile virus (WNv) transmission in Atlanta, Georgia, United States. In each experiment, we allowed lab-reared F1 Cx. quinquefasciatus to feed freely overnight on two avian individuals of a different species (i.e., northern cardinals, American robins, blue jays, brown thrashers, and gray catbirds). We then estimated WNv transmission potential using vectorial capacity and R0. We found that mosquito blood feeding success was extremely variable among experimental replicates and that patterns of host choice only occasionally aggregated to a particular bird species. Vectorial capacity was highest for American robins and blue jays due to these species' higher reservoir competence for WNv and greater probabilities of mosquito selection of these species. Despite species-specific differences in vectorial capacity, total community capacity was similar among species pairs. R0 estimates were qualitatively similar to capacity, and R0 was below and above unity across species pairs. Our results provide empirical evidence that C. quinquefasciatus is an opportunistic blood feeder and highlight how variability in vector-host contact rates as well as host community composition can influence the likelihood of WNv transmission in avian communities. |
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