I am a doctoral student in the Department of Epidemiology at the UNC Gillings School of Global Public Health with an interest in the mathematical modeling of infectious diseases.
My research particularly concerns the interaction between mathematical/computational models of infectious disease and observational epidemiological methods. Currently, I am working on the mathematical modeling of healthcare-associated pathogens, particularly those with a surface-mediated component to their transmission, such as Clostridium difficile.
Background Influenza infections pose a serious burden of illness in the United States. We explore... more Background Influenza infections pose a serious burden of illness in the United States. We explored age, influenza strains, and seasonal epidemic curves in relation to influenza-associated mortality. Methods The state of Wisconsin death records for the years 1967–2004 were analyzed for three distinct populations: children, general population, and elderly. Yearly parameters of duration, intensity, and peak timing were obtained from Annual Harmonic Regression coefficients.
Stochastic transmission models are highly important in infectious disease epidemiology. The quant... more Stochastic transmission models are highly important in infectious disease epidemiology. The quantity of data produced by these models is challenging to display and communicate. A common approach is to display the model results in the familiar form of a mean or median and 95% interval, plotted over time. This approach has drawbacks, however, including the potential for ambiguity and misinterpretation of model results. Instead, we propose 2 alternative approaches for visualizing results from stochastic models. These proposed approaches convey the information provided by the median and 95% interval, as well as information about unexpected outcomes that may be of particular interest for stochastic epidemic models.
Please cite this paper as: Lofgren et al. (2010) Disproportional effects in populations of concer... more Please cite this paper as: Lofgren et al. (2010) Disproportional effects in populations of concern for pandemic influenza: insights from seasonal epidemics in Wisconsin, 1967–2004. Influenza and Other Respiratory Viruses 4(4), 205–212.Background Influenza infections pose a serious burden of illness in the United States. We explored age, influenza strains, and seasonal epidemic curves in relation to influenza-associated mortality.Methods The state of Wisconsin death records for the years 1967–2004 were analyzed for three distinct populations: children, general population, and elderly. Yearly parameters of duration, intensity, and peak timing were obtained from Annual Harmonic Regression coefficients.Results Overall, elderly had the highest rate and intensity of influenza mortality. The children and infant subpopulations showed an earlier and wider range in duration of peak timing than elderly. During A/Hong Kong/1/68 pandemic years, the elderly subpopulation showed no change in mortality rates while a sharp increase was observed for the children and infant subpopulations. In epidemic years such as 1966–1969, children and infants showed a dramatic decrease in the severity of influenza outbreaks over time. The elderly had increased baseline mortality in years (1986–1987) where predominant strain was characterized as A/Singapore/6/86.Conclusions Our findings indicate that the younger populations may have benefited from the lack of a major shift in viral strains for a number of decades. Furthermore, we demonstrate considerable heterogeneity in the spread of seasonal influenza across age categories, with implications both for the modeling of influenza seasonality, risk assessment, and effective distribution and timing of vaccine and prophylactic interventions.
Background Influenza infections pose a serious burden of illness in the United States. We explore... more Background Influenza infections pose a serious burden of illness in the United States. We explored age, influenza strains, and seasonal epidemic curves in relation to influenza-associated mortality. Methods The state of Wisconsin death records for the years 1967–2004 were analyzed for three distinct populations: children, general population, and elderly. Yearly parameters of duration, intensity, and peak timing were obtained from Annual Harmonic Regression coefficients.
Stochastic transmission models are highly important in infectious disease epidemiology. The quant... more Stochastic transmission models are highly important in infectious disease epidemiology. The quantity of data produced by these models is challenging to display and communicate. A common approach is to display the model results in the familiar form of a mean or median and 95% interval, plotted over time. This approach has drawbacks, however, including the potential for ambiguity and misinterpretation of model results. Instead, we propose 2 alternative approaches for visualizing results from stochastic models. These proposed approaches convey the information provided by the median and 95% interval, as well as information about unexpected outcomes that may be of particular interest for stochastic epidemic models.
Please cite this paper as: Lofgren et al. (2010) Disproportional effects in populations of concer... more Please cite this paper as: Lofgren et al. (2010) Disproportional effects in populations of concern for pandemic influenza: insights from seasonal epidemics in Wisconsin, 1967–2004. Influenza and Other Respiratory Viruses 4(4), 205–212.Background Influenza infections pose a serious burden of illness in the United States. We explored age, influenza strains, and seasonal epidemic curves in relation to influenza-associated mortality.Methods The state of Wisconsin death records for the years 1967–2004 were analyzed for three distinct populations: children, general population, and elderly. Yearly parameters of duration, intensity, and peak timing were obtained from Annual Harmonic Regression coefficients.Results Overall, elderly had the highest rate and intensity of influenza mortality. The children and infant subpopulations showed an earlier and wider range in duration of peak timing than elderly. During A/Hong Kong/1/68 pandemic years, the elderly subpopulation showed no change in mortality rates while a sharp increase was observed for the children and infant subpopulations. In epidemic years such as 1966–1969, children and infants showed a dramatic decrease in the severity of influenza outbreaks over time. The elderly had increased baseline mortality in years (1986–1987) where predominant strain was characterized as A/Singapore/6/86.Conclusions Our findings indicate that the younger populations may have benefited from the lack of a major shift in viral strains for a number of decades. Furthermore, we demonstrate considerable heterogeneity in the spread of seasonal influenza across age categories, with implications both for the modeling of influenza seasonality, risk assessment, and effective distribution and timing of vaccine and prophylactic interventions.
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Papers by Eric Lofgren