Victoria J. Davey

Health Outcomes and Costs of Community Mitigation Strategies for an Influenza Pandemic in the United States

BACKGROUND The optimal community-level approach to control pandemic influenza is unknown. METHODS We estimated the health outcomes and costs of combinations of 4 social distancing strategies and 2 antiviral medication strategies to mitigate an influenza pandemic for a demographically typical US community. We used a social network, agent-based model to estimate strategy effectiveness and an economic model to estimate health resource use and costs. We used data from the literature to estimate clinical outcomes and health care utilization. RESULTS At 1% influenza mortality, moderate infectivity (R(o) of 2.1 or greater), and 60% population compliance, the preferred strategy is adult and child social distancing, school closure, and antiviral treatment and prophylaxis. This strategy reduces the prevalence of cases in the population from 35% to 10%, averts 2480 cases per 10,000 population, costs

Infectious disease modeling and military readiness.

2700 per case averted, and costs

The Impact of the 2004–2005 Influenza Vaccine Shortage in the Veterans Health Administration

31,300 per quality-adjusted life-year gained, compared with the same strategy without school closure. The addition of school closure to adult and child social distancing and antiviral treatment and prophylaxis, if available, is not cost-effective for viral strains with low infectivity (R(o) of 1.6 and below) and low case fatality rates (below 1%). High population compliance lowers costs to society substantially when the pandemic strain is severe (R(o) of 2.1 or greater). CONCLUSIONS Multilayered mitigation strategies that include adult and child social distancing, use of antivirals, and school closure are cost-effective for a moderate to severe pandemic. Choice of strategy should be driven by the severity of the pandemic, as defined by the case fatality rate and infectivity.

Herbicide exposure, Vietnam service, and hypertension risk in army chemical corps veterans

Advances in infectious disease modeling may offer opportunities to mitigate the effect of emerging infectious diseases upon military readiness (1–3). In August 2005, the US Department of Defense (DoD) Global Emerging Infections Surveillance and Response System (GEIS) sponsored a meeting on the epidemiologic applications of infectious disease modeling in support of DoD readiness. Several recommendations were made at this conference to include the identification of organizations with “…demonstrated expertise in model development and operation for collaboration with the DoD and civilian organizations that are developing simulation models or conducting exercises” (4). Despite this recommendation, infectious disease modeling efforts in support of DoD have remained somewhat disjointed. An infectious disease modeling collaboration between DoD-GEIS and The Johns Hopkins Applied Physics Laboratory, begun in 2007, again identified this issue. Concerned that opportunities for collaboration might be missed and that unintended redundancy might be occurring, DoD-GEIS sponsored a second conference on May 12–13, 2008, for infectious disease modelers engaged in DoD projects or on models useful to the DoD. Over 30 participants from 10 agencies met for a day and a half at the Infectious Disease Modeling Meeting on the campus of the Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland, USA (Appendix). The first day consisted of presentations detailing past and current work by the participating organizations. These presentations are available on the secure DoD-GEIS website for governmental organizations, collaborators, and academic institutions (request access from http://www.AFHSC.mil/about_GEIS.asp). The second day consisted of a roundtable discussion of how to optimize DoD-relevant infectious disease modeling efforts; specifically, how to maximize opportunities for collaboration and coordination while minimizing unintended redundancy. The roundtable discussion first turned to who was at the table, and importantly, who was not. Many participants had also attended the 2005 conference, although some had not, and some of the key attendees at the 2005 conference were not present for the 2008 meeting. A strong recommendation was again made to identify all key organizations involved in infectious disease modeling of use to DoD. Additionally, because of the blurred lines of responsibility among federal agencies, participants thought that many other non-DoD federal organizations should participate in these types of discussions. Some participants called for the creation of a formal organization or society of infectious disease modelers. The Models of Infectious Disease Agent Study (MIDAS; http://www.nigms.nih.gov/Initiatives/MIDAS/Background/Factsheet.htm) group was mentioned as already serving as a nexus for the modeling community, but the need for a larger, coordinating body was expressed. Representatives from the Armed Forces Health Surveillance Center (the parent organization of DoD-GEIS; http://afhsc.army.mil/About_AFHSC.asp) indicated a willingness to be involved in future efforts in a coordinating capacity. Participants also addressed the ambiguity associated with the term modeling, even within the infectious disease modeling community. Models may be used to provide indicators or warnings, surveillance data, or casualty prediction or to assist with consequence management, resource allocation, or policy development. Many models provide various combinations of these functions. Some participants believed it was important to organize modeling efforts by the functionality of the models in question. A stimulating discussion centered on who should have access to infectious disease models. Some thought that models should remain only in the hands of the experts who create them and can manage and interpret them. Others believed that state and community officials, who presumably have much greater local knowledge but less mathematical acumen, should be allowed access to the models. The conference ended by reiterating the recommendation that the entire community of those working on disease modeling of interest to DoD should not only be identified but also strongly encouraged to meet again within the year. In addition to sharing ideas and work, participants of the 2008 conference recommended the development of a format and plan for ongoing communication and collaboration. This plan could include the formation of productive work groups to address definitions, e.g., the meaning of modeling, and to develop recommendations on the use of infectious disease models. The creation of a professional society for federal disease modelers could facilitate these actions and was identified for serious consideration.

Effective, Robust Design of Community Mitigation for Pandemic Influenza: A Systematic Examination of Proposed US Guidance

BackgroundThe Veterans Health Administration (VHA) serves a population at high risk of influenza-related morbidity and mortality. The national public health response to the vaccine shortage of the 2004–2005 season resulted in prioritization of recipients and redistribution of available supply.ObjectiveTo characterize the impact of the 2004–2005 influenza vaccine shortage on vaccination among users of VHA facilities.DesignAnalysis using data from the cross-sectional VHA Survey of Healthcare Experiences of Patients.ParticipantsOutpatients seen in VHA clinics during the months September 2004–March 2005.MeasurementsSociodemographics, vaccination prevalence, setting of vaccination, and reasons cited for not getting vaccinated.ResultsInfluenza vaccination prevalence among VHA outpatients aged 50–64 was 56% and for those aged ≥65 was 86%. Compared to the 2 previous seasons, this estimate was lower for patients age 50–64 but similar for patients ≥65. After adjustment for patient characteristics, unvaccinated patients aged 50–64 were 8.3 (95% CI 6.0, 11.4) times as likely to cite that they were told they were not eligible for vaccination because of the national shortage compared to patients ≥65. Regional VHA variation in vaccination receipt and shortage-related reasons for nonvaccination was small.ConclusionsThe national influenza vaccine shortage of 2004–2005 primarily affected VHA users aged 50–64, consistent with the tiered prioritization guidance issued by the Centers for Disease Control and Prevention and Advisory Committee on Immunization Practices. Despite the shortage, vaccination prevalence among VHA users ≥65 remained high.

Modeling Hepatitis C.

Objective: We examined hypertension risk in Army Chemical Corps (ACC) veterans who sprayed defoliant in Vietnam. Methods: We analyzed data from the 2013 health survey of 3086 ACC veterans and investigated the association between self-reported physician-diagnosed-hypertension (SRH) and herbicide-spray-history adjusting for Vietnam-service-status, rank, age, tobacco/alcohol use, race, and body mass index (BMI). Spray-history was verified against serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) (n = 636). SRH was confirmed by blood pressure (BP) measurement by trained medical technicians and medical record reviews. Results: Herbicide-spray-history (ORadjusted[95%confidence interval {CI}] = 1.74[1.44,2.11]) and Vietnam-service-status (ORadjusted = 1.26[1.05,1.53]) were significantly associated with SRH. The association was highest when comparing Vietnam-service-sprayers to non-Vietnam-service-nonsprayers (ORadjusted = 2.21[1.76,2.77]). Serum TCDD was highest for Vietnam-service-sprayers. Mean systolic BPs were significantly higher among veterans with SRH than those without (P ⩽ 0.001). Medical records and SRH overall agreement was 89%. Conclusion: Occupational herbicide exposure history and Vietnam-service-status were significantly associated with hypertension risk.