CDC Model Research Articles

Comparison of Models for Excess Mortality of Influenza Applied to Japan

To elucidate the social effects of an influenza outbreak, the World Health Organization recommends a concept for excess mortality attributable to an influenza outbreak. However, because several models exist to estimate excess mortality, we would like to ascertain the most appropriate of three models: the Center for Disease Control and Prevention (CDC) model, the seasonal autoregressive integrated moving average (SARIMA) model, and the National Institution of Infectious Diseases (NIID) model. Excess mortality is defined as the difference between the actual number of deaths and the epidemiological threshold. The epidemiological threshold is defined as upper bound of 95% confidence interval (CI) of the baseline. The actual number of deaths might be less than the baseline, which implies inconsistent with the definition of baseline. Especially, actual deaths fewer than the lower bound of 95% CI of baseline suggest the inappropriateness of a model of excess mortality. Among 123 months during epidemic periods, the NIID model found excess mortality in 56 months, CDC model in 31 months, and SARIMA model in 35 months. Conversely, the NIID model found negative excess mortality in only 2 months, but the CDC model and SARIMA model found it respectively for 10 and 33 months. Negative excess mortality represents the logical inconsistency of the model. Therefore, NIID model might be the best among the three models considered.

Outbreaks associated with treated recreational water — United States, 2000–2014

Outbreaks associated with exposure to treated recreational water can be caused by pathogens or chemicals in venues such as pools, hot tubs/spas, and interactive water play venues (i.e., water playgrounds). During 2000-2014, public health officials from 46 states and Puerto Rico reported 493 outbreaks associated with treated recreational water. These outbreaks resulted in at least 27,219 cases and eight deaths. Among the 363 outbreaks with a confirmed infectious etiology, 212 (58%) were caused by Cryptosporidium (which causes predominantly gastrointestinal illness), 57 (16%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms), and 47 (13%) by Pseudomonas (which causes folliculitis ["hot tub rash"] and otitis externa ["swimmers' ear"]). Investigations of the 363 outbreaks identified 24,453 cases; 21,766 (89%) were caused by Cryptosporidium, 920 (4%) by Pseudomonas, and 624 (3%) by Legionella. At least six of the eight reported deaths occurred in persons affected by outbreaks caused by Legionella. Hotels were the leading setting, associated with 157 (32%) of the 493 outbreaks. Overall, the outbreaks had a bimodal temporal distribution: 275 (56%) outbreaks started during June-August and 46 (9%) in March. Assessment of trends in the annual counts of outbreaks caused by Cryptosporidium, Legionella, or Pseudomonas indicate mixed progress in preventing transmission. Pathogens able to evade chlorine inactivation have become leading outbreak etiologies. The consequent outbreak and case counts and mortality underscore the utility of CDC's Model Aquatic Health Code (https://www.cdc.gov/mahc) to prevent outbreaks associated with treated recreational water.

Outbreaks Associated with Treated Recreational Water - United States, 2000-2014.

Outbreaks associated with exposure to treated recreational water can be caused by pathogens or chemicals in venues such as pools, hot tubs/spas, and interactive water play venues (i.e., water playgrounds). During 2000-2014, public health officials from 46 states and Puerto Rico reported 493 outbreaks associated with treated recreational water. These outbreaks resulted in at least 27,219 cases and eight deaths. Among the 363 outbreaks with a confirmed infectious etiology, 212 (58%) were caused by Cryptosporidium (which causes predominantly gastrointestinal illness), 57 (16%) by Legionella (which causes Legionnaires' disease, a severe pneumonia, and Pontiac fever, a milder illness with flu-like symptoms), and 47 (13%) by Pseudomonas (which causes folliculitis ["hot tub rash"] and otitis externa ["swimmers' ear"]). Investigations of the 363 outbreaks identified 24,453 cases; 21,766 (89%) were caused by Cryptosporidium, 920 (4%) by Pseudomonas, and 624 (3%) by Legionella. At least six of the eight reported deaths occurred in persons affected by outbreaks caused by Legionella. Hotels were the leading setting, associated with 157 (32%) of the 493 outbreaks. Overall, the outbreaks had a bimodal temporal distribution: 275 (56%) outbreaks started during June-August and 46 (9%) in March. Assessment of trends in the annual counts of outbreaks caused by Cryptosporidium, Legionella, or Pseudomonas indicate mixed progress in preventing transmission. Pathogens able to evade chlorine inactivation have become leading outbreak etiologies. The consequent outbreak and case counts and mortality underscore the utility of CDC's Model Aquatic Health Code (https://www.cdc.gov/mahc) to prevent outbreaks associated with treated recreational water.

The Effect of Adding Comorbidities to Current Centers for Disease Control and Prevention Central-Line–Associated Bloodstream Infection Risk-Adjustment Methodology

BACKGROUND Risk adjustment is needed to fairly compare central-line-associated bloodstream infection (CLABSI) rates between hospitals. Until 2017, the Centers for Disease Control and Prevention (CDC) methodology adjusted CLABSI rates only by type of intensive care unit (ICU). The 2017 CDC models also adjust for hospital size and medical school affiliation. We hypothesized that risk adjustment would be improved by including patient demographics and comorbidities from electronically available hospital discharge codes. METHODS Using a cohort design across 22 hospitals, we analyzed data from ICU patients admitted between January 2012 and December 2013. Demographics and International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) discharge codes were obtained for each patient, and CLABSIs were identified by trained infection preventionists. Models adjusting only for ICU type and for ICU type plus patient case mix were built and compared using discrimination and standardized infection ratio (SIR). Hospitals were ranked by SIR for each model to examine and compare the changes in rank. RESULTS Overall, 85,849 ICU patients were analyzed and 162 (0.2%) developed CLABSI. The significant variables added to the ICU model were coagulopathy, paralysis, renal failure, malnutrition, and age. The C statistics were 0.55 (95% CI, 0.51-0.59) for the ICU-type model and 0.64 (95% CI, 0.60-0.69) for the ICU-type plus patient case-mix model. When the hospitals were ranked by adjusted SIRs, 10 hospitals (45%) changed rank when comorbidity was added to the ICU-type model. CONCLUSIONS Our risk-adjustment model for CLABSI using electronically available comorbidities demonstrated better discrimination than did the CDC model. The CDC should strongly consider comorbidity-based risk adjustment to more accurately compare CLABSI rates across hospitals. Infect Control Hosp Epidemiol 2017;38:1019-1024.

IMPLEMENTING THE COLLABORATIVE DEMENTIA CARE MODEL IN THE REAL WORLD

Multiple randomized clinical trials demonstrated the efficacy of the collaborative dementia care model (CDC) in improving quality of dementia care. However, the penetration of the CDC model has been very low. The Center for Medicare and Medicaid Innovation funded a demonstration project to implement the CDC model within primary care clinics in central Indiana. Using the tools of Implementation Science including the framework of the complex adaptive system theory, dementia care process mapping, and work force task shifting, an interdisciplinary team of implementation scientists converted the CDC model into a sustainable and scalable population brain health management program called the aging brain care program (ABC). In 2016, the ABC program served more than 1700 patients suffering from dementia or mild cognitive impairment with a mean age of 74.6 (SD 8.3), 78% being female, and 46.5% being African Americans. The mean number of comorbid conditions was 3.3 (SD 1.8) and the mean MMSE score was 25.5 (SD 4.9). The cognitive, functional, behavioral and psychological burden perceived by informal caregivers and as measured by the Healthy Aging Brain Care Monitor decreased by 5.8 points over 12 months with a responder rate of 51%. For the health care system, the ABC program led to an average cost saving of $1076 (95% CI of $98 - $2412) per patient per year. The tools of Implementation science are capable of creating sustainable and scalable evidence based dementia care program and facilitate the process of building distribution channels to increase the penetration rate of the CDC model within the American healthcare systems.

Electronically Available Comorbidities Should Be Used in Surgical Site Infection Risk Adjustment.

Healthcare-associated infections such as surgical site infections (SSIs) are used by the Centers for Medicare and Medicaid Services (CMS) as pay-for-performance metrics. Risk adjustment allows a fairer comparison of SSI rates across hospitals. Until 2016, Centers for Disease Control and Prevention (CDC) risk adjustment models for pay-for-performance SSI did not adjust for patient comorbidities. New 2016 CDC models only adjust for body mass index and diabetes. We performed a multicenter retrospective cohort study of patients undergoing surgical procedures at 28 US hospitals. Demographic data and International Classification of Diseases, Ninth Revision codes were obtained on patients undergoing colectomy, hysterectomy, and knee and hip replacement procedures. Complex SSIs were identified by infection preventionists at each hospital using CDC criteria. Model performance was evaluated using measures of discrimination and calibration. Hospitals were ranked by SSI proportion and risk-adjusted standardized infection ratios (SIR) to assess the impact of comorbidity adjustment on public reporting. Of 45394 patients at 28 hospitals, 573 (1.3%) developed a complex SSI. A model containing procedure type, age, race, smoking, diabetes, liver disease, obesity, renal failure, and malnutrition showed good discrimination (C-statistic, 0.73) and calibration. When comparing hospital rankings by crude proportion to risk-adjusted ranks, 24 of 28 (86%) hospitals changed ranks, 16 (57%) changed by ≥2 ranks, and 4 (14%) changed by >10 ranks. We developed a well-performing risk adjustment model for SSI using electronically available comorbidities. Comorbidity-based risk adjustment should be strongly considered by the CDC and CMS to adequately compare SSI rates across hospitals.

Mosquito communities and disease risk influenced by land use change and seasonality in the Australian tropics.

BackgroundAnthropogenic land use changes have contributed considerably to the rise of emerging and re-emerging mosquito-borne diseases. These diseases appear to be increasing as a result of the novel juxtapositions of habitats and species that can result in new interchanges of vectors, diseases and hosts. We studied whether the mosquito community structure varied between habitats and seasons and whether known disease vectors displayed habitat preferences in tropical Australia.MethodsUsing CDC model 512 traps, adult mosquitoes were sampled across an anthropogenic disturbance gradient of grassland, rainforest edge and rainforest interior habitats, in both the wet and dry seasons. Nonmetric multidimensional scaling (NMS) ordinations were applied to examine major gradients in the composition of mosquito and vector communities.ResultsWe captured ~13,000 mosquitoes from 288 trap nights across four study sites. A community analysis identified 29 species from 7 genera. Even though mosquito abundance and richness were similar between the three habitats, the community composition varied significantly in response to habitat type. The mosquito community in rainforest interiors was distinctly different to the community in grasslands, whereas forest edges acted as an ecotone with shared communities from both forest interiors and grasslands. We found two community patterns that will influence disease risk at out study sites, first, that disease vectoring mosquito species occurred all year round. Secondly, that anthropogenic grasslands adjacent to rainforests may increase the probability of novel disease transmission through changes to the vector community on rainforest edges, as most disease transmitting species predominantly occurred in grasslands.ConclusionOur results indicate that the strong influence of anthropogenic land use change on mosquito communities could have potential implications for pathogen transmission to humans and wildlife.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1675-2) contains supplementary material, which is available to authorized users.

Promoting palliative care access to persons with cancer: A model for mapping statewide services.

127 Background: The CDC comprehensive cancer initiatives value comprehensive quality care within its mission and program development. Currently, over 75% of hospitals in the United States have palliative care services for cancer patients (CAPC 2011). In order to promote access to quality palliative care in the community outside the hospital, an evaluation is essential. The CDC model of comprehensive cancer care and prevention control structure is an appropriate mechanism to perform such an evaluation. From 2014-2015, the Massachusetts Comprehensive Cancer and Prevention Control Network Palliative Care Workgroup performed a survey to hospitals, home health agencies, hospices, long term care facilities, and community providers to determine palliative care services available to cancer patients across the state. Methods: Using the National Consensus Project for Quality Palliative Care Clinical Practice Guidelines, a robust palliative survey tool was created by the Massachusetts Comprehensive Cancer and Prevention Control Palliative Care Workgroup. It was individualized to each of the following settings - hospitals, home health organizations, hospices, skilled nursing facilities, and community health agencies. Follow-up telephonic key informant interviews regarding palliative care services were conducted within the various settings, service organizations, and insurers. Results: The results of qualitative and quantitative data will be concluded in August. Initial results reveal significant disparities in access to palliative care across by geography and setting of care. Hospices and hospitals had the most access to palliative care services. Long term care settings and community health settings had the least access. Conclusions: Data reveals disparities in palliative care access within Massachusetts by geography, race, and setting of cancer care. This data will serve as the basis of regional networks to promote better access to palliative care for cancer patients across all settings. It is hoped this evaluation process will serve as a model for other states to perform a similar evaluation.

Important features of home-based support services for older Australians and their informal carers.

In Australia, newly initiated, publicly subsidised 'Home-Care Packages' designed to assist older people (≥ 65 years of age) living in their own home must now be offered on a 'consumer-directed care' (CDC) basis by service providers. However, CDC models have largely developed in the absence of evidence on users' views and preferences. The aim of this study was to determine what features (attributes) of consumer-directed, home-based support services are important to older people and their informal carers to inform the design of a discrete choice experiment (DCE). Semi-structured, face-to-face interviews were conducted in December 2012-November 2013 with 17 older people receiving home-based support services and 10 informal carers from 5 providers located in South Australia and New South Wales. Salient service characteristics important to participants were determined using thematic and constant comparative analysis and formulated into attributes and attribute levels for presentation within a DCE. Initially, eight broad themes were identified: information and knowledge, choice and control, self-managed continuum, effective co-ordination, effective communication, responsiveness and flexibility, continuity and planning. Attributes were formulated for the DCE by combining overlapping themes such as effective communication and co-ordination, and the self-managed continuum and planning into single attributes. Six salient service features that characterise consumer preferences for the provision of home-based support service models were identified: choice of provider, choice of support worker, flexibility in care activities provided, contact with the service co-ordinator, managing the budget and saving unspent funds. Best practice indicates that qualitative research with individuals who represent the population of interest should guide attribute selection for a DCE and this is the first study to employ such methods in aged care service provision. Further development of services could incorporate methods of consumer engagement such as DCEs which facilitate the identification and quantification of users' views and preferences on alternative models of delivery.

The CDC Model for Biomonitoring of Iodine Status in Pregnant Women in the National Health and Nutrition Examination Survey

The CDC Model for Biomonitoring of Iodine Status in Pregnant Women in the National Health and Nutrition Examination Survey

Estimated Annual Perinatal Hepatitis B Virus Infections in the United States, 2000-2009.

Ninety percent of perinatal hepatitis B virus (HBV) infections result in chronic HBV (CHBV), which carries 25% risk of premature death from progressive liver injury, cirrhosis, and liver cancer. In 1990, the Centers for Disease Control and Prevention (CDC) funded Perinatal Hepatitis B Prevention Programs (PHBPP) to ensure postexposure prophylaxis for exposed infants and accelerate elimination of perinatal CHBV in the United States. From 2000 to 2009, the annual rates of perinatal CHBV reported by PHBPP (0.8%-2.4%) were consistently lower than expected rates from CDC models (3.0%-4.1%), suggesting that rates of CHBV might be higher among infants whose outcomes were not identified by PHBPP. To better understand the factors impacting modeled expected number and rates of perinatal CHBV, we examined historic CDC models, applied updated inputs to the 2009 CDC model, and performed sensitivity analyses over a range of parameter values. Models employed estimates of the annual number of births to hepatitis B surface antigen (HBsAg)-positive pregnant women, and data from PHBPP and National Immunization Surveys. Published literature provided prenatal HBsAg screening rates, efficacy of postexposure prophylaxis (PEP), and perinatal HBV transmission rates. The updated 2009 model predicted 952 perinatal CHBV infections, equivalent to a baseline rate of 3.84%, among infants of HBsAg-positive women. Sensitivity analyses yielded a possible range of perinatal CHBV rates between 0.60% and 15.41%. The proportion of infants receiving timely PEP, the efficacy of PEP, and perinatal HBV transmission rate were major "drivers" of CHBV rates. Three-way sensitivity analysis yielded possible perinatal CHBV rates between 0.79% and 13.64%. Modeling provided useful programmatic goals for achieving elimination of perinatal CHBV in the United States. Limitations of data inputs likely contributed to discrepancies between predicted and reported rates.

CDC Kerala 3: At-risk baby clinic service using different screening tools--outcome at 12 months using Developmental Assessment Scale for Indian Infants.

To describe CDC Kerala experience of establishing an at-risk baby clinic and the comparison of different developmental screening tools at 12 mo against the gold standard Developmental Assessment Scale for Indian Infants (DASII). At risk baby clinic of CDC, Kerala was established as a facility for follow up of NICU graduates from Sree Avittam Thirunal Hospital at 2, 4, 6, 8 and 12 mo corrected age and during each visit the mother is taught the CDC model early stimulation by developmental therapists and encouraged to continue to do the same at home. At 12 mo, assessment results of four simple developmental tools were compared with the gold standard DASII administered by a senior developmental therapist. Out of a total of 800 babies, outcome measurements at 12 mo were available for 604 infants. The prevalence of developmental delay using the screening tools, CDC grading for standing, Amiel Tison angles and DDST II (Denver II) gross motor were 24.8, 24 and 24.3% respectively and using DASII, a diagnostic tool (13.3%). Also the combination of Amiel Tison angles, CDC standing grading and DDST gross motor against DASII motor DQ had high specificity (94.15%) and negative predictive value (NPV) (70.18%) but with a very low sensitivity of 14.58% and low positive predictive value (PPV) of 53.85%. It was observed that a significant odds ratio for DASII mental deviation quotient (DQ) was seen for neonatal seizures (2.34) and low birth weight (1.49). The prevalence of developmental delay using the screening tools, CDC grading for standing, Amiel Tison angles and DDST II (Denver II) gross motor were 24.8, 24 and 24.3% respectively and together they had a high specificity, NPV and accuracy against DASII motor DQ as gold standard at one year assessment.

Collection ofCulicoides(Diptera: Ceratopogonidae) Using CO2and Enantiomers of 1-Octen-3-ol in the United Kingdom

The host kairomones carbon dioxide (CO2) and 1-octen-3-ol elicit a host seeking response in a wide range of haematophagous Diptera. This study investigates the response of Culicoides biting midges (Diptera: Ceratopogonidae) to these cues using field-based experiments at two sites in the United Kingdom with very different species complements. Traps used for surveillance (miniature CDC model 512) and control (Mosquito Magnet Pro) were modified to release ratios of (R)- and (S)-1-octen-3-ol enantiomers in combination with CO2 and, in the case of the latter trap type, a thermal cue. Abundance and species diversity were then compared between these treatments and against collections made using a trap with a CO2 lure only, in a Latin square design. In both habitats, results demonstrated that semiochemical lures containing a high proportion of the (R)-enantiomer consistently attracted a greater abundance of host-seeking Culicoides females than any other treatment. Culicoides collected using an optimal stimulus of 500 ml/min CO2 combined with 4.1 mg/h (R)-1-octen-3-ol were then compared with those collected on sheep through the use of a drop trap. While preliminary in nature, this trial indicated Culicoides species complements are similar between collections made using the drop trap in comparison to the semiochemical-baited CDC trap, and that there are advantages in using (R)-1-octen-3-ol.

Economic Burden from Health Losses Due to Foodborne Illness in the United States

The Centers for Disease Control and Prevention (CDC) recently revised their estimates for the annual number of foodborne illnesses; 48 million Americans suffer from domestically acquired foodborne illness associated with 31 identified pathogens and a broad category of unspecified agents. Consequently, economic studies based on the previous estimates are now obsolete. This study was conducted to provide improved and updated estimates of the cost of foodborne illness by adding a replication of the 2011 CDC model to existing cost-of-illness models. The basic cost-of-illness model includes economic estimates for medical costs, productivity losses, and illness-related mortality (based on hedonic value-of-statistical-life studies). The enhanced cost-of-illness model replaces the productivity loss estimates with a more inclusive pain, suffering, and functional disability measure based on monetized quality-adjusted life year estimates. Costs are estimated for each pathogen and a broader class of unknown pathogens. The addition of updated cost data and improvements to methodology enhanced the performance of each existing economic model. Uncertainty in these models was characterized using Monte Carlo simulations in @Risk version 5.5. With this model, the average cost per case of foodborne illness was $1,626 (90% credible interval [CI], $607 to $3,073) for the enhanced cost-of-illness model and $1,068 (90% CI, $683 to $1,646) for the basic model. The resulting aggregated annual cost of illness was $77.7 billion (90% CI, $28.6 to $144.6 billion) and $51.0 billion (90% CI, $31.2 to $76.1 billion) for the enhanced and basic models, respectively.

The quality of three decision-analytic diabetes models: a systematic health economic assessment

Aims: Diabetes mellitus has important economic impacts worldwide. Interventions to prevent diabetes-related complications are often analyzed using model-based cost–effectiveness analyses. As model results are usually influenced by structural assumptions and by the data used, decision-makers should be able to assess the quality of diabetes models. The aim of this study was to assess the quality of selected diabetes models and to determine if modeling recommendations by the American Diabetes Association are considered. Methods: The quality of three selected diabetes models (Archimedes Model, CDC Model and Center for Outcomes Research [CORE] Diabetes Model) was assessed using systematic methods. Results: This systematic approach to assess model quality proved to be feasible and highlighted two areas for improvement: the rationale for model structure and methods to identify parameter values, which should be presented more transparently. Conclusions: Overall, the need for a quality assessment of diabetes models is emphasized.

Simplified and improved monitoring traps for sampling sand flies

Simplified and improved monitoring traps for sampling sand flies Gunter C. Muller1, Edita, E. Revay2, and John C. Beier3 1Department of Microbiology and Molecular Genetics , IMRIC, Kuvin Centre for the Study of Infectious and Tropical Diseases, Faculty of Medicine, Hebrew University, Jerusalem 91120, Israel, guntercmuller@hotmail.com 2Department of Anatomy and Cell Biology, Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel 3Department of Epidemiology and Public Health, University of Miami Miller School of Medicine, Miami, FL 33136, U.S.A.

Primeiro registro de Evandromyia (Aldamyia) sericea (Floch & Abonnenc) (Diptera, Psychodidae, Phlebotominae) para a região Sudeste do Brasil

Esse é o primeiro registro de Evandromyia (Aldamyia) sericea para o Sudeste do Brasil e, até então, o registro mais ao sul da espécie no mundo. Os espécimes foram coletados na Reserva Biológica de Duas Bocas, município de Cariacica, estado do Espírito Santo. As capturas de flebotomíneos foram feitas mensalmente de abril a junho de 2008 durante quatro noites consecutivas usando duas armadilhas automáticas do tipo CDC e uma armadilha de Shannon modificada para cada noite. O encontro dessa espécie é consistente com a hipótese de proximidade filogeográfica entre a Floresta Amazônica e a Mata Atlântica.

Update on Acute Asthma

There have been several important changes in the updated NIH asthma guidelines regarding the management of acute asthma. At home during an exacerbation, doubling the dose of inhaled corticosteroids is not recommended. Pre-hospital, a standing order for albuterol is important in implementation of protocols such as the CDC model protocol. There are new cut points of 40% and 70% predicted peak expiratory flow rates. When someone presents to the emergency department with a flow rate less than 40% predicted (approximately 200 L/min for typical adult woman and 250 L/min for typical adult man), there are several adjunct treatments that merit consideration, such as heliox and intravenous magnesium sulfate. Consider initiating inhaled corticosteroids at discharge from the emergency department. Inhaled anticholinergics can be used in the first hours of presentation to the emergency department, but are not recommended during inpatient hospitalization.

Ability of Regional Hospitals to Meet Projected Avian Flu Pandemic Surge Capacity Requirements

Hospital surge capacity is a crucial part of community disaster preparedness planning, which focuses on the requirements for additional beds, equipment, personnel, and special capabilities. The scope and urgency of these requirements must be balanced with a practical approach addressing cost and space concerns. Renewed concerns for infectious disease threats, particularly from a potential avian flu pandemic perspective, have emphasized the need to be prepared for a prolonged surge that could last six to eight weeks. The surge capacity that realistically would be generated by the cumulative Greater Dayton Area Hospital Association (GDAHA) plan is sufficient to meet the demands of an avian influenza pandemic as predicted by the [US] Centers for Disease Control and Prevention (CDC) models. Using a standardized data form, surge response plans for each hospital in the GDAHA were assessed. The cumulative results were compared to the demand projected for an avian influenza pandemic using the CDC's FluAid and FluSurge models. The cumulative GDAHA capacity is sufficient to meet the projected demand for bed space, intensive care unit beds, ventilators, morgue space, and initial personal protective equipment (PPE) use. There is a shortage of negative pressure rooms, some basic equipment, and neuraminidase inhibitors. Many facilities lack a complete set of written surge policies, including screening plans to segregate contaminated patients and staff prior to entering the hospital. Few hospitals have agreements with nursing homes or home healthcare agencies to provide care for patients discharged in order to clear surge beds. If some of the assumptions in the CDC's models are changed to match the morbidity and mortality rates reported from the 1918 pandemic, the surge capacity of GDAHA facilities would not meet the projected demand. The GDAHA hospitals should test their regional distributors' ability to resupply PPE for multiple facilities simultaneously. Facilities should retrofit current air exchange systems to increase the number of potential negative pressure rooms and include such designs in all future construction. Neuraminidase inhibitor supplies should be increased to provide treatment for healthcare workers exposed in the course of their duties. Each hospital should have a complete set of policies to address the special considerations for a prolonged surge. Additional capacity is required to meet the predicted demands of a threat similar to the 1918 pandemic.

Seismically and geodetically determined nondouble‐couple source mechanisms from the 2000 Miyakejima volcanic earthquake swarm

The volcanic eruption on Miyakejima, Japan, in 2000 was marked by the largest earthquake swarm ever recorded in Japan, a seismicity migration accompanying a dike intrusion as the dike propagated from Miyakejima to the northwest, and formation of a caldera on Mount Oyama on Miyakejima. In this study, we propose a seismic source model which can be used to model both seismic and geodetic displacements from volcanic earthquakes. Our model, the “crack + double‐couple” (CDC) model, combines tensile opening with shear slip along a single fault plane. We find that this model can fit both seismic and GPS data from the 1 July and 30 July earthquakes, the largest two in the Miyakejima sequence. The results of our GPS inversions for these two earthquakes are consistent with the seismic mechanisms and aftershock locations, and the GPS mechanisms successfully forward predict the observed regional seismograms. The 1 July earthquake, located near the northwest tip of the dike, has a large opening component and a geodetic moment about 5 times larger than that inferred from the seismic data alone. The source process for this event consists of tensile failure, which occurred quickly, and a much slower accumulation of shear slip. We apply the CDC model to 16 additional earthquakes from this sequence and find that the CDC model fits the seismic data for these earthquakes at least as well as established seismic moment tensor models.