In April 2023, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by one new family, 14 new genera, and 140 new species. Two genera and 538 species were renamed. One species was moved, and four were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

This article summarizes what is currently known about the 2019 novel coronavirus and offers interim guidance.

In February 2020, CDC issued guidance advising persons and health care providers in areas affected by the coronavirus disease 2019 (COVID-19) pandemic to adopt social distancing practices, specifically recommending that health care facilities and providers offer clinical services through virtual means such as telehealth.* Telehealth is the use of two-way telecommunications technologies to provide clinical health care through a variety of remote methods.(†) To examine changes in the frequency of use of telehealth services during the early pandemic period, CDC analyzed deidentified encounter (i.e., visit) data from four of the largest U.S. telehealth providers that offer services in all states.(§) Trends in telehealth encounters during January-March 2020 (surveillance weeks 1-13) were compared with encounters occurring during the same weeks in 2019. During the first quarter of 2020, the number of telehealth visits increased by 50%, compared with the same period in 2019, with a 154% increase in visits noted in surveillance week 13 in 2020, compared with the same period in 2019. During January-March 2020, most encounters were from patients seeking care for conditions other than COVID-19. However, the proportion of COVID-19-related encounters significantly increased (from 5.5% to 16.2%; p<0.05) during the last 3 weeks of March 2020 (surveillance weeks 11-13). This marked shift in practice patterns has implications for immediate response efforts and longer-term population health. Continuing telehealth policy changes and regulatory waivers might provide increased access to acute, chronic, primary, and specialty care during and after the pandemic.

To help inform policy discussions about postpandemic telemedicine reimbursement and regulations, we conducted dual nationally representative surveys among primary care physicians and patients. Although majorities of both populations reported satisfaction with video visits during the pandemic, 80 percent of physicians would prefer to provide only a small share of care or no care via telemedicine in the future, and only 36 percent of patients would prefer to seek care by video or phone. Most physicians (60 percent) felt that the quality of video telemedicine care was generally inferior to the quality of in-person care, and both patients and physicians cited the lack of physical exam as a key reason (90 percent and 92 percent, respectively). Patients who were older, had less education, or were Asian were less likely to want to use video for future care. Although improvements to home-based diagnostic tools could improve both the quality of and the desire to use telemedicine, virtual primary care will likely be limited in the immediate future. Policies to enhance quality, sustain virtual care, and address inequities in the online setting may be needed.

A universal taxonomy of viruses is essential for a comprehensive view of the virus world and for communicating the complicated evolutionary relationships among viruses. However, there are major differences in the conceptualisation and approaches to virus classification and nomenclature among virologists, clinicians, agronomists, and other interested parties. Here, we provide recommendations to guide the construction of a coherent and comprehensive virus taxonomy, based on expert scientific consensus. Firstly, assignments of viruses should be congruent with the best attainable reconstruction of their evolutionary histories, i.e., taxa should be monophyletic. This fundamental principle for classification of viruses is currently included in the International Committee on Taxonomy of Viruses (ICTV) code only for the rank of species. Secondly, phenotypic and ecological properties of viruses may inform, but not override, evolutionary relatedness in the placement of ranks. Thirdly, alternative classifications that consider phenotypic attributes, such as being vector-borne (e.g., "arboviruses"), infecting a certain type of host (e.g., "mycoviruses," "bacteriophages") or displaying specific pathogenicity (e.g., "human immunodeficiency viruses"), may serve important clinical and regulatory purposes but often create polyphyletic categories that do not reflect evolutionary relationships. Nevertheless, such classifications ought to be maintained if they serve the needs of specific communities or play a practical clinical or regulatory role. However, they should not be considered or called taxonomies. Finally, while an evolution-based framework enables viruses discovered by metagenomics to be incorporated into the ICTV taxonomy, there are essential requirements for quality control of the sequence data used for these assignments. Combined, these four principles will enable future development and expansion of virus taxonomy as the true evolutionary diversity of viruses becomes apparent.

BACKGROUND: In 2020, at the onset of the COVID-19 pandemic, the United States experienced surges in healthcare needs, which challenged capacity throughout the healthcare system. Stay-at-home orders in many jurisdictions, cancellation of elective procedures, and closures of outpatient medical offices disrupted patient access to care. To inform symptomatic persons about when to seek care and potentially help alleviate the burden on the healthcare system, Centers for Disease Control and Prevention (CDC) and partners developed the CDC Coronavirus Self-Checker ("Self-Checker"). This interactive tool assists individuals seeking information about COVID-19 to determine the appropriate level of care by asking demographic, clinical, and nonclinical questions during an online "conversation." OBJECTIVE: This paper describes user characteristics, trends in use, and recommendations delivered by the Self-Checker between March 23, 2020, and April 19, 2021, for pursuing appropriate levels of medical care depending on the severity of user symptoms. METHODS: User characteristics and trends in completed conversations that resulted in a care message were analyzed. Care messages delivered by the Self-Checker were manually classified into three overarching conversation themes: (1) seek care immediately; (2) take no action, or stay home and self-monitor; and (3) conversation redirected. Trends in 7-day averages of conversations and COVID-19 cases were examined with development and marketing milestones that potentially impacted Self-Checker user engagement. RESULTS: Among 16,718,667 completed conversations, the Self-Checker delivered recommendations for 69.27% (n=11,580,738) of all conversations to "take no action, or stay home and self-monitor"; 28.8% (n=4,822,138) of conversations to "seek care immediately"; and 1.89% (n=315,791) of conversations were redirected to other resources without providing any care advice. Among 6.8 million conversations initiated for self-reported sick individuals without life-threatening symptoms, 59.21% resulted in a recommendation to "take no action, or stay home and self-monitor." Nearly all individuals (99.8%) who were not sick were also advised to "take no action, or stay home and self-monitor." CONCLUSIONS: The majority of Self-Checker conversations resulted in advice to take no action, or stay home and self-monitor. This guidance may have reduced patient volume on the medical system; however, future studies evaluating patients' satisfaction, intention to follow the care advice received, course of action, and care modality pursued could clarify the impact of the Self-Checker and similar tools during future public health emergencies.

In March 2022, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by two new families (bunyaviral Discoviridae and Tulasviridae), 41 new genera, and 98 new species. Three hundred forty-nine species were renamed and/or moved. The accidentally misspelled names of seven species were corrected. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

During an influenza pandemic, healthcare facilities are likely to be filled to capacity, leading to delays in seeing a provider and obtaining treatment. Flu on Call is a collaborative effort between the US Centers for Disease Control and Prevention and partners to develop a toll-free telephone helpline to reduce the burden on healthcare facilities and improve access to antivirals for people who are ill during an influenza pandemic. This study tested the feasibility of Flu on Call during a 1-day simulation using a severe pandemic scenario. Trained volunteer actors placed calls to the helpline using prepared scripts that were precoded for an expected outcome ("disposition") of the call. Scripts represented callers who were ill, those calling for someone else who was ill, and callers who were only seeking information. Information specialists and medical professionals managed the calls. Results demonstrated that Flu on Call may effectively assist callers during a pandemic, increase access to antiviral prescriptions, and direct patients to the appropriate level of care. Overall, 84% of calls exactly matched the expected call disposition; few calls (2%) were undermanaged (eg, the caller was ill but not transferred to a medical professional or received advice from the medical professional that was less intensive than what was warranted). Callers indicated a high level of satisfaction (83% reported their needs were met). Because of the high volume of calls that may be received during a severe pandemic, the Flu on Call platform should evolve to include additional triage channels (eg, through internet, chat, and/or text access).

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

During a severe pandemic, especially one causing respiratory illness, many people may require mechanical ventilation. Depending on the extent of the outbreak, there may be insufficient capacity to provide ventilator support to all of those in need. As part of a larger conceptual framework for determining need for and allocation of ventilators during a public health emergency, this article focuses on the strategies to assist state and local planners to allocate stockpiled ventilators to healthcare facilities during a pandemic, accounting for critical factors in facilities' ability to make use of additional ventilators. These strategies include actions both in the pre-pandemic and intra-pandemic stages. As a part of pandemic preparedness, public health officials should identify and query healthcare facilities in their jurisdiction that currently care for critically ill patients on mechanical ventilation to determine existing inventory of these devices and facilities' ability to absorb additional ventilators. Facilities must have sufficient staff, space, equipment, and supplies to utilize allocated ventilators adequately. At the time of an event, jurisdictions will need to verify and update information on facilities' capacity prior to making allocation decisions. Allocation of scarce life-saving resources during a pandemic should consider ethical principles to inform state and local plans for allocation of ventilators. In addition to ethical principles, decisions should be informed by assessment of need, determination of facilities' ability to use additional ventilators, and facilities' capacity to ensure access to ventilators for vulnerable populations (eg, rural, inner city, and uninsured and underinsured individuals) or high-risk populations that may be more susceptible to illness.

Recent high-profile infectious disease outbreaks illustrate the importance of selecting appropriate control measures to protect a wider range of employees, other than those in healthcare settings. In such settings, where routine exposure risks are often high, control measures may be more available, routinely implemented, and studied for effectiveness. In the absence of evidence-based guidelines or established best practices for selecting appropriate control measures, employers may unduly rely on personal protective equipment (PPE) because of its wide availability and pervasiveness as a control measure, circumventing other effective options for protection. Control banding is one approach that may be used to assign job tasks into risk categories and prioritize the application of controls. This article proposes an initial control banding framework for workers at all levels of risk and incorporates a range of control options, including PPE. Using the National Institutes of Health (NIH) risk groups as a surrogate for toxicity and combining the exposure duration with the exposure likelihood, we can generate the risk of a job task to the worker.

Legal Perspectives is aimed at informing healthcare providers, emergency planners, public health practitioners, and other decision makers about important legal issues related to public health and healthcare preparedness and response. The articles describe these potentially challenging topics and conclude with the authors' suggestions for further action. The articles do not provide legal advice. Therefore, those affected by the issues discussed in this column should seek further guidance from legal counsel. Readers may submit topics of interest to the column's editor, Lainie Rutkow, JD, PhD, MPH, at lrutkow@jhu.edu. Governors play a fundamental role in emergency preparedness and can help facilitate rapid responses to emergencies. However, laws that operate successfully under normal circumstances can inadvertently create barriers during emergencies, delaying a timely response. State laws could thus limit, or even prohibit, necessary response efforts. To combat this risk, legislatures have passed emergency powers laws in each state granting governors the authority to declare a state of emergency and to exercise certain emergency powers to meet the needs of the emergency. Researchers conducted a 50-state legal assessment, which identified and examined state laws that give governors the discretion to modify existing laws or create new laws to respond effectively to any type of declared emergency. This article outlines the findings of that assessment, which identified 35 states that explicitly permit governors to suspend or amend both statutes and regulations; 7 states in which governors are permitted to amend regulations during a declared emergency but are not explicitly authorized to modify or remove statutes; and 8 states and the District of Columbia that provide no explicit authority to governors to change statutes or regulations during a declared emergency. The article also provides examples of how this power has been used in the past to demonstrate the utility and scope of this authority in a variety of public health threats.

Antiviral drugs are likely to be a frontline countermeasure needed to minimize disease impact during an influenza pandemic. As part of pandemic influenza preparedness efforts, the Centers for Disease Control and Prevention, in coordination with state health departments, has plans in place to distribute and dispense antiviral drugs from public stockpiles. These plans are currently under review and include evaluation of the benefits of commercial distribution and dispensing through community pharmacies. To ensure this alternative distribution and dispensing system is viable, it is critical to assess pharmacist acceptability and to understand the pharmacist perspective on dispensing these antivirals during a response. In this study, we examine community pharmacist reactions to the proposed alternative antiviral distribution and dispensing system using a nationally representative survey of pharmacists. Overall, pharmacists were highly receptive to this alternative system and voiced a willingness to participate personally, and most thought their own pharmacy would participate in such an effort. This was true across pharmacists with different personal and professional backgrounds, as well as those in different pharmacy settings. However, sizable shares of pharmacists said they were worried about facing shortages of the antivirals, the risk of exposure to disease for themselves and their families, managing their usual patients who need their prescriptions filled for medications other than antivirals, keeping order in the pharmacy, and potential liability concerns. These findings should be interpreted as an indication of acceptability of the concept, encouragement for the next steps in alternative distribution and dispensing system design, and a guide to potential barriers that may need to be addressed proactively.

Telephone nurse triage lines, such as the Centers for Disease Control and Prevention's (CDC) Flu on Call((R)), a national nurse triage line, may help reduce the surge in demand for health care during an influenza pandemic by triaging callers, providing advice about clinical care and information about the pandemic, and providing access to prescription antiviral medication. We developed a Call Volume Projection Tool to estimate national call volume to Flu on Call((R)) during an influenza pandemic. The tool incorporates 2 influenza clinical attack rates (20% and 30%), 4 different levels of pandemic severity, and different initial "seed numbers" of cases (10 or 100), and it allows variation in which week the nurse triage line opens. The tool calculates call volume by using call-to-hospitalization ratios based on pandemic severity. We derived data on nurse triage line calls and call-to-hospitalization ratios from experience with the 2009 Minnesota FluLine nurse triage line. Assuming a 20% clinical attack rate and a case hospitalization rate of 0.8% to 1.5% (1968-like pandemic severity), we estimated the nationwide number of calls during the peak week of the pandemic to range from 1,551,882 to 3,523,902. Assuming a more severe 1957-like pandemic (case hospitalization rate = 1.5% to 3.0%), the national number of calls during the peak week of the pandemic ranged from 2,909,778 to 7,047,804. These results will aid in planning and developing nurse triage lines at both the national and state levels for use during a future influenza pandemic.

The 1918 influenza pandemic spread rapidly around the globe, leading to high mortality and social disruption. The countermeasures available to mitigate the pandemic were limited and relied on nonpharmaceutical interventions. Over the past 100 years, improvements in medical care, influenza vaccines, antiviral medications, community mitigation efforts, diagnosis, and communications have improved pandemic response. A number of gaps remain, including vaccines that are more rapidly manufactured, antiviral drugs that are more effective and available, and better respiratory protective devices. (Am J Public Health. Published online ahead of print September 25, 2018: e1-e4. doi:10.2105/AJPH.2018.304586).

The Zika Contraception Access Network established a network of 153 physicians across Puerto Rico as a short-term emergency response during the 2016-2017 Zika virus outbreak to provide client-centered contraceptive counseling and same-day contraception services at no cost for women who chose to prevent pregnancy. Between May 2016 and August 2017, 21 124 women received services. Contraception was used as a medical countermeasure to reduce adverse Zika-related reproductive outcomes during the outbreak and may be considered a key strategy in other emergencies.

Prompt treatment of ill persons with influenza antivirals will be an important part of a future pandemic influenza response. This essay reviews key lessons learned from the 2009 H1N1 pandemic and the changing landscape of antiviral drug availability, and identifies and describes the multiple components needed to ensure the timely administration of antiviral drugs during a future pandemic. Fortunately, many of these planning efforts can take place before a pandemic strikes to improve outcomes during a future public health emergency.

In 2015, the Centers for Disease Control and Prevention (CDC) collaborated with the National Association of County and City Health Officials (NACCHO) to develop and conduct the Scripted Surge Pharmacy Pandemic Exercise to assess the capacity of pharmacies to administer vaccines and dispense medications during a severe influenza pandemic and to evaluate their various approaches to this activity. A mass merchant pharmacy and a supermarket pharmacy were recruited in 2 different states. At each pharmacy, 2 consecutive 90-minute exercise runs were completed in which actors, simulating patients, presented themselves to the pharmacy counter and requested a vaccine and/or prescription(s). Each run was slightly different in terms of patient flow, staffing, and physical configuration. Individual plays were timed, and a quality assessment was conducted as each patient left the store. Despite the complexities of the pandemic scenario, the number of vaccines administered and prescriptions dispensed surpassed what that pharmacy could typically accomplish during current peak hours of operation. Furthermore, the number of requests successfully processed increased between the first and second runs at each site, suggesting that processing efficiency improved with practice and experience. Few unexpected outcomes were observed, most of which were attributable to exercise artificialities, and they were judged unlikely to occur under real-world scenarios and routine pharmacy practice. The experience gained from this exercise indicates that pharmacies can likely play an important role in improving access to vaccinations and medications during a future pandemic.

In 2018, the family Arenaviridae was expanded by inclusion of 1 new genus and 5 novel species. At the same time, the recently established order Bunyavirales was expanded by 3 species. This article presents the updated taxonomy of the family Arenaviridae and the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.

In 2018, the order Mononegavirales was expanded by inclusion of 1 new genus and 12 novel species. This article presents the updated taxonomy of the order Mononegavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.

We modeled the potential cost-effectiveness of increasing access to contraception in Puerto Rico during a Zika virus outbreak. The intervention is projected to cost an additional $33.5 million in family planning services and is likely to be cost-saving for the healthcare system overall. It could reduce Zika virus-related costs by $65.2 million ($2.8 million from less Zika virus testing and monitoring and $62.3 million from avoided costs of Zika virus-associated microcephaly [ZAM]). The estimates are influenced by the contraception methods used, the frequency of ZAM, and the lifetime incremental cost of ZAM. Accounting for unwanted pregnancies that are prevented, irrespective of Zika virus infection, an additional $40.4 million in medical costs would be avoided through the intervention. Increasing contraceptive access for women who want to delay or avoid pregnancy in Puerto Rico during a Zika virus outbreak can substantially reduce the number of cases of ZAM and healthcare costs.

In response to the 2014-2016 Ebola virus disease (Ebola) epidemic in West Africa, CDC prepared for the potential introduction of Ebola into the United States. The immediate goals were to rapidly identify and isolate any cases of Ebola, prevent transmission, and promote timely treatment of affected patients. CDC's technical expertise and the collaboration of multiple partners in state, local, and municipal public health departments; health care facilities; emergency medical services; and U.S. government agencies were essential to the domestic preparedness and response to the Ebola epidemic and relied on longstanding partnerships. CDC established a comprehensive response that included two new strategies: 1) active monitoring of travelers arriving from countries affected by Ebola and other persons at risk for Ebola and 2) a tiered system of hospital facility preparedness that enabled prioritization of training. CDC rapidly deployed a diagnostic assay for Ebola virus (EBOV) to public health laboratories. Guidance was developed to assist in evaluation of patients possibly infected with EBOV, for appropriate infection control, to support emergency responders, and for handling of infectious waste. CDC rapid response teams were formed to provide assistance within 24 hours to a health care facility managing a patient with Ebola. As a result of the collaborations to rapidly identify, isolate, and manage Ebola patients and the extensive preparations to prevent spread of EBOV, the United States is now better prepared to address the next global infectious disease threat.The activities summarized in this report would not have been possible without collaboration with many U.S. and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

OBJECTIVE: A large-scale public health emergency, such as a severe influenza pandemic, can generate large numbers of critically ill patients in a short time. We modeled the number of mechanical ventilators that could be used in addition to the number of hospital-based ventilators currently in use. METHODS: We identified key components of the health care system needed to deliver ventilation therapy, quantified the maximum number of additional ventilators that each key component could support at various capacity levels (i.e., conventional, contingency, and crisis), and determined the constraining key component at each capacity level. RESULTS: Our study results showed that US hospitals could absorb between 26,200 and 56,300 additional ventilators at the peak of a national influenza pandemic outbreak with robust pre-pandemic planning. CONCLUSIONS: The current US health care system may have limited capacity to use additional mechanical ventilators during a large-scale public health emergency. Emergency planners need to understand their health care systems' capability to absorb additional resources and expand care. This methodology could be adapted by emergency planners to determine stockpiling goals for critical resources or to identify alternatives to manage overwhelming critical care need.

While influenza transmission is thought to occur primarily by droplet spread, the role of airborne spread remains uncertain. Understanding the beliefs and attitudes of infectious disease physicians regarding influenza transmission and respiratory and barrier protection preferences can provide insights into workplace decisions regarding respiratory protection planning. Physicians participating in the Infectious Diseases Society of America's Emerging Infections Network were queried in November 2013 to determine beliefs and attitudes on influenza transmission. A subset of physicians involved in their facility's respiratory protection decision making were queried about respirator and surgical mask choices under various pandemic scenarios; availability of, and challenges associated with, respirators in their facility; and protective strategies during disposable N95 shortages. The majority of 686 respondents (98%) believed influenza transmission occurs frequently or occasionally via droplets; 44% of respondents believed transmission occurs via small particles frequently (12%) or occasionally (32%). Among the subset of respondents involved in respiratory protection planning at their facility, over 90% preferred surgical masks during provision of non-aerosol-generating patient care for seasonal influenza. However, for the same type of care during an influenza pandemic, two-thirds of respondents opted for disposable N95 filtering facepiece respirators. In settings where filtering facepiece (disposable) N95 respirators were in short supply, preferred conservation strategies included extended use and reuse of disposable N95s. Use of reusable (elastomeric facepiece) respirator types was viewed less favorably. While respondents identified droplets as the primary mode of influenza transmission, during a high-severity pandemic scenario there was increased support for devices that reduced aerosol-based transmission. Use of potentially less familiar respirator types may partially relieve shortages of disposable N95s but also may require significant education efforts so that clinicians are aware of the characteristics of alternative personal protective equipment.

BACKGROUND: The first case of Ebola diagnosed in the United States and subsequent cases among 2 healthcare workers caring for that patient highlighted the importance of hospital preparedness in caring for Ebola patients. METHODS: From October 21, 2014 to November 11, 2014, infectious disease physicians who are part of the Emerging Infections Network (EIN) were surveyed about current Ebola preparedness at their institutions. RESULTS: Of 1566 EIN physician members, 869 (55.5%) responded to this survey. Almost all institutions represented in this survey showed a substantial degree of preparation for the management of patients with suspected and confirmed Ebola virus disease. Despite concerns regarding shortages of personal protective equipment, approximately two thirds of all respondents reported that their facilities had sufficient and ready availability of hoods, full body coveralls, and fluid-resistant or impermeable aprons. The majority of respondents indicated preference for transfer of Ebola patients to specialized treatment centers rather than caring for them locally. In general, we found that larger hospitals and teaching hospitals reported higher levels of preparedness. CONCLUSIONS: Prior to the Centers for Disease Control and Prevention's plan for a tiered approach that identified specific roles for frontline, assessment, and designated treatment facilities, our query of infectious disease physicians suggested that healthcare facilities across the United States were making preparations for screening, diagnosis, and treatment of Ebola patients. Nevertheless, respondents from some hospitals indicated that they were relatively unprepared.

BACKGROUND: To inform planning for an influenza pandemic, we estimated US demand for N95 filtering facepiece respirators (respirators) by healthcare and emergency services personnel and need for surgical masks by pandemic patients seeking care. METHODS: We used a spreadsheet-based model to estimate demand for 3 scenarios of respirator use: base case (usage approximately follows epidemic curve), intermediate demand (usage rises to epidemic peak and then remains constant), and maximum demand (all healthcare workers use respirators from pandemic onset). We assumed that in the base case scenario, up to 16 respirators would be required per day per intensive care unit patient and 8 per day per general ward patient. Outpatient healthcare workers and emergency services personnel would require 4 respirators per day. Patients would require 1.2 surgical masks per day. RESULTS AND CONCLUSIONS: Assuming that 20% to 30% of the population would become ill, 1.7 to 3.5 billion respirators would be needed in the base case scenario, 2.6 to 4.3 billion in the intermediate demand scenario, and up to 7.3 billion in the maximum demand scenario (for all scenarios, between 0.1 and 0.4 billion surgical masks would be required for patients). For pandemics with a lower attack rate and fewer cases (eg, 2009-like pandemic), the number of respirators needed would be higher because the pandemic would have longer duration. Providing these numbers of respirators and surgical masks represents a logistic challenge for US public health agencies. Public health officials must urgently consider alternative use strategies for respirators and surgical masks during a pandemic that may vary from current practices.

An outbreak in China in April 2013 of human illnesses due to avian influenza A(H7N9) virus provided reason for US public health officials to revisit existing national pandemic response plans. We built a spreadsheet model to examine the potential demand for invasive mechanical ventilation (excluding "rescue therapy" ventilation). We considered scenarios of either 20% or 30% gross influenza clinical attack rate (CAR), with a "low severity" scenario with case fatality rates (CFR) of 0.05%-0.1%, or a "high severity" scenario (CFR: 0.25%-0.5%). We used rates-of-influenza-related illness to calculate the numbers of potential clinical cases, hospitalizations, admissions to intensive care units, and need for mechanical ventilation. We assumed 10 days ventilator use per ventilated patient, 13% of total ventilator demand will occur at peak, and a 33.7% weighted average mortality risk while on a ventilator. At peak, for a 20% CAR, low severity scenario, an additional 7000 to 11 000 ventilators will be needed, averting a pandemic total of 35 000 to 55 000 deaths. A 30% CAR, high severity scenario, will need approximately 35 000 to 60 500 additional ventilators, averting a pandemic total 178 000 to 308 000 deaths. Estimates of deaths averted may not be realized because successful ventilation also depends on sufficient numbers of suitably trained staff, needed supplies (eg, drugs, reliable oxygen sources, suction apparatus, circuits, and monitoring equipment) and timely ability to match access to ventilators with critically ill cases. There is a clear challenge to plan and prepare to meet demands for mechanical ventilators for a future severe pandemic.

Following the detection of a novel influenza strain A(H7N9), we modeled the use of antiviral treatment in the United States to mitigate severe disease across a range of hypothetical pandemic scenarios. Our outcomes were total demand for antiviral (neuraminidase inhibitor) treatment and the number of hospitalizations and deaths averted. The model included estimates of attack rate, healthcare-seeking behavior, prescription rates, adherence, disease severity, and the potential effect of antivirals on the risks of hospitalization and death. Based on these inputs, the total antiviral regimens estimated to be available in the United States (as of April 2013) were sufficient to meet treatment needs for the scenarios considered. However, distribution logistics were not examined and should be addressed in future work. Treatment was estimated to avert many severe outcomes (5200-248 000 deaths; 4800-504 000 hospitalizations); however, large numbers remained (25 000-425 000 deaths; 580 000-3 700 000 hospitalizations), suggesting that the impact of combinations of interventions should be examined.

The U.S. Department of Health and Human Services (HHS), CDC, other U.S. government agencies, the World Health Organization (WHO), and international partners are taking multiple steps to respond to the current Ebola virus disease (Ebola) outbreak in West Africa to reduce its toll there and to reduce the chances of international spread. At the same time, CDC and HHS are working to ensure that persons who have a risk factor for exposure to Ebola and who develop symptoms while in the United States are rapidly identified and isolated, and safely receive treatment. HHS and CDC have actively worked with state and local public health authorities and other partners to accelerate health care preparedness to care for persons under investigation (PUI) for Ebola or with confirmed Ebola. This report describes some of these efforts and their impact.