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In September 2004, an outbreak of community-associated methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infections (SSTI) was reported among members of a religious community. We conducted a retrospective cohort study on all 175 community members; performed a nasal carriage survey, and environmental swab testing. We identified 24 MRSA cases (attack rate 14%). In multivariate analysis, sauna use [odds ratio (OR) 19.1, 95% confidence interval (CI) 2.7-206.1] and antimicrobial use within 12 months before infection (OR 11.7, 95% CI 2.9-47.6) were risk factors for infection. MRSA nasal carriage rate was 0.6% (1/174). Nine of 10 clinical isolates and an isolate from an administrative office within the community had the pulsed-field gel electrophoresis type USA300. Targeted hygiene improvement, wound care, and environmental cleaning were implemented. We describe the first reported outbreak of MRSA SSTI in a religious community. Adherence to appropriate personal and environmental hygiene might be critical factors in controlling transmission. [ABSTRACT FROM AUTHOR]

BACKGROUND: In January 2003, white particulate matter (WPM) was detected in blood components. Because the composition and cause of WPM was not understood at that time, there was uncertainty about whether WPM could endanger patient safety. To investigate possible adverse patient events associated with WPM, transfusion reaction rates were examined. STUDY DESIGN AND METHODS: A questionnaire was distributed to Georgia medical centers. Data collected included the number of components transfused and reported adverse reactions by component type from January 2002 through January 2003, and date, reaction type, and blood supplier for events in January 2003. RESULTS: Of 124 transfusion services contacted, 108 (87%) responded. During the survey period, there were 1213 reported transfusion reactions and 528,412 units transfused, or 2.3 reactions per 1000 units transfused; for RBCs, 2.4 (range, 1.8-3.1); plasma, 1.5 (range, 0.6-3.5); and PLTs, 3.4 (2.1-5.4) per 1000 units. Transfusion reaction rates by component for January 2003 did not differ significantly from the rate for January 2002 or for the calendar year. The 86 reported reactions that occurred in January 2003 were attributed to bacterial contamination (n = 2, 2.3%), other febrile nonhemolytic (n = 49, 57.0%), allergic (n = 14, 16.3%), and 'other' reactions (n = 21, 24.4%); the proportions of reaction types did not differ significantly during the month. CONCLUSION: No overall changes in reported adverse reaction rates occurred over the survey period or in the proportion of reaction types during January 2003 when WPM was detected. Statewide surveillance of transfusion reactions could be useful to evaluate potential threats to blood safety. [ABSTRACT FROM AUTHOR]

OBJECTIVES: As an alternative to statewide, mandated surveillance for antibiotic-resistant Streptococcus pneumoniae, a sentinel surveillance network of 27 hospitals was developed in Washington State. METHODS: The utility of targeted surveillance in population centers was assessed, current laboratory susceptibility testing practices were evaluated, and a baseline of pneumococcal resistance in Washington State was obtained for use in a statewide campaign promoting the judicious use of antibiotics. RESULTS: Between July 1997 and June 1998, 300 cases were reported; 67 (22%) had diminished susceptibility to penicillin. Only 191 (64%) were fully tested with penicillin and an extended-spectrum cephalosporin (ESC) as nationally recommended; 10.5% were resistant to penicillin and 6.8% were resistant to an ESC. The number of isolates inadequately tested declined through the year. The findings were similar to those from more comprehensive active surveillance in Oregon for the same time period. CONCLUSIONS: Targeted surveillance may be an adequate alternative for limited monitoring of antibiotic resistance for states that choose not to mandate reporting. [ABSTRACT FROM AUTHOR]

Background: Outbreaks of travel-related Legionnaires' disease present a public-health challenge since rapid, sensitive, and specific diagnostic tests are not widely used and because detection of clusters of disease among travellers is difficult. We report an outbreak of Legionnaires' disease among cruise ship passengers that occurred in April, 1994, but that went unrecognised until July, 1994.Methods: After rapid diagnosis of Legionnaires' disease in three passengers by urine antigen testing, we searched for additional cases of either confirmed (laboratory evidence of infection) or probable Legionnaires' disease (pneumonia of undetermined cause). A case-control study was conducted to compare exposures and activities on the ship and in ports of call between each case-passenger and two or three matched control-passengers. Water samples from the ship, from sites on Bermuda, and from the ship's water source in New York City were cultured for legionellae and examined with PCR.Findings: 50 passengers with Legionnaires' disease (16 confirmed, 34 probable) were identified from nine cruises embarking between April 30 and July 9, 1994. Exposure to whirlpool spas was strongly associated with disease (odds ratio 16.2, 95% Cl 2.8-351:7); risk of acquiring Legionnaires' disease increased by 64% (95% Cl 12-140) for every hour spent in the spa water. Passengers spending time around the whirlpool spas, but not in the water, were also significantly more likely to have acquired infection. Legionella pneumophila serogroup 1 was isolated only from the sand filter in the ship's whirlpool spa. This isolate matched a clinical isolate from the respiratory secretions of a case-passenger as judged by monoclonal antibody subtyping and by arbitrarily primed PCR.Interpretation: This investigation shows the benefit of obtaining a recent travel history, the usefulness or urine antigen testing for rapid diagnosis of legionella infection, and the need for improved surveillance for travel-related Legionnaires' disease. New strategies for whirlpool spa maintenance and decontamination may help to minimise transmission of legionellae from these aerosol-producing devices. [ABSTRACT FROM AUTHOR]

The article reports that human tissue-processing company Biomedical Tissue Services Ltd. (BTS) recovered tissues from human donors who were not screened properly for certain infectious diseases and who might not have met donor eligibility requirements. The tissues were sent to five processors and distributed to all 50 states and other nations. The U.S. Food and Drug Administration, along with BTS and tissue processors who received the suspect tissues, issued a recall of all BTS recovered tissues. In its tissue recovery processes, BTS violated the Current Good Tissue Practice Rules, which has rules to prevent the introduction, transmission, or spread of communicable diseases. Transmission of infection via tissue allografts is rare, but still documented.

Competing Interests: LB declares an appointment at the non-profit organisation Right to Care. All authors are members of the Strategic and Technical Advisory Group on Infectious Hazards with Pandemic and Epidemic Potential (STAG-IH) that provides independent advice to WHO. We declare no competing interests.

A network of global respiratory disease surveillance systems and partnerships has been built over decades as a direct response to the persistent threat of seasonal, zoonotic, and pandemic influenza. These efforts have been spearheaded by the World Health Organization, country ministries of health, the US Centers for Disease Control and Prevention, nongovernmental organizations, academic groups, and others. During the COVID-19 pandemic, the US Centers for Disease Control and Prevention worked closely with ministries of health in partner countries and the World Health Organization to leverage influenza surveillance systems and programs to respond to SARS-CoV-2 transmission. Countries used existing surveillance systems for severe acute respiratory infection and influenza-like illness, respiratory virus laboratory resources, pandemic influenza preparedness plans, and ongoing population-based influenza studies to track, study, and respond to SARS-CoV-2 infections. The incorporation of COVID-19 surveillance into existing influenza sentinel surveillance systems can support continued global surveillance for respiratory viruses with pandemic potential.

This report updates the 2019-20 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines in the United States (MMWR Recomm Rep 2019;68[No. RR-3]). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For each recipient, a licensed and age-appropriate vaccine should be used. Inactivated influenza vaccines (IIVs), recombinant influenza vaccine (RIV4), and live attenuated influenza vaccine (LAIV4) are expected to be available. Most influenza vaccines available for the 2020-21 season will be quadrivalent, with the exception of MF59-adjuvanted IIV, which is expected to be available in both quadrivalent and trivalent formulations.Updates to the recommendations described in this report reflect discussions during public meetings of ACIP held on October 23, 2019; February 26, 2020; and June 24, 2020. Primary updates to this report include the following two items. First, the composition of 2020-21 U.S. influenza vaccines includes updates to the influenza A(H1N1)pdm09, influenza A(H3N2), and influenza B/Victoria lineage components. Second, recent licensures of two new influenza vaccines, Fluzone High-Dose Quadrivalent and Fluad Quadrivalent, are discussed. Both new vaccines are licensed for persons aged ≥65 years. Additional changes include updated discussion of contraindications and precautions to influenza vaccination and the accompanying Table, updated discussion concerning use of LAIV4 in the setting of influenza antiviral medication use, and updated recommendations concerning vaccination of persons with egg allergy who receive either cell culture-based IIV4 (ccIIV4) or RIV4.The 2020-21 influenza season will coincide with the continued or recurrent circulation of SARS-CoV-2 (the novel coronavirus associated with coronavirus disease 2019 [COVID-19]). Influenza vaccination of persons aged ≥6 months to reduce prevalence of illness caused by influenza will reduce symptoms that might be confused with those of COVID-19. Prevention of and reduction in the severity of influenza illness and reduction of outpatient illnesses, hospitalizations, and intensive care unit admissions through influenza vaccination also could alleviate stress on the U.S. health care system. Guidance for vaccine planning during the pandemic is available at https://www.cdc.gov/vaccines/pandemic-guidance/index.html.This report focuses on recommendations for the use of vaccines for the prevention and control of seasonal influenza during the 2020-21 season in the United States. A brief summary of the recommendations and a link to the most recent Background Document containing additional information are available at https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/flu.html. These recommendations apply to U.S.-licensed influenza vaccines used within Food and Drug Administration (FDA)-licensed indications. Updates and other information are available from CDC's influenza website (https://www.cdc.gov/flu). Vaccination and health care providers should check this site periodically for additional information., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for the disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

In 2018, the world commemorated the centennial of the 1918 influenza A(H1N1) pandemic, the deadliest pandemic in recorded history; however, little mention was made of the 50th anniversary of the 1968 A(H3N2) pandemic. Although pandemic morbidity and mortality were much lower in 1968 than in 1918, influenza A(H3N2) virus infections have become the leading cause of seasonal influenza illness and death over the last 50 years, with more than twice the number of hospitalizations from A(H3N2) as from A(H1N1) during the past six seasons. We review the emergence, progression, clinical course, etiology, epidemiology, and treatment of the 1968 pandemic and highlight the short- and long-term impact associated with A(H3N2) viruses. The 1968 H3N2 pandemic and its ongoing sequelae underscore the need for improved seasonal and pandemic influenza prevention, control, preparedness, and response efforts.

An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in Wuhan, Hubei Province, China in December 2019, and has spread throughout China and to 31 other countries and territories, including the United States (1). As of February 23, 2020, there were 76,936 reported cases in mainland China and 1,875 cases in locations outside mainland China (1). There have been 2,462 associated deaths worldwide; no deaths have been reported in the United States. Fourteen cases have been diagnosed in the United States, and an additional 39 cases have occurred among repatriated persons from high-risk settings, for a current total of 53 cases within the United States. This report summarizes the aggressive measures (2,3) that CDC, state and local health departments, multiple other federal agencies, and other partners are implementing to slow and try to contain transmission of COVID-19 in the United States. These measures require the identification of cases and contacts of persons with COVID-19 in the United States and the recommended assessment, monitoring, and care of travelers arriving from areas with substantial COVID-19 transmission. Although these measures might not prevent widespread transmission of the virus in the United States, they are being implemented to 1) slow the spread of illness; 2) provide time to better prepare state and local health departments, health care systems, businesses, educational organizations, and the general public in the event that widespread transmission occurs; and 3) better characterize COVID-19 to guide public health recommendations and the development and deployment of medical countermeasures, including diagnostics, therapeutics, and vaccines. U.S. public health authorities are monitoring the situation closely, and CDC is coordinating efforts with the World Health Organization (WHO) and other global partners. Interim guidance is available at https://www.cdc.gov/coronavirus/index.html. As more is learned about this novel virus and this outbreak, CDC will rapidly incorporate new knowledge into guidance for action by CDC, state and local health departments, health care providers, and communities., Competing Interests: The author has completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

This report updates the 2018-19 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines in the United States (MMWR Recomm Rep 2018;67[No. RR-3]). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. A licensed, recommended, and age-appropriate vaccine should be used. Inactivated influenza vaccines (IIVs), recombinant influenza vaccine (RIV), and live attenuated influenza vaccine (LAIV) are expected to be available for the 2019-20 season. Standard-dose, unadjuvanted, inactivated influenza vaccines will be available in quadrivalent formulations (IIV4s). High-dose (HD-IIV3) and adjuvanted (aIIV3) inactivated influenza vaccines will be available in trivalent formulations. Recombinant (RIV4) and live attenuated influenza vaccine (LAIV4) will be available in quadrivalent formulations.Updates to the recommendations described in this report reflect discussions during public meetings of ACIP held on October 25, 2018; February 27, 2019; and June 27, 2019. Primary updates in this report include the following two items. First, 2019-20 U.S. trivalent influenza vaccines will contain hemagglutinin (HA) derived from an A/Brisbane/02/2018 (H1N1)pdm09-like virus, an A/Kansas/14/2017 (H3N2)-like virus, and a B/Colorado/06/2017-like virus (Victoria lineage). Quadrivalent influenza vaccines will contain HA derived from these three viruses, and a B/Phuket/3073/2013-like virus (Yamagata lineage). Second, recent labeling changes for two IIV4s, Afluria Quadrivalent and Fluzone Quadrivalent, are discussed. The age indication for Afluria Quadrivalent has been expanded from ≥5 years to ≥6 months. The dose volume for Afluria Quadrivalent is 0.25 mL for children aged 6 through 35 months and 0.5 mL for all persons aged ≥36 months (≥3 years). The dose volume for Fluzone Quadrivalent for children aged 6 through 35 months, which was previously 0.25 mL, is now either 0.25 mL or 0.5 mL. The dose volume for Fluzone Quadrivalent is 0.5 mL for all persons aged ≥36 months (≥3 years).This report focuses on the recommendations for use of vaccines for the prevention and control of influenza during the 2019-20 season in the United States. A brief summary of these recommendations and a Background Document containing additional information are available at https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/flu.html. These recommendations apply to U.S.-licensed influenza vaccines used within Food and Drug Administration-licensed indications. Updates and other information are available from CDC's influenza website (https://www.cdc.gov/flu). Vaccination and health care providers should check this site periodically for additional information., Competing Interests: The authors each report that they have nothing to disclose. This report includes discussion of the unlabeled use of influenza vaccines in the instance of influenza vaccination of persons with a history of egg allergy. A history of severe allergic reaction to the vaccine or any of its components (which include egg for some vaccines) is a labeled contraindication to receipt of most IIVs and LAIV4. However, ACIP and CDC recommended that persons with a history of allergic reaction of any severity to egg should receive any licensed, recommended influenza vaccine that is appropriate for their age and health status. Persons with a history of severe allergic reaction to egg should be vaccinated in an inpatient or outpatient medical setting (including, but not necessarily limited to, hospitals, clinics, health departments, and physician offices); vaccine administration should be supervised by a health care provider who is able to recognize and manage severe allergic reactions. No postvaccination waiting period is recommended specifically for egg-allergic persons. However, ACIP recommends that vaccine providers consider observing patients (seated or supine) for 15 minutes following administration of any vaccine to decrease the risk for injury should syncope occur.

One hundred years have passed since the 1918 influenza pandemic caused substantial illness globally, with an estimated 50 million deaths. A number of factors, including World War I, contributed to the spread of the pandemic virus, which often caused high symptomatic attack rates and severe illness. Major achievements over the last 100 years have been made in influenza prevention, diagnosis, and treatment; however, the potential for a severe pandemic to emerge remains unchanged. We provide a review of the historical context and clinical aspects of illness due to the influenza A(H1N1) virus as it emerged and spread in 1918, with a focus on the experience in the United States. Understanding the significant social disruption and burden of illness from the 1918 pandemic can help us imagine the possible impacts of a high severity pandemic if it were to emerge now., (Published by Elsevier Inc.)

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.

This report updates the 2017-18 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines in the United States (MMWR Recomm Rep 2017;66[No. RR-2]). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. A licensed, recommended, and age-appropriate vaccine should be used. Inactivated influenza vaccines (IIVs), recombinant influenza vaccine (RIV), and live attenuated influenza vaccine (LAIV) are expected to be available for the 2018-19 season. Standard-dose, unadjuvanted, inactivated influenza vaccines will be available in quadrivalent (IIV4) and trivalent (IIV3) formulations. Recombinant influenza vaccine (RIV4) and live attenuated influenza vaccine (LAIV4) will be available in quadrivalent formulations. High-dose inactivated influenza vaccine (HD-IIV3) and adjuvanted inactivated influenza vaccine (aIIV3) will be available in trivalent formulations.Updates to the recommendations described in this report reflect discussions during public meetings of ACIP held on October 25, 2017; February 21, 2018; and June 20, 2018. New and updated information in this report includes the following four items. First, vaccine viruses included in the 2018-19 U.S. trivalent influenza vaccines will be an A/Michigan/45/2015 (H1N1)pdm09-like virus, an A/Singapore/INFIMH-16-0019/2016 (H3N2)-like virus, and a B/Colorado/06/2017-like virus (Victoria lineage). Quadrivalent influenza vaccines will contain these three viruses and an additional influenza B vaccine virus, a B/Phuket/3073/2013-like virus (Yamagata lineage). Second, recommendations for the use of LAIV4 (FluMist Quadrivalent) have been updated. Following two seasons (2016-17 and 2017-18) during which ACIP recommended that LAIV4 not be used, for the 2018-19 season, vaccination providers may choose to administer any licensed, age-appropriate influenza vaccine (IIV, RIV4, or LAIV4). LAIV4 is an option for those for whom it is appropriate. Third, persons with a history of egg allergy of any severity may receive any licensed, recommended, and age-appropriate influenza vaccine (IIV, RIV4, or LAIV4). Additional recommendations concerning vaccination of egg-allergic persons are discussed. Finally, information on recent licensures and labeling changes is discussed, including expansion of the age indication for Afluria Quadrivalent (IIV4) from ≥18 years to ≥5 years and expansion of the age indication for Fluarix Quadrivalent (IIV4), previously licensed for ≥3 years, to ≥6 months.This report focuses on the recommendations for use of vaccines for the prevention and control of influenza during the 2018-19 season in the United States. A Background Document containing further information and a brief summary of these recommendations are available at https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/flu.html.These recommendations apply to U.S.-licensed influenza vaccines used within Food and Drug Administration-licensed indications. Updates and other information are available at CDC's influenza website (https://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information., Competing Interests: Recommendations for routine use of vaccines in children, adolescents, and adults are developed by the Advisory Committee on Immunization Practices (ACIP). ACIP is chartered as a federal advisory committee to provide expert external advice and guidance to the Director of CDC on use of vaccines and related agents for the control of vaccine-preventable diseases in the civilian population of the United States. Recommendations for routine use of vaccines in children and adolescents are harmonized to the greatest extent possible with recommendations made by the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American College of Obstetricians and Gynecologists (ACOG). Recommendations for routine use of vaccines in adults are harmonized with recommendations of AAFP, ACOG, and the American College of Physicians (ACP). ACIP recommendations approved by the CDC Director become agency guidelines on the date published in the Morbidity and Mortality Weekly Report (MMWR). Additional information is available at https://www.cdc.gov/vaccines/acip. Emmanuel B. Walter reports grants from Novavax and Merck & Co, outside the submitted work. Other content experts and CDC planners wish to disclose they have no financial interests or other relationships with the manufacturers of commercial products, suppliers of commercial services, or commercial supporters. This report includes discussion of the unlabeled use of influenza vaccines in the instance of vaccination of persons with a history of egg allergy. A history of severe allergic reaction to influenza vaccine or any of its components (including egg) is a labeled contraindication to receipt of most IIVs and LAIV. However, ACIP and CDC recommend that persons with egg allergy of any severity should receive any licensed, recommended, and age-appropriate influenza vaccine that is otherwise appropriate for their health status. Persons with a history of severe allergic reaction to egg should be vaccinated in an inpatient or outpatient medical setting (including, but not necessarily limited to, hospitals, clinics, health departments, and physician offices). Vaccine administration should be supervised by a health care provider who is able to recognize and manage severe allergic conditions. No postvaccination observation period is recommended specifically for egg-allergic persons. However, ACIP recommends that vaccine providers consider observing patients (seated or supine) for 15 minutes following administration of any vaccine to decrease the risk for injury should syncope occur.

The need for closer linkages between scientific and programmatic areas focused on addressing vaccine-preventable and acute respiratory infections led to establishment of the National Center for Immunization and Respiratory Diseases (NCIRD) at the Centers for Disease Control and Prevention. During its first 10 years (2006-2015), NCIRD worked with partners to improve preparedness and response to pandemic influenza and other emergent respiratory infections, provide an evidence base for addition of 7 newly recommended vaccines, and modernize vaccine distribution. Clinical tools were developed for improved conversations with parents, which helped sustain childhood immunization as a social norm. Coverage increased for vaccines to protect adolescents against pertussis, meningococcal meningitis, and human papillomavirus-associated cancers. NCIRD programs supported outbreak response for new respiratory pathogens and oversaw response of the Centers for Disease Control and Prevention to the 2009 influenza A(H1N1) pandemic. Other national public health institutes might also find closer linkages between epidemiology, laboratory, and immunization programs useful.

Intranasally administered live attenuated influenza vaccine (LAIV) was initially licensed in the United States in 2003 as a trivalent formulation (LAIV3) (FluMist, MedImmune, LLC). Quadrivalent live attenuated influenza vaccine (LAIV4) (FluMist Quadrivalent, MedImmune) has been licensed in the United States since 2012 and was first available during the 2013-14 influenza season, replacing LAIV3. During the 2016-17 and 2017-18 influenza seasons, the Advisory Committee on Immunization Practices (ACIP) recommended that LAIV4 not be used because of concerns about low effectiveness against influenza A(H1N1)pdm09-like viruses circulating in the United States during the 2013-14 and 2015-16 seasons (1,2). On February 21, 2018, ACIP recommended that LAIV4 be an option for influenza vaccination of persons for whom it is appropriate for the 2018-19 season (3). This document provides an overview of the information discussed in the decision-making process leading to this recommendation. A description of methodology and data reviewed will be included in the background materials that will supplement the 2018-19 ACIP Influenza Recommendations, which will replace the 2017-18 ACIP influenza statement (2), and which will also contain guidance for the use of LAIV4., Competing Interests: Emmanuel B. Walter reports grants from Novartis V&D, Novavax, and Merck & Co, outside the submitted work. No other conflicts of interest were reported.

Assessments of influenza season severity can guide public health action. We used the moving epidemic method to develop intensity thresholds (ITs) for 3 US surveillance indicators from the 2003-2004 through 2014-2015 influenza seasons (excluding the 2009 pandemic). The indicators were: 1) outpatient visits for influenza-like illness; 2) influenza-related hospitalizations; and 3) influenza- and pneumonia-related deaths. ITs were developed for the population overall and separately for children, adults, and older adults, and they were set at the upper limit of the 50% (IT50), 90% (IT90), and 98% (IT98) 1-sided confidence intervals of the geometric mean of each season's 3 highest values. Severity was classified as low if ≥2 systems peaked below IT50, moderate if ≥2 peaked between IT50 and IT90, high if ≥2 peaked between IT90 and IT98, and very high if ≥2 peaked above IT98. We pilot-tested this method with the 2015-2016 season and the 2009 pandemic. Overall, 4 seasons were classified as low severity, 7 as moderate, 2 as high, and none as very high. Among the age groups, older adults had the most seasons (n = 3) classified as high, and children were the only group to have seasons (n = 2) classified as very high. We will apply this method to classify the severity of future seasons and inform pandemic response.

Animal influenza viruses can reassort or mutate to infect and spread sustainably among people and cause a devastating worldwide pandemic. Since the first evidence of human infection with an animal influenza virus, in 1958, 16 different novel, zoonotic influenza A virus subtype groups in 29 countries, Taiwan, and Hong Kong have caused human infections, with differing severity and frequency. The frequency of novel influenza virus detection is increasing, and human infections with influenza A(H5N1) and A(H7N9) viruses are now annual seasonal occurrences in Asia. The study of the epidemiology and virology of animal influenza viruses is key to understanding pandemic risk and informing preparedness. This supplement brings together select recent articles that look at the risk of emergence and transmission of and approaches to prevent novel influenza virus infections., (Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.)

Among all influenza viruses assessed using CDC's Influenza Risk Assessment Tool (IRAT), the Asian lineage avian influenza A(H7N9) virus (Asian H7N9), first reported in China in March 2013,* is ranked as the influenza virus with the highest potential pandemic risk (1). During October 1, 2016-August 7, 2017, the National Health and Family Planning Commission of China; CDC, Taiwan; the Hong Kong Centre for Health Protection; and the Macao CDC reported 759 human infections with Asian H7N9 viruses, including 281 deaths, to the World Health Organization (WHO), making this the largest of the five epidemics of Asian H7N9 infections that have occurred since 2013 (Figure 1). This report summarizes new viral and epidemiologic features identified during the fifth epidemic of Asian H7N9 in China and summarizes ongoing measures to enhance pandemic preparedness. Infections in humans and poultry were reported from most areas of China, including provinces bordering other countries, indicating extensive, ongoing geographic spread. The risk to the general public is very low and most human infections were, and continue to be, associated with poultry exposure, especially at live bird markets in mainland China. Throughout the first four epidemics of Asian H7N9 infections, only low pathogenic avian influenza (LPAI) viruses were detected among human, poultry, and environmental specimens and samples. During the fifth epidemic, mutations were detected among some Asian H7N9 viruses, identifying the emergence of high pathogenic avian influenza (HPAI) viruses as well as viruses with reduced susceptibility to influenza antiviral medications recommended for treatment. Furthermore, the fifth-epidemic viruses diverged genetically into two separate lineages (Pearl River Delta lineage and Yangtze River Delta lineage), with Yangtze River Delta lineage viruses emerging as antigenically different compared with those from earlier epidemics. Because of its pandemic potential, candidate vaccine viruses (CVV) were produced in 2013 that have been used to make vaccines against Asian H7N9 viruses circulating at that time. CDC is working with partners to enhance surveillance for Asian H7N9 viruses in humans and poultry, to improve laboratory capability to detect and characterize H7N9 viruses, and to develop, test and distribute new CVV that could be used for vaccine production if a vaccine is needed.

This report updates the 2016-17 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (MMWR Recomm Rep 2016;65[No. RR-5]). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. A licensed, recommended, and age-appropriate vaccine should be used.For the 2017-18 season, quadrivalent and trivalent influenza vaccines will be available. Inactivated influenza vaccines (IIVs) will be available in trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in trivalent (RIV3) and quadrivalent (RIV4) formulations. Live attenuated influenza vaccine (LAIV4) is not recommended for use during the 2017-18 season due to concerns about its effectiveness against (H1N1)pdm09 viruses during the 2013-14 and 2015-16 seasons. Recommendations for different vaccine types and specific populations are discussed. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is available.Updates to the recommendations described in this report reflect discussions during public meetings of ACIP held on October 20, 2016; February 22, 2017; and June 21, 2017. New and updated information in this report includes the following:•Vaccine viruses included in the 2017-18 U.S. trivalent influenza vaccines will be an A/Michigan/45/2015 (H1N1)pdm09-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent influenza vaccines will contain these three viruses and an additional influenza B vaccine virus, a B/Phuket/3073/2013-like virus (Yamagata lineage).• Information on recent licensures and labelling changes is discussed, including licensure of Afluria Quadrivalent (IIV4; Seqirus, Parkville, Victoria, Australia); Flublok Quadrivalent (RIV4; Protein Sciences, Meriden, Connecticut); and expansion of the age indication for FluLaval Quadrivalent (IIV4; ID Biomedical Corporation of Quebec, Quebec City, Quebec, Canada), previously licensed for ≥3 years, to ≥6 months.• Pregnant women may receive any licensed, recommended, age-appropriate influenza vaccine.• Afluria (IIV3; Seqirus, Parkville, Victoria, Australia) may be used for persons aged ≥5 years, consistent with Food and Drug Administration-approved labeling.• FluMist Quadrivalent (LAIV4; MedImmune, Gaithersburg, Maryland) should not be used during the 2017-18 season due to concerns about its effectiveness against influenza A(H1N1)pdm09 viruses in the United States during the 2013-14 and 2015-16 influenza seasons.This report focuses on the recommendations for use of vaccines for the prevention and control of influenza during the 2017-18 season in the United States. A Background Document containing further information and a summary of these recommendations are available at https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/flu.html. These recommendations apply to licensed influenza vaccines used within Food and Drug Administration-licensed indications, including those licensed after the publication date of this report. Updates and other information are available at CDC's influenza website (https://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information.

Avian influenza viruses, notably H5 subtype viruses, pose a continuous threat to public health due to their pandemic potential. In recent years, influenza virus H5 subtype split vaccines with novel oil-in-water emulsion based adjuvants (e.g. AS03, MF59) have been shown to be safe, immunogenic, and able to induce broad immune responses in clinical trials, providing strong scientific support for vaccine stockpiling. However, whether such vaccines can provide protection from infection with emerging, antigenically distinct clades of H5 viruses has not been adequately addressed. Here, we selected two AS03-adjuvanted H5N1 vaccines from the US national pre-pandemic influenza vaccine stockpile and assessed whether the 2004-05 vaccines could provide protection against a 2014 highly pathogenic avian influenza (HPAI) H5N2 virus (A/northern pintail/Washington/40964/2014), a clade 2.3.4.4 virus responsible for mass culling of poultry in North America. Ferrets received two doses of adjuvanted vaccine containing 7.5µg of hemagglutinin (HA) from A/Vietnam/1203/2004 (clade 1) or A/Anhui/1/2005 (clade 2.3.4) virus either in a homologous or heterologous prime-boost vaccination regime. We found that both vaccination regimens elicited robust antibody responses against the 2004-05 vaccine viruses and could reduce virus-induced morbidity and viral replication in the lower respiratory tract upon heterologous challenge despite the low level of cross-reactive antibody titers to the challenge H5N2 virus. This study supports the value of existing stockpiled 2004-05 influenza H5N1 vaccines, combined with AS03-adjuvant for early use in the event of an emerging pandemic with H5N2-like clade 2.3.4.4 viruses., (Published by Elsevier Inc.)

Influenza hemagglutination inhibition (HI) and virus microneutralization assays (MN) are widely used for seroprevalence studies. However, these assays have limited field portability and are difficult to fully automate for high throughput laboratory testing. To address these issues, three multiplex influenza subtype-specific antibody detection assays were developed using recombinant hemagglutinin antigens in combination with Chembio, Luminex ® , and ForteBio ® platforms. Assay sensitivity, specificity, and subtype cross-reactivity were evaluated using a panel of well characterized human sera. Compared to the traditional HI, assay sensitivity ranged from 87% to 92% and assay specificity in sera collected from unexposed persons ranged from 65% to 100% across the platforms. High assay specificity (86-100%) for A(H5N1) rHA was achieved for sera from exposed or unexposed to hetorosubtype influenza HAs. In contrast, assay specificity for A(H1N1)pdm09 rHA using sera collected from A/Vietnam/1204/2004 (H5N1) vaccinees in 2008 was low (22-30%) in all platforms. Although cross-reactivity against rHA subtype proteins was observed in each assay platform, the correct subtype specific responses were identified 78%-94% of the time when paired samples were available for analysis. These results show that high throughput and portable multiplex assays that incorporate rHA can be used to identify influenza subtype specific infections., (Published by Elsevier B.V.)

During March 2013-February 24, 2017, annual epidemics of avian influenza A(H7N9) in China resulted in 1,258 avian influenza A(H7N9) virus infections in humans being reported to the World Health Organization (WHO) by the National Health and Family Planning Commission of China and other regional sources (1). During the first four epidemics, 88% of patients developed pneumonia, 68% were admitted to an intensive care unit, and 41% died (2). Candidate vaccine viruses (CVVs) were developed, and vaccine was manufactured based on representative viruses detected after the emergence of A(H7N9) virus in humans in 2013. During the ongoing fifth epidemic (beginning October 1, 2016),* 460 human infections with A(H7N9) virus have been reported, including 453 in mainland China, six associated with travel to mainland China from Hong Kong (four cases), Macao (one) and Taiwan (one), and one in an asymptomatic poultry worker in Macao (1). Although the clinical characteristics and risk factors for human infections do not appear to have changed (2,3), the reported human infections during the fifth epidemic represent a significant increase compared with the first four epidemics, which resulted in 135 (first epidemic), 320 (second), 226 (third), and 119 (fourth epidemic) human infections (2). Most human infections continue to result in severe respiratory illness and have been associated with poultry exposure. Although some limited human-to-human spread continues to be identified, no sustained human-to-human A(H7N9) transmission has been observed (2,3).

Mathematical models incorporate various data sources and advanced computational techniques to portray real-world disease transmission and translate the basic science of infectious diseases into decision-support tools for public health. Unlike standard epidemiologic methods that rely on complete data, modeling is needed when there are gaps in data. By combining diverse data sources, models can fill gaps when critical decisions must be made using incomplete or limited information. They can be used to assess the effect and feasibility of different scenarios and provide insight into the emergence, spread, and control of disease. During the past decade, models have been used to predict the likelihood and magnitude of infectious disease outbreaks, inform emergency response activities in real time (1), and develop plans and preparedness strategies for future events, the latter of which proved invaluable during outbreaks such as severe acute respiratory syndrome and pandemic influenza (2-6). Ideally, modeling is a multistep process that involves communication between modelers and decision-makers, allowing them to gain a mutual understanding of the problem to be addressed, the type of estimates that can be reliably generated, and the limitations of the data. As models become more detailed and relevant to real-time threats, the importance of modeling in public health decision-making continues to grow.

This report updates the 2015-16 recommendations of the Advisory Committee on Immunization Practices (ACIP) regarding the use of seasonal influenza vaccines (Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep 2015;64:818-25). Routine annual influenza vaccination is recommended for all persons aged ≥6 months who do not have contraindications. For the 2016-17 influenza season, inactivated influenza vaccines (IIVs) will be available in both trivalent (IIV3) and quadrivalent (IIV4) formulations. Recombinant influenza vaccine (RIV) will be available in a trivalent formulation (RIV3). In light of concerns regarding low effectiveness against influenza A(H1N1)pdm09 in the United States during the 2013-14 and 2015-16 seasons, for the 2016-17 season, ACIP makes the interim recommendation that live attenuated influenza vaccine (LAIV4) should not be used. Vaccine virus strains included in the 2016-17 U.S. trivalent influenza vaccines will be an A/California/7/2009 (H1N1)-like virus, an A/Hong Kong/4801/2014 (H3N2)-like virus, and a B/Brisbane/60/2008-like virus (Victoria lineage). Quadrivalent vaccines will include an additional influenza B virus strain, a B/Phuket/3073/2013-like virus (Yamagata lineage).Recommendations for use of different vaccine types and specific populations are discussed. A licensed, age-appropriate vaccine should be used. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended product is otherwise appropriate. This information is intended for vaccination providers, immunization program personnel, and public health personnel. Information in this report reflects discussions during public meetings of ACIP held on October 21, 2015; February 24, 2016; and June 22, 2016. These recommendations apply to all licensed influenza vaccines used within Food and Drug Administration-licensed indications, including those licensed after the publication date of this report. Updates and other information are available at CDC's influenza website (http://www.cdc.gov/flu). Vaccination and health care providers should check CDC's influenza website periodically for additional information.

During 2014-2016, CDC, working with U.S. and international partners, mounted a concerted response to end the unprecedented epidemic of Ebola virus disease (Ebola) in West Africa. CDC's response, which was the largest in the agency's history, was directed simultaneously at controlling the epidemic in West Africa and strengthening preparedness for Ebola in the United States. Although experience in responding to approximately 20 Ebola outbreaks since 1976 had provided CDC and other international responders an understanding of the disease and how to stop its spread, the epidemic in West Africa presented new and formidable challenges. The initial response was slow and complicated for several reasons, including wide geographic spread of cases, poor public health and societal infrastructure, sociodemographic factors, local unfamiliarity with Ebola, and distrust of government and health care workers. In the United States, widespread public alarm erupted after Ebola cases were diagnosed in Dallas, Texas, and New York City, New York. CDC, in collaboration with its U.S. and international counterparts, applied proven public health strategies as well as innovative new approaches to help control the Ebola epidemic in West Africa and strengthen public health readiness in the United States. Lessons learned include the recognition that West African and other countries need effective systems to detect and stop infectious disease threats, the need for stronger international surge capacity for times when countries are overwhelmed by an outbreak, and the importance of improving infection prevention and control in health care settings. 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).

In the years prior to 2013, avian influenza A H7 viruses were a cause of significant poultry mortality; however, human illness was generally mild. In March 2013, a novel influenza A(H7N9) virus emerged in China as an unexpected cause of severe human illness with 36% mortality. Chinese and other public health officials responded quickly, characterizing the virus and identifying more than 400 cases through use of new technologies and surveillance tools made possible by past preparedness and response efforts. Genetic sequencing, glycan-array receptor-binding assays, and ferret studies reveal the H7N9 virus to have increased binding to mammalian respiratory cells and to have mutations associated with higher virus replication rates and illness severity. New risk-assessment tools indicate H7N9 has the potential for further mammalian adaptation with possible human-to-human transmission. Vigilant virologic and epidemiologic surveillance is needed to monitor H7N9 and detect other unexpected novel influenza viruses that may emerge.

The complexities of planning for and responding to the emergence of novel influenza viruses emphasize the need for systematic frameworks to describe the progression of the event; weigh the risk of emergence and potential public health impact; evaluate transmissibility, antiviral resistance, and severity; and make decisions about interventions. On the basis of experience from recent influenza responses, CDC has updated its framework to describe influenza pandemic progression using six intervals (two prepandemic and four pandemic intervals) and eight domains. This updated framework can be used for influenza pandemic planning and serves as recommendations for risk assessment, decision-making, and action in the United States. The updated framework replaces the U.S. federal government stages from the 2006 implementation plan for the National Strategy for Pandemic Influenza (US Homeland Security Council. National strategy for pandemic influenza: implementation plan. Washington, DC: US Homeland Security Council; 2006. Available at http://www.flu.gov/planning-preparedness/federal/pandemic-influenza-implementation.pdf). The six intervals of the updated framework are as follows: 1) investigation of cases of novel influenza, 2) recognition of increased potential for ongoing transmission, 3) initiation of a pandemic wave, 4) acceleration of a pandemic wave, 5) deceleration of a pandemic wave, and 6) preparation for future pandemic waves. The following eight domains are used to organize response efforts within each interval: incident management, surveillance and epidemiology, laboratory, community mitigation, medical care and countermeasures, vaccine, risk communications, and state/local coordination. Compared with the previous U.S. government stages, this updated framework provides greater detail and clarity regarding the potential timing of key decisions and actions aimed at slowing the spread and mitigating the impact of an emerging pandemic. Use of this updated framework is anticipated to improve pandemic preparedness and response in the United States. Activities and decisions during a response are event-specific. These intervals serve as a reference for public health decision-making by federal, state, and local health authorities in the United States during an influenza pandemic and are not meant to be prescriptive or comprehensive. This framework incorporates information from newly developed tools for pandemic planning and response, including the Influenza Risk Assessment Tool and the Pandemic Severity Assessment Framework, and has been aligned with the pandemic phases restructured in 2013 by the World Health Organization.

Background: Rapid influenza diagnostic tests (RIDTs) can be used at the point-of-care and are often the only influenza tests readily available in outpatient facilities., Objectives: To determine the use of RIDTs and antiviral prescription practices in outpatient facilities., Study Design: Surveys were mailed to U.S. physician's offices, emergency departments, and community health centers in 2008 (pre-2009 H1N1 pandemic) and 2010 (post-2009 H1N1 pandemic). The 2010 survey included questions to evaluate changes in testing and treatment practices among various risk groups subsequent to the 2009 H1N1 pandemic., Results: In both surveys, respondents using RIDTs relied on RIDT results to guide prescribing antiviral medications. Greater than two-thirds of these respondents reported prescribing antiviral medications both pre- and post-pandemic for patients within 48h of onset of flu-like symptoms with a positive RIDT (69% pre-pandemic; 67% post-pandemic). After the pandemic (2010 survey), outpatient providers also reported prescribing antivirals to those with flu-like symptoms for 31% of children <2 years, 23% of children 2-5 years, 37% of pregnant patients, and 74% of other patients at high risk; while these figures were higher than pre-pandemic, they represent a failure to use CDC guidelines to prescribe antivirals for patients with suspected influenza who are at higher risk for complications., Conclusions: Clinicians in outpatient facilities often relied on RIDT findings to aid in making antiviral treatment decisions; however their treatment practices were not always consistent with CDC guidelines. The use of RIDTs and antiviral medicines were influenced by the 2009 H1N1 pandemic., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Thirteen human infections with an influenza A(H3N2) variant (H3N2v) virus containing a combination of gene segments not previously associated with human illness were identified in the United States from August 2011 to April 2012. Because laboratory confirmation of influenza virus infection is only performed for a minority of ill persons and routine clinical tests may not identify H3N2v virus, the count of laboratory-confirmed H3N2v virus infections underestimates the true burden of illness., Methods: To account for this underascertainment, we adapted a multiplier model created at the beginning of the influenza A(H1N1) 2009 pandemic to estimate the true burden of H3N2v illness. Data to inform each of these parameters came from the literature and from special projects conducted during the 2009 H1N1 pandemic and the 2010-2011 influenza season. The multipliers were calculated as the simple inverses of the proportions at each step, and we accounted for variability and uncertainty in model parameters by using a probabilistic or Monte Carlo approach., Results: We estimate that the median multiplier for children was 200 (90% range, 115-369) and for adults was 255 (90% range, 152-479) and that 2055 (90% range, 1187-3800) illnesses from H3N2v virus infections may have occurred from August 2011 to April 2012, suggesting that the new virus was more widespread than previously thought., Conclusions: Illness from this variant influenza virus was more frequent than previously thought. Continued surveillance is needed to ensure timely detection and response to H3N2v virus infections.

BACKGROUND. During August 2011-April 2012, 13 human infections with influenza A(H3N2) variant (H3N2v) virus were identified in the United States; 8 occurred in the prior 2 years. This virus differs from previous variant influenza viruses in that it contains the matrix (M) gene from the Influenza A(H1N1)pdm09 pandemic influenza virus. METHODS. A case was defined as a person with laboratory-confirmed H3N2v virus infection. Cases and contacts were interviewed to determine exposure to swine and other animals and to assess potential person-to-person transmission. RESULTS. Median age of cases was 4 years, and 12 of 13 (92%) were children. Pig exposure was identified in 7 (54%) cases. Six of 7 cases with swine exposure (86%) touched pigs, and 1 (14%) was close to pigs without known direct contact. Six cases had no swine exposure, including 2 clusters of suspected person-to-person transmission. All cases had fever; 12 (92%) had respiratory symptoms, and 3 (23%) were hospitalized for influenza. All 13 cases recovered. CONCLUSIONS. H3N2v virus infections were identified at a high rate from August 2011 to April 2012, and cases without swine exposure were identified in influenza-like illness outbreaks, indicating that limited person-to-person transmission likely occurred. Variant influenza viruses rarely result in sustained person-to-person transmission; however, the potential for this H3N2v virus to transmit efficiently is of concern. With minimal preexisting immunity in children and the limited cross-protective effect from seasonal influenza vaccine, the majority of children are susceptible to infection with this novel influenza virus.

Ten years have elapsed since the World Health Organization issued its first global alert for an unexplained illness named severe acute respiratory syndrome (SARS). The anniversary provides an opportunity to reflect on the international response to this new global microbial threat. While global surveillance and response capacity for public health threats have been strengthened, critical gaps remain. Of 194 World Health Organization member states that signed on to the International Health Regulations (2005), <20% had achieved compliance with the core capacities required by the deadline in June 2012. Lessons learned from the global SARS outbreak highlight the need to avoid complacency, strengthen efforts to improve global capacity to address the next pandemic using all available 21st century tools, and support research to develop new treatment options, countermeasures, and insights while striving to address the global inequities that are the root cause of many of these challenges.

The effects of influenza on a population are attributable to the clinical severity of illness and the number of persons infected, which can vary greatly between seasons or pandemics. To create a systematic framework for assessing the public health effects of an emerging pandemic, we reviewed data from past influenza seasons and pandemics to characterize severity and transmissibility (based on ranges of these measures in the United States) and outlined a formal assessment of the potential effects of a novel virus. The assessment was divided into 2 periods. Because early in a pandemic, measurement of severity and transmissibility is uncertain, we used a broad dichotomous scale in the initial assessment to divide the range of historic values. In the refined assessment, as more data became available, we categorized those values more precisely. By organizing and prioritizing data collection, this approach may inform an evidence-based assessment of pandemic effects and guide decision making.

Diagnostic tests for detecting emerging influenza virus strains with pandemic potential are critical for directing global influenza prevention and control activities. In 2008, the Centers for Disease Control and Prevention received US Food and Drug Administration approval for a highly sensitive influenza polymerase chain reaction (PCR) assay. Devices were deployed to public health laboratories in the United States and globally. Within 2 weeks of the first recognition of 2009 pandemic influenza H1N1, the Centers for Disease Control and Prevention developed and began distributing a new approved pandemic influenza H1N1 PCR assay, which used the previously deployed device platform to meet a >8-fold increase in specimen submissions. Rapid antigen tests were widely used by clinicians at the point of care; however, test sensitivity was low (40%-69%). Many clinical laboratories developed their own pandemic influenza H1N1 PCR assays to meet clinician demand. Future planning efforts should identify ways to improve availability of reliable testing to manage patient care and approaches for optimal use of molecular testing for detecting and controlling emerging influenza virus strains.

Background: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasingly reported over the past decade, including in Asian/Pacific Islanders (A/PIs)., Methods: We conducted ethnographic interviews in O'ahu and Kaua'i, Hawai'i, with 10 Asian/Pacific Islanders identified as having a history of CA-MRSA infections., Results: Most (7/10) thought skin infections were not a new problem in Hawai'i. Most (8/9) attempted to self-treat the infection prior to seeking medical care with a range of home remedies and store- bought solutions. Most respondents did not initially comprehend the severity of their infection and only sought medical treatment after concern from family, unbearable pain, and/or other symptoms of illness., Conclusion: Clinicians should be aware of the reportedly frequent use of home remedies by this population, as it may potentially contribute to interactions when treatments are combined. If clinicians and public health professionals do not address perceptions and misperceptions of how MRSA is acquired, it will be very difficult to prevent infection, and may also delay individuals from seeking treatment., (Hawaii Medical Journal Copyright 2010.)

Since its identification in April 2009, an A(H1N1) virus containing a unique combination of gene segments from both North American and Eurasian swine lineages has continued to circulate in humans. The lack of similarity between the 2009 A(H1N1) virus and its nearest relatives indicates that its gene segments have been circulating undetected for an extended period. Its low genetic diversity suggests that the introduction into humans was a single event or multiple events of similar viruses. Molecular markers predictive of adaptation to humans are not currently present in 2009 A(H1N1) viruses, suggesting that previously unrecognized molecular determinants could be responsible for the transmission among humans. Antigenically the viruses are homogeneous and similar to North American swine A(H1N1) viruses but distinct from seasonal human A(H1N1).

Objective: To describe the national scope and magnitude of outpatient adverse drug events (ADEs) that lead to emergency department (ED) visits in children and adolescents., Study Design: To conduct an active surveillance of patients 18 years of age or younger who came to EDs with ADEs from Jan 1, 2004, to Dec 31, 2005, through a nationally representative, stratified probability sample of 63 US hospitals with EDs. The main outcome measures were national estimates of the number, type, patient demographics, and clinical characteristics of ADEs., Results: Annually, an estimated 158,520 patients

Objective: Methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged in the community, causing disease among healthy people lacking traditional risk factors for MRSA infection. This article describes an outbreak of MRSA among healthy full-term newborns., Design: Cases were identified and corresponding medical information collected. Telephone interviews were conducted with mothers of cases and surveillance cultures from mothers and newborns were performed. MRSA isolates were genotyped., Setting: Hospital in Chicago, Illinois, USA., Participants: Newborns, their mothers and hospital healthcare workers., Intervention: Nursery infection control practices were enhanced. The MRSA-colonised healthcare workers received intranasal mupirocin., Main Outcome: Within 4-23 days of birth, 11 newborns were identified with pustules, vesicles or blisters located on the head, groin, perineum, ears, legs, chin and trunk. All received antimicrobials and recovered without incident., Results: None of 432 peripartum women, one of 399 newborns, and two of 135 healthcare workers were nasal MRSA carriers. Available isolates from six patients, two healthcare workers, and one from an MRSA-colonised newborn were similar by pulsed-field gel electrophoresis. Other than contact with the hospital, no common exposures of MRSA transmission were identified., Conclusions: MRSA strains that initially emerged in the community are now causing disease in healthcare settings. Providers should be aware that MRSA can cause skin infections among healthy newborns. Adherence to standard infection control practices is important to prevent transmission of MRSA in nurseries.

Background: In contrast to pharmaceutical manufacturers, compounding pharmacies adhere to different quality-control standards, which may increase the likelihood of undetected outbreaks. In 2005, the Centers for Disease Control and Prevention received reports of cases of Serratia marcescens bloodstream infection occurring in patients who underwent cardiac surgical procedures in Los Angeles, California, and in New Jersey. An investigation was initiated to determine whether there was a common underlying cause., Methods: A matched case-control study was conducted in Los Angeles. Case record review and environmental testing were conducted in New Jersey. The Centers for Disease Control and Prevention performed a multistate case-finding investigation; isolates were compared using pulsed-field gel electrophoresis analysis., Results: Nationally distributed magnesium sulfate solution (MgSO(4)) from compounding pharmacy X was the only significant risk factor for S. marcescens bloodstream infection (odds ratio, 6.4; 95% confidence interval, 1.1-38.3) among 6 Los Angeles case patients and 18 control subjects. Five New Jersey case patients received MgSO(4) from a single lot produced by compounding pharmacy X; culture of samples from open and unopened 50-mL bags in this lot yielded S. marcescens. Seven additional case patients from 3 different states were identified. Isolates from all 18 case patients and from samples of MgSO(4) demonstrated indistinguishable pulsed-field gel electrophoresis patterns. Compounding pharmacy X voluntarily recalled the product. Neither the pharmacy nor the US Food and Drug Administration could identify a source of contamination in their investigations of compounding pharmacy X., Conclusions: A multistate outbreak of S. marcescens bloodstream infection was linked to contaminated MgSO(4) distributed nationally by a compounding pharmacy. Health care personnel should take into account the different quality standards and regulation of compounded parenteral medications distributed in large quantities during investigations of outbreaks of bloodstream infection.