|
|
|
|
|
| ||
|
November 3, 2009JAMA news releases are made available to the public after 3 pm US Central time on the first 4 Tuesdays of each month. The Archives of Journals news releases are made available to the public after 3 pm Central time on Mondays. We also provide a list of previous news releases. THIS WEEK'S CONTENTS
JAMA NEWS RELEASES
(Embargoed for Release: 3 p.m. CT Tuesday, November 3, 2009)
The following were previously released early online:
JAMA REPORT (VIDEO SCRIPT)
INFORMATION CONTAINED IN THESE NEWS RELEASES IS PROTECTED BY COPYRIGHT. JOURNAL ATTRIBUTION IS REQUIRED. JOURNALISTS CAN NOW ACCESS EMBARGOED JAMA/ARCHIVES STUDIES ON-LINE. Go to www.jamamedia.org for more information and to apply for access. TV Note: This week's JAMA Report video is on the factors associated with death or hospitalization from H1N1 infection in California. The report will be fed Tuesday, November 3, from 9:00 - 9:15 a.m. ET and 2:00 - 2:15 p.m. ET, on Galaxy 28 (C-Band), Transponder 15, downlink frequency: 4000 vertical, audio 6.2/6.8. For more information, call 312/464-JAMA. The JAMA Report video is also now available on Pathfire every Tuesday, in VNF Provider A. Please look for the JAMA Report tab. Please Note: The FOR THE MEDIA website now has a search feature to enable media to find previous JAMA/Archives news releases on specific medical topics. This search feature link is located on the home page at www.jamamedia.org EMBARGOED FOR RELEASE UNTIL 3 P.M. (CT), Tuesday, November 3, 2009
Report on H1N1 Cases in California Shows Hospitalization Can Occur At All Ages, With Many Severe
CHICAGO—In contrast with some common perceptions regarding 2009 influenza A(H1N1) infections, an examination of cases in California indicates that hospitalization and death can occur at all ages, and about 30 percent of hospitalized cases have been severe enough to require treatment in an intensive care unit, according to a study in the November 4 issue of JAMA. "Since April 17, 2009, when the first 2 cases of pandemic influenza A(H1N1) virus infection were reported in California, the virus has rapidly spread throughout the world," the authors write. They add that preliminary comparisons with seasonal influenza suggest that this influenza infection disproportionately affects younger ages and causes generally mild disease. Janice K. Louie, M.D., M.P.H., of the California Department of Public Health, Richmond, Calif., and colleagues examined the clinical and epidemiologic features of the first 1,088 hospitalized and fatal cases due to pandemic 2009 influenza A(H1N1) infection reported in California, between April 23 and August 11, 2009. On April 20 of this year the California Department of Public Health and 61 local health departments initiated enhanced surveillance for hospitalized and fatal cases of this infection. The researchers found that of the 1,088 A(H1N1) cases, 344 (32 percent) were children younger than 18 years, with infants having the highest rate of hospitalization and persons age 50 years or older having the highest rate of death once hospitalized. The median (midpoint) age of all cases was 27 years. Fever, cough, and shortness of breath were the most common symptoms. Underlying conditions previously associated with severe influenza were reported in 68 percent of cases. Other underlying medical illnesses recorded included obesity, hypertension, hyperlipidemia and gastrointestinal disease. The median length of hospitalization among all cases was 4 days. Three hundred forty cases (31 percent) were admitted to intensive care units, and of the 297 intensive care cases with available information, 65 percent required mechanical ventilation. Of the 884 cases with available information, 79 percent received antiviral treatment, including 496 patients (71 percent) with established risk factors for severe influenza. Of the 833 patients who had chest radiographs, 66 percent had infiltrates (evidence of infection involving the lungs), suggestive of pneumonia or acute respiratory distress syndrome. Rapid antigen tests were falsely negative in 34 percent of cases evaluated. "Overall fatality was 11 percent (118/1,088) and was highest (18 percent - 20 percent) in persons aged 50 years or older," the researchers write. "Of the deaths, 8 (7 percent) were children younger than 18 years. Among fatal cases, the median time from onset of symptoms to death was 12 days." The most common causes of death were viral pneumonia and acute respiratory distress syndrome. "In the first 16 weeks of the current pandemic, 2009 influenza A(H1N1) appears to be notably different from seasonal influenza, with fewer hospitalizations and fatalities occurring in elderly persons. In contrast with the common perception that pandemic 2009 influenza A(H1N1) infection causes only mild disease, hospitalization and death occurred at all ages, and up to 30 percent of hospitalized cases were severely ill. Most hospitalized cases had identifiable established risk factors; obesity may be a newly identified risk factor for fatal pandemic 2009 influenza A(H1N1) infection and merits further study."
"Clinicians should maintain a high level of suspicion for pandemic 2009 influenza A(H1N1) infection in patients presenting currently with influenza-like illness who are older than 50 years or have known risk factors for influenza complications, regardless of rapid test results. Hospitalized infected cases should be carefully monitored and treated promptly with antiviral agents," the authors conclude.
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org. NO EMBARGO - PREVIOUSLY RELEASED EARLY ONLINE
New Study Evaluates Surgical Masks vs. N95 Respirators for Preventing Influenza Among Health Care Workers
CHICAGO—Surgical masks appear to be no worse than, and nearly as effective as N95 respirators in preventing influenza in health care workers, according to a study released early online today by JAMA. The study was posted online ahead of print because of its public health implications. It will be published in the November 4 issue of JAMA. Influenza is the most important cause of medically attended acute respiratory illness worldwide and the authors write there is heightened concern this year because of the influenza pandemic due to the H1N1 virus. "Data about the effectiveness of the surgical mask compared with the N95 respirator for protecting health care workers against influenza are sparse," the authors provide as background information in the article. "Given the likelihood that N95 respirators will be in short supply during a pandemic and not available in many countries, knowing the effectiveness of the surgical mask is of public health importance." Mark Loeb, M.D., M.Sc., from McMaster University, Hamilton, Ontario, Canada, and colleagues conducted a randomized controlled trial of 446 nurses in eight Ontario hospitals to compare the surgical mask with the N95 respirator in protecting health care workers against influenza. The nurses were randomized into two groups: 225 were assigned to receive surgical masks and 221 were assigned to receive the fitted N95 respirator which they were to wear when caring for patients with febrile (fever) respiratory illness. The primary outcome of the study was laboratory-confirmed influenza. Effectiveness of the surgical mask was assessed as non-inferiority of the surgical mask compared with the N95 respirator. Between September 23, 2008 and December 8, 2008, "influenza infection occurred in 50 nurses (23.6 percent) in the surgical mask group and in 48 (22.9 percent) in the N95 respirator group (absolute risk difference -0.73 percent)," indicating non-inferiority of the surgical mask the authors report. Even among those nurses who had an increased level of the circulating pandemic 2009 H1N1 influenza strain, non-inferiority was demonstrated between the surgical mask group and the N95 respirator group for the 2009 influenza A(H1N1). "Our data show that the incidence of laboratory-confirmed influenza was similar in nurses wearing the surgical mask and those wearing the N95 respirator. Surgical masks had an estimated efficacy within 1 percent of N95 respirators," the authors write. "That is, surgical masks appeared to be no worse, within a prespecified margin, than N95 respirators in preventing influenza."
In conclusion the authors state: "Our findings apply to routine care in the health care setting. They should not be generalized to settings where there is a high risk for aerosolization, such as intubation or bronchoscopy, where use of an N95 respirator would be prudent. In routine health care settings, particularly where the availability of N95 respirators is limited, surgical masks appear to be non-inferior to N95 respirators for protecting health care workers against influenza."
Editor's Note: This study was supported by the Public Health Agency of Canada. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Editorial: Respiratory Protection Against Influenza
In an accompanying editorial, Arjun Srinivasan, M.D., from the Centers for Disease Control and Prevention (CDC), Atlanta, and Trish M. Perl, M.D., M.Sc., from the School of Medicine and Bloomberg School of Public Health, Johns Hopkins University, Baltimore, write: "The 2009 influenza A(H1N1) pandemic has revived debate about the role of respiratory protection in preventing the transmission of influenza to health care personnel." The "N95 particulate respirators protect wearers from small particles when appropriately designed and worn." The World Health Organization and Society for Healthcare Epidemiology of America recommend the use of medical masks for most patient care. The CDC and Institute of Medicine recommend the use of N95 respirators during care of patients infected with the H1N1 influenza.
"That this study is, to our knowledge, the first and only published randomized trial assessing respiratory protection for preventing influenza transmission is a sad commentary on the state of research in this area. Uncovering the truth and identifying the most appropriate way to protect health care personnel will require that other investigators build on this study ...," they write. "Ultimately, accumulating a body of evidence on this topic will provide much-needed answers."
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org. NO EMBARGO - PREVIOUSLY RELEASED EARLY ONLINE
H1N1 Critical Illness Can Occur Rapidly; Predominantly Affects Young Patients
CHICAGO—Critical illness among Canadian patients with 2009 influenza A(H1N1) occurred rapidly after hospital admission, often in young adults, and was associated with severely low levels of oxygen in the blood, multi-system organ failure, a need for prolonged mechanical ventilation, and frequent use of rescue therapies, according to a study to appear in the November 4 issue of JAMA. This study is being published early online to coincide with its presentation at a meeting of the European Society of Intensive Care Medicine. Infection with the 2009 influenza A(H1N1) virus has been reported in virtually every country in the world. The World Health Organization declared the first phase six (phase indicating widespread human infection) global influenza pandemic of the century on June 11, 2009. The largest number of confirmed cases occurred in North America between March and July 2009, according to background information in the article. Anand Kumar, M.D., of the Health Sciences Centre and St. Boniface Hospital, Winnipeg, Manitoba, Canada, and colleagues with the Canadian Critical Care Trials Group H1N1 Collaborative conducted an observational study of critically ill patients with 2009 influenza A(H1N1) in 38 adult and pediatric intensive care units (ICUs) in Canada between April 16 and August 12, 2009. The study focused on the death rate at 28 and 90 days, as well as the frequency and duration of mechanical ventilation and the duration of ICU stay. The researchers found that a total of 168 patients had confirmed or probable 2009 influenza A(H1N1) infection and became critically ill during this time period, and 24 (14.3 percent) died within the first 28 days from the onset of critical illness. Five more patients died within 90 days. The average age of the patients with confirmed or probable 2009 influenza A(H1N1) was 32.3 years, 113 were female (67.3 percent), and 50 were children (29.8 percent). "Our data suggest that severe disease and mortality in the current outbreak is concentrated in relatively healthy adolescents and adults between the ages of 10 and 60 years, a pattern reminiscent of the W-shaped curve [rise and fall in the population mortality rate for the disease, corresponding to age at death] previously seen only during the 1918 H1N1 Spanish pandemic," the authors write. Patients with 2009 influenza A(H1N1) infection-related critical illness experienced symptoms for a median (midpoint) of four days before entering the hospital, but worsened rapidly and required care in the ICU within one or two days. Shock and multi-system organ failure were common, and 136 patients (81 percent) received mechanical ventilation, with the median duration being 12 days. The average ICU stay was 12 days. Lung rescue therapies included neuromuscular blockade, inhaled nitric oxide and high-frequency oscillatory ventilation.
"In conclusion, we have demonstrated that 2009 influenza A(H1N1) infection-related critical illness predominantly affects young patients with few major comorbidities and is associated with severe hypoxemic respiratory failure, often requiring prolonged mechanical ventilation and rescue therapies," the authors write. "With such therapy, we found that most patients can be supported through their critical illness."
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Editorial: Preparing for the Sickest Patients With 2009 Influenza A(H1N1)
In an accompanying editorial, Douglas B. White, M.D., M.A.S., and JAMA Contributing Editor Derek C. Angus, M.D., M.P.H., of the University of Pittsburgh School of Medicine, write that many U.S. hospitals may not have adequate numbers of physicians or staffing structures to facilitate timely treatment of the most seriously ill patients with 2009 influenza A(H1N1).
"Hospitals must develop explicit policies to equitably determine who will and will not receive life support should absolute scarcity occur," they write. "Any deaths from 2009 influenza A(H1N1) will be regrettable, but those that result from insufficient planning and inadequate preparation will be especially tragic," they conclude.
Editor's Note: Please see the article for additional information, including financial disclosures, funding and support, etc. For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org. NO EMBARGO - PREVIOUSLY RELEASED EARLY ONLINE
Critical Illness From 2009 H1N1 in Mexico Associated With High Fatality Rate
CHICAGO—Critical illness from 2009 influenza A(H1N1) in Mexico occurred among young patients, was associated with severe acute respiratory distress syndrome and shock, and had a fatality rate of about 40 percent, according to a study to appear in the November 4 issue of JAMA. This study is being published early online to coincide with its presentation at a meeting of the European Society of Intensive Care Medicine. Novel 2009 influenza A(H1N1) was first reported in the southwestern United States and Mexico in March 2009. Between March 18 and June 1, 2009, 5,029 cases and 97 documented deaths occurred in Mexico. The population and health care system in Mexico City experienced the first and greatest early burden of critical illness, according to background information in the article. Guillermo Domínguez-Cherit, M.D. of Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán," Mexico City, and colleagues conducted an observational study of critically ill patients at six hospitals in Mexico that treated the majority of such patients with confirmed, probable, or suspected 2009 influenza A(H1N1) between March 24 and June 1, 2009. The study focused on the death rate, rate of critical illness and mechanical ventilation, and length of stay in the hospital and the intensive care unit. Among 899 patients admitted to hospitals with confirmed, probable, or suspected 2009 influenza A(H1N1), 58 became critically ill. The critically ill patients had a median (midpoint) age of 44 years. Most were treated with antibiotics, and 45 patients were treated with anti-influenza drugs known as neuraminidase inhibitors, including oseltamivir and zanamivir. Fifty-four patients required mechanical ventilation. "Our analysis of critically ill patients with 2009 influenza A(H1N1) reveals that this disease affected a young patient group," the authors write. "Fever and respiratory symptoms were harbingers of disease in almost all cases. There was a relatively long period of illness prior to presentation to the hospital, followed by a short period of acute and severe respiratory deterioration." By 60 days, 24 of the critically ill patients (41.4 percent) died. Nineteen patients died within the first two weeks after becoming critically ill. "Patients who died had greater initial severity of illness, worse hypoxemia [abnormally low levels of oxygen in the blood], higher creatinine kinase levels, higher creatinine levels, and ongoing organ dysfunction," the authors report.
"Early recognition of disease by the consistent symptoms of fever and a respiratory illness during times of outbreak, with prompt medical attention including neuraminidase inhibitors and aggressive support of oxygenation failure and subsequent organ dysfunction, may provide opportunities to mitigate the progression of illness and mortality observed in Mexico," they conclude.
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org. NO EMBARGO - PREVIOUSLY RELEASED EARLY ONLINE
Most H1N1 Patients With Respiratory Failure Treated With Oxygenating System Survive Illness
CHICAGO—Despite the severity of disease and the intensity of treatment, most patients in Australia and New Zealand who experienced respiratory failure as a result of 2009 influenza A(H1N1) and were treated with a system that adds oxygen to the patient's blood survived the disease, according to a study to appear in the November 4 issue of JAMA. This study is being published early online because of its public health importance. The influenza A(H1N1) pandemic affected Australia and New Zealand during the 2009 southern hemisphere winter, causing an epidemic of critical illness. Some patients developed severe acute respiratory distress syndrome (ARDS) and were treated with extracorporeal membrane oxygenation (ECMO), according to background information in the article. ARDS is a lung condition that leads to respiratory failure due to the rapid accumulation of fluid in the lungs. ECMO is a type of life support that circulates blood through a system that adds oxygen. ECMO was used for the patients in this study because they developed very low blood oxygen levels that developed rapidly despite standard ventilator (or respirator) settings. ECMO is generally used for a limited time because of the risks of bleeding, clotting, infection, and organ failure. The Australia and New Zealand Extracorporeal Membrane Oxygenation (ANZ ECMO) Influenza Investigators in collaboration with the Australian and New Zealand Intensive Care Research Centre at Monash University in Melbourne, conducted an observational study of patients with 2009 influenza A(H1N1)-associated ARDS treated with ECMO in 15 intensive care units (ICUs) in Australia and New Zealand between June 1 and August 31, 2009. The researchers looked at incidence, clinical features, the degree of lung dysfunction, technical characteristics, the duration of ECMO, complications, and survival. The study found that 68 patients with severe influenza-associated ARDS were treated with ECMO, including 53 with confirmed 2009 influenza A(H1N1). An additional 133 patients with influenza A received mechanical ventilation, but not ECMO, in the same ICUs. The 68 patients who received ECMO had a median (midpoint) age of 34.4 years and half were men. "Affected patients were often young adults, pregnant or postpartum, obese, had severe respiratory failure before ECMO, and received prolonged mechanical ventilation and ECMO support," the authors write. The median duration of ECMO support was ten days. At the time of reporting, 54 of the 68 patients had survived and 14 (21 percent) had died. Six patients remained in ICU, including two who were still receiving ECMO. Sixteen patients were still hospitalized, but out of ICU, and 32 had been discharged from the hospital.
"Despite their illness severity and the prolonged use of life support, most of these patients survived," the authors conclude. "This information should facilitate health care planning and clinical management for these complex patients during the ongoing pandemic."
Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. For more information, contact JAMA/Archives media relations at 312/464-JAMA (5262) or e-mail mediarelations{at}jama-archives.org.
JAMA REPORTS
VIDEO: Windows Media | Quicktime
STUDY SHOWS YOUNG AND ELDERLY CALIFORNIANS EXPERIENCED SEVERE ILLNESS, HIGHER HOSPITALZATION RATES AND DEATH FROM EARLY N1N1 FLU
INTRO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
VIDEO:
AUDIO:
TAG: |
|
|
