I’ve reposted this study in response to the previous posting about the dangers of H1N1 and the regular flu vaccines. I hope the statistics  will give us insite on the chances of catching one and ending up in the hopistal’s ICU.

Critical Care Services and 2009 H1N1 Influenza in Australia and New Zealand conducted by The ANZIC Influenza Investigators and published by the New England journal of Medicine on October 8, 2009.

As of September 6, 2009, the World Health Organization had reported over 277,607 laboratory-confirmed cases of 2009 H1N1 influenza, world-wide with at least 3205 deaths, this study focused on patients that needed critical care on the intensive care units (ICUs) in Australia and New Zealand from June 1 through August 31, 2009.

The study identified 722 patients with confirmed infection with the 2009 H1N1 virus (28.7 cases per million inhabitants) were admitted to an ICU in Australia or New Zealand. 

The study identified infants (0 to 1 year of age) and adults 25 to 64 years of age to be at particular risk. Pregnant women, adults with a BMI greater than 35, and indigenous Australian and New Zealand populations also appeared to have an increased risk. In-hospital mortality, estimated on the basis of data available at the time of this report, exceeded 16%. Patients infected with the 2009 H1N1 virus were in the ICU for a total of 8815 bed-days (350 per million inhabitants). The median duration of treatment in the ICU was 7.0 days (interquartile range, 2.7 to 13.4)

The age-specific incidence rates were highest among infants and adults 25 to 64 years of age. Although the ICU admission varied across the age groups and was low for patients 65 years of age or older, the risk of death increased with increasing age.

A total of 66 of the 722 patients (9.1%) admitted to the ICU with 2009 H1N1 influenza were pregnant women. Of the 722 patients, 669 (92.7%) were under 65 years of age and of the 601 adults for whom data were available, 172 (28.6%) had a body-mass index (the weight in kilograms divided by the square of the height in meters) greater than 35.

Data on existing pulmonary disease were missing for 15 of the 722 patients with 2009 H1N1 influenza in our study; of the remaining 707 patients, 231 (32.7%) had asthma or another chronic pulmonary disease.

Data on the use of mechanical ventilation in the ICU were available for 706 patients; of these, 456 (64.6%) underwent mechanical ventilation for a median of 8 days (interquartile range, 4 to 16).

As of September 7, 2009, a total of 103 of the 722 patients (14.3% ) had died, and 114 (15.8%) remained in the hospital.

The proportion of patients who died in the hospital in our study is no higher than that previously reported among patients with seasonal influenza A who were admitted to an ICU. Patients admitted to an ICU with seasonal influenza A predominantly are elderly and have coexisting conditions. Among patients admitted to ICU, older age, the presence of coexisting conditions, and a requirement for invasive ventilation were independently associated with increased risk of death, but because there were greater numbers of younger patients in our cohort, the majority of deaths occurred in younger patients

The next study was conducted in the U.S. by the 2009 Pandemic Influenza A (H1N1) Virus Hospitalizations Investigation Team and published also by the New England journal of Medicine on the same date, October 8, 2009.

Hospitalized Patients with 2009 H1N1 Influenza in the United States, April–June 2009

Background: During the spring of 2009, a pandemic influenza A (H1N1) virus emerged and spread globally. We describe the clinical characteristics of the patients who were hospitalized with 2009 H1N1 influenza in the United States from April 2009 to mid-June 2009.

Methods: Using medical charts, we collected data on 272 patients who were hospitalized for at least 24 hours for influenza-like illness and who tested positive for the 2009 H1N1 virus with the use of a real-time reverse-transcriptase–polymerase-chain-reaction assay.

Results: Of the 272 patients we studied, 25% were admitted to an intensive care unit and 7% died. Forty-five percent of the patients were children under the age of 18 years, and 5% were 65 years of age or older. Seventy-three percent of the patients had at least one underlying medical condition; these conditions included asthma; diabetes; heart, lung, and neurologic diseases; and pregnancy. Of the 249 patients who underwent chest radiography on admission, 100 (40%) had findings consistent with pneumonia. Of the 268 patients for whom data were available regarding the use of antiviral drugs, such therapy was initiated in 200 patients (75%) at a median of 3 days after the onset of illness. Data suggest that the use of antiviral drugs was beneficial in hospitalized patients, especially when such therapy was initiated early.

Conclusions: During the evaluation period, 2009 H1N1 influenza caused severe illness requiring hospitalization, including pneumonia and death. Nearly three quarters of the patients had one or more underlying medical conditions. Few severe illnesses were reported among persons 65 years of age or older. Patients seemed to benefit from antiviral therapy. 

All credits on these publications are given to the New England Journal of Medicine, the ANZIC Inflienza Investigators, the U.S. 2009 Pandemic Influenza A (H1N1) Virus Hospitalizations Investigation Team and all their affiliates. Reposted for educational purposes only. No copyright infringement intended. Read complete text and references of these studies in their website:  www.nejm.org

Photo source: publicdomainclip-art.blogspot.com

Other H1N1  Related Topics:

Influenza A (H1N1) Facts

How Can I Protect Myself From H1N1?

How do I know if I have influenza A(H1N1)?

What should I do if I think I have the illness?

What about using a mask? What does WHO recommend?

Should I go to work if I have the flu but am feeling OK?

Can I travel?

What about using a mask? What does WHO recommend?