# 4556
Although many observers have been quick to pronounce the pandemic H1N1 virus of 2009 as being `mild’, `overhyped’, or even a `non-event’ - the gathering and analysis of the data on its global impact is still in its early stages.
As expected, the virus has produced a wide spectrum of illness. And it hit some regions and peoples harder than others.
A scenario I blogged (somewhat acerbically) about a year ago in A Tale of Two Pandemics.
While I believe the jury is still out on what this virus ends up doing, pundits who snort, and write about the H1N1 virus with derision and scorn, may actually have a point.
At least if you are relatively well off financially, live in a developed country with good medical care, are in relatively good health, and are older than the `target age’ for this virus – which seems to be from about 5 years – to 24 years of age.
If you meet these requirements (and shouldn’t everybody?), then this virus understandably scores pretty low on your daily threat assessment.
As more data comes in we are learning just how complex and diverse the effects of the pandemic have been around the world.
One such study was published yesterday in Plos One, entitled:
Pandemic Influenza (H1N1) 2009 Is Associated with Severe Disease in India
Akhilesh C. Mishra*, Mandeep S. Chadha, Manohar L. Choudhary, Varsha A. Potdar
National Institute of Virology, Pune, IndiaAbstract
Background
Pandemic influenza A (H1N1) 2009 has posed a serious public health challenge world-wide. In absence of reliable information on severity of the disease, the nations are unable to decide on the appropriate response against this disease.Methods
Based on the results of laboratory investigations, attendance in outpatient department, hospital admissions and mortality from the cases of influenza like illness from 1 August to 31 October 2009 in Pune urban agglomeration, risk of hospitalization and case fatality ratio were assessed to determine the severity of pandemic H1N1 and seasonal influenza-A infections.
Results
Prevalence of pandemic H1N1 as well as seasonal-A cases were high in Pune urban agglomeration during the study period. The cases positive for pandemic H1N1 virus had significantly higher risk of hospitalization than those positive for seasonal influenza-A viruses (OR: 1.7). Of 93 influenza related deaths, 57 and 8 deaths from Pune (urban) and 27 and 1 death from Pune (rural) were from pandemic H1N1 positive and seasonal-A positive cases respectively. The case fatality ratio 0.86% for pandemic H1N1 was significantly higher than that of seasonal-A (0.13%) and it was in category 3 of the pandemic severity index of CDC, USA. The data on the cumulative fatality of rural and urban Pune revealed that with time the epidemic is spreading to rural areas.
Conclusions
The severity of the H1N1 influenza pandemic is less than that reported for ‘Spanish flu 1918’ but higher than other pandemics of the 20th century. Thus, pandemic influenza should be considered as serious health threat and unprecedented global response seems justified.
The entire study is available online for your perusal.
Although these researchers peg the CFR (Case Fatality Ratio) of novel H1N1 as being significantly higher than seasonal influenza, this is a limited study and considerable controversy exists over the best way to count (or more precisely, estimate) seasonal and pandemic CFRs.
The observation that this pandemic was less severe than 1918 (by a wide margin) seems self-evident.
The author’s assertion that 2009 was more severe than the other pandemics of the 20th century is more controversial, as is their comparison of the virus’s CFR to a CDC Category 3 pandemic.
Although, if we use YLL (Years of Life Lost), the costs of the 2009 pandemic appear to equal or exceed 1968, and may be approaching that of 1957.
For more on YLL calculations,and other measures of pandemic severity, see:
When Words Fail Us
The Measure Of A Pan
There’s No Flu Like A New Flu
Study: Years Of Life Lost Due To 2009 Pandemic
Again, it will take time and analysis before we will know with any degree of certainty the real impact of the novel H1N1 virus. This is but one study, and not the final word.
And lest we forget, the pandemic is still ongoing.
The final chapter may not have been written, and may not be for a couple of more years.
