Wednesday, October 28, 2009

The Tip Of The Iceberg

 


# 3896

 

 

A reoccurring theme in this blog over the past 5 months or so has been that we really don’t have a very good handle on the number of people who have died from the H1N1 virus. 

 

While the WHO lists `at least’ 5,000 deaths  and the US count from the CDC is  `more than 1,000’, these number are incomplete, and don’t represent the full toll of this virus.

 

And the WHO and the CDC say that with every release of their numbers, but apparently a number of people don’t `get it’. They insist on using those numbers to `prove’ that H1N1 isn’t much of a pandemic or worthy of our concern.  

 

After all, these are `official’ numbers.

 

I’ve laid out my reasoning before on why we undercount deaths, most recently in Dead Reckoning, but before that in Numbers Don’t Tell The Whole Story, and  A Decided Lack Of Data

 

The World Health Organization has numerous documents on global mortality statistics available here, but the repeated caveat in all of them is the `lack of completeness and coverage’. 

 


The WHO can only guesstimate the number of people who die every year from malaria, AIDS, dysentery, or  heart attacks.  They are no better able to report the number of deaths due to influenza.

 

Even in the US, where more than 6,000 people die every day, the number of deaths attributed to the H1N1 virus is most certainly an undercount.  When it comes to influenza, only pediatric P&I (pneumonia & influenza) deaths are required to be reported. 

 

And those numbers are considerable elevated since the emergence of H1N1. 

 

image

 

Unless an adult dies in the hospital while under treatment for influenza or pneumonia, their deaths are unlikely to be linked to the H1N1 virus. 

 

And even those deaths are not required to be reported to the CDC.

 

When we get reports out of China, Asia, Russia, or countries in Africa stating the number of H1N1 related deaths, that information has to be tempered with the knowledge that most of these countries do limited surveillance, and reporting.

 

Today, in the China Daily newspaper, we get a WHO official that states pretty much the same thing. That the number of deaths from H1N1 in China (and in the world) are badly undercounted.

 

A hat tip to Shiloh on FluTrackers for posting this report.  

 

H1N1 deaths 'tip of iceberg'

By Shan Juan (China Daily)
Updated: 2009-10-28 07:58

The death toll on the Chinese mainland and around the world from the H1N1 flu virus could be much higher than previously thought, experts warned yesterday.

 

The World Health Organization's representative in China, Michael O'Leary, said the number of reported H1N1 fatalities may be the "tip of the iceberg".

 

He made the warning yesterday, one day after the mainland reported its third official H1N1 death.

 

O'Leary said the fact that many deaths around the world are not being scrutinized with lab tests means most H1N1 deaths likely go unrecorded.

 

So far, the world has reported 5,000 H1N1 deaths.

 

Zeng Guang, chief epidemiologist with the Chinese Center for Disease Control and Prevention (CDC) agreed, saying lab limitations mean some flu deaths may not be followed up in the lab.

 

"So far, no clear evidence can prove that, but the underestimation of H1N1 deaths, if it is happening, is definitely not intended," he said.

 

The Hong Kong Health Department has estimated that the number of undiagnosed flu cases could be 25 times higher than the official number. The mainland has not estimated how many cases slip under the radar.

 

(Continue . . . )

 


This article uses the .4% CFR (4 in 1000) as an estimate, but again, no one really knows what that number is. 

 

Seasonal flu is thought to claim about 1 life in 1,000 (.1% CFR) infections.  But that varies from year to year, and once again, that is an estimate (and by no means universally accepted).

 

Here in the United States, and in most of Europe, a .4% CFR is probably far too high.  In China, or Africa, that number could actually be low.   It is just too soon to tell.

 

The CDC is intentionally vague on the number of H1N1 deaths in the US, simply because they know that they aren’t counting all of the cases.  

 

But what seems abundantly clear is that we aren’t seeing huge numbers of deaths. This pandemic (for now) appears on a par with 1968 (or perhaps 1957),  but certainly not 1918.

 

After this pandemic is over, I’m sure analysts will dissect the existing records and try to come up with a better number.

 

But even so, that will be an estimate, not an actual count.   And that number will no doubt spark debate for years to come.