Influeza/MRSA a fatal combination

[Skeptic Ginger]

In 2005 CA-MRSA was described as:

Press Release - 04 April 2005; Community MRSA is re-emergence of 1950s pandemic, study suggests

Pandemic bug returns as community MRSA strain

If I get time later this weekend I'll see if I can find infection rates in the 50s and today to see where we are at in the pandemic currently.

 

[Skeptic Ginger]

No, though I can understand how you may have got that impression from my post.



Yes.

If there was a forth 5-year interval then it would be possible to determine if the growth is closer to exponential or linear.

For example, the effect of improved monitoring and reporting over time could give an impression of accelerating growth.

CA-MRSA cases have increased exponentially, Ivor. But by all means, go and confirm that for yourself. Heaven knows the number of sources I have cited so far have not made that clear.

 

[Ivor the Engineer]

CA-MRSA cases have increased exponentially, Ivor.

<snip>

Ok.

What is special about co-infection with influenza which makes it so lethal? Or would any severe co-infection lead to a similar mortality rate?

 

[T.A.M.]

Ok.

What is special about co-infection with influenza which makes it so lethal? Or would any severe co-infection lead to a similar mortality rate?

That is a very valid question, and one I was trying to get at in some of my earlier posts.

For instance, if a simultaneous Herpes Zoster (Shingles) infection would produce similar mortality, or if a community acquired Bacterial Pneumonia co-infection would, then the influenza is merely one of many catalysts that provides the opportunity (through immune overexhaustion so to speak).

TAM

 

[Eos of the Eons]

Because it's hard to treat, MRSA is sometimes called a "super bug."

...the average age of a person with CA-MRSA was only 23

This form, community-associated MRSA, or CA-MRSA, is responsible for serious skin and soft tissue infections and for a serious form of pneumonia.

The Lung Association’s Faces of Influenza campaign aims to put a “face” on influenza (the eighth leading cause of death when combined with pneumonia)

Pneumonia is what kills the most people after they get the flu. MRSA caused pneumonia is very deadly, especially for young people. It is a growing concern when it was rarely a concern before.
http://abcnews.go.com/Health/ColdFlu/story?id=4727218&page=1

Contracting both the flu and MRSA at the same time is far more than simple coincidence, scientists believe. Rather, they suspect that the damage inflicted on the lungs and airways by the flu virus allows MRSA germs to sneak into vulnerable tissues and gain a foothold.

MRSA used to be rare outside of hospitals. Now it is getting more common.

 

[CFLarsen]

Ah, so now we are "in" the pandemic already.

It sure spreads quickly!!

 

[Eos of the Eons]

It is a superbug, with very little standing in its way.

 

[CFLarsen]

Ebola qualifies, too.

We have a lot of "pandemics", it seems.

 

[T.A.M.]

That is a very valid question, and one I was trying to get at in some of my earlier posts.

For instance, if a simultaneous Herpes Zoster (Shingles) infection would produce similar mortality, or if a community acquired Bacterial Pneumonia co-infection would, then the influenza is merely one of many catalysts that provides the opportunity (through immune overexhaustion so to speak).

TAM

Sorry. Of course, I meant non MRSA CAP.

TAM

 

[Cuddles]

Ebola qualifies, too.

We have a lot of "pandemics", it seems.

I was unaware of the rapidly rising number of ebola infections being reported in hospitals throughout the western world. Do fill us in on that.

 

[Eos of the Eons]

What stand in Ebola's way is the fact that it is sooooo deadly. A microbe that doesn't let its hosts survive long enough to spread it around beyond isolated villages isn't going to cause a pandemic. MRSA is an opportunist though. It can be spread around a lot before a host is taken down by something like the flu-allowing MRSA to bring the host down permanently.

 

[CFLarsen]

If the qualification for a pandemic is that X is a superbug, with very little standing in its way, then ebola qualifies as a pandemic. But we don't have an Ebola pandemic.

It always helps to read what people say in context.

It is particularly Ebola's quick rate of mortality that makes it so dangerous. While we are lucky that it originated in remote villages, there is nothing that prevents it from spreading to larger towns: It can evolve into something that kills more slowly, thereby giving it time to spread.

Even if it doesn't, the mere fact that people are able to travel around the globe in a very short time makes it dangerous to even go into the areas. If you take the disease with you, it can spread all over the world in a matter of days.

 

[Eos of the Eons]

If the qualification for a pandemic is that X is a superbug, with very little standing in its way, then ebola qualifies as a pandemic. But we don't have an Ebola pandemic.

I never said that was a qualification for a pandemic. I only meant it as one reason why it has led up to a pandemic. Superbug is most definitely NOT a qualification. Superbug plus not killing the host too quickly, and most often not killing the host until it has a unique opportunity are possible reasons (not qualifications) why it can become a pandemic, but are not qualifications. Ebola is very most unlikely a kind of superbug that could ever become pandemic. Superbug alone is never a qualificaton for a pandemic.

Reasons and situations can lead to pandemics, but reasons and situations are most definitely not qualifications.

The qualifications have already been posted.

You, Claus my dear, have not given adequate reasons why MRSA is not pandemic.

 

[Skeptic Ginger]

Superbug in this case is a newspaper/lay person term. It is not relevant to the science involved. However, what has made CA-MRSA reach pandemic levels is the fact that the PVL producing gene has been extremely successful giving it an evolutionary advantage. This has led to staph a. with this gene being more pathogenic and led to it spreading worldwide.

What is interesting is the question of why did a similarly greater pathogenic staph a. strain become a worldwide pandemic in the 50s and what made the pandemic subside? I'll be doing some more investigating of this and will post about what I find in this thread, if I find anything.

Links I have already posted addressed your questions, Ivor, about the reason the influenza and MRSA are synergistic. It's obvious a couple of people are posting objections to the thread discussion without bothering to read much if any of the supporting citations. And TAM, you also seem to have missed the citations which clearly explained this was a co-infection occurring, not a secondary infection. And a similar synergistic co-infection with staph.a. happened in the '68 Hong King flu pandemic as well.

While many articles use co-infection to refer to secondary infection, several have begun using the terms to mean two different things.

 

[Skeptic Ginger]

If the qualification for a pandemic is that X is a superbug, with very little standing in its way, then ebola qualifies as a pandemic. But we don't have an Ebola pandemic.

Tsk tsk. Such an obvious false analogy. Not to mention the error in 'set logic'. Because a pandemic organism is described as a superbug (even if it were a scientifically valid term and even if 'superbug' was a prerequisite for a pandemic organism which it is not) does not mean all superbugs are going to be pandemic organisms.

It is particularly Ebola's quick rate of mortality that makes it so dangerous. While we are lucky that it originated in remote villages, there is nothing that prevents it from spreading to larger towns: It can evolve into something that kills more slowly, thereby giving it time to spread.

You are ignoring a basic rule of infectious disease, the more rapidly something kills its host, the less likely it will have time to spread. And no one knows what ebola is capable of evolving into. Not every pathogen evolves equally easily.

One reason ebola has spread in the populations it did was because the villagers involved had a ritual of washing the bodies of dead relatives. That exposed them to infectious body fluids. Once that was discovered, the spread of ebola was curtailed. The WHO sends in a team to address ebola outbreaks and as they did with SARS, outbreaks of these organisms which are rapidly fatal are amenable to control measures by the world's public health teams.

Even if it doesn't, the mere fact that people are able to travel around the globe in a very short time makes it dangerous to even go into the areas. If you take the disease with you, it can spread all over the world in a matter of days.

Yes, and that occurred with SARS. But what didn't occur were mild undetected spreaders. Everyone with ebola and SARS pretty much became so ill they were visible to the health care community. If people had mild cases of SARS we would have had a much harder time stopping the multiple outbreaks. Same with ebola.

Staph a. bacteria are universal and they frequently share genes. Influenza is universal and occurs seasonably in just about every corner of the globe. SARS and ebola have completely different characteristics.

 

[Skeptic Ginger]

Regarding the synergism between these 2 organisms vs other secondary bacterial pneumonias with influenza:

Co-infection of Staphylococcus aureus or Haemophilus paragallinarum exacerbates H9N2 influenza A virus infection in chickens

Abstract
H9N2 influenza viruses are frequently isolated from chicken meat and bone marrow imported from China to Japan since 2001. These isolates were experimentally inoculated into specific pathogen-free chickens intranasally. Viruses were recovered from the meat and bone marrow of birds showing no overt signs. On the other hand, chickens co-infected with H9N2 virus and either Staphylococcus aureus or Haemophilus paragallinarum showed clinical signs severer than those shown by birds infected only with the virus alone or each of the bacteria alone. In addition, H9N2 viruses were more efficiently recovered from the chickens co-infected with S. aureus or H. paragallinarum than those from the birds infected with only the virus. The present results indicate that co-infection of H9N2 influenza virus with S. aureus or H. paragallinarum enhances the replication of the virus in chickens, resulting in exacerbation of the H9N2 virus infection.

Co-infection of the cotton rat (Sigmodon hispidus) with Staphylococcus aureus and influenza A virus results in synergistic disease

 

[Skeptic Ginger]

Once again for Ivor on the numbers:

“Influenza-Associated Pediatric Mortality in the United States: Increase of Staphylococcus aureus co-infection”
L Finelli et al. Pediatrics October 2008

...researchers reviewed Centers for Disease Control (CDC) demographic, clinical and laboratory data on influenza-associated pediatric deaths during the three flu seasons between the fall of 2004 and the spring of 2007. During each flu season, the number of influenza-S. aureus co-infections increased – 2 percent, 6 percent and 30 percent, respectively.

So in the coming 2008 flu season given that curve we could see an increase on the order of several hundred percent.

 

[Skeptic Ginger]

And more on the growing number of cases for Claus:

Methicillin-resistant Staphylococcus aureus: An emerging problem in horses? 2003

That's people, horses, pigs, countries on every continent, distinguishing genetics accounting for the pandemic and a specific trend in flu/CA MRSA synergistic co-infections.

That is what is referred to as a pandemic.

 

[CFLarsen]

I think I have given every reason why MRSA is not a pandemic, e.g., we haven't seen pandemic alerts from the big health organizations such as WHO. Just because some people are anxious to proclaim that it is one doesn't make it one.

I also think I pointed out that if the qualification for a pandemic is that X is a superbug, with very little standing in its way, then ebola would also qualify.

I also think it wasn't me who pointed to superbugs.

I also haven't ignored the problem of an infectuous disease killing too fast. To quote myself:

It is particularly Ebola's quick rate of mortality that makes it so dangerous. While we are lucky that it originated in remote villages, there is nothing that prevents it from spreading to larger towns: It can evolve into something that kills more slowly, thereby giving it time to spread.

Even if it doesn't, the mere fact that people are able to travel around the globe in a very short time makes it dangerous to even go into the areas. If you take the disease with you, it can spread all over the world in a matter of days.

As we saw with SARS.

There are mild cases of SARS. Mortality is max 1% in those under 25 years, and rises to 15% in the 45-64 year group. It is more than 50% in the oldest group 65 years and up, mostly due to previous illness that leave them weak. Mostly, people aren't infectuous after 10 days after the fever has gone down.

Compare to Ebola, who can kill a person within 2 days, with far more devastating damage to the body.

Now, can we cut the manure? MRSA, serious as it is, is not a pandemic.

 

[EHocking]

...What is interesting is the question of why did a similarly greater pathogenic staph a. strain become a worldwide pandemic in the 50s and what made the pandemic subside? I'll be doing some more investigating of this and will post about what I find in this thread, if I find anything....

The World Health Organisation's Epidemic and Pandemic Alert and Response pages could probably help you.

There's an article on the need to increase stocks and/or capability to produce pneumonia vaccines on the premise that a pandemic is not out of the question. Concern being that current maximum production might be enough to vaccinate 600million people and if we start now there may be sufficient capability to vaccinate 1/3 of the word's population in the event of a pneumonia/MRSA pandemic. . . . in 3 to 4 years.

I have to admit that I was beginning to think that the opening posts of this thread were edging towards the hysterical - then I read the reports at the WHO site which are rather sobering.