Tag Archives: influenza

“Ward based PCR”

There are a couple of new systems just on the market which I suspect will revolutionise PCR testing, particularly where an urgent result is desirable. This is often the case when trying to diagnose Influenza and RSV in the acute care setting.

Cepheid and Roche have both released benchtop PCR systems for Influenza and RSV testing which can be placed in the ward/ED environment, requires minimal training and can give you a highly sensitive result for influenza/RSV in well under an hour.

“Highly sensitive” are the key words here. This is in contrast to rapid antigen tests for Influenza and RSV which although can be useful in certain circumstances, are limited in their clinical usefulness by sub-standard sensitivity. RSV and Influenza rapid antigen tests are now living on borrowed time….

The other highlight is “under an hour”. This allows real-time management of the patient in the ED./acute assessment ward (including treatment, isolation, cohorting, discharge etc.) based on the result of the PCR test.

The big downsides of course are the cost and the “one at a time access”. More expensive (the cost will come down)than traditional batched PCRs it might be a while before such testing systems become commonplace. (A lot depends on the funding model of your healthcare system.)

But they will, you can be sure of that.

Michael

Influenza Pandemic: Plan or Panic

I have been keeping half an eye on the current situation with the H7N9 avian influenza strain currently infecting humans in Eastern China. For more details on this click here.

3D_Influenza_virus

The current Outbreak made me ask myself two questions:

  •  If the 1919-20 pandemic Influenza strain (Spanish Flu) emerged in today’s world, would it have the same devastating impact that it had back in 1919?
  •  Is there a chance we could have in the future a pandemic of equal (or greater) severity as the Spanish Flu?

My personal answers to these questions are No and Yes respectively.

The world has changed a lot since 1919. In 1919 there was massive displacement of population following WW1, there was great poverty and there were no antibiotics to deal with post influenza bacterial pneumonia. Nor was there any Influenza vaccines. For these reasons I don’t think the 1919 pandemic strain would have had nearly the same impact today.

But yes, I do think we could potentially have another pandemic as severe as 1919. It would just take a more pathogenic Influenza virus to do this, and we know that antigenic shift and mixing of Influenza strains from different species certainly have the potential of creating very pathogenic viruses. Fortunately most of these strains turn out to have low transmissability between humans.

We have had at least four recognised Influenza pandemics in the past century (Spanish Flu 1919-20, Asian Flu 1957-58, Hong Kong Flu 1968-69, Swine Flu 2009-10). The next one will not be a matter of “If”, but “When”. Fortunately the 2009 H1N1 Influenza pandemic, although very transmissable, was no more pathogenic than the usual seasonal strains.

None of us particularly enjoy putting in a lot of work to plan for something which may or may not happen during our working lifetimes. But this is what needs to happen. I am not saying it is easy either. To try and draft a policy to prepare for an Influenza pandemic of totally unpredictable size and severity is one of the hardest things I have had to do as a microbiologist. Some might say that drafting such a policy is close to impossible. But we need to try, in an attempt to at least reduce the inevitable panic that ensues….

Even though the “Swine Flu” pandemic was relatively mild in pandemic terms, hopefully we will use this recent experience to hone our policies for when the next pandemic strikes.

Michael

“Predicting the Unpredictable”

Even though it is the middle of the summer here in the Southern Hemisphere, it is time to start thinking about the forthcoming Influenza season.

I usually try and predict how “severe” each season is going to be, based on past seasons and what is happening on the other side of the world. However I am wrong as often as I am right. Of some comfort is the fact that people with much more Influenza expertise than me have similar success rates when trying to predict Influenza seasons. It is a little bit like trying to predict the stockmarket. Equally difficult to predict is which individuals are going to suffer from Influenza and which ones are going to get very sick.

However what we can predict is the following:

1) Influenza has the capability of causing severe illness and occasionally death.

2) The Influenza vaccine will give good coverage against most of the circulating Influenza strains.

For the reasons above I happily take my Influenza vaccine thankyou very much. Life is too short to suffer or die from what is a largely preventable illness most of the time.

Michael

Over the next two to three weeks I will be focusing on building up the “resource” part of this website, with powerpoints, tutorials and MCQs etc. To create time for this I will reduce the daily posts to 3-4/week. Any feedback is much appreciated!