Tag Archives: influenza

“The Sputum Factory”

It is the peak of the (Southern Hemisphere) influenza season here in New Zealand. Influenza has come early this year, and the season has been relatively busy to date, with a fairly even mix of Influenza A&B.

And it is not just influenza, there is plenty of circulating RSV, rhinoviruses and all those other less well known respiratory viruses that we know best by their appearance on extended respiratory viral panel menus.

However it is not just GPs and Emergency departments that feel the effects of the wave of respiratory viruses during the winter season. Microbiology departments get a surge in sputum samples arriving at the laboratory. Recently it has felt like my laboratory is simply a sputum processing factory!

And this is because any microorganism which infects the respiratory epithelial cells (bacteria or viruses) will inflame the respiratory epithelial cells and increase the production of “purulent” sputum. It doesn’t matter whether it is a bacterium or virus. Can the sputum colour discriminate between the two?? Only in the textbooks…

Sputum for bacterial culture is one of my least favourite microbiology samples! This is not just because of its appearance, but more because it suffers from appalling sensitivity and specificity when diagnosing bacterial pathogens, even when a pre-screening Gram stain is performed, as many labs do nowadays.

If sputum culture was subject to to FDA approval as a “diagnostic assay”, it wouldn’t have a prayer…

During the winter season when respiratory viruses abound, the prevalence of bacterial infection in the tested population will be relatively lower, with a consequent further deterioration in positive predictive value.

There are many guidelines that show the extremely limited value of sputum culture, particularly from the community setting, for the management of non-specific cough symptoms, acute bronchitis, and COPD. The most common clinical details we receive on sputum samples are things like “Cough”, “cough with purulent sputum”, “COPD”, or simply nothing at all. Yet we still accept these samples without question.

As a profession, sometimes I think we are too soft…

My lab is planning to introduce restrictions on what sputum samples are acceptable from the community setting, according to the published guidelines, so hopefully by next winter, we will be a haven of tranquility as opposed to a sputum processing factory.

Michael

Apologies for the picture, but it had to be done!

 

“Flu in Kathmandu”

When I was offered the chance to go to a WHO influenza meeting in Kathmandu, I grabbed it with both hands. Such opportunities certainly don’t come by every day…

However the trip to Nepal did not get off to the best of starts.

On the flight to Kathmandu, I started to get toothache. By the time we landed I was in agony. The pain was compounded by the fact that my suitcase didn’t make the connection at Singapore. Ouch!

Things could only get better…

However my initial impressions of Kathmandu did little to lift my spirits. There were three power cuts in the first 24 hours, apparently a hangover from the 2015 earthquake. I had to pass on coffee in my hotel room as the tapwater had a distinct greeny brown tinge to it. I then attempted to do some initial exploration of the city on foot, but crossing roads in this city is not for the faint-hearted! Eventually fatigue and my nerves got the better of me and I retreated to the safer confines of my hotel room, wondering just what I had got myself into…

But things did eventually improve (as they almost always do!). The conference started the next day and it was good to focus for a change on just one microbiological subject (influenza) for two and a half days, as this allowed the acquisition of some in-depth knowledge. It was also good to speak to representatives from countries that I have very little knowledge of and have certainly never met anybody from before , i.e.  Timor Leste, Mongolia, Bhutan. The Nepalese people themselves were very friendly and as most of them knew a little bit of English, it was easy to strike up a conversation.

And my suitcase eventually turned up, albeit the day before I was due to leave (carry-on bag next time!). As for my toothache, the hotel concierge kept me going with a steady supply of paracetamol, which took the edge off the pain and allowed me to function. I fear a visit to the dentist will be required though on return to NZ.

The highlight of the whole trip was the final day visit of local hospitals, public health laboratories, and the Nepal National Influenza Centre. This was a fantastic opportunity to meet local laboratory professionals, and to discuss what particular challenges they faced in a sometimes challenging environment. I was extremely impressed at the systems they had in place.


“Lab and hospital tour in Kathmandu”

So despite the challenges the trip turned out to be hugely educational, both in an academic and cultural sense. I learnt a good deal about Influenza, and even more about Nepal. It is very different to New Zealand! I look forward to going back there one day,  hopefully to do some trekking in the Himalayas.

And I have made a new resolution:- to attend at least one microbiology conference a year in a place I have never been to before, even if I have to pay for it myself.

Michael

 

“Susceptibility to Influenza”

If you live in the Northern Hemisphere you may have found that your laboratory was swamped by incoming influenza tests this season?

You would not be alone.

Influenza is an unpredictable beast. In my own neck of the woods, New Zealand, the 2015 season was busier than usual, the 2016 season was almost non-existent, and the 2017 season was very average.

Nobody knows what will happen with influenza during 2018.. (Note that as NZ is in the Southern Hemisphere, our winter is June, July , August, right in the middle of the year).

Often you will see Influenza “experts” on TV making predictions about how severe the forthcoming influenza season will be. However such predictions come with huge pinches of salt. You might well be better off predicting the stock market…

The truth is that we don’t really know how bad the forthcoming influenza season is going to be, whether you are an expert or just an interested bystander.

And as a result we have no idea how much each influenza season is going to cost a diagnostic laboratory that performs influenza testing.

Let’s say a bog standard Influenza/RSV PCR costs approximately $30. In a quiet season 1000 tests might get performed in a medium sized hospital. However in a busy season 5000 tests might be required, with an excess cost of $120000. This would of course cause the laboratory manager some sleepless nights!

I am glad I am not a laboratory manager..

And then there might be an influenza pandemic…

The same goes for Public Health Laboratories. The numbers of samples coming in for antigenic sub-typing will be closely related to the severity of the influenza season.

Contracts that laboratory providers have with healthcare funders need to take this unpredictability into account. Some sort of clause like “The diagnostic laboratory will perform up to X Influenza PCRs during the Influenza season. If this number is exceeded, further funding will be negotiated”. Unfortunately this is often not the case. Often laboratory providers will be so desperate to get the contract signed and sealed that they will accept these risks, and manage such problems reactively.

From a financial point of view, microbiology laboratories are very susceptible to influenza test volumes, just like they are susceptible to emerging diseases and MDROs, cohorts where “unexpected testing” may need to take place.

There will of course be some laboratories who are reimbursed per test performed (fee for service). Those places of course would be hoping for a pandemic every year!, but such laboratories/funding arrangements are getting less and less common. The funders are not daft!

I hope for a quiet influenza season this year, and that is nothing to do with my personal risk! (I look forward to receiving the quadrivalent vaccine in the next couple of months).

Michael