Tag Archives: influenza

“Influenza in NZ 2020: Gone AWOL…”

Confessions of a Microbiologist, , ,

We are currently heading towards the end of July, which is well through the winter respiratory virus season in the Southern Hemisphere. And still we have not seen any Influenza (or RSV for that matter) circulating in New Zealand. At first I thought it was the lockdown through March and April which was blocking viral transmission through social distancing. However we are now a couple of months post-lockdown… Social distancing has essentially all but disappeared and still there is no Influenza and RSV in New Zealand. This must be now due to the fact we have a closed border and the fact that nobody can currently enter New Zealand without staying in a quarantine facility for 2 weeks on arrival. This seems to be blocking any potential influenza and RSV introductions into NZ*

The winter respiratory virus season still has a couple of months to run here, but things are looking very promising. An average influenza season in NZ causes an average of 400-500 fatalities. There is little doubt that RSV will also cause significant mortality in those with advanced respiratory disease and in the frail elderly. I would suspect that respiratory viruses as a group would count for well over 1000 fatalities per annum in NZ, not to mention several thousand hospital admissions. In contrast the 22 COVID-19 fatalities, although tragic, seems a meagre toll…

Clearly we (NZ) cannot keep our international borders closed indefinitely, because human nature will simply not allow it. We do however have to be very smart about re-opening our borders, using all the risk mitigation tools we can lay our hands on. We have a nation of 5 million COVID-19 virgins to look after, but that is another story.

When the borders do re-open can we still control the winter influenza season? We may not be as successful as we have been this year but I think 2020 has shown that control of seasonal influenza is entirely possible by trying to minimise “introductions” and their subsequent effects.  I would suggest the following measures:

  • Having a low threshold for testing, treating(oseltamivir) and isolating  travellers coming back into New Zealand who have respiratory symptoms
  • Influenza & RSV in returning travellers should be notifiable to Public Health so that the appropriate measures can be taken.
  • Influenza vaccination should be strongly encouraged for travellers coming into New Zealand, particularly those coming from the Northern Hemisphere
  • Routinely vaccinate all children to further reduce the chances of transmission, should any introductions occur

Put quite simply, we set the bar too low for seasonal influenza control in NZ. We regard the winter influenza season as an inevitability. We shouldn’t. We are a small island nation, and our COVID-19 response has shown that we can be united and disciplined when we want to be!

“We set the bar too low for seasonal influenza control in New Zealand”

Let’s make the NZ winter influenza season the exception as opposed to the rule…

Michael

Interestingly rhinoviruses, although much suppressed during the lockdown period, survived and are now flourishing, and possibly filling a niche created by the influenza and RSV vacuum. See this interesting blog post from Australia

 

“The Sputum Factory”

Confessions of a Microbiologist, ,

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”

Confessions of a Microbiologist, The Wandering Microbiologist, ,

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