Tag Archives: RSV

“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

 

“Ward based PCR”

Future of Microbiology, , ,

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