While the COVID-19 pandemic may be over, our concerns about another virus leading to another one will likely never go away. What viruses are concerning doctors and health officials now? Here to discuss current health concerns is infectious disease specialist Dr. Michael Calderwood, chief quality officer at Dartmouth Hitchcock Medical Center.
By Rosemary Ford and Caitlin Agnew
This article has been edited for length and clarity.
Melanie Plenda:
As an infectious disease specialist, how are things looking this season? What are you watching and what are your concerns?
Michael Calderwood:
We often see in the winter months, and particularly after the holidays at the end of December, an increase in a number of viral illnesses, many of them hitting at the same time. Things like the common cold — which is caused actually by a few different viruses — flu, RSV and norovirus and the impact that's had on families.
Melanie Plenda:
In terms of bird flu, what is concerning about this virus, and why are we watching human cases so closely?
Michael Calderwood:
Avian influenza, which goes by the other name H5N1, can cause very severe illness in animals and has the potential to be transmissible to humans. We have seen cases, and have now recorded our first death from avian influenza in the United States.
That individual who died was older and had some comorbidities, and so it wasn't unexpected that they might have a more severe outcome from that illness. The worry is that if it were to mutate and become more transmissible — meaning that we have human to human transmission or spread in communities — it can cause very severe illness. Also, it has that potential to cause a pandemic that is what is worrying.
Melanie Plenda:
Can you tell us more about the recent human cases?
Michael Calderwood:
Up until this point, we have seen fairly mild illness, and when we think about avian influenza, a lot of what we have seen is individuals who are working with animals — it may infect things such as the eyes from direct contact or cause mild respiratory illness. This individual ended up with a severe lower respiratory tract illness, ended up in an ICU and died. Again, that is the severe form, and as this mutates, the worry as we could see more of that.
Melanie Plenda:
How are health officials tracking this and other cases of flu?
Michael Calderwood:
We have the ability to test for all the different types of flu, so when individuals come into health care — whether that be seeing a provider in the outpatient setting or coming into an emergency or hospital setting — we can test for flu and tell what type of flu it is. There is state-level and national-level testing actually looking to characterize what is circulating. That's gone on for years, because it's important to know what's circulating so that we can match the vaccines and make sure that we are updating those each year.
Melanie Plenda:
What about COVID? Is that still a concern this season?
Michael Calderwood:
If you look at the respiratory viruses that are circulating right now, COVID is actually the lowest that it has been in recent years, and a lot of that is related to population immunity, much through vaccination.
We are seeing more influenza — that began to peak a little bit about a week earlier than it has in years past. RSV is about 20% higher this year. And we are seeing a number of other viruses. I will say that we actually have tests for a lot of viruses that we didn't routinely use in past years. We would always say, ‘“This is just the common cold,”, but not test for it. Now we can put a name to it and say what is circulating. It doesn't mean it wasn't always there. It just means that we are detecting it more on tests.
Melanie Plenda:
We’ve also heard a lot recently about norovirus. Can you tell us more about what that is and why it’s concerning?
Michael Calderwood:
Norovirus is a highly transmissible virus, and it causes a gastrointestinal illness. It really attacks pretty much the entire family, if one were to get it. When it comes into a household, you see pretty much everyone in the family falling ill. It's about 48 hours, typically, in terms of its duration. But that 48 hours is very severe. You're having vomiting and diarrhea at the same time, feeling very rundown and fatigue. We tend to see over time that new strains will emerge. This is the first new strain in about seven years.
Prior to this, people who had been exposed to norovirus had some level of immunity and maybe didn't have as severe of an illness. With this new strain being introduced into the population, this year is worse for norovirus, and a lot of people's holiday plans were unfortunately disrupted by this. I've described this as being quite memorable. Thankfully, my family and I have not suffered this time, but we have had it in the past, and it is definitely something that sets you back when it runs through your family.
Melanie Plenda:
How worried should we be about that?
Michael Calderwood:
I would say that this is a natural trend, that every decade or so you're going to see a new strain that develops. This is running its course. I would say that I'm not particularly worried long term about the impact of this.
Melanie Plenda:
What should we do to stay healthy?
Michael Calderwood:
So there are a number of things. Obviously, as the weather turns cold, we're going to spend more time inside and gather with others. As we've learned in years past, when you are ill you're at risk of transmitting that illness to others, and particularly respiratory illness. So staying home when you're sick, thinking about wearing a mask to protect others when you need to go out in the community. Frequent hand washing is critical at all times, but particularly in the winter months, when we know that we have more of these illnesses that are spread by secretions, such as a runny nose.
Then, as we think about things like norovirus, washing hands with norovirus is best with soap and water. Alcohol-based hand rubs are very good for respiratory viruses, but norovirus in particular requires soap, water, and bleach is important for cleaning the environment. I also mentioned food-handling, and at any time you want to be thinking about how you are handling raw food and how you're washing your hands.
Melanie Plenda:
When should we seek medical help?
Michael Calderwood:
When you are feeling ill — a lot of us kind of have a sense. So if we begin to have difficulty breathing - many people these days actually may have the ability to measure their oxygen at home — If you see your oxygen levels are dropping. Obviously, if people are having difficulty breathing while they sleep, or if you see anyone that appears to be changing color. These are very severe things that you'd want to bring people into the hospital for.
But the other thing is who might benefit from treatment? We have medicines for flu, we have medicines for a number of different conditions. and so coming in to be tested, we can treat your COVID, we can treat your flu — and particularly if you have underlying illnesses that would predispose you, whether it be your age or your diabetes or medicines that suppress your immune system — we can help to protect you, get you better sooner if you take these medicines.
Melanie Plenda:
Has the pandemic changed or had an impact on the way the hospital responds to these and other virus concerns?
Michael Calderwood:
What was interesting is that we actually had pretty good systems in place even before the pandemic. We are always taking a global look and seeing what might be on the horizon.Obviously, a lot of this grew out of earlier pandemics, whether this be from the initial SARS or from the risk of Ebola, or even the 2009 H1N1. We have teams that are meeting regularly to say, “What do we need to be concerned about that is coming around the corner?”
I actually remember the initial conversations in December 2019 as we began to see the emergence of SARS COVID 2, the virus that causes COVID. But we had systems in place to say, “How do we begin to screen people? How do we make sure that we are setting up the hospital to be able to handle that?” Obviously, the pandemic made us strengthen some of those systems. I am worried about the fact that we are reducing some of our public health infrastructure at a time when it will increasingly be necessary, but I would say that the hospitals continue to be on a footing of preparedness.
Melanie Plenda:
What about society as a whole? Should we think about changing the way we live or vacation or work when we see some of these things?
Michael Calderwood:
I would say that you always want to be looking at where you're traveling and what might be circulating, and for particular places, it is helpful to get some pre-travel consultation. We here at Dartmouth Health have a travel clinic and can help to think about vaccines and medicines you might take to protect yourself during your travel.
The other thing is to understand the availability of health care resources where you're going, particularly if you take medicines and have underlying illness, understand if you were to fall sick, how would you get help? What are the hospitals? How could you fly home if you were sick? These are standard things I would say for anyone who is traveling, not that I'm particularly worried and saying don't travel to location X, Y or Z at the present time, but it's always important to understand what is in those areas you might be traveling to.
I love to travel. I think travel is something that we can do a lot more of, and it's nice to be able to get back to it after the pandemic, but we just think about how we do it safely.
Melanie Plenda:
That was fascinating. Infectious disease expert Dr. Michael Calderwood, chief quality officer at Dartmouth Hitchcock Medical Center, thank you so much for joining us today.
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