Public Health

What illnesses are going around? RSV, COVID-19, influenza, measles outbreak, plus avian flu news [Podcast]


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AMA Update

What illnesses are going around? RSV, COVID-19, influenza, measles outbreak, plus avian flu news

Apr 17, 2024

Which states have found bird flu in dairy cows? Why is measles coming back? What states are having a measles outbreak? When is respiratory virus season over?

Our guest is AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH. American Medical Association Chief Experience Officer Todd Unger hosts.


  • Andrea Garcia, JD, MPH, vice president, science, medicine & public health, American Medical Association

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Unger: Hello, and welcome to the AMA Update video and podcast. Today we have our weekly look at the headlines with the AMA's Vice President of Science, Medicine, and Public Health, Andrea Garcia. I'm Todd Unger, AMA's chief experience officer. Welcome back, Andrea.

Garcia: Thanks, Todd. It's great to be here as always.

Unger: Well, let's begin where we left off last week, and that's with bird flu. Andrea, what updates do we have on that topic?

Garcia: Well, that virus is continuing to spread among cattle, but I think the good news is there have been no new reports of human infection here in the U.S. There was some news according to the CDC that Vietnam has reported its first human infection with a low pathogenic avian influenza virus, that's H9N2.

It's a different subtype of avian flu than the highly pathogenic avian flu that's most reported globally and that's causing the outbreaks in poultry and cattle here in the U.S. At this time, there is no indication that this human infection in Vietnam is causing person-to-person spread or poses a threat to U.S. public health.

Unger: Well, that's good news. On the other hand, you did mention increased spread here among cattle, and that's obviously a problem. What is that looking like?

Garcia: There was a report in Reuters that indicated North Carolina and South Dakota became the seventh and eighth states to identify avian flu in a dairy herd. And just as a reminder, when we talked last week, the USDA had reported infections across six states, so Texas, Kansas, Ohio, Michigan, Idaho and New Mexico.

So now we're seeing dairy farmers across the country going on the defensive to try and prevent further spread. Many are banning visitors and disinfecting vehicles coming onto their land. Some are even cutting down trees to discourage wild birds from landing, since that first case in Texas and Kansas appear to have originated with birds.

Many are increasing their safety and cleaning procedures. In that Reuters article, one dairy farmer described her farm as a gated community for cows, where only the most essential people are allowed to go since people can unintentionally contribute to that spread by carrying in contaminated bird droppings on their boots or on their vehicles. The good news is that, as we discussed last week, cows do seem to recover, whereas the disease is lethal in poultry.

Unger: I never thought I'd heard that term gated community for cattle, but I understand folks wanting to protect their herds, and that's a big problem. So we'll continue to pay attention to this. Has the increased spread change the risk at all to people?

Garcia: No. The CDC says that the risk for most people remains low. However, some dairy farmers are concerned about a potential drop in demand for milk and cheese due to fear. The USDA did report finding bird flu in some unpasteurized milk samples, but agricultural officials say that pasteurized milk is safe. Farmers are also isolating those infected cattle and dumping their milk.

Unger: All right, Andrea, thank you so much for the update there. Let's turn now to another disease that is back in the headlines and continues to be for the past several weeks, and that's the measles. Andrea, what's going on there?

Garcia: Well, two new cases, one in Las Vegas, the other in Los Angeles, have really put this disease back in the news. More measles cases have also been reported in Georgia and here in Illinois. Unfortunately, the cases in both Las Vegas and Los Angeles were found in people who visited popular tourist destinations that are often, as you know, filled with people. The one in LA reportedly visited Universal Studios and the Santa Monica Pier over Easter weekend. The one in Vegas reportedly visited the MGM Grand resort on the strip and then additional nearby locations.

Measles on the Rise

Measles has recently experienced a resurgence in many parts of the world. Learn about this significant public health challenge and what physicians need to know.

So public health officials are warning that unvaccinated individuals who were at these reported locations during the designated dates and times may be at risk for developing measles within 21 days from that exposure date. Last Thursday, the CDC said that the rapid rise in measles cases in the first few months of 2024 threatens the U.S. elimination status. And that's a situation we haven't faced since 2019 when prolonged outbreaks posed a similar problem.

Unger: Well, Andrea, where exactly do we stand in terms of cases?

Garcia: Well, Todd, on Thursday, we saw the CDC release an analysis of measles activity. And that was from January 1 of 2020 to March 28 of 2024. That said that cases in that first quarter of 2024 have risen 17-fold compared to that mean first quarter average that we've seen from 2020 to 2023. As of the March 28 data cutoff for that analysis, we had seen 97 cases of measles reported to the CDC, and then as of April 11, we have a total of 121 measles cases reported by 18 jurisdictions. So that number is definitely continuing to increase.

Of those 121 cases, 86 were linked to seven outbreaks, including a large one here in Chicago where most of those 61 cases that have been identified have been linked to that outbreak at a migrant shelter. If we look at the measles cases this year, though, 47% have occurred in children younger than five. Young children also had that highest level of hospitalization, at about 65%. And of people infected, 82% were unvaccinated or had an unknown vaccination status.

Of the 20 outbreaks, which we know involves three or more cases that we've seen since 2020, so far seven of those have occurred in 2024. And for further context, in all of 2023, we had 58 cases. And we are only in April. So maintaining that measles elimination status, which we know helps reduce cases, deaths and costs, means that no outbreaks have persisted for 12 months or more in a setting where we know the surveillance system is working well.

Unger: So tell us a little bit more about this status. What do we need to do to help maintain the status?

Garcia: Well, CDC has said that really comes down to increasing MMR vaccination coverage, especially in those close-knit and under-vaccinated communities. And as a reminder, that vaccine is incredibly safe and effective. We know that two shots are about 97% effective at preventing measles. I think the other steps include encouraging vaccination before international travel and then rapidly investigating those suspected measles cases.

Most measles cases are still imported. However, of those, 61% in U.S. residents who were eligible for vaccination but were unvaccinated or had an unknown vaccination status. So the CDC is also reportedly seeing a shift this year in overseas regions where people were likely exposed.

So during that study period that we talked about earlier, the two most common WHR regions where we saw cases were from the Eastern Mediterranean or the Middle East and Africa, but six of the 2024 cases were reported to have originated in European and Southeast Asian regions. So that's a 50% increase from earlier in the study period.

So according to the CDC, along with under-vaccination here in the U.S. population, there's a global gap in measles vaccination that is also fueling this rise in cases. And if we look at those numbers more closely, first dose coverage declined from 86% in 2019 to 83% in 2022, leaving nearly 22 million children younger than one vulnerable to the virus.

Unger: Andrea, besides this huge, as you point out, global vaccination gap, is there anything else that is kind of fueling this now? Why is it happening?

Garcia: Well, in the U.S., some of it is driven, of course, by misinformation, which is causing parents to seek vaccine exemptions. Every year, that number of kids in kindergarten with measles vaccination is going down.

Years ago, a fraudulent study claimed there was a link between the vaccine and autism. Of course, that study was later debunked. And other studies have searched for a connection but failed to find one. So to be very clear, there's no connection between the MMR vaccine and autism. So here's where physicians and particularly pediatricians can play an important role in curbing that spread of misinformation by talking to parents, being very clear about the evidence and the very real dangers and potential long-term effects of measles.

According to the CDC, in the decades before the measles vaccine was available, 48,000 people were hospitalized per year. One thousand people developed dangerous brain inflammation, and 400 to 500 people died.

Unger: So big risks there, and we need to close that gap. The evidence is really clear and getting those vaccinations, if you haven't already, so critical. Andrea, we haven't talked about RSV, COVID, and the flu and the array of other viruses for a while. The weather does seem, of course, to be getting nicer, thank goodness, it is here in Chicago, and we're now well into spring. Are we kind of out of the woods with viruses for the moment?

Garcia: Well, it appears so. And according to a recent report in the Associated Press, which was sharing CDC data, the 2023, '24 respiratory virus season is slowing for all three viruses. Overall, respiratory illness activity is currently the highest in the central U.S. North Dakota is the only state that is experiencing high activity levels at the moment.

The CDC gauges this activity by tracking doctor visits that involve a patient showing flu-like symptoms. And for that week of April 5, those made up only about 2.76% of all visits. The other metric, as you know, we look at is the test positivity rate for each virus, which can help inform which viruses are the most prevalent. While results are delayed for the CDC data set, flu has had the highest test positivity rate since mid-December.

Hospitalizations, of course, give us that idea of severity associated with each virus. COVID is hospitalizing people at a rate of 2.21 per 100,000. That's the highest rate among the three viruses. However, hospitalization rates for all three viruses are declining. I think the key takeaway from all of this as well, activity levels are still elevated. We're seeing decreasing trends across each of these metrics, which do suggest that the season is waning.

Unger: All right. Well, why don't we finish up then with that piece of good news. Andrea, thanks so much for being here and keeping us informed. To all the folks out there listening, if you found this discussion valuable, you can support more programming like it by becoming an AMA member at

We'll be back soon with another AMA Update. In the meantime, you can find all our videos and podcasts at Thanks for joining us today and please take care.

Disclaimer: The viewpoints expressed in this video are those of the participants and/or do not necessarily reflect the views and policies of the AMA.

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