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Featured topic and speakers
Featured topic and speakers
How many human cases of bird flu are there in the U.S.? Does flu vaccine protect against bird flu? Why are measles coming back? Has a new strain of mpox spread in Africa?
Our guest is AMA Vice President of Science, Medicine and Public Health Andrea Garcia, JD, MPH. AMA Chief Experience Officer Todd Unger hosts.
Speaker
- Andrea Garcia, JD, MPH, vice president, science, medicine & public health, American Medical Association
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. Andrea, welcome back.
Garcia: Thanks, Todd. It's great to be here.
Unger: Well, one thing we didn't talk about last week was bird flu, but there have been some updates to discuss, including new CDC efforts to better protect farm workers. Andrea, tell us more about that.
Garcia: Yeah, Todd, so it was early last week when we saw the CDC announced two new $5 million investments. And those are to help protect farm workers who are at heightened risk of exposure to highly pathogenic avian influenza or bird flu. The first is going to fund partner organizations, including the National Center for Farmworker Health, to support overall outreach and education efforts focused on farm worker safety and health. The second investment is going to go towards increased efforts to get the seasonal flu vaccine to U.S. livestock, dairy and poultry workers, and thus to control and prevent seasonal flu among this group in light of the ongoing H5N1 outbreaks.
Unger: So, Andrea, how will offering seasonal flu vaccine help with bird flu?
Garcia: Well, that's a great question, since we know the seasonal flu vaccine does not actually prevent infection from highly pathogenic avian influenza. However, it can reduce the prevalence and severity of seasonal flu, and it might reduce that very rare risk of having both seasonal flu and bird flu at the same time. Having dual infections, while rare, could theoretically result in genetic re-assortment of the two different influenza A viruses and lead to a new influenza A virus that has a different combination of genes, which could potentially pose a significant public health concern.
Of course, preventing seasonal flu infection and severe disease outcomes is just good public health practice. This population, we know, typically has lower vaccination rates than the general public. While these vaccines will not be required for farm workers, reducing barriers to getting the vaccine and increasing uptake can help reduce that strain on rural health care systems in the fall and winter when we know more people are likely to have respiratory illnesses. The thinking is also that, if fewer people get seasonal flu in the fall and winter, we may be able to better detect if a person is sick with avian flu. This seasonal flu vaccine campaign for farm workers should be starting on or around October 1. So, it's certainly something we're going to continue to monitor on our end over the coming months.
Unger: Thank you so much for that update. And before we leave the topic of bird flu, a new study was released last week, suggesting that bird flu cases in people may be going undetected. Andrea, tell us more about that and what it means.
Garcia: So this study has not yet been peer reviewed. What was posted online last Wednesday, it was covered by Kaiser Family Foundation Health News. It was also reported on a CNN article on Friday. It basically confirms what we suspected, and that's highly pathogenic avian influenza cases are likely being underreported.
The concern here is containment. Right now, we know of 13 human cases of bird flu related to this outbreak. All have been traced to direct contact with infected animals and were mild cases in which everyone recovered. If cases are going unreported, however, it becomes difficult to track if the virus is becoming more contagious, and a large surge of infections outside of that farm worker community would trigger the government's flu surveillance system. But by then, it would be too late.
Unger: Really interesting. So Andrea, what did this study look at exactly?
Garcia: So it looked for signs of prior undiagnosed infections and people who had been exposed to sick dairy cattle and who had become ill and recovered. They analyzed blood samples from 14 farm workers from two dairy farms that had outbreaks in Texas earlier this year, and they found antibodies in two of them. It's a small sample, but the research team is saying that it's the percentage that is concerning.
It's a nearly 15% hit rate from only two dairy farms out of more than 170 with bird flu outbreaks in 13 states this year. One of the workers with antibodies had reportedly been taking medicine for a lingering cough. The other had reportedly recently recovered from a respiratory illness. She didn't know what had caused it but told researchers that untested farm workers around her had been sick, too.
Unger: Wow. So what does that mean in the big picture?
Garcia: Well, I think it means something that we already knew. We need more testing, and we also need better precautions. I think the good news here is both workers who tested positive for antibodies had symptoms, which supports an earlier Michigan study that showed asymptomatic cases of bird flu are rare. However, there are a lot of barriers to testing farm workers, even if they do have symptoms.
We know many are reticent to seek care, because they don't have insurance, or they're worried about losing their employment if they get sick. According to a KFF analysis, about one-fifth of the workers on livestock farms are uninsured, and a similar share have household incomes of less than $40,000 a year. So we still certainly have a lot of work to do to instill trust, and that's something we can only do by getting farm owners on board.
Unger: Well, just connecting our first part of the story here, perhaps, the CDC's new investments will help with that as well. Andrea, I want to turn now to another disease that we haven't talked about much in the past few weeks but has slowly been gaining ground here in the U.S., and that's the measles. Andrea, what's going on there?
Garcia: Well, Todd, there was an article in U.S. News and World Report late last week that was based on CDC data, and the number of both cases and outbreaks of measles so far this year has tripled over last year, and we are only through July. If we look at those numbers, a total of 188 measles cases have been reported, and that's across 25 states, New York City and DC. And that's as of July 25.
We only had 58 cases recorded in all of 2023. Almost all of the cases that were reported this year, about 43% have occurred in children under the age of five, and 32% were among individuals 20 and older. We know that approximately 95% of those cases have involved individuals who were either unvaccinated, had an unknown vaccination status, or who had only received one dose of the MMR vaccine.
Unger: Well, that's very telling, because of course, the vaccine is extremely effective, right?
Garcia: That's right. That vaccine is estimated to be 93% effective against measles after one dose, 97% effective after two doses, and it's not just cases that we're seeing increase. It's outbreaks too.
So far, health officials have reported a total of 13 outbreaks, which involve three or more cases, compared to just four outbreaks in all of last year. We know that nearly two-thirds of measles cases this year have been associated with outbreaks, and the largest, which occurred at a migrant shelter right here in Chicago in March. Once we see vaccine uptake start to lag, we know that infection can spread quickly, and just as a reminder, measles is highly contagious. It can affect up to 90% of people who are unprotected if they come in contact was someone with the illness.
Unger: And this is especially frustrating, because I think, at one point, we eliminated measles pretty much from the U.S. Is that right?
Garcia: Yeah, we did. Measles was declared eliminated in this country back in 2000, and that, I think, was thanks in large part, to the success of an extensive vaccination program that included states requiring kindergartners to get the MMR vaccine before being allowed to go to public school. Since then, vaccination, we know, has started to lag, and there's been that uptick in cases globally. Both of those have contributed to the increasing numbers that we're seeing now.
Airports are one of the most common high-risk areas for exposure since people are coming into the country after traveling internationally. The bottom line is we've really taken a step backwards here. Measles is not a disease anyone wants, and it can lead to very serious complications. And physicians can certainly help by continuing to urge their patients who are not yet vaccinated to begin the two-dose series as soon as possible.
Unger: All right, well, thank you for that update. Andrea, to finish up this week's update, I want to check in on another virus that we haven't talked much about in the last few weeks, and that is Mpox. What's the news there?
Garcia: Yeah, there is a lot of news here. In fact, over the weekend, it was reported that the WHO chief is considering convening an expert committee to advise on whether the growing Mpox outbreak in Africa should be declared a public health emergency of international concern. That's the highest alarm the WHO can sound, and that WHO director can declare an emergency on the advice of a committee of experts in the field. A public health emergency of international concern really has only been declared seven times since 2009, so over H1N1, swine flu, polio virus, ebola, Zika virus, ebola again, and then COVID-19 and Mpox.
Unger: So what's driving the need to possibly sound an alarm again?
Garcia: Well, since last September, cases have surged in the Democratic Republic of Congo, and that's due to a more deadly clade of the virus that has also recently now been detected in nearby African countries. While the UN Health Agency, the Africa Center for Disease Control and Prevention, and local governments and partners are increasing their response to the outbreak, the WHO director said that more funding and support are needed. And to put it into his words, the virus can and must be contained with intensified public health measures, including surveillance, community engagement, treatment and targeted deployment of vaccines for those at higher risk of infection.
Unger: All right, and that's something we'll monitor continuously as it unfolds. That wraps up this week. Thank you as always for being here, Andrea, and for sharing the information.
If you found this discussion valuable, you can support more programming like it by becoming an AMA member at ama-assn.org/join, and you can always find all our videos and podcasts at ama-assn.org/podcasts. Thanks for joining us today. 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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