Public Health

More cases of bird flu in California, new avian flu testing, Rwanda Marburg virus outbreak update

. 11 MIN READ

AMA Update covers a range of health care topics affecting the lives of physicians, residents, medical students and patients. From private practice and health system leaders to scientists and public health officials, hear from the experts in medicine on COVID-19, medical education, advocacy issues, burnout, vaccines and more.

How is bird flu detected in humans? Is there a Marburg virus outbreak? How does Marburg virus spread? What are the vaccines required for kindergarten?

AMA's Vice President of Science, Medicine and Public Health, Andrea Garcia, JD, MPH, discusses new bird flu testing, latest bird flu cases in the U.S., vaccines for children in kindergarten, XEC COVID variant and KP.3.1.1 cases, plus Marburg virus in Rwanda. AMA Chief Experience Officer Todd Unger hosts.

Speaker

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

Advancing public health

AMA membership offers unique access to savings and resources tailored to enrich the personal and professional lives of physicians, residents and medical students.

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. Great to be here and appreciate you as always having me back. 

Unger: Well, this week, again, lots to talk about. More cases of bird flu, respiratory season and vaccinations, and an outbreak of an Ebola-like virus in Rwanda. Let's begin with a quick check on bird flu. Last week, we were waiting on antibody tests from several health care workers who had been in contact with a Missouri patient who had bird flu. Andrea, did we get any answers? 

Garcia: Todd, unfortunately, we haven't yet. And it was actually reported last week that the CDC has had to develop a new test to look for those antibodies. That's because key genetic changes to the main protein on the exterior of the virus means that our existing tests might not have been reliable. It sounds like it'll be mid-October before that work can be completed. 

There was an NBC News article published last Friday. Infectious disease expert Michael Osterholm said he would be very surprised if any of the sick health care workers had bird flu, given that officials had a very hard time getting viable virus from the patient. Obviously, there's strong interest in understanding whether human to human transmission occurred, but it's going to be a while longer before we get those answers. 

Unger: Well, can you take us through what we do and don't know about the health care workers who became sick. 

Garcia: Well, we know that one of the health care professionals did test negative for influenza at the time, suggesting that their symptoms weren't related to bird flu. The antibody tests, however, are needed to help rule out the remaining five health professionals as their symptoms were only discovered after the investigation began. So they weren't tested at the time when they were sick. 

The timelines on when exactly these health care professionals became sick also remains pretty unclear. We don't know if they became ill the same day they were in contact with the patient or the next day or several days later. Obviously, that's an important piece of information because after we see exposure to H5N1, people typically develop symptoms within about three to five days. 

Depending on that timing of symptom onset, it's possible the health care professionals could have been sick with a different virus such as COVID. We know that Missouri patient was hospitalized back in August. We know that was the time when COVID was surging. Now we're obviously headed into respiratory virus season. People may be sick with other viruses too. 

Unger: All right. Well, thank you for that update. Unrelated to the Missouri patient, there were headlines about another possible human case of bird flu last week. What do we need to know about that case? 

Garcia: Actually, there have been two cases that have been since confirmed and a third is suspected. And according to the CDC, all of the patients were dairy workers in California who did have exposure to infected dairy cows. 

The CDC did release a statement about those two confirmed cases last Thursday, saying that an investigation is being led by California and is ongoing, but that the identification of H5 in people with exposure to infected animals is not unexpected, and it doesn't change the CDC's risk assessment for the general public, which does continue to be low. 

The agency did say that there is no known link or contact between that first and second confirmed case in California. These appear to be two separate instances of animal to human spread of the virus, not human to human transmission. 

And then on Saturday, the California Department of Public Health reported that potential third infection in a worker who also had contact with sick cows. And as of this filming, the department was waiting on that confirmatory testing from the CDC. 

Unger: Andrea, I'm assuming there's no connection between this third case and either of the first two. Is that correct? 

Garcia: Yeah. All three individuals had contact with animals, and that was at three different farms. And then all of them experienced mild symptoms, including eye redness and discharge. None of the individuals were hospitalized. If confirmed by the CDC, that third illness would push the nation's human H5 case count since the first of the year up to 17. 

All but one that Missouri patient that we've been discussing have been connected to contact with sick dairy cows or poultry. I think what is notable is that these are the first human cases of H5 in California where the outbreak among dairy herds there was first reported just two months ago at the end of August. 

Since that time, the disease has spread rapidly among dairy cows there, making it the hardest hit state with about 82 to outbreaks to date. As the nation's largest dairy producer, California has made efforts to ramp up surveillance around affected farms with weekly bulk milk testing. 

Unger: Well, that is certainly something we'll continue to keep an eye on. Andrea, you mentioned earlier the term respiratory season. Of course, we're just about to enter that. Anything surprising happening there, including what's going on with COVID? 

Garcia: Well, according to the CDC's latest respiratory virus update, COVID activity continues to decline. And nationally, the wastewater viral activity level for COVID is moderate. The West is seeing that highest level of wastewater in terms of viral activity. 

Emergency department visits and hospitalizations for COVID also continue to trend downward. Ed visits are the highest for infants and older adults. And hospitalization rates are highest for seniors. Deaths due to COVID remain stable. 

There are about 2% of all U.S. deaths at this point, according to the CDC data levels of KP.3.1.1 That variant continues to rise. They're currently at 58.7%. And the proportion of the XEC variant remains at 6%. That's the variant to watch at the moment. 

And both RSV and flu levels remain low, but detections are starting to rise in the Southeast, including in Florida, especially in young children. Obviously, now is the time to get vaccinated for both COVID and flu and RSV if you are eligible. 

Unger: Absolutely, but sadly, that message doesn't seem to be getting to everyone. We continue to see that vaccination rates are falling among children. Andrea, what's the information that we need to know there? 

Garcia: Yeah, Todd, there was data posted last Wednesday that showed that U.S. kindergarten vaccination rates decreased last year. And the proportion of children with exemptions rose to an all time high. It was reported by the Associated Press that the share of kids exempted from vaccine requirements rose to 3.3% That's up from 3% the year before. 

And meanwhile, 92.7% of kindergartners got their required vaccines. That's down from a pre-pandemic rate of 95%, which is that level we need to ensure that a single infection doesn't spark an outbreak. 

And I know that percentage seems small, but it translates to about 80,000 kids not getting vaccinated. It, of course, helps explain the increase we've seen both in whooping cough and in measles this season. Both are at their highest levels since 2019. And we know that physicians will need to continue to address misinformation and perceptions that these vaccines are either harmful or just not important. 

Unger: That'll be a big challenge. And it seems like that perception that you mentioned has only gotten worse since the pandemic. Andrea, closing us out today, let's turn to a health alert issued last week by the CDC over an outbreak in Rwanda. What's happening there, and do we need to be concerned? 

Garcia: Well, the CDC issued a health advisory last Thursday to inform physicians and health departments about the Republic of Rwanda's first confirmed outbreak of Marburg virus disease. That advisory said there had been 36 lab confirmed cases, at least 19 of which were health care workers and 11 deaths, and that was as of October 2. A more recent article in MPR indicated that those numbers have since grown to 56 cases and 12 deaths. That virus has a fatality rate that can reach as high as 88%. 

The WHO has deemed the risk of this outbreak as very high at the national level, high at the regional level, and then low at the global level. There have been no confirmed cases reported in the U.S. And the WHO did confirm in a statement that at least one person who was in contact with a Marburg patient has traveled to Belgium. So physicians should definitely be aware of that potential for imported cases. 

Unger: Now, Andrea, there might be a lot of people out there who are not that familiar with Marburg virus. Tell us a little bit more about that. 

Garcia: Well, Todd, it's a rare but highly fatal viral hemorrhagic fever caused by infection with one or two zoonotic viruses, both of which are within that same family as the Ebola virus. Symptoms include fever, headache, muscle and joint pain, fatigue, loss of appetite, GI symptoms or unexplained bleeding. 

A person infected with a Marburg virus is not contagious before the symptoms appear. It is spread through direct contact with broken skin or mucous membranes with the body fluids of someone who is sick or who recently died from their infection. People can also contact it from infected animals, needles or other objects or surfaces contaminated with the virus. Marburg virus is not spread through airborne transmission. Although there is no vaccine for Marburg, Rwanda is now testing an experimental vaccine that has shown some promise in primates. 

Unger: Well, although the risk at the global level is currently low, what do physicians here need to know? 

Garcia: Well, the CDC has issued very detailed interim recommendations that can be found on the CDC website. The big takeaways are to systematically assess patients with exposure, risk, and compatible symptoms for the possibility of Marburg virus disease through a triage and evaluation process that includes a travel history, isolate and manage patients with exposure, risk and symptoms until you receive a negative test result. 

And if a patient does test positive, they will be transferred to a regional emerging special pathogens treatment center. It's also really important for physicians to remember to contact their state, territorial, local or tribal health department immediately if Marburg is suspected. 

Unger: Well, Andrea, thank you so much for that information. And hopefully, the vaccine proves to be effective. That wraps up this week's episode. As always, thanks so much for being here, Andrea, and for sharing this information. 

If you found this discussion valuable, you can support more programming like it by becoming an AMA member at ama-assn.org/join. 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.

Subscribe to AMA Update

Get videos with expert opinions from the AMA on the most important health care topics affecting physicians, residents, medical students and patients—delivered to your inbox.

AMA Update podcast logo

FEATURED STORIES