FluTrackers.com
@FluTrackers
·
42s
US -We are going to count any #H5N1 re-infection of a
herd as a new infection and include this event in our herd count.
A re-infection should be counted for clarity of the current
situation.
Same with human cases. Any positive test results should be counted.
Just unreal...
Announcement
Collapse
No announcement yet.
Discussion thread: H5N1 avian flu in US dairy cows including human cases (poultry, dairy workers) - March 24, 2024 +
Collapse
X
-
Translation Google
Avian influenza in humans: unresolved questions
Pascal Lapointe Thursday, November 28, 2024
Three cases in two months have alarmed bird flu observers: three people who had no contact with infected livestock. One of them is a teenager in whom the virus is showing signs of adapting to humans.
That doesn't mean the worst-case scenario is happening. "This is not, by any stretch of the imagination, Day 1 of a pandemic," University of Pennsylvania microbiologist Scott Hensley told the medical journal STAT on Nov. 18. "There's no indication of human-to-human transmission, which is good. But that's the scenario we're worried about."
His remarks are a reference to the fact that every time a virus succeeds in transmitting itself from an animal to a human, this does not mean that it has acquired the mutations necessary to then transmit itself between humans. Except that since 1997 when it was identified in Hong Kong, the H5N1 avian flu has shown an ability to infect first all sorts of bird species, then more and more species of mammals including, more recently , cows.
Since this spring, 52 farm workers in the United States have been diagnosed with the H5N1 virus, due to exposure to infected poultry or cows. That figure is suspected to be an underestimate, as many farmers have been reluctant to allow routine testing of their herds. Health officials in Washington and the affected regions have also been criticized for not cracking down harder on farmers.
Of the three cases not linked to farms, two are in the United States. The first was reported in September in Missouri. The second is a child in California, who was reported on November 19. Neither required hospitalization. The third is a teenager in British Columbia, who was hospitalized on November 8 and was described at the time as being in “critical condition.”
It is in this adolescent that the sequencing of the virus's genes, deposited by Canadian researchers in a public database, reveals three differences described as "keys" for possible transmission between humans.
More specifically, these are mutations in hemagglutinin , a protein that, present on the surface of the virus, attaches to the cells that the virus is trying to "invade". In other words, these mutations would, in theory, enhance the virus's ability to "attach" to human cells.
Not all of the viruses identified in the teen contain these mutations, suggesting that researchers were dealing with a "mixture" of two types of the virus , one similar to the one currently found in poultry — not cows, unlike the two U.S. cases — and a second, believed to be the newcomer. The British Columbia Ministry of Health said Nov. 26 that follow-up with relatives had revealed no other infections.
Just as the 52 farmworkers could be an undercount, so too could these three cases: So far, the vast majority of these human cases have not resulted in serious symptoms, meaning many more may have slipped under the radar. That’s precisely what worries observers : “The bottom line is that there’s more community transmission than is being detected,” Dr. Abraar Karan, an infectious disease researcher at Stanford University, told Salon magazine on Nov. 26 .
Leave a comment:
-
H5N1 influenza: some troubling preliminary signals
A few data sources to keep an eye onSometimes three data points can tell us a lot. Back in early May 2021, the REACT study in the UK reported the results of genomic sequencing of three newly detected infections in London. Unlike routine COVID case data, these infections had been identified among people randomly tested in the community. And two of the three turned out to be the Delta variant.NOV 27
At the time, it was still unclear how much Delta was spreading in the community, as opposed to just reflecting imported cases from India. But thanks to REACT, we knew two out of three randomly detected infections were Delta in London. It wasn’t a definitive signal, but it was an important one.
Which brings us to the current H5N1 avian influenza situation in North America. In recent weeks, there have been three unusual cases reported. In September, there was a hospitalised case in Missouri who had no known contact with animals. Then, earlier this month, a severely ill case in British Columbia without a clear source of infection. And finally, an infected child in California reported last week, again with the source of infection unknown.
When assessing potential epidemic threats, unusual cases like these may mean little, or they may mean a lot. So it’s important to also look at other emerging evidence as well. Here are a couple of recent findings that have also stood out:- Scott Hensley had a useful thread on Bluesky that discusses evidence of a potential mutational change at residue 226 of the HA surface protein of the virus from British Columbia. This is notable, because a study earlier this month showed that mutations at this location can change the preference of H5N1 to bind to the α2-6 sialic acids on cells in the upper airway (as it does with human adapted human viruses), rather than α2-3 sialic acids found on cells deeper in the lungs (as avian viruses historically do). In short, such a mutation could mean the virus is becoming better adapted to humans. In the comments, Jesse Bloom also points to a potential change at residue 190, which is also known to be important for which types of acids viruses bind to.
- Sam Scarpino also had an interesting thread on Bluesky looking at wastewater surveillance in California. He noted that several urban areas are seeing an increase in influenza virus concentration in wastewater alongside an increase in the frequency of H5 positive tests among the water samples. This could be evidence of undetected human infections (which we know can happen from antibody studies among dairy workers). H5N1 has recently been found in raw milk on sale in California, which may be one possible route of exposure.
These are just early data points, of course. But the challenge is that outbreaks that don’t go anywhere can generate similar early signals to outbreaks that lead to major epidemics. As with every emerging disease threat, we therefore need a better understanding of what we’re facing, and a clearer plan for what to do about it.
Thanks for reading Understanding the unseen! This post is public so feel free to share it.
Leave a comment:
-
Despite warnings from bird flu experts, it’s business as usual in California dairy country
By Susanne Rust and Melissa Gomez
Nov. 26, 2024 3 AM PT
...
“We are in a soup of virus. I mean, there’s virus everywhere around us at this point,” said Dr. Marcela Uhart, a wildlife veterinarian with UC Davis’ One Health institute, who is based in Argentina, speaking at symposium held by the O’Neill Institute at Georgetown Law recently. (11/15) “This virus is circulating left and right in mammals and in birds, as far as we can tell, some of them are not showing any signs of disease.”
In October, The Times visited Tipton, a dairy town in Tulare County, and spoke with several residents, including Elodia Ibañez, who said the number of reported human cases in California — which in mid-October was 16, and is now 23 — sounded too low. She said her husband, a dairy worker, told her that two of his co-workers had red, swollen eyes, but they had continued working despite displaying bird flu symptoms.
...
“My dad and uncle have told me there’s a bunch of dairies that have had outbreaks,” Anthony said. He said his dad and uncle take steps to stay safe, but many workers likely are not reporting getting sick because they don’t want to get in trouble.
“Some of them are here not legally. They’re relying on that job, they don’t want to jeopardize that,” he said.
...
It’s this blindness to — and ignorance of — the virus’ reach that has infectious disease and health experts concerned.
...
New research and discussions with dairy farmers in the Central Valley suggests H5N1 bird flu is more widespread among people than the reported numbers indicate.
Leave a comment:
-
We are starting to see increase in flu cases over last few days in urgent cares and EDs but no increase in hospitalizations. Will see what next few weeks bring. I have not heard of any poultry or cow infections in our area from San Diego county or positive bird reports.
-
Has H5N1 been tracked all along in wastewater? Wondering if this is something we've never seen before. If it's an animal source, what has changed? Does San Diego have infected herds?
If this is spreading in the community with no severe cases showing up in ERs, what does that mean?
Leave a comment:
-
Correct link to San Diego Wastewater on 11.23.24WastewaterSCAN Data Dashboard tracks infectious diseases across the US via wastewater surveillance.
Leave a comment:
-
From September 16, 2024(no new report yet from county): San Diego County has a closed sewage system, meaning that its stormwater and wastewater do not intentionally intermix. This greatly reduces, but does not eliminate, the probability that this detection is from an environmental source such as migrating birds.
-
Leave a comment:
-
Hat tip: X
WastewaterSCAN Dashboard
H5, Florida
...
...
https://data.wastewaterscan.org/trac...ChartId=b4155c
Leave a comment:
-
- Likes 1
Leave a comment:
-
VILSACK: AVIAN FLU IN HOGS DIFFERENT THAN CATTLE
November 1, 2024 By Carah Hart Filed Under: Livestock, News, USDA
...
“It’s not even the same necessarily compared to what we see in the poultry circumstances,” says Vilsack. “We tested poultry and clearly, they had the virus. That led us to test the swine. This was a very small, family farm operation with 70 birds, a couple of pigs and a couple of mini pigs.”
...
“It’s important to know this happened, but there’s nothing for them to do. Pork producers deal with a variety of viruses on an ongoing basis. They’re very familiar.”
...
Hear the press conference with Vilsack.
Audio:
Ag Secretary Tom Vilsack says the avian influenza confirmed in hogs on a backyard farm operation in Oregon at the end of October is a different variation from the H5N1 that’s been found in cattle. “It’s not even the same necessarily compared to what we see in the poultry circumstances,” says Vilsack. “We tested poultry […]
- Likes 1
Leave a comment:
Leave a comment: