Abraar Karan, MD, MS, MPH, DTM&H

A prevention plan for avoiding a bird flu epidemic The H5N1 bird flu has been making news for driving up the price of eggs nationwide, but it also has the potential to spur a major epidemic if its circulation among poultry, cattle and humans is not ca...

"Just because we don't have a #BirdFlu epidemic today doesn't mean it's not possible to have one tomorrow — meaning now is the time to "put on our seatbelts" by taking measures that minimize our risk," #StanDOM's @abraarkaran.bsky.social tells @stanfordmedicine.bsky.social Scope. stan.md/3FVThop

I was interviewed in this Business Insider short documentary on #H5N1 bird flu, including the impact on egg prices & why this outbreak is fundamentally different from past ones. @stanforddeptmed.bsky.social @stanfordpress.bsky.social youtu.be/O-j2dhQdk44?...

My interview with ABC 7 News discussing the massive funding cuts to state health departments and the effect this will have on our health. This includes cuts to infectious disease surveillance programs that will make us more blind to what’s circulating among us. @stanforddeptmed.bsky.social

Interviewed in this piece for Stanford medicine @stanforddeptmed.bsky.social blog on #H5N1 control strategies

scopeblog.stanford.edu/2025/03/27/b...

Bird flu on the rise The Lancet Voice · Episode

Was delighted to be joined by @abraarkaran.bsky.social to discuss bird flu in the US for the new Lancet Voice - an ultra-informed and clear speaker! We talk transmission, how things might play out, the Trump admin taking it seriously, and lots more! open.spotify.com/episode/2t9H...

My interview on The Lancet Voice podcast on #H5N1

We cover all aspects of the outbreak, including where we are now; how we got here; where we need to go, & why there are serious challenges ahead.

Available on all major platforms

In work led by Ben Pinksy, Grant Higerd-Rusli, Matthew Hernandez & @abraarkaran.bsky.social, in @thelancet.bsky.social, we describe the importance of testing a broader range of people for #H5N1 bird flu in order to check for potentially hidden spread & new routes of transmission

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-transmission of cow H5 to poultry farms has been observed but also unclear how; thought to be by shared workers

They outline that human infections are likely being missed; and we may be the vectors propagating further spread between mammals and between species.

mGem: Transmission and exposure risks of dairy cow H5N1 influenza virus | mBio Highly pathogenic avian influenza (HPAI) H5N1 virus of the 2.3.4.4b clade has been circulating in North America since 2022 (1–3). On 25 March 2024, a strain in this clade, genotype B3.13, was confirmed to be infecting dairy cows in Texas and Kansas (Fig. 1A). Since then, dairy herds in several other states tested positive for this strain and spillover into dairy workers has followed (4–7). Infections of other domestic and peridomestic animals, such as cats and raccoons, have also occurred on the same premises containing infected cows (7, 8). Notably, the spread of cow H5N1 to poultry flocks has resulted in the culling of millions of birds and the infection of workers involved in culling operations on multiple occasions (9). As of 12 December 2024, over 800 dairy herds in 16 states have had confirmed infections, including three of the five biggest dairy-producing states (Fig. 1B) (10, 11). At least 58 known human cases of H5N1 including those exposed to dairy cows, poultry, or unknown exposure source have been reported by the CDC as of 12 December 2024 (12). Disturbingly, in September, cow H5N1 infections were confirmed in two housemates in Missouri without livestock contact (13, 14). Understanding how cow H5N1 transmits within and between farms is critical for curtailing the outbreak. Below, we discuss knowledge regarding the spread of cow H5N1 between farms, between cows, and the risk to humans.

Good review article on #H5N1 bird flu & gaps that need to be addressed.
-lack cow-specific data in terms of infections on farms
-unclear how cows are continuing to be infected although multiple hypotheses

journals.asm.org/doi/10.1128/...

Our new paper in The Lancet outlines the importance of expanding testing early in outbreaks. Through efforts led by the Pinsky lab at Stanford, we picked up a case of #H5N1 that otherwise wouldn’t have been tested by typical testing criteria.
www.thelancet.com/journals/lan...

The #measles communication by RFK Jr is problematic. Steroids (to reduce airway inflammation) & antibiotics (if bacterial superinfection) may be used in cases depending on particular clinical circumstances. Firing off a list like this adds to public confusion. And why no mention of vaccination?

Steps to prevent and respond to an H5N1 epidemic in the USA Nature Medicine - Steps should be taken now to prevent an epidemic of H5N1 in humans and prepare for an outbreak should it occur.

In Nature Medicine, we highlight 8 steps to prevent H5N1 🦅 🐄 🐓 (bird flu) from becoming a pandemic.

Free access at rdcu.be/ea153

w/ @ranudhillon.bsky.social @abraarkaran.bsky.social Robert Garry

Our commentary in Nature on immediate steps to combat the #H5N1 bird flu outbreak. @ranudhillon.bsky.social @sri-srikrishna.bsky.social

www.nature.com/articles/s41...

If testing via PCR for Ebola/Marburg & other endemic zoonotic pathogens is negative, the next clear step for someone with high risk zoonotic exposures (bat consumption) here would be to do pathogen agnostic sequencing.

Steps to prevent and respond to an H5N1 epidemic in the USA Nature Medicine - Steps should be taken now to prevent an epidemic of H5N1 in humans and prepare for an outbreak should it occur.

If H5N1 evolves to spread between people, it could spur a pandemic

In @naturemedicine.bsky.social, @sri-srikrishna.bsky.social Robert Garry @abraarkaran.bsky.social & I discuss the mutations it may take for this to happen & what we could do now to stop it & be prepared in case it does
rdcu.be/ea153

New version of bird flu infects Nevada dairy worker This version of the virus is circulating broadly in wild birds and is different from the virus that has been causing dairy cow outbreaks since early 2024, the CDC said.

Quoted in this Washington Post piece on #H5N1 genotype D1.1 being found in a Nevada dairy worker; what this tells us about the ongoing outbreak; and why it matters

www.washingtonpost.com/health/2025/...

Both severe cases of #H5N1 - including the death in Louisiana, and the teenager in critical condition in Canada- were D1.1 genotype viruses. This has now been detected in dairy cattle, where most of the infections in humans have been occurring (previous dairy spillovers were w/ B3.13)

Global health has become the latest target of the current administration’s cuts. But as both covid19 & H5N1 have shown, our epidemic response systems have significant holes. Communicable disease threats know no boundaries; & US isolationism makes us more blind to what is coming our way.

Suspected #Marburg virus disease outbreak in Tanzania; 9 cases and 8 deaths per WHO

January is the other peak shedding month for Marburg virus from Rousette bats

Reading reports that HEPA air purifiers are difficult to obtain in LA. Reminder you can quickly put together a box fan w/ MERV filter - we have been using these for a while in our #covid19 study.
Instructions here:
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2/ Broader testing protocols can pick up 'outliers' like the case we picked up through Stanford in a child in Alameda County. These cases are very important because they can shed light on blindspots in the response.

1/ With infectious disease outbreaks, we suffer most in our blindspots. Lack of broad testing contributes to this- we saw it with covid19, mpox and now H5N1.

Multiple companies including Quest, Labcorp and Hologic either have available or are developing diagnostics for #H5N1 #birdflu.

1) This #H5N1 case is showing us what can happen when the virus continues to evolve in an infected host. Remember this was a person now in medical care and isolation. If this occurs in a person who doesn’t access the medical system for whatever reason, the consequences could be very different.

3) Important to remember this is genotype D1.1 (different than what is infecting dairy cows). This is the same as what caused severe disease in the patient in British Columbia.

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2) These mutations were not identified in the birds that likely infected the patient suggesting they occured while the patient was infected.

Important CDC update on the severe #H5N1 case in Louisiana patient

1) Some of the virus population detected in this patient had amino acid changes that facilitate binding upper respiratory tract cells. No human-human transmission detected though.

www.cdc.gov/pertussis/ph...

#Pertussis cases are up —make sure you are up to date on TDaP and remember pertussis protection wanes faster than other vaccine components

“Preliminary data show that more than six times as many cases have been reported as of week 49 reported on December 7, 2024, compared to the same time in 2023.”

Spoke to @kristensze.bsky.social about Trump’s NIH Director nominee, Stanford colleague Dr. Jay Bhattacharya. In 2020, I had debated Dr. Kulldorff (co-author of Great Barrington Declaration) on Democracy Now regarding Covid19 policy. (Video truncated here due to 1 min limit)

Technical Update: Summary Analysis of the Genetic Sequence of a Highly Pathogenic Avian Influenza A(H5N1) Virus Identified in a Child in California CDC provides an update on genetic sequencing of the first pediatric case of avian influenza A(H5N1)

Excellent work by the Pinsky Lab, CDPH, CDC…and some folks working behind the scenes to protect us all!
@stanforddeptmed.bsky.social @stanfordcigh.bsky.social @stanforduniversity.bsky.social @abraarkaran.bsky.social @helenbranswell.bsky.social

www.cdc.gov/bird-flu/spo...