Abraar Karan Profile picture
@stanford infectious disease doctor
m rose Profile picture Eric Nelson, Ph.D. Profile picture DocM55 🌈🧬 Profile picture mike norrie Profile picture AlgoCompSynth by znmeb Profile picture 39 added to My Authors
May 15 6 tweets 1 min read
1/ It is a mistake to discount new cases just because death rate remains relatively low

Big surges of cases tells us something important: we are not good at slowing spread, which means we are betting on many things

first, that future variants will be ‘mild’ (no guarantee) 2/ Second, we are betting on future vaccines being durable + effective (unknown) & that we can roll these out faster than an epidemic surge (we cannot)

We are betting that we will have widespread vaccine uptake quickly (unlikely) despite our low booster uptake right now
May 12 4 tweets 3 min read
1/ Interesting report from @BrighamWomens -- lack of long-range airborne transmission from a highly infectious index case in a positive pressure room; unmasked; had high flow nasal cannula; coughing.
Authors speculate that high air changes/hour were key
ncbi.nlm.nih.gov/pmc/articles/P… 2/ "We speculate that the lack of transmission in this case was due to the high rate of air changes in the patient’s room, which would have rapidly diluted aerosols..."

We can learn a lot from excellent hospital infection prevention systems and upgrade public indoor air cleaning
May 10 5 tweets 1 min read
1/ Public health & politicians ruined one of the lowest hanging fruit in the epidemic since the start which was masking

What they should have done

1) Quickly upgraded recommendation to high filtration, namely N95, back in Feb 2020 (there were many of us who said to back then) 2) Made the best models— most comfortable NIOSH cleared— available for free & easy to find in all major public places

3) Offered free fit-testing sites for people to use esp if having trouble achieving seal

4) Mandated HiFi masks indoors in crowded public settings
May 10 4 tweets 1 min read
I understand why people are attending special events that are deeply important to them despite a risk of infection

I don’t understand why anyone would unmask now in crowded settings w strangers like public transit where there is no benefit and only cost

washingtonpost.com/health/2022/05… 2/ For whatever reason, the ability to do something is instead replaced by a false ‘all or nothing’ framework whereby you either always mask or never mask. Even if you do not always mask everywhere for all things, doing so in mundane high risk settings still matters!
May 4 9 tweets 2 min read
First human challenge studies of #SARSCoV2 of 34 subjects

academic.oup.com/cid/article/74… “Viral shedding was first detected by qPCR of throat swab samples after a median of 40 hours (~1.67 days) and in throat samples after 58 hours (~2.4 days)”
Apr 15 4 tweets 2 min read
1/ Just finished a grant proposal to bring N95 respirators & air filtration devices into high risk crowded homes to try & prevent transmission from index #covid19 cases during future waves. Thanks to many including @kprather88 for help in bringing aerosol experts onto the team. 2/ We hope to generate useful data through real world rollout of interventions for communities by bringing in resources that can prevent spread.

Hoping we secure the funding to be able to carry this work out!
Apr 7 6 tweets 2 min read
1/ We are told to mask up, get vaccinated, get on with it

We are also told the government is funding #LongCovid research bc we don't know what we are dealing with or the long term costs to our health 2/ We are told to employ personal measures and be responsible

Yet we are dealing with an airborne virus for which personal responsibility is inadequate when we need engineering controls to better filter the air around us ASAP
Apr 7 4 tweets 2 min read
In the hospital, when we are dealing w/ airborne pathogens, not only do we wear N95 respirators—we also place patients in rooms with significantly higher air changes per hour/ negative pressure/ HEPA filters etc

If this is what is needed in hospitals, then what about the public? 2/ The irony is that many hospitalized #covid19 patients are less infectious than when they were in the community! They are suffering often from inflammatory effects of the virus & immune response. Peak infectiousness is often happening in places without enough air filtration
Apr 6 6 tweets 2 min read
1/ I have appreciated @gregggonsalves recent threads. One of the points to me is that there is a strange denial that is pervasive around #covid19. We have seen it come and go over the past 2 years; usually, it disappears when we are hit once again. 2/ The strange part of the most recent wave of denial is that a number of health experts joined in. I agree w/ them that vaccines are excellent; but there seems to be very little conversation or acknowledgment that wide-spread infections are a very bad thing when we know little
Apr 2 4 tweets 1 min read
“Risk for cardiac complications was significantly higher after #SARSCoV2 infection than after mRNA COVID-19 vaccination for both males and females in all age groups.”

cdc.gov/mmwr/volumes/7… 2/ Remember this specific point came up many times — will those who brought special attention to questioning risk of vaccines but not questioning risk of infections w the same scrutiny now address this?
Mar 29 7 tweets 3 min read
Must read:
"We pay a price for our failure to modify infection control policies to reflect the predominance of aerosol-based transmission. These include preventable patient and healthcare worker infections, misallocation of limited resources, and loss of trust in our expertise." Image 2/ Authors, who I am lucky to call mentors & colleagues from @BrighamWomens, highlight the importance of the inoculum dose (how much virus is inhaled during your exposure). They also highlight this paradox: we use N95/better ventilation for patients who are less contagious
Mar 28 4 tweets 2 min read
Having worked on a state #covid19 response for most of 2020, one important realization: public health is one of the many demands on state political leaders. Pub health got attention during a crisis, but effective PH is far more abt prevention & preparedness than crisis response. 2/ Issue is that post-crisis, public health again is pushed to the back burner as politicians are busy putting out fires and worrying about re-election. So the window for preparation, again and again, closes as another surge starts. This cycle has played out for 2 years
Mar 25 7 tweets 2 min read
1/ Yesterday CDC recommended that hospitals & healthcare facilities allow patients to keep their own N95 masks on

Some would think by now, these facilities should be offering visitors these respirators during a pandemic— but we are celebrating just being allowed to wear our own 2/ The science has not changed. The policy has lagged behind for two years. People are appropriately frustrated. More broadly, policy & comms around N95 masks have lagged for the community too, where ventilation standards are poorer and the average mask 👎🏼 than in the hospital
Mar 13 11 tweets 7 min read
1/ Over time, the effects of #covid19 on heart, brain, lungs, vascular system, sensory system, kidneys & more will become better understood

Until then, any reassurance that massive levels of infection are ‘ok’ for society is a gamble—a gamble with unknown long-term costs. 2/ Recent work highlighting effects of #SARSCoV2 on brain structure
nature.com/articles/s4158…
Mar 10 6 tweets 2 min read
1/ Over the past two years, we have discovered therapeutics that work for #covid19 such as Remdesivir; later we figured out the optimal time to use them. Months from now, we will have even more data & meds to use.

Delaying infections does have a benefit 2/ Over the past two years, we have discovered that #covid19 has effects on the body that are significant, even if they don’t kill you. The virus affects the heart, brain, vascular system & more. The costs become clearer over time.

Delaying infections makes those costs clearer
Mar 10 5 tweets 2 min read
Perhaps unsurprising, those most readily downplaying the risks of #covid19 infection, incl #longcovid, have also never treated a covid patient.

You’ll be hard pressed to find many doctors doing this— we have seen enough patients die, or survive & still suffer afterwards. 2/ We have had a lot of spread — & we are at risk of a lot more (unmasking of course not helping). Telling ourselves it is mild doesn’t make that true, esp re more chronic health consequences.

Masking alone won’t solve this either. There’s a lot more needed than that.
Mar 1 5 tweets 1 min read
1/ The US #covid19 dialogue is overly focused on how restrictions are being lifted and what experts think about that

The questions I care about right now:
-what are we doing for preparedness?
-what are we doing for health equity? 2/ I want specifics from my government and leaders

How is indoor air/ventilation going to be improved in schools, businesses and public places? What's the timeline? What's the cost? Who is paying? What's the accountability mechanism if this doesn't happen?
Feb 20 4 tweets 2 min read
1/ Unmasked exposures & Long Covid 🧵

There is potentially a relationship between inoculum dose (amount of virus you are exposed to when you get infected) & development of #LongCovid

Having higher early viral load may increase risk of Long Covid

nytimes.com/2022/01/25/hea… 2/ Earlier in the epidemic, @MonicaGandhi9 & Dr Rutherford from UCSF brought up variolation hypothesis as it relates to masking

Could masks have the benefit of reducing the viral load you are exposed to & could this potentially lessen severity of disease + prime immune system
Feb 20 5 tweets 3 min read
More hospital-based spread of #covid19 during #Omicron than any prior waves. We knew this was a problem from prior waves— yet there is ongoing resistance to acknowledge it, to test for it, or do more to prevent it.

@politico
politico.com/news/2022/02/1… 2/ We wrote about this issue in @JAMA_current outlining ways to slow hospital-based spread with Omicron.

It remains to be seen whether this will be utilized in hospitals, or if we’ll keep the status quo and pretend this isn’t a problem.

jamanetwork.com/journals/jama/…
Feb 19 4 tweets 1 min read
False dichotomies like lockdowns versus dropping all safety measures (“restrictions) are largely unhelpful & serve only to polarize

We can have safer schools.

We can have safer workplaces.

We can have safer public spaces.

We can drive & keep incidence down. 2/ The immediate reflexive response to this is always “but vaccines”

‘Vaccine only’ strategies will not work

The roll out of boosters every season (or more) will not keep up with future virus surges

They won’t fully protect us if we are faced urgently w a deadlier variant
Feb 7 4 tweets 2 min read
In our ⁦@JAMA_current⁩ piece, we lay out a few key reasons that hospital-based #covid19 transmission is likely underappreciated.

1/ few hospitals systematically test patients throughout and following their hospital stays. jamanetwork.com/journals/jama/… 2/ “Most hospitals only test patients for SARS-CoV-2 at the time of admission and therefore may miss some infections acquired after admission, especially because approximately 40% of SARS-CoV-2 infections are mild or asymptomatic and thus do not trigger repeat testing.”