#MicroRounds (Day 733): Hypothetical case: a parent hears their child use the toilet but not flush (typical behavior!).

But upon entering the bathroom they're horrified to see this worm in the bowl with their kid's poop! How freaked out should they be?? #ASMClinMicro #IDTwitter Cont.: Here's some additional information (from your friendly neighborhood parasitology lab).
1) Yes, it's actually a worm.
2) You zoom in close and see this on one of the ends of the worm...

What does a mask do? Blocks respiratory droplets coming from your mouth and throat.

Two simple demos:

First, I sneezed, sang, talked & coughed toward an agar culture plate with or without a mask. Bacteria colonies show where droplets landed. A mask blocks virtually all of them. What about keeping your distance?

Second demo: I set open bacteria culture plates 2, 4 and 6 feet away and coughed (hard) for ~15s. I repeated this without a mask.

As seen by number of bacteria colonies, droplets mostly landed <6 ft, but a mask blocked nearly all of them.

Good thread on sensitivity & specificity of first emergency use authorization (EUA) #COVID19 serology test, Cellex, means for testing a low-prevalence population: increased risk of false positives

BUT IT'S ACTUALLY WORSE THAN THIS bc these numbers =/= *clinical* sensitivity 1/

https://twitter.com/zbinney_NFLinj/status/1245789672833417217

A huge question (if not THE question) in #SARSCoV2 lab diagnostics is the rate of false negatives and false positives.

This can be calculated IF (and it's a crucial "if") you know the True Disease Status of people and then test them with your test approach. Like this:
2/

News and updates about the status of laboratory diagnostics for #COVID19 are coming thick and fast today.

A quick thread on that topic, starting with @HelenBranswell's timely article (why aren't you following her??) as a jumping off point:
1/n

https://twitter.com/HelenBranswell/status/1233126407578017797

First, we know that the CDC has tested few cases of possible #COVID19 patients.

In an MMWR from last week, they said they'd tested "1,007 people" but news this week is saying "<500"? I don't understand that discrepancy.

Suffice to say it's far, FAR below what is needed! 2/n

HOO BOY I just read the "Harvard Study Proves 'Unvaccinated Children Pose No Risk'" garbage, bunk, actually-just-an-open-letter-from-an-antivax-immunologist and I am DANGEROUSLY INFURIATED.

I will NOT be linking to this article. But it is garbage. *RAGE SCREAM* #VaccinesWork What is notable is the approach: Consistently demonstrating that vaccines are 1) effective and thereby 2) changing the landscape of commonly seen infections to prove that vaccines DON'T prevent spread of disease??

It's a baffling strategy that doesn't work.
#VaxFactsFebruary

Antibiotic testing. Let's go.

Tentatively calling this #tweetorial "Antibiotic testing: why and how and huh?"

Important caveat: this is a HUGE topic. I’m mostly going to focus on 1) basic rationale and 2) laboratory methods. And 3) try not to say anything wrong/misleading! Question #1: Why would a person want to know if bacteria A is resistant to antibiotic B?