Chair Schulman on testing methods, lab capacity, and turnaround times
Schulman asks about PCR vs. culture testing, turnaround times, lab capacity, and whether 30 certified labs are sufficient. Martin explains PCR takes 24-48 hours, culture takes two weeks, and there are no current capacity concerns. He also describes patient diagnostic testing including urine antigen tests.
How can people protect themselves from potential exposure?
The number one most important way folks can protect themselves when we have these clusters is to understand the signs and symptoms.
And to get in to see a doctor.
This is a highly treatable condition, but it does require individuals getting to appropriate care and getting evaluated.
The department conducted over 360 tests and collected samples from more than 180 cooling towers during the Upper East Side outbreak.
Where do collected samples go for analysis, and how does DOHMH choose where to send the samples?
So those samples are coming to us, to our public health lab, where we are doing our own testing.
An evaluation of those samples.
In the announcement that was made yesterday about some of the proposals, one of them talked about faster testing.
What was that faster testing of?
I wasn't clear on that.
So we are always looking to improve our system and identify ways to further strengthen our regulatory apparatus.
Was it testing of the cooling towers or it's testing of the individuals?
It's testing of the cooling towers.
Okay.
So that's one of the things that we want to do is figure out if there are new types of novel testing measures to speed up.
The testing.
How many laboratories are currently certified and available to analyze cooling tower samples for Legionella in New York City?
30.
I'm sorry?
30.
30?
Yep.
Is that enough?
At this moment, we don't have concerns about capacity, and we also have our own testing capacity.
Those labs, they're standardized testing.
In other words, everything is done the same way in each lab?
That's right.
So the New York State currently does that certification for these labs.
And so that's the sort of...
Do different labs have different turnaround times for, you know, again, going back to for the lab tests?
Unfortunately, we are at the mercy of the bacterial culture process with the testing that we do with rotabacterial culture testing.
That takes two weeks here, and it takes two weeks up in Albany.
It's the same, unfortunately.
Okay.
Do these laboratories have sufficient capacity to meet the new monthly testing requirements, particularly during the summer or a community outbreak?
Yeah, at this moment we don't have concerns about the capacity.
No, okay.
Please explain the difference between a PCR test and a culture test.
The PCR test is asking the question, is there evidence of Legionella DNA in the sample?
The DNA can't tell us if it's live or dead, right?
It could be that there was Legionella bacteria at some point.
Culture is asking a different question.
It's asking right now.
Is there live bacteria in the sample?
So these are two separate questions.
What is the turnaround time to receive results from each test, and then are there any other testing methods which may be more efficient or effective?
There are three main tests that we use.
The first is PCR testing.
The turnaround time is between 24 to 48 hours.
Culture testing is the second.
That takes up to two weeks.
And then there's whole genome sequencing, which takes a much longer time.
So the PCR testing is done when somebody shows up with symptoms and is...
Ah, the testing that I just mentioned is the testing of the samples of the water and the cooling towers.
The testing of the individual, there's a number of different tests that we do if somebody has potential Legionnaire's disease.
Right.
We do a urine.
antigen tests, we can do x-rays, we do other blood tests.
And so that sort of picture gets put together by doing these different types of testing all together.
So if somebody had, so the initial test when somebody comes in and that's positive, then they would get treatment at that point or it has to wait for other testing?
Let me hand it over to Deputy Commissioner Andrea Howard.
Yes.
So as when a patient goes to see a provider,
the first thing that clinician would do, you know, based upon the signs and symptoms, would evaluate that patient and then make a decision on a differential diagnosis.
For Legionnaire's disease, first of all, you have to have pneumonia and you have to have a positive Legionella test.
A urinary antigen test can take a few days to come back.
A culture of the sputum could take up to two weeks.
Right.
However, as a practicing infectious disease physician, if I had a strong suspicion that someone had Legionnaire's disease, you could start them presumptively on treatment right away.
Right.
And in addition, to consider other diagnoses, including other forms of pneumonia.
Right.