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Newell: A crash-course in understanding Louisiana's coronavirus data

Newell Normand
April 01, 2020 - 3:06 pm

Today’s coronavirus infection and death numbers aren’t any better than yesterday’s. Wednesday saw 34 new deaths reported and another 1,187 cases of COVID-19 come back positive over a 24 hour period. To get an update about how the response to these stark statistics is unfolding at the state level, Newell invited Louisiana’s Assistant State Health Officer Dr. Joe Kanter onto the program. 

“Everyone is hoping against hope that the numbers will begin to flatten,” Newell began. “This is a tough day for the state of Louisiana.”

“I agree with that… but it's difficult to gain too much from these individual day changes,” Kanter said. “I think we need to be a little bit more patient and look at trends week-by-week. I don't want folks to look at one day’s numbers and think that’s an accurate indication of where the trend is going at that point in time.”

“I made that observation yesterday, that I think it’s more important to look at it week-over-week rather than day-over-day, with so many moving parts. Correct me if I’m wrong, but aren’t we conducting more tests at the present time, and the throughput relative to the labs is improving and we’re getting results in a much quicker fashion?” Newell continued.

“That’s right,” Kanter agreed. “The number of tests is going up very quickly, almost at 40,000 right now. Over 90% of those are being done at commercial labs, and in addition, you have some large hospital systems that are bringing in-house capacity online. Both Oschner and LCMC can do these very quickly in-house now, that’s really good. The other thing to know is that additional deaths added to the tally doesn’t necessarily mean that that number of individuals expired in the past 24 hours, it just means that’s when those deaths were reported. Someone may pass away and the test will come back after they die, or it takes a couple of days to get that properly verified and reported. Again, it’s difficult to put too much stock in these day-by-day numbers.”

Many listeners to Newell’s program are eager to know - how are individuals like Sean Payton, who tested positive but have since recovered, reflected in the infection data?

“Have y’all been able to receive and assess data about those successful discharges?” Newell asked.

“Yes and no,” came the answer. “We know how many patients have tested positive, and we know how many are currently in hospitals, and we know how many have expired. So you can take those numbers and subtract to get a number of patients discharged from hospitals still alive. That’s a good number to have, but the question of when someone ‘recovers’ doesn't have a clear definition. We generally think that when you’ve been without a fever or any symptoms for three days, you are past the infectious period. What constitutes a full recovery doesn’t have a clear diagnosis, but I can tell you that informally, the numbers we’ve been seeing from hospitals here in terms of how many patients are able to get off of ventilators successfully have been encouraging. In informal conversations with ICU teams in Seattle, they told us a few days ago that they were seeing 90% fatalities on patients who are intubated and put on ventilators. Our preliminary numbers are much better than that, so that’s encouraging to us.” 

“Have we been able to determine the precision of the testing we are doing as it relates to getting false negatives and false positives?” Newell asked.

“Interesting question. The test itself, from a laboratory point of view, is extremely accurate. If there’s any virus on that swab, these methods will detect it with a high degree of accuracy. The problem comes with how the test is performed clinically, how well the swab is conducted. If you don’t get any sample on the swab at the point of care, then the lab isn’t going to pick it up. That’s where we see the variability. I’ve seen numbers thrown around like 70-75% accuracy when you factor in the possibility of getting an ineffective swab.”

Hear the entire interview in the audio player below.

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