COVID19 update, May 20, 2020: reinfection unlikely; correlation between HbA1C and vulnerability to severe disease; German RKI recommendations on masks

Just a quick update today, as workday has been pretty intense.

(1) Dr. John Campbell’s vlog has a special edition on a new report from the South Korean CDC. There have been a number of worrying reports that people tested positive again after recovering, fueling speculation that this could become a chronic disease, like HIV or Hepatitis B. (As he explains, these viruses slip into the cell nucleus and insinuate themselves into the human genome.[*]) Worse, that people could be infectious for life.

However, as it turns out, the tests were false positives. The RT-PCR test detects the presence of a short fragment of RNA that’s specific to the virus, but cannot tell whether this is a remnant of long-destroyed virus, or belongs to a viable virus particle. So when cured patients cough up worn-out lung cells in their sputum, such remnants will trigger a false positive test. This appears to have been the case here.

Just as I was typing today’s update, Dr. Seheult posted a video on the exact same study. He has the link to the English version of the Korean CDC report in the description. (Dr. Campbell had to go off second-hand reports, as only the Korean-language version had been released at the time.) Dr. Seheult’s video adds much more detail.

I believe this is the great COVID19 news of the day.

(2) Yesterday, the good doctor posted another video with a couple of different segments. One is about a recently published evaluation of four new antibody tests using arrays of known positive and negative samples. “Comparison of Four New Commercial Serologic Assays for Determination of SARS-CoV-2 IgG”

The second is about a paper in the Journal of Diabetes Research, showing a clear link between high levels of glycosylated hemoglobin (high HbA1C values) and severe COVID19. “Glycosylated Hemoglobin Is Associated With Systemic Inflammation, Hypercoagulability, and Prognosis of COVID-19 Patients”

Those of you who are struggling with diabetes (or are trying to avoid going there, as I am) will recognize HbA1C — while blood glucose gives an immediate picture, HbA1C gives an “integral”, as it were, of your blood sugar picture over the last few months, and is less prone to fluctuation due to exertion or recent food or drink intake. [**]

(3) Recently, the topic of face masks has generated extreme passions on both sides, at least in the US. (In Israel, the mask mandate came about as a compromise between the Ministry of Economics, which pushed for accelerated reopening of stores, and the Ministry of Health which wasn’t keen on that. The latter acquiesced in exchange for getting its way on masks. As far as I can tell in my Tel-Aviv borough, the mandate is not being enforced visibly, and indeed in some places is honored more in the breach than the observance.)
Now I would like to think that both sides in the US debate would agree that Germany doesn’t mess around in such matters. (Besides, its statistics in the epidemic speak for themselves.) So what does the Robert Koch Institute (RKI) — their infectious diseases authority — have to say on the matter? Here is their position paper on the subject, which may surprise both the “no masks!” and “must wear masks, because science!” sides. Summarizing in translation:

  • most important are good hand hygiene, sneeze-cough hygiene, and maintaining an effective distance of 1.5m (5ft)
  • high-grade multilayer masks are foreseen for healthcare workers
  • we recommend keeping a simple textile mask handy to wear in specific situation in public, namely where no 1.5m distance can be maintained (e.g., on public transit). [***]
  • that said, some people are unable to wear masks at all due to health conditions
  • links to “proper wear and care” recommendations for different mask types
  • notably absent: any recommendation, let alone requirement, that people need to wear masks in public at all times

[*] What Dr. Campbell skips over is that the RNA is first copied to a double strand of DNA using an enzyme called reverse transcriptase — yes, the RT of RT-PCR testing.

[**] Our red blood cells don’t last much longer getting pumped around our bodies, and hence are continuously replaced by newly manufactured ones, with an average turnover of about 4 months.

[***] I feel compelled to belabor the point that momentary passing-by at closer distance does not mean you are suddenly at risk of infection. Our own Ministry of Health, which recommends 2m (6ft6), only counts exposure as ‘closer than the safe distance for 15 minutes or longer.