COVID19 update, May 28, 2020: ACE inhibitors beneficial; asymptomatic infection rate as high as 80%; NYT on California economy in freefall

(1) The lead story of Chemical and Engineering News, the house organ of the American Chemical Society, is about rethinking the role of ACE inhibitors (angiotensin converting enzyme inhibitors, a commonly used family of blood pressure drugs).

https://cendigitalmagazine.acs.org/2020/05/22/rethinking-the-role-of-blood-pressure-drugs-in-covid-19/content.html

“Once thought to boost levels of ACE2 , the novel coronavirus’s doorway into human cells, these widely used medicines are now contenders to treat the respiratory disease”

(2) Meanwhile,  the Daily Telegraph has a popular write-up of an intriguing paper that just appeared in Thorax, a daughter journal of the British Medical Journal. It suggests the asymptomatic infection rate may be much higher than the 35% in the revised CDC figures

http://doi.org/10.1136/thoraxjnl-2020-215091

ABSTRACT: We describe what we believe is the first instance of complete COVID-19 testing of all passengers and crew on an isolated cruise ship during the current COVID-19 pandemic. Of the 217 passengers and crew on board, 128 tested positive for COVID-19 on reverse transcription–PCR (59%). Of the COVID-19-positive patients, 19% (24) were symptomatic; 6.2% (8) required medical evacuation; 3.1% (4) were intubated and ventilated; and the mortality was 0.8% (1). The majority of COVID-19-positive patients were asymptomatic (81%, 104 patients). We conclude that the prevalence of COVID-19 on affected cruise ships is likely to be significantly underestimated, and strategies are needed to assess and monitor all passengers to prevent community transmission after disembarkation.

The Uruguayan Ministry of Health provided on board SARS-CoV-2 virus testing of all passengers and crew, which occurred on 3 April (day 20; Atgen-Diagnostica, Montevideo) with CDC 2019-nCoV Real-Time RT-PCR Diagnostic Panel.

In the body text we find that: 

 

[The 128 who tested positive on RT-PCR]  included all passengers who tested negative on the VivaDiag qSARS-CoV-IgM/IgG Rapid [antibody] Test. There were 10 instances where two passengers sharing a cabin recorded positive and negative results.

[…]

From the departure date in mid-March 2020 and for the next 28 days, the expedition cruise ship had no outside human contact and was thus a totally isolated environment in this sense. […]

[…]

We conclude from this observational study that

  • The prevalence of COVID-19 on affected cruise ships is likely to be significantly underestimated, and strategies are needed to assess and monitor all passengers to prevent community transmission after disembarkation.
  • Rapid  [antibody] COVID-19 testing of patients in the acute phase is unreliable.
  • The majority of COVID-19-positive patients were asymptomatic (81%).
  • The presence of discordant COVID-19 results in numerous cabins suggests that there may be a significant false-negative rate with RT-PCR testing. Follow-up testing is being performed to determine this.
  • The timing of symptoms in some passengers (day 24) suggests that there may have been cross contamination after cabin isolation.

 

Just how reliable is RT-PCR really?  According to this piece in IEEE Spectrum, current test setups reach are essentially 100% sensitive (no false negatives) and 96% specific (4% false positives) with lab-generated samples., i.e., if you feed them virus cultures. The trouble begins when you have to collect specimens from actual patients.  According to this piece in MD Magazine,   “Of the specimens collected [from known COVID-19 patients], bronchoalveolar lavage fluid specimens demonstrated the highest positive rates of at 93% (n = 14). This was followed by sputum at 72% (n = 75), nasal swabs at 63% (n = 5), fibrobronchoscope brush biopsy at 46% (6/13), pharyngeal swabs at 32% (n = 126), feces at 29% (n = 44) and blood at 1% (n = 3). The authors of that study pointed out that testing of specimens from multiple sites may improve the sensitivity and reduce false-negative test results.” 

 

(3) Via David Bernstein: the WSJ on New York’s long road to recovery even after a lifting of the lockdown. (Archived copy here.)

And via Instapundit, the NYTimes on The price of a lockdown: economic freefall in California

(archived copy ) To be fair, the tourism industry would have been bludgeoned with or without a lockdown, as the (proportionally less important) Swedish tourism sector has learned.

But a large part of the rest could have been mitigated, and can still be mitigated, by not going the “37-step reopening over 10 years” route in California.  (Heck, when did The Babylon Bee forget it was a satirical publication?) But — as much as this sickens even the jaded student of history — I suspect that for some politicians, ensuring that the recovery does not happen before November is worth any price…  

 

Finally, to my Jewish readers, happy Shavuot! There will probably not be an edition on the holiday unless breaking developments warrant it.

 

ADDENDUM: an op-ed in The Lancet in defense of prophylactic use of hydroxychloroquine in India.

One thought on “COVID19 update, May 28, 2020: ACE inhibitors beneficial; asymptomatic infection rate as high as 80%; NYT on California economy in freefall

  1. Thanks for the update, as always. Interesting that nasal swabs only come back at 63%… Not real good!

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