Weekly Update: July 20th - July 27th

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In COVID-19 news this week, the CDC has revised the quarantine duration for patients with the disease, inhaled interferon shows promise, but data is very limited, transmission from older children is not uncommon and myocarditis is common among those with COVID-19 but the long term sequelae in survivors seem minor.  Finally, hydroxychloroquine still doesn’t work.

 Based on testing data, the CDC has determined that, except in rare cases (severe disease, immunosuppressed), the SARS-CoV-2 virus is no longer infectious 10 days after the onset of symptoms in patients with mild illness.  Accordingly, the duration of quarantine for symptomatic individuals has been reduced to 10 days after symptom onset from the current 14 days as long as the patient is afebrile for 24 hours without the use of fever reducing drugs. Note that this does not change the length of quarantine for exposed individuals. Isolation is still 14 days after exposure.
Other points of note:

  • A test-based strategy for leaving quarantine is no longer recommended (though can be used if needed to end quarantine in less than 10 days).
  • Serologic testing should not be used to determine the presence or absence of SARS-CoV-2.
  • PCR should not be done within the first 90 days of a previous positive. It likely represents viral RNA shedding and not new infection.

The full guideline is found here.

 Inhaled interferon shows promise in reducing the severity of COVID-19 but we do not yet have published data. This randomized, controlled trial of a proprietary inhaled interferon with a planned 400 patients was stopped early after 101 patients were enrolled. The combined endpoint of death and need for mechanical ventilation was lower in those getting inhaled interferon. It isn’t clear from the press release that mortality was statistically better in the treatment group. The limited press release is not enough to push us to change our current practice.  
The press release is here.

 Household transmission of SARS-CoV-2 from those aged 10-19 is more likely than from other age groups (although household transmission is less likely from those 0-9 years of age).
This is a study from Korea of 59,000 contacts of 5700 COVID-19 patients looking at positivity rates among contacts. Within households, there was an 11.8% COVID-19 positive rate overall (somewhat reassuring itself). The authors broke down household contacts by age. The index patient was 10-19 years old (124 individuals) in 18.6% (95% CI 14.0%–24.0%) of the families. Positive rate in families with an index case age 0-9 (29 individuals) was only 5.3% (95% CI 1 1.3%–13.7.0%). They do note that as more children are exposed when returning to school, their role in transmission will likely increase simply because of the increased number of exposures and positives in children.  And, the numbers are still small in the 0-9 year age group.
Park YJ et al. Contact tracing during coronavirus disease outbreak, South Korea, 2020. Emerg Infect Dis. 2020 Oct (early release) https://doi.org/10.3201/eid2610.201315

The majority of hospitalized patients with COVID-19 have an elevated high sensitivity troponin T. Some patients have myocarditis but a preserved ejection fraction after discharge.
This is a series of 828 patients discharged from a single hospital in Britain. Seventy-one percent had an elevate high-sensitivity troponin-T (hsTnT) of which 41% died (compared to 8% of those without an elevated hsTnT). They excluded patients with PE or a history of ACS or another reason for an elevated troponin. A complete evaluation including cardiac MRI was only done on 29 patients (4%).  Of these 29, 69% had “residual lung parenchymal changes”. Findings suggestive of myocarditis were seen in 45% of the 29. The mean left ventricular ejection fraction was normal, however (68%).

Unfortunately, even though they started with 828 patients in their series, only 4% had a complete workup after excluding known causes of an elevated hsTnT (which is clearly a marker for overall higher mortality).  In those with presumed COVID-19 related myocarditis, the ejection fraction and wall motion were normal. There were some residual lung parenchymal changes but the clinical significance is not clear. It is hard to know what to do with this data at this point. Longer term follow-up will tell if there is any clinical significance to these findings.
Knight DS et al. COVID-19: Myocardial injury in survivors. Circulation 2020 Jul 14; [e-pub]. (https://doi.org/10.1161/CIRCULATIONAHA.120.049252)

Finally, hydroxychloroquine still doesn’t work.
This is a randomized, multicenter open label study of consecutive patients admitted for presumed COVID-19 less than 14 days after symptom onset (667 patients were enrolled but only 504 patients were found to be COVID-19 positive. Exclusion criteria included the need for > 4L of oxygen or use of study drug/macrolide for >24 hours before enrollment.  Five-hundred and four patients were randomized 1:1:1 to get standard care alone, or plus hydroxychloroquine, or hydroxychloroquine + azithromycin. Treatment was continued for 7 days.
There was no difference in any outcome between the groups including death, discharge, need for oxygen, continued limits on activities after discharge, etc.
We already have data that hydroxychloroquine does not work for severe COVID-19 disease. We now have data that it does not work for mild-moderate disease requiring hospitalization. This also tells us that if it walks like a duck and quacks like a duck it is a house wren.  A significant percentage of the patients enrolled for presumed COVID-19 did not test positive. Remember the “normal” diseases when seeing a patient with symptoms and signs that may be attributable to COVID-19.
Cavlacanti, AB et al. J Hydroxychloroquine with or without Azithromycin in Mild-to-Moderate Covid-19. NEJM July 23, 2020 DOI: 10.1056/NEJMoa2019014




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