Weekly Update, April 12th - April 18th

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An update of significant developments in regarding the COVID-19 pandemic for the week of April 13th through April 19th.

1) Some pregnant women are COVID-19 positive and asymptomatic.
A letter in the New England Journal reports that of 211 asymptomatic pregnant women being delivered in New York, 1 in 8 (13.7%) were COVID-19 positive and of these 90% were asymptomatic.  

This is not unexpected given the degree of disease in New York and the fact that we know a significant portion of patients with COVID-19 are asymptomatic. 

The testing of women who go into labor should be individualized to each community and should follow the local testing practice pattern. 

This is consistent with expert opinion that recommend COVID-19 testing for women scheduled for induction or Cesarean section 24-28 hours before admission and again on presentation.  If screening is positive, the induction or operative delivery should be delayed if medically possible.  All patients (obstetrical or not, in labor or not) should be screened for symptoms.  A summary of these recommendations can be found here.

Desmond S, Fuchs K, D’Alton. M. Universal Screening for SARS-CoV-2 in Women Admitted for Delivery (letter). April 13, 2020 DOI: 10.1056/NEJMc2009316

2) Data regarding surgical masks is mixed but mostly positive. 

A study of 246 patients with various viruses and not just COVID-19, showed a significant reduction of virus in the aerosol and droplets of those wearing masks. For the patients tested who had non-COVID19 coronavirus there was a significant decrease in virus particles in those wearing surgical masks (in respiratory droplets, from 30% to 0%; aerosols, 40% to 0%).  The same is true for influenza infection (respiratory droplets, 26% to 4%; aerosols, 35% to 22%).  Masks did not seem to reduce the number of virus particles for rhinovirus.

In a 2nd study of only 4 patients with collection medium only 20cm from an individual’s face the number of virus particles cultured was similar between those using and not using masks.  However, this is only 4 patients and it does not tell us about virus spread outside of 20cm (e.g. is the velocity and distance of virus dispersement different than without a mask?).

Leung NHL et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med 2020 Apr 2; [e-pub]. (https://doi.org/10.1038/s41591-020-0843-2)  
Bae S et al. Effectiveness of surgical and cotton masks in blocking SARS–CoV-2: A controlled comparison in 4 patients. Ann Intern Med 2020 Apr 6; [e-pub]. (https://doi.org/10.7326/M20-1342)

3) A randomized, double-blinded trial of chloroquine for COVID-19 was stopped early in Brazil because of the development of a prolonged QT and a trend toward a higher mortality with chloroquine 600mg BID. 
Eighty-one of a planned 400 hospitalized patients were enrolled using either 600mg BID of chloroquine for 10 days or 450mg BID for 5 days.  All patients also got azithromycin and ceftriaxone. The high-dose arm was stopped early because of significant prolongation of the QT in 25% with a trend towards increased mortality (17% in the high dose group vs. 13% with the lower dose).   It is recommended to continue to follow the IDSA guidelines for treatment which can be found here.     
Silva Borba MG, de Almeida F,  Sousa Sampaio V. et al. Chloroquine diphosphate in two different dosages as adjunctive therapy of hospitalized patients with severe respiratory syndrome in the context of coronavirus (SARS-CoV-2) infection: Preliminary safety results of a randomized, double-blinded, phase IIb clinical trial (CloroCovid-19 Study) doi: https://doi.org/10.1101/2020.0... 

4) 30% ethanol is enough to inactivate the COVID-19 virus after 30 seconds of contact (Note: that this is not standard of care but might be applicable in low resource areas).
Questions about disinfected surfaces in the time of COVID-19 are legion.  A study published by the CDC in the “Emerging Infectious Diseases” on 14 April 2020  suggests that 30% ethanol is just as effective as 80% ethanol.  They did quantitative inactivation studies of COVID-19 viruses and looked at various dilutions of ethanol and 2-propranol.  The caveat is the contact has to be for at least 30 seconds.  All of the WHO-recommended solutions work, as well. 

Discussion:  This is not recommended this as a routine practice.  If resources are very limited, this offers another option.  

Kratzel A, Todt D, V’kovski P, Steiner S, Gultrom M, Thao TTN, et al. Inactivation of severe acute respiratory syndrome coronavirus 2 by WHO-recommended hand rub formulations and alcohols. Emerg Infect Dis. 2020 Jul [date cited]. https://doi.org/10.3201/eid2607.200915

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