Should I treat my patient with Covid-19 with ivermectin?

Despite its potential antiviral activity,1 there is insufficient data at this time to recommend either for or against the use of ivermectin for the treatment of Covid-19, per NIH Covid-19 guidelines.2 This conclusion is based on lack of robust, adequately powered and designed clinical trials.2

Although some studies (published or preprint) have reported benefits of ivermectin (eg, shorter time to resolution of disease or viral clearance, greater reduction in inflammatory markers, and lower mortality rates) in Covid-19, others have found either no benefit or worsening of disease with ivermectin therapy.2-6

Unfortunately, methodological problems have plagued many of these studies.1 For example, a randomized-controlled preprint study from Egypt reported clinical improvement and decreased mortality in Covid-19 patients treated with ivermectin.  Unfortunately, the ivermectin group also received hydroxychloroquine plus a “standard therapy”, defined in the study as azithromycin, vitamin C, zinc, lactoferrin and acetylcysteine.3

A retrospective study from Bangladesh involving hospitalized patients with Covid-19,  reported lower mortality in those receiving only 1 dose of ivermectin (12 mg) within 24 h of admission.  However, 60% of the non-ivermectin group also received antibiotics, often for undefined “secondary infection” (vs 15% of ivermectin group)4, making it difficult to interpret the results.

In contrast, a retrospective preprint study from Peru found significantly higher rates of death and/or ICU transfer among hospitalized patients treated with ivermectin or hydroxychloroquine+azithromycin.4

The plausibility of studies supporting treatment of Covid-19 with ivermectin has been further questioned because, despite its apparent antiviral activity in vitro,1 pharmacokinetic and pharmacodynamic studies suggest that doses up to 100 times higher than those approved for use in humans would be needed to achieve potentially effective plasma concentrations.2,7

Bonus Pearl: Did you know that ivermectin enhances the activity of GABA receptors, resulting in paralysis of somatic muscles, poor pharyngeal function and starvation of parasites and worms? 8 Fortunately, ivermectin’s affinity for parasite is 100 times more than for brain of mammals because of the blood brain barrier.

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References

  1. Lehrer S, Rheinstein PH. Ivermectin docks to the SARS-CoV-2 spike receptor-binding domain attached to ACE2. In vivo 2020;34:3023-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652439/pdf/in_vivo-34-3023.pdf
  2. NIH. The Covid-19 treatment guidelines panel’s statement on the use of ivermectin for the treatment of COVID-19. Last updated Jan 14, 2021. https://www.covid19treatmentguidelines.nih.gov/statement-on-ivermectin/. Accessed January 18, 2021.
  3. Elgazzar A, Hany B, Abo Youssef S, et al. Efficacy and safety of ivermectin for treatment and prophylaxis of COVID-19 pandemic. Research Square Preprint 2020. https://assets.researchsquare.com/files/rs-100956/v2/39b225ad-5df4-4da7-9cbd-233bf26a0eb4.pdf
  4. Ahmed S, karim MM, Ross AG, et al. A five-day course of ivermectin for the treatment of COVID-19 may reduce the duration of illness. International J Infect Dis 2021;103:214-16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7709596/
  5. Soto-Becerra P, Culquichicon C, Hurtado-Roca Y, et al. Real-world effectiveness of hydroxychloroquine, azithromycin, and ivermectin among hospitalized COVID-19 patients: results of a target trial emulation using observational data from a nationwide healthcare system in Peru. MedRxive 2020. https://www.medrxiv.org/content/10.1101/2020.10.06.20208066v3.full.pdf
  6. Chachar AZ, Khan KA, Asif M, et al. Effectiveness of ivermetctin in SARS-CoV-1/COVID-19 patients. International J Sciences 2020; 9:31-35. https://c19ivermectin.com/chachar.html
  7. Chaccour C, hammann F, Ramon-Garcia S, et al. Ivermectin and COVID-19: Keeping rigor in times of urgency. Am J Trop med hyg 2020;102:1156-7. https://pubmed.ncbi.nlm.nih.gov/32314704/  
  8. Kaur H, Shekhar N, Sharma S, et al. Ivermectin as a potential drug for treatment of COVID-19:an in-sync review with clinical and computational attributes. Pharmacological Reports. Published online January 3, 2021. Great review https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7778723/pdf/43440_2020_Article_195.pdf

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Should I treat my patient with Covid-19 with ivermectin?

Beyond masks and hand hygiene, what factors impact transmission of Covid-19 in indoor gatherings?

Aside from factors specific to the source individual (eg, viral load in exhaled air, “superspreader” features, etc…) and host characteristics (eg, older age, obesity, immunocompromised state), transmission of SARS-CoV-2 in indoor settings may be impacted by several factors, including social distancing, ventilation of rooms/ direction of airflow, room occupancy, exposure time and higher risk activities, such as eating, talking loud, heavy breathing during exercise, laughing, coughing and sneezing. 1-4

  1. Physical distance from infected individuals. Although a “safe” distance of 6 feet has often been cited, increasing evidence suggests that SARS-CoV-2 may be spread not only by larger droplets but also by airborne route (ie, beyond 6 feet or shortly after an infected person leaves the area). In fact, 8 of 10 studies on horizontal droplet distance have reported droplets traveling more than 6 feet (2 meters), some cases up to 26 feet (8 meters), and 1 study documented virus at 13 feet (4 meters). Transmission beyond 6 feet is not surprising since even as early as 1948 beta streptococci were found 9.5 feet from 10% of people who were infected!1
  2. Quality of ventilation and direction of airflow in the room. Poorly ventilated rooms would be expected to have more potentially infectious droplets in the air for longer periods of time, even after an infected person leaves the area.
  3. Room occupancy. The higher the occupancy the more likely to have exhaled contaminated air from 1 or more infected persons (symptomatic or asymptomatic) with exposure of susceptible hosts.
  4. Exposure time. Exposure to contaminated air in the room even for a relatively short period of time (ie, >5-15 minutes) is likely to increase the risk of transmission.
  5. Activity of infected individual. Many activities such as singing, speaking loudly, eating, laughing, breathing heavily during exercise, coughing and sneezing may increase risk of Covid-19 transmission in indoor settings.

Recall that over one-half of Covid-19 transmissions are due to asymptomatic individuals.5 In this setting and in the presence of factors discussed above, it’s easy to see how transmission of Covid-19 in indoor settings can occur readily, possibly explaining cases without apparent source.

Bonus Pearl: Did you know that the odds of Covid-19 transmission may be 18.7 times greater indoors compared to open-air environment and the odds of superspreading event in closed environments may be 32.6 times higher?4

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References

  1. Bahl P, Doolan C, de Silva C, et al. Airborne or droplet precautions for health workers treating coronavirus disease 2019? J Infect Dis 2020. Published online April 16, 2020. https://pubmed.ncbi.nlm.nih.gov/32301491/
  2. Jones NR, Quereshi Z, Temple RJ, et al. Two metres or one: what is the evidence for physical distancing in covid-19? BMJ 2020;370:m3223. https://www.bmj.com/content/370/bmj.m3223/rr-18
  3. Johansson MA, Quandelacy TM, Kada S, et al. SARS-CoV-2 transmission from people without COVID-19 symptoms. JAMA Network open. 2021;4():e2035057. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2774707?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=010721
  4. Nishiura H, Oshitani H, Kobayashi T, et al. Closed environments facilitate secondary transmission of coronavirus disease 2019 (COVID-19). MedRxiv 2020. https://www.medrxiv.org/content/10.1101/2020.02.28.20029272v2.full.pdf
  5. Leclerc QJ, Fuller NM, Knight LE,e tal. What settings have been linked to SARS-CoV-2 transmission clusters? Wellcome Open Research October, 2020. https://wellcomeopenresearch.org/articles/5-83    

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Beyond masks and hand hygiene, what factors impact transmission of Covid-19 in indoor gatherings?

Can race affect the accuracy of pulse oximetry measurement?

It can! In persons with darkly pigmented skin, pulse oximeters may overestimate arterial oxygen saturation, such that some individuals with oxygen saturation within an acceptable range by pulse oximetry may actually be hypoxemic by arterial blood measurement.1-3

A 2020 study involving 2 large patient populations with oxygen saturations of 92-96% by pulse oximetry, found occult hypoxemia (<88% arterial oxygen saturation) in ~12% of patients who were Black vs ~4% of those who were White. Black individuals were 3 times more likely to have occult hypoxemia than White patients.1

Overestimation of oxygen saturation—particularly at low arterial oxygen saturation— by pulse oximetry in dark-skinned individuals has been previously reported by several studies, although some have not found significant differences at normal saturations, and the degree of discordance may vary among various pulse oximeters.2,3

The reason for the apparent discrepancy between oxygen saturation measured by pulse oximetry vs arterial blood sample in those with dark skin is unclear. Some have suggested “pulse oximeter optical factors” and theorized that provision of correction factors, tables, or even built-in user -optional adjustments may be necessary.2

Given the frequent use of pulse oximetry for medical decision making in Covid-19, these studies should serve as a cautionary note when interpreting oxygen saturation by pulse oximeter in dark-skinned patients with Covid-19.

Bonus Pearl: Did you know that falsely-LOW oxygen saturation has been reported with blue and green nail polish but not red?4

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References

  1. Sjoding MW, Dickson RP, Valley TS. Racial bias in pulse oximetry measurement. N Engl J Med 2020;383:2477-78. https://pubmed.ncbi.nlm.nih.gov/33326721/
  2. Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesthesiology 2005;102:715-9. https://pubs.asahq.org/anesthesiology/article/102/4/715/7364/Effects-of-Skin-Pigmentation-on-Pulse-Oximeter
  3. Zeballos RJ, Weisman. Reliability of noninvasive oximetry in Black subjects during exercise and hypoxia. Am Rev Resp Dis 1991;144:1240-4. https://www.atsjournals.org/doi/pdf/10.1164/ajrccm/144.6.1240
  4. Cote CJ, Goldstein EA, Fuchsman WH. The effect of nail polish on pulse oximetry. Anesth Analg 1988;75:683-6. https://pubmed.ncbi.nlm.nih.gov/3382042/

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Can race affect the accuracy of pulse oximetry measurement?

Is the discovery of new variants of SARS-CoV-2 expected to impact the transmissibility, clinical course or vaccine efficacy in Covid-19?

To date, the discovery of new variants of SARS-CoV-2 has raised concerns primarily around their association with higher than expected transmission rates, not increased severity, risk of death or impairment in vaccine efficacy. 1-5

The new variants of SARS-CoV-2—first recognized in the U.K (strain B.1.1.7), then South Africa (B.1.351), and now many parts of the world, including US and Canada—seem to be associated with higher rates of transmission without any evidence for more severe disease or hospitalization.3 Based on mathematical models, it is suggested that the new variant may be up to 70% more transmissible than the original virus.1 However, it is important to point out that, to date, there are no published studies that corroborates this finding in laboratory animals and some have questioned whether these new strains are truly more transmissible.1

The B.1.1.7 strain has several mutations involving the spike protein (the surface  protein that attaches to host cells) at least 1 of which (N501Y) seems to improve the virus’s ability to bind to cells.1 Preliminary laboratory studies have also found higher viral replication rates in upper respiratory tract of hamsters when challenged with another SARS-CoV-2 variant with spike protein mutation (D614G) compared to the lungs.4  Both “stickiness” to cells and high replication rates in upper respiratory tract alone may explain more rapid spread of the virus without increased severity of disease.

Preliminary reports also suggest that that antibodies against the original strain  neutralize the B.1.1.7 strain, supporting the efficacy of the current Covid-19 vaccine in protecting against this strain.1

A theoretical concern, however, based on a preprint publication, is the suboptimal binding and neutralization of new strains by commercially available monoclonal antibodies.2

The potential increased transmissibility of new SARS-CoV-2 variants only underscores the importance of public health measure such as masks, social distancing and hand hygiene, now more than ever before!

Bonus Pearl: Did you know that despite lack of clear increase in the severity of disease associated with new variants of SARS-CoV-2, increased rate of transmission will lead to more people getting infected and therefore die from its complications. That’s why, more than ever before, we should double down our efforts to stick to public health measures to mask, social distance and exercise hand hygiene during this critical period of the pandemic. Please spread the word, again!

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References

  1. Reardon S. The U.K. coronavirus mutation is worrying but not terrifying. Scientific American. December 24, 2020. https://www.scientificamerican.com/article/the-u-k-coronavirus-mutation-is-worrying-but-not-terrifying/
  2. Starr TN, Greaney AJ, Addetia A, et al. Prospective mapping of viral mutations that escape antibodies used to treat COVID-19. Bio Rxiv 2020. https://www.biorxiv.org/content/10.1101/2020.11.30.405472v1
  3. CDC. Interim: Implications of the emerging SARS-CoV-2 variant VOC 202012/01. Accessed Jan 12, 2020. https://www.cdc.gov/coronavirus/2019-ncov/more/scientific-brief-emerging-variant.html
  4. Plante JA, Liu Y, Liu J, et al. Spike mutation D614G alters SARS-CoV-2 fitness. Nature. Published online 26, 2020. https://pubmed.ncbi.nlm.nih.gov/33106671/
  5. Baric RS. Emergence of a highly fit SARS-CoV-2 variant. N Engl J Med 2020; 383;2684-2686. https://www.nejm.org/doi/full/10.1056/NEJMcibr2032888

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Is the discovery of new variants of SARS-CoV-2 expected to impact the transmissibility, clinical course or vaccine efficacy in Covid-19?

What’s the connection between Covid-19 and persistent fatigue?

Fatigue is one of the most common symptoms in patients with Covid-19, both during the acute illness as well during the weeks or months that follows it. Depending on the study, fatigue has been reported in around 30%-80% of patients at 2-3 weeks to 6 months or longer after the onset of illness (1-4).

In a study of hospitalized patients with Covid-19, ~80% of patients complained of fatigue during the acute illness, with ~50% having persistent fatigue at a mean follow-up of 60 days following onset of illness (1). Persistent fatigue was the most common symptom during the post-Covid-19 period, followed by dyspnea, joint pain, chest pain and cough.

In another study, 52.3% of patients with Covid-19 complained of persistent debilitating fatigue at a median of 10 weeks after initial onset of symptoms, despite a negative test for the virus (2). Of interest, there was no association between severity of Covid-19 illness/need for hospitalization and post-covid fatigue.  No association was found between routine laboratory markers of inflammation, WBC profile, LDH, C-reactive protein or interleukin-6 levels and persistent fatigue.

A CDC survey of outpatients with Covid-19 patients at 14-21 days from test date found persistent fatigue in one-third of patients (3).   

A MedRxive study (pending peer review) of over 3700 patients with definite (27%) or probable diagnosis of Covid-19 from 56 countries (>90% not hospitalized) reported fatigue in 78% of patients after 6 months (4).

Although the true nature or course of persistent fatigue following Covid-19 has yet to be clearly defined, In some respects, it’s reminiscent of chronic fatigue syndrome associated with many acute viral infections, such as SARS, EBV, and enteroviruses (5-7).

Bonus pearl: Did you know that persistent fatigue following Covid-19 may be more frequent than that following influenza in which >90% of outpatients recover within about 2 weeks (3)?

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References

  1. Carfi A, Bernabei R, Landi. Persistent symptoms in patients after acute COVID-19.JAMA 2020;324:603-605. https://pubmed.ncbi.nlm.nih.gov/32644129/
  2. Townsend L, Dyer AH, Jones K, et al. Persistent fatigue following SARS-CoV-2 infection is common and independent of severity of initial infection. PLOS ONE 2020. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0240784   
  3. Tenforde MW, Kim SS, Lindsell CJ, et al. Duration and risk factors for delayed return to usual health among outpatients with COVID-19 in a multistate health care systems network—United States, March—June 2020. MMWR 2020;69:993-98. https://www.cdc.gov/mmwr/volumes/69/wr/mm6930e1.htm
  4. Davis HE, Assaf GS, MCorkell L, et al. Characterizing long COVID in an international cohort:7 months of symptoms and their impact. MedRxive 2020. https://www.medrxiv.org/content/10.1101/2020.12.24.20248802v2.full.pdf
  5. Chia JKS, Chia AY. Chronic fatigue syndrome is associated with chronic infection of the stomach. Clin Pathol 2008;61:43-48. https://jcp.bmj.com/content/61/1/43
  6. Moldofsky H, Patcai J. Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case control study. BMC Neurol 2011;11:37. https://pubmed.ncbi.nlm.nih.gov/21435231/
  7. Hickie I, Davenport T, Whitfield D, et al. Post-infective and chronic fatigue syndrome precipitated by pathogens: prospective cohort study. BMJ 2006;333:575. https://jcp.bmj.com/content/61/1/43

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital or its affiliated institutions. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

What’s the connection between Covid-19 and persistent fatigue?

What’s the connection between Covid-19 and hypokalemia?

The association of hypokalemia with hospitalized Covid-19 patients has been recognized since the early days of the pandemic, with more severe cases associated with lower concentration of serum potassium.1-4

A study involving 175 hospitalized patients with Covid-19 found low serum potassium in 54% of patients with 18% having severe hypokalemia (<3.0 mmol/L) and 37% having serum potassium 3.-3.5 mmol/L.  Compared to patients with mild to moderate Covid-19, those with severe or critical disease were more likely to have low serum potassium (3.5 mmol/L or less) (85% vs 45%).1

Another study involving 306 hospitalized patients with Covid-19, nearly a third (31%) had hypokalemia (3.5 mmol/L or less). Hypokalemia was associated with invasive mechanical ventilation, longer hospital and ICU stays.2 In contrast, a non-peer-reviewed MedRxive study found no association between hypokalemia and ICU admission or in-hospital mortality, possibly related to milder hypokalemia in the patients studied.3

Although various mechanisms may be invoked to explain hypokalemia in hospitalized Covid-19 patients (eg, poor intake, diuretics, corticosteroids, diarrhea, etc…), the most fascinating explanation may revolve around the direct impact of SARS-CoV-2 on the renin-angiotensin system.5  Because this virus uses the enzymatic receptor of ACE2 to penetrate the host cell, it can lead to downregulation of ACE2. Since ACE2 serves as a counterbalance to ACE by transforming a part of angiotensin I and II before they attach to angiotensin II type 1 receptor (AT1R), aldosterone effect is enhanced with resultant hypokalemia. High urinary excretion of potassium in many patients with Covid-19 seem to support the latter hypothesis.1,3  

Who would have predicted the versatility of this virus in causing hypokalemia in addition to all the other physiologic derangements it causes?  

Bonus Pearl: Did you know that there may be an association between lower prevalence of dry cough in patients with Covid-19 and hypokalemia, possibly related to low ACE2—therefore bradykinin— activity mediated by SARS-CoV-2? 2

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References

  1. Chen D, Li X, Song Q, et al. Assessment of hypokalemia and clinical characteristics in patients with coronavirus disease 2019 in Wenzhou, China. JAMA Network Open 2020;3(6):e2011122. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2767008
  2. Moreno-Perez O, Leon-Ramirez JM, Fuertes-Kenneally L, et al. Hypokalemia as a sensitive biomarker of disease severity and the requirement for invasive mechanical ventilation requirement in COVID-19 pneumonia: A case series of 306 Mediterranean patients. International J Infect Dis 2020;100:449-54. https://www.ijidonline.com/article/S1201-9712(20)30749-9/pdf
  3. Gaetano A, Annachiara F, Francesco F, et al. Hypokalemia in patients with COVID-19. MedRxive preprint. Doi:https://doi.org/10.1101/2020.0614.20131169. https://www.medrxiv.org/content/10.1101/2020.06.14.20131169v2.full.pdf
  4. Lippi G, South Am, Henry BM. Electrolyte imbalances in patients with severe coronavirus disease 2019 (COVID-19). Ann Clin Biochem 2020;57:262-65. https://pubmed.ncbi.nlm.nih.gov/32266828/
  5. Silhol F, Sarlon G, Deharo JC, et al. Downregulation of ACE2 induces overstimulation of renin-angiotensin system in COVID-19: Should we block the renin-angiotensin system? Hypertension Research 2020;43:854-856. https://www.nature.com/articles/s41440-020-0476-3

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

What’s the connection between Covid-19 and hypokalemia?

Can my patient with Covid-19 get reinfected?

Patients with prior history of Covid-19 have been shown to get reinfected, sometimes less severe and sometimes more severe than the first bout.1-3 What we don’t really know is how often reinfection actually occurs, either with or without symptoms.

Symptomatic reinfection with genetically distinct SARS-CoV-2 following Covid-19 has been reported from several countries, including the USA. 1  A case series of 4 patients (age range of 33-51 y) found the severity of second infection ranging from asymptomatic to more severe disease requiring hospitalization.  First infection was mild in these cases with an intervening period of 48-142 days.1  BNO News, a Dutch website, lists many more “officially confirmed cases” as well as over a thousand “suspected reinfection cases”.4

Reinfection with Covid-19 in at least some people should not be too surprising. Some may have a suboptimal immune response to the first infection (eg with mild infection) that may be short-lasting, while others may have a better response.  Even in those with adequate response, SARS-CoV-2 antibodies may drop rapidly (half-life 36 days according to one study).3 Immunity to several other seasonal respiratory coronaviruses (cousins of SARS-CoV-2) also seems short lived (as short as 6 months).5 How much other arms of the immune system besides antibodies (eg, T cell immunity) play a role in conferring longer lasting immunity remains unclear.

These findings suggest that we cannot rely on natural infection to provide us individual or herd immunity.  Immunization is likely a better answer!

Bonus Pearl: Did you know that preliminary reports suggest that antibody loss with Covid-19 is more rapid than that found for SARS-CoV-1, the agent of SARS pandemic of 2003?3

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References

  1. Iwasaki A. What reinfections mean for COVID-19. Lancet Infect Dis 2020. Published online October 12, 2020. https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(20)30783-0/fulltext
  2. Tillett RL, Sevinsky JR, Hartley PD, et al. Genomic evidence for reinfection with SARS-CoV-2: a case study. Lancet Infect Dis 2020. Published online October 12, 2020. https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(20)30764-7.pdf
  3. Ibarrondo J, Fulcher JA, Goodman-Meza D, et al. Rapid decay of anti-SARS-CoV-2 antibodies in persons with mild Covid-19. N Engl J Med 2020; September 10. https://www.nejm.org/doi/full/10.1056/nejmc2025179
  4. Kunzman K. Contagion Live. October 12, 2020. https://www.contagionlive.com/view/us-reports-first-confirmed-covid-19-reinfection-patient. Accessed Dec 23, 2020.
  5. Edridge AWD, Kaczorowska J, Hoste ACR, et al. Seasonal coronavirus protective immunity is short-lasting. Nature Medicine 2020;26:1691-93. https://pubmed.ncbi.nlm.nih.gov/32929268/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

 

 

Can my patient with Covid-19 get reinfected?

How effective are face masks in reducing transmission of Covid-19?

Overall, review of data to date suggests that face masks are quite effective in reducing the transmission of coronaviruses, including SARS-CoV-2, the cause of Covid-19. A Lancet 2020 meta-analysis involving over 12,000 subjects, found that transmission of coronaviruses (SARS-CoV-2, SARS and MERS) was reduced with face masks by 85% (adjusted O.R. 0.15, 95%CI 0.07-0.34).1

More specific to Covid-19, a study from Mass General Brigham hospitals found a significant drop in healthcare worker (HCW) SARS-CoV-2 PCR positivity rate from 21.3% to 11.5% following adoption of universal masking of HCWs and patients.2

An U.S. epidemiologic survey of 2,930 unique counties plus New York City found mandating face mask use in public was associated with a significant decline in the daily Covid-19 growth rate. 3 It was estimated that more than 200,000 Covid-19 cases were averted by May 22, 2020 as a result of the implementation of these mandates.

Another 2020 meta-analysis involving 21 studies reported an overall efficacy of masks (including surgical and N-95 masks) of 80% in healthcare workers and 47% in non-healthcare workers for respiratory virus transmission (including SARS, SARS-CoV-2 and influenza).4

A criticism of above reports has been their primarily retrospective nature. A randomized-controlled Danish study found a statistically insignificant 20% reduction in incident SARS-CoV-2 infection among mask wearers (5,6).    Despite its randomized-controlled design, this study had several limitations, including relatively low transmission rate in the community and lack of universal mask wearing in public during the study period. In addition, less than one-half of participants in the mask group reported adherence to wearing masks, and there was no assurance that masks were worn correctly when they did wear them. 

At most, this study suggests that it’s not enough for the uninfected to wear masks; the infected—often with little or no symptoms— should also wear them to help curb the pandemic.

So please do your part and tell your friends and family members to do the same by masking up while we are at war with Covid-19!

Bonus Pearl: Did you know that universal wearing of masks in the public in response to a respiratory virus pandemic is nothing new?  It was adopted as far back as 100 years ago during the 1918 Spanish influenza pandemic!

References

  1. Chu DK, Akl EA, Duda S, et al. Physical distancing, face masks, and eye protection to prevent person-to-person transmission of SARS-CoV-2 and COVID-19: a systematic review and meta-analysis. Lancet 2020;395: 1973-87. https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(20)31142-9.pdf
  2. Wang X, Ferro EG, Zhou G, et al. Association between universal masking in a health care system and SARS-CoV-2 positivity among health care workers. JAMA 2020;324:703-4. https://jamanetwork.com/journals/jama/fullarticle/2768533
  3. Lyu W, Wehby GL. Community use of face masks and COVID-19: evidence from a natural experiment of state mandates in the US. Health Affairs 2020;39: July 16. https://www.healthaffairs.org/doi/full/10.1377/hlthaff.2020.00818
  4. Liang M, Gao L, Cheng Ce, et al. Efficacy of face mask in preventing respiratory virus transmission: A systematic review and meta-analysis. Travel Med Infect Dis 2020;36:1-8. https://pubmed.ncbi.nlm.nih.gov/32473312/ 
  5. Bundgaard H, Bundgaard JS, Tadeusz DE, et al. Effectiveness of adding a mask recommendation to other public health measures to prevent SARS-CoV-2 infection in Danish mask wearers. Ann Intern Med 2020; November 18. https://pubmed.ncbi.nlm.nih.gov/33205991/
  6. Frieden TR Cash-Goldwasser S. Of masks and methods. Ann Intern Med 2020; November 18. https://www.acpjournals.org/doi/10.7326/m20-7499

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Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliate healthcare centers. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How effective are face masks in reducing transmission of Covid-19?

What’s the connection between break rooms and transmission of Covid-19 in health care settings?

Emerging data suggest that healthcare workers (HCWs) may be at increased risk of Covid-19 in break rooms when consuming food or when in the presence of others without a mask.1-4

In a study of over 700 HCWs screened for SARS-CoV-2 by PCR at a university hospital, staying in the same personnel break room as an HCW without a medical mask for more than 15 min and consuming food within 1 meter of an HCW were significantly associated with SARS-CoV-2 infection.1 Consumption of food in break rooms by personnel was thereafter “forbidden” in this facility. Interestingly, 28% of infected personnel in this study lacked symptoms at the time of testing.

A recent outbreak at a Boston hospital involving both patients and HCWs months after institution of strict infection control measures (including universal masking of visitors and HCWs and PCR testing of all patients on admission) traced the outbreak to a variety of factors, including HCWs eating in crowded work rooms.2,3

A CDC study of risk factors among adults 18 years or older with Covid-19 in the community identified dining at a restaurant as significant risk factors for Covid-19.4

Transmission of SARS-CoV-2 during eating or drinking is not surprising because masks cannot be effectively worn during food consumption. Combine eating or drinking with talking, laughing and suboptimal ventilation system and we have all the elements of perfect storm for transmission of Covid-19 during food breaks.

Bonus Pearl: Did you know that, in addition to dining at a restaurant, patients with Covid-19 without known close contact with infected persons have reported higher likelihood of going to bar/coffee shop? 4

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References

 

  1. Celebi G, Piskin N, Beklevic AC, et al. Specific risk factors for SARS-CoV-2 transmission among health care workers in a university hospital. Am J Infect Control 2020;48:1225-30. https://pubmed.ncbi.nlm.nih.gov/32771498/
  2. Freyer FJ. Brigham and Women’s hospital completes investigation of coronavirus outbreak. Boston Globe, October 19, 2020. https://www.bostonglobe.com/2020/10/19/metro/brigham-womens-hospital-completes-investigation-coronavirus-outbreak/
  3. Freyer FJ. At the Brigham, “battle-weary” staff may have allowed virus to slip in. Boston Globe, September 24, 2020. https://www.bostonglobe.com/2020/09/24/metro/brigham-womens-hospital-reports-cluster-10-covid-19-cases/
  4. Fisher KA, Tenforde MW, Felstein LR, et al. Community and close contact exposures associated with COVID-19 among symptomatic adults ≥18 years in 11 outpatient health care facilities—United States, July 2020. MMWR 2020;69:1258-64. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7499837/

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis or its affiliates. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

 

 

What’s the connection between break rooms and transmission of Covid-19 in health care settings?

How might measuring viral load in respiratory specimens be helpful clinically in patients with Covid-19?

Although far from being perfect, there are emerging scientific data that suggest measuring viral load in respiratory specimens of patients with Covid-19 could be helpful in at least 2 ways: 1. Help determine who may be infectious (therefore isolated or undergo contact tracing); and 2. Identify patients at high risk for severe disease and death (1-4).

In a study involving 3,790 nasopharyngeal samples testing positive for SARS-CoV-2 by PCR, a significant correlation was found between isolation of the virus by culture—therefore potential contagiousness—and viral load determined by cycle threshold (CT) (ie, the number of cycles needed to detect the virus with higher numbers thought to be associated with lower risk of contagion) (2). Some have suggested that patients with CT above 33-34 are no longer contagious (3).

In another study involving 978 patients with Covid-19, high viral load in nasopharyngeal specimens was associated with higher risk of intubation (O.R. 2.7, 1.7-4.4), and mortality (6.1, 2.9-12.5) (4).

In addition, simultaneous presence of high viral loads in the respiratory specimens in the population suggests an expanding outbreak, while low viral loads may imply that the outbreak is waning (1).

Some have cautioned against over-reliance on viral loads in Covid-19 due to factors such as variation in the technique of obtaining specimens and testing instruments (5).

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References
1. Service RF. Covid-19. A call for diagnostic tests to report viral load. Science 2020, October 2;370:22. https://www.sciencemag.org/news/2020/09/one-number-could-help-reveal-how-infectious-covid-19-patient-should-test-results
2. Jaafar R, Aherfi S, Wurtz N, et al. Correlation between 3790 qPCR positives samples and positive cell cultures including 1941 SARS-CoV-2 isolates. Clin Infect Dis 2020, September. https://pubmed.ncbi.nlm.nih.gov/32986798/
3. La Scola B, Le Bideau M, Andreani J, et al. Viral RNA as determined by cell culture as a management tool for discharge of SARS-CoV-2 patients from infectious disease wards. Eur J Clin Microbiol Infect Dis 2020;39:1059-1061. https://pubmed.ncbi.nlm.nih.gov/32342252/
4. Magleby R, Westblade LF, Trzebucki A, et al. Impact of severe acute respiratory syndrome coronavirus 2 viral load on risk of intubation and mortality among hospitalized patients with coronavirus disease 2019. Clin Infect Dis 2020. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa851/5865363
5. Rhoads D, Peaper DR, She RC, et al. College of American Pathologists (CAP) Microbiology Committee perspective: caution must be used in interpreting the cycle threshold (Ct) value. Clin Infect Dis 12 August, 2020. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa1199/5891762

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How might measuring viral load in respiratory specimens be helpful clinically in patients with Covid-19?