How long should my patient recovering from Covid-19 remain on isolation precautions?

For the great majority of patients with Covid-19, the risk of shedding viable SARS-CoV2 diminishes considerably as the time from onset of symptoms nears 10 days or more, with the risk higher among those who have severe (eg, sp02 <94%)  or critical disease (eg, in need of ICU care) or who are immunocompromised. 1-4  

For patients with mild-moderate illness who are not immunocompromised, the CDC recommends isolation for “at least 10 days” from onset of symptoms as long as at least 24 hours have passed since last fever without the use of fever-reducing medications and symptoms  (eg, cough, shortness of breath) have improved.  For patients with severe to critical illness or who are severely immunocompromised, “at least 10 days” and up to 20 days since onset of symptoms—with qualifications as above— is recommended. 1

A 2021 meta-analysis found that although SARS-CoV-2 RNA shedding in respiratory and stool samples may be prolonged, duration of viable virus was relatively short with no study detecting live virus beyond day 9 of illness.2

In contrast, another study involving patients with severe or critical illness (23% immunocompromised, 2/3 on mechanical ventilation) found  that the median time of infectious virus shedding was 8 days (range 0-20) and concluded that detection of infectious virus was common after 8 days or more since onset of symptoms; the probability of isolating infectious SARS-CoV-2 was  ≤5% when the duration of symptoms was 15.2 days (95% CI 13.4-17.2). In the same study, a single patient had infectious particles for up to 20 days following onset of symptoms. 3

The take home point is that although 10 days of isolation since onset of symptoms should be sufficient for mild to moderate Covid-19, for those with severe or critical disease or immunocompromised state, a longer duration up to 20 days may be needed.  The setting and status of the potential contacts (eg, an immunocompromised person in household setting) should also be considered in our decision making. 4

Bonus Pearl: Did you know that infectious particles are unlikely to be isolated from respiratory tract samples once patients develop a serum neutralizing antibody titer of at least 1:80, potentially useful information in deciding when a patient may come off isolation? 3

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

 

References

  1. Discontinuation of transmission-based precautions and disposition of patients with SARS-CoV-2 infection in healthcare settings. https://www.cdc.gov/coronavirus/2019-ncov/hcp/disposition-hospitalized-patients.html#definitions. Accessed March 24, 2021
  2. Cevik M, Tate M, Lloyd O, et al. Sars-Cov-2, SARS-CoV, and MERS-CoV viral load dynamics, duration of viral shedding, and infectiousness: a systematic review and meta-analysis. Lancet Microbe 2021;2:e13-22. https://www.thelancet.com/pdfs/journals/lanmic/PIIS2666-5247(20)30172-5.pdf
  3. Van Kampen JJA, van de Vijver DAMC, Fraaij PLA, et al. Duration and key determinants of infectious virus shedding in hospitalized patients with coronavirus disease-2019 (COVID-19). Nature Communications 2021;12:267. https://www.nature.com/articles/s41467-020-20568-4
  4. Kadire SR, Fabre V, Wenzel RP. Doctor, how long should I isolate? NEJM, March 2021 https://www.nejm.org/doi/pdf/10.1056/NEJMclde2100910?articleTools=true

 

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 long should my patient recovering from Covid-19 remain on isolation precautions?

My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?

Although extremely high WBC count in the absence of myeloproliferative disease may be associated with solid tumors and other causes, infections are often the most common cause of leukemoid reaction (LR), including tuberculosis, Clostridiodes difficile colitis, shigellosis, salmonellosis, pneumonia, abscesses, as well as  parasitic infections (eg, malaria), fungal infections (mucormycosis), and viral diseases (eg, HIV, EBV, Chickungunya fever).1-4   

In a study of 173 hospitalized patients (mean age 69 y) with leukemoid reaction (defined in this study as WBC ≥30,000/µl), infection was the most common cause of LR (48%), followed by tissue ischemia/stress (28%), inflammation (eg, pancreatitis, diverticulitis without perforation) and obstetric diagnoses (7% each) and malignant tumor (5%).1 

In the same study, the most common infections were “sepsis”, pneumonia and urinary tract infections.  Bacteremia was documented in 13%, while Clostridiodes difficile toxin assay was positive in 7% of patients.  The highest WBC counts were observed in patients with either a positive blood culture or positive C. difficile toxin.  In-hospital mortality rate was very high at 62%.

Similarly, in a study involving 105 hospitalized patients, the most common cause was infection, followed by malignancy and other causes. 2 In a smaller study of 25 patients with “extreme” leukocytosis (defined as WBC ≥50,000/µl) infection was considered the cause in 52% and malignancy in 44% of patients; about one-third were bacteremic (eg, Pseudomonas sp, Streptococcus pneumoniae, E. coli).3

Bonus Pearl: Did you know that besides infections and malignancy, drugs (eg, corticosteroids, epinephrine) and ingestion of ethylene glycol have also been associated with LR? 1,3,4

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

  1. Potasman I, Grupper M. Leukemoid reaction:Spectrum and prognosis of 173 adult patients. Clin Infect Dis 2013;57:e177-81. https://pubmed.ncbi.nlm.nih.gov/23994818/
  2. Portich JP, Faulhaber GAM. Leudemoid reaction: A 21st-century study. https://pubmed.ncbi.nlm.nih.gov/31765058/
  3. Halkes CJM, Dijstelbloem HM, Eelman Rooda SJ, et al. Extreme leucocytosis: not always leukaemia. The Netherlands J Med 2007;65:248-51. https://pubmed.ncbi.nlm.nih.gov/17656811/
  4. Kumar P, Charaniya R, Sahoo R, et al. Leukemoid reaction in Chickungunya fever. J Clin Diagn Res 2016;10:OD05-OD06. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4948452/

 

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!

My elderly patient has a WBC count of 60,000 without obvious hematologic malignancy.  How likely is it that his leukocytosis is related to an infection?

My elderly patient developed a flare-up of her gout few days after receiving Covid-19 vaccine. Is there a connection between immunization and gout flare?

Although the connection between Covid-19 vaccination and gout flare has yet to be established, higher rates of gout/gout flare following the administration of several other vaccines (eg, influenza, tetatnus, recombinant zoster) have been reported.1  Thus, it is conceivable that Covid-19 vaccine may also be associated with gout flare as more and more people are immunized.  

A 2019 prospective study of over 500 patients with gout found that vaccination was associated with 2-fold higher odds of gout flare (aO.R. 1.99; 95% ci 1.01-3.89) during the 2 day period following immunization; no information on the type of vaccines administered was provided, however.1  Similarly,  higher risk of gout (3.6-fold) has been reported in recipients of recombinant zoster vaccine following immunization.1

An intriguing mechanism explaining the association of vaccination and gout flare is the activation of the Nlrp3 inflammasome, a multiprotein complex produced in response to diverse stimuli such as uric acid crystals and ATP released from tissue injury/necrotic cells.2 Of interest, ~25% of patients with asymptomatic hyperuricemia have been found to have evidence of monosodium urate crystals in and around their joints by advanced imaging, such that vaccination may potentially bring out more inflammatory response and gout flare.

Although aluminum adjuvants intended to increase the immunogenicity of one-half of all routine adult vaccines (eg, tetanus, diphteria, pertussis) have been shown to activate the Nlrp3 inflammasome in vitro, neither currently available mRNA vaccines (Pfizer, Moderna) nor the Johnson&Johnson vaccine contains aluminum as an adjuvant. 4  

Despite the potential for gout flare following adult vaccination, it should be emphasized that the absolute risk is still low and pales compared to the overwhelming benefits of vaccination in general.1

Bonus Pearl: Did you know that, in addition to the usual uric acid lowering drugs, losartan, fenofibrate and some non-steroidal anti-inflammatory drugs, such as indomethacin, also lower serum uric acid levels? 5,6

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

  1. Yokose C, McCormick N, Chen C, et al. Risk of gout flares after vaccination: a prospective case-crossoverstudy. Ann Rheum Dis 2019;78:1601-1604. https://ard.bmj.com/content/early/2019/07/31/annrheumdis-2019-215724.info?versioned=true
  2. Lyer SS, Pulskens WP, Sadler JJ, et al. Necrotic cells trigger a sterile inflammatory response throught the Nlrp3 inflammasome. PNAS 2009;106:20388-20393. https://pubmed.ncbi.nlm.nih.gov/19918053/
  3. Yokose C, Choi H. Response to “Clarification regarding the statement of the association between the recombinant zoster vaccine (RZV) and gout flares’ by Didierlaurent etal. Ann Rheum Dis Month, December 2019. https://ard.bmj.com/content/annrheumdis/early/2019/12/18/annrheumdis-2019-216670.full.pdf
  4. Covid-19 vaccine information. https://covidvaccine.mo.gov/ Accessed March 16, 2021.
  5. Daskalopoulou SS, Tzovaras V, Mikhailidis DP, et al. Effect on serum uric acid levels of drugs prescribed for indications other than treating hyperuricaemia. Current Pharmaceutical Design 2005;11:4161-75. https://www.eurekaselect.com/60510/article
  6. Tiitinen S, Nissila M, Ruutsalo HM, et al. Effect of nonsteroidal anti-inflammatory drugs on the renal excretion of uric acid. Clin Rheumatol 1983;2:233-6. https://pubmed.ncbi.nlm.nih.gov/6678696/#:~:text=The%20effect%20of%209%20nonsteroidal,studied%20had%20no%20significant%20influence.

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!

My elderly patient developed a flare-up of her gout few days after receiving Covid-19 vaccine. Is there a connection between immunization and gout flare?

Why might Lactated Ringer’s (LR) solution be preferred over normal saline (NS) for fluid resuscitation in acute pancreatitis?

Although the data is limited, fluid resuscitation with lactated Ringer’s (LR) solution in acute pancreatitis has been associated with lower risk of persistent systemic inflammatory response syndrome (SIRS) compared to normal saline (NS),  with an additional trend toward lower mortality.1-3

A 2018 meta-analysis of 3 randomized-controlled trials (RCTs) and 2 retrospective studies involving 428 patients found a significantly lower odds of developing SIRS at 24 hours (OR 0.38, CI 0.15-0.98).   Mortality was also lower in the LR group (OR 0.61, 95% CI 0.28-1.29), though it did not reach statistical significance. 1

A small 2011 RCT was the first to suggest the “protective” effect of LR in acute pancreatitis, reporting significant reduction in the prevalence of SIRS after 24 hours when compared to NS (84% vs 0%);  patients on LR also had a significantly lower C-reactive protein (CRP) (104 mg/L vs 51.4 mg/L) at 24 hours. 2   Significantly lower CRP levels were also reported at 48 and 72 hours when LR was compared to NS in another RCT in acute pancreatitis.3

As for potential mechanisms for the observed beneficial effects of LR on the pancreatic tissue in acute pancreatitis, hyperchloremic metabolic acidosis (with its attendant low extracellular pH) often seen in large volume NS resuscitation was initially thought to contribute to pancreatic injury.2  A more plausible explanation, however, may relate to the direct anti-inflammatory effect of lactate itself.  Of interest, lactate has been shown to inhibit macrophage induction invitro 4  and suppress innate immunity in experimental models of pancreatitis. 3 Who would have guessed!

Bonus Pearl: Did you know that Ringer’s solution gets its name from Sydney Ringer, a 19th century physician who demonstrated the importance of salts of sodium, potassium, calcium and chloride in precise proportions for cellular function?  LR solution was actually concocted in the 1930s by a St. Louis pediatrician, Alexis Hartmann, and was also known as the “Hartmann’s solution”. 4

Liked this post? Download the app on your smart phone and sign up below to catch future pearls right into your inbox, all for free!

Subscribe to Blog via Email

Enter your email address to subscribe to this blog and receive notifications of new posts by email.

References

  1. Iqbal U, Anwar H, Scribani M. Ringer’s lactate versus normal saline in acute pancreatitis: A systematic review and meta-analysis. J Dig Dis 208;19:335-341. https://onlinelibrary.wiley.com/doi/epdf/10.1111/1751-2980.12606
  2. Wu BU, Hwang JQ, Gardner TH, et al. Clin Gastroenterol Hepatol 2011;9:710-17. https://www.cghjournal.org/article/S1542-3565(11)00454-X/abstract
  3. de-Madaria E, Herrera-Marante I, Gonzalez-Camacho V, et al. Fluid resuscitation with lactated Ringer’s solution vs normal saline in acute pancreatitis: A triple-blind, randomized, controlled trial. UEG J 2017;6:63-72. file:///C:/Users/manifa/OneDrive%20-%20Mercy%20Online/pancreatitis%20LR2spain.pdf
  4. Lee JA. Sydney Ringer (1834-1910) and Alexis Hartmann (1898-1964). Anaesthesia 1981;36:1115-21. https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2044.1981.tb08698.x

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!

 

Why might Lactated Ringer’s (LR) solution be preferred over normal saline (NS) for fluid resuscitation in acute pancreatitis?