How often is Covid-19 in hospitalized patients complicated by bacterial infection?

Despite frequent use of empiric antibiotics in hospitalized patients with Covid-19,current data suggests a low rate of documented bacterial co-infection (BCI) in such patients. In fact, the overall reported rate of BCI in hospitalized patients with Covid-19 is generally no greater than 10%.1-3   It’s quite likely that most patients with Covid-19 and chest radiograph changes solely have a coronavirus (SARS-CoV-2) lung infection,4 particularly early in the course of the disease.  

A meta-analysis involving 30 studies (primarily retrospective) found that overall 7% of hospitalized Covid-19 patients had a laboratory-confirmed BCI with higher proportion among ICU patients (14%).Mycoplasma pneumoniae was the most common (42% of BCIs), followed by Pseudomonas aeruginosa and H. influenzae.  Notably, diagnosis of M. pneumoniae infection was based on antibody testing for IgM, which has been associated with false-positive results. Other caveats include lack of a uniform definition of respiratory tract infection among studies and potential impact of concurrent or prior antibiotic therapy on the yield of bacteriologic cultures. 5,6

A low prevalence of BCI was also found in a UK study involving 836 hospitalized Covid-19 patients: 3.2% for early BCI (0-5 days after admission) and 6.1% throughout hospitalization, including hospital-acquired infections.Staphylococcus aureus was the most common respiratory isolate among community-acquired cases, while Pseudomonas spp. was the predominant healthcare associated respiratory isolate.  Similarly, S. aureus. and Streptococcus pneumoniae were the most commonly isolated organisms from blind bronchoalveolar lavage of critically ill patients with Covid-19 during their first 5 days of admission, while gram-negative bacilli became dominant later during the hospitalization.8

The discordance between high rates of antibiotic treatment and confirmed bacterial co-infection in Covid-19 patients is likely a reflection of the difficulty in distinguishing Covid-19 pneumonia from bacterial pneumonia based on clinical or radiographic findings alone.

We need better tests to help distinguish bacterial vs Covid-19 pneumonia. Some have suggested using a low serum procalcitonin to help guide the withholding of or early discontinuation of antibiotics, especially in less severe Covid-19 cases. Formal studies of the accuracy of procalcitonin in Covid-19 are needed to test this hypothesis, given its suboptimal sensitivity in bacterial community-acquired pneumonia. 

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.

 

Reference

  1. Stevens RW, Jensen K, O’Horo JC, et al. Antimicrobial prescribing practices at a tertiary-care center in patients diagnosed with COVID-19 across the continuum of care. Infect Control Hosp Epidemiology 2020. https://reference.medscape.com/medline/abstract/32703323
  2. Lansbury L, Lim B, Baskaran V, et al. Co-infections in people with COVID-19: a systematic review and meta-analysis. J Infect 2020;81:266-75. https://pubmed.ncbi.nlm.nih.gov/32473235/
  3. Rawson TM, Moore LSP, Zhu N. Bacterial and fungal co-infection in individuals with coronavirus: A rapid review to support COVID-19 antimicrobial prescribing. Clin Infect Dis 2020 (Manuscrpit published online ahead of print 2 June ). Doi:10.1093/cid/ciaa530.https://pubmed.ncbi.nlm.nih.gov/32358954/
  4. Metlay JP, Waterer GW. Treatment of community-acquired pneumonia during the coronavirus 2019 (COVID-19) pandemic. Ann Intern Med 2020; 173:304-305. https://pubmed.ncbi.nlm.nih.gov/32379883/
  5. Chang CY, Chan KG. Underestimation of co-infections in COVID-19 due to non-discriminatory use of antibiotics. J Infect 2020;81:e29-30. https://pubmed.ncbi.nlm.nih.gov/32628960/
  6. Rawson TM, Moore LSP, Zhu N, et al. Bacterial pneumonia in COVID-19 critically ill patients: A case series. Reply letter. Clin Infect Dis 2020. https://academic.oup.com/cid/advance-
  7. Hughes S, Troise O, Donaldson H, et al. Bacterial and fungal coinfection among hospitalized patients with COVID-19: a retrospective cohort study in a UK secondary-care setting. Clin Microbiol Infect 2020. https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(20)30369-4/fulltext
  8. Dudoignon E, Camelena F, Deniau B, et al. Bacterial pneumonia in COVID-19 critically ill patients: A case series. Clin Infect Dis 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7337703/

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 often is Covid-19 in hospitalized patients complicated by bacterial infection?

Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

First, a shout-out to dedicated healthcare workers everywhere who have selflessly given of themselves to care for the sick during this pandemic. Thank you! Together, I know we will get through it!

Although our understanding of Covid-19 infection is far from complete, in the spirit of clarity and brevity of my posts on Pearls4Peers, here are some key points I have gleaned from review of existing literature and the CDC that may be useful as we care for our hospitalized patients with suspected or confirmed Covid-19 infection.

  • Isolation precautions.1 Per CDC, follow a combination of airborne (particularly when aerosol generating procedures is anticipated, including nebulizer treatment) and contact precaution protocols. Routinely use masks or respirators, such as N-95s (subject to local availability and policy) and eye protection. Don gowns (subject to local availability and policy) and gloves and adhere to strict hand hygiene practices.

 

  • Diagnostic tests1-9
    • Laboratory tests. Routine admission labs include CBC, electrolytes, coagulation panels and liver and renal tests. Other frequently reported labs include LDH, C-reactive protein (CRP) and procalcitonin. Testing for high sensitivity troponin I has also been performed in some patients, presumably due to concern over ischemic cardiac injury or myocarditis.2 Check other labs as clinically indicated.
    • Chest radiograph/CT chest. One or both have been obtained in virtually all reported cases with CT having higher sensitivity for detection of lung abnormalities.
    • EKG. Frequency of checking EKGs not reported in many published reports thought 1 study reported “acute cardiac injury” in some patients, based in part on EKG findings.4 Suspect we will be checking EKGs in many patients, particularly those who are older or are at risk of heart disease.
    • Point-of-care ultrasound (POCUS). This relatively new technology appears promising in Covid-19 infections, including in rapid assessment of the severity of pneumonia or ARDS at presentation and tracking the evolution of the disease. 9 Don’t forget to disinfect the probe between uses!

 

  • Treatment 1-8
    • Specific therapies are not currently available for treatment of Covid-19 infections, but studies are underway.
    • Supportive care includes IV fluids, 02 supplementation and nutrition, as needed. Plenty of emotional support for patients and their families will likely be needed during these times.
    • Antibiotics have been used in the majority of reported cases, either on admission or during hospitalization when superimposed bacterial pneumonia or sepsis could not be excluded.
      • Prescribe antibiotics against common community-acquired pneumonia (CAP) pathogens, including those associated with post-viral/influenza pneumonia such as Streptococcus pneumoniae (eg, ceftriaxone), and Staphylococcus aureus (eg, vancomycin or linezolid if MRSA is suspected) when concurrent CAP is suspected.
      • Prescribe antibiotics against common hospital-acquired pneumonia (HAP) (eg, vancomycin plus cefepime) when HAP is suspected.
    • Corticosteroids should be avoided because of the potential for prolonging viral replication, unless indicated for other reasons such as COPD exacerbation or septic shock. 1
    • Monitor for deterioration in clinical status even when your hospitalized patient has relatively minor symptoms. This is because progression to lower respiratory tract disease due to Covid-19 often develops during the 2nd week of illness (average 9 days).
    • ICU transfer may be necessary in up to 30% of hospitalized patients due to complications such as ARDS, secondary infections, and multi-organ failure.

 

Again, thank you for caring for the sick and be safe! Feel free to leave comments or questions.

 

 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. CDC. Interim clinical guidance for management of patients with confirmed coronavirus disease (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
  2. Ruan Q, Yang K, Wang W, Jiang L, et al. Clinical predictors of mortality due to COVID-19 based on analysis of data of 150 patients with Wuhan, China. Intensive Care Med 2020. https://link.springer.com/article/10.1007/s00134-020-05991-x
  3. Holshue ML, BeBohlt C, Lindquist S, et al. First case of 2019 novel coronavirus in the United States. N Engl J Med 2020;382:929-36. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
  4. Huang C, Wang Y, Li Xingwang, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506. https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(20)30183-5.pdf
  5. Young BE, Ong SWX, Kalimuddin S, et al. Epideomiologic features and clinical course of patients infected with SARS-CoV-2 Singapore. JAMA, March 3, 2020. Doi.10.1001/jama.2020.3204 https://www.ncbi.nlm.nih.gov/pubmed/32125362
  6. Chen N, Zhou M, Dong X, et al. Epidemiological and clinical chacteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020;395:507-13. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30211-7/fulltext
  7. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl Med 2020, Feb 28, 2020. https://www.nejm.org/doi/full/10.1056/NEJMoa2002032
  8. Zhang J, Zhou L, Yang Y, et al. Therapeutic and triage strategies for 2019 novel coronavirus disease in fever clinics. Lancet 2020;8: e11-e12. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30071-0/fulltext 9.
  9. Peng QY, Wang XT, Zhang LN, et al. Findings of lung ultrasonography of novel corona virus pneumonia during the 2019-2020 epidemic. Intensive Care Med 2020. https://doi.org/10.1007/s00134-020-05996-
Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

Catch these selected key clinical pearls on coronavirus disease (Covid-19)!

Although the Covid-19 pandemic is continuing to evolve and our knowledge of its epidemiology and pathophysiology is still far from complete, you may find the following pearls based on published literature to date useful when discussing this disease with your colleagues or the public. 1-11

  • Age group: Primarily an adult disease. Children (< 15-year-old) account for only a minority of symptomatic patients (<1%); ~50% of patients are between 15-49 years of age with 15% in the ≥ 65 year group. 1
  • Incubation period: A bit longer than seasonal flu. Median 4.0 days (IQR 2.0-7.0 days); an upper range up to 24 days has also been reported. In contrast, for seasonal flu the median incubation period is shorter (median 2.0 days, 1.0-7.0 days. 1,4,11
  • Transmission: Contact, droplet, and possibly airborne. On average each person may transmit Covid-19 virus to 2-3 other persons (vs <2 people for seasonal flu). Unlike SARS or MERS, but more akin to the seasonal flu, asymptomatic persons may also be able to transmit the disease. 4,5,11
  • Comorbid conditions (eg, diabetes, hypertension, COPD…): Present in about 1/3 of reported patients. 1
  • Symptoms 1,5
    • ~80% of patients may be either asymptomatic or have mild disease
    • Fever may be absent in ~50% of patients on presentation but will eventually develop in ~90% of hospitalized patients
    • Cough (2/3 dry) is present in majority (~80%) of cases
    • Rhinorrhea is uncommon (<10%), in contrast to the seasonal influenza
    • GI symptoms (nausea/vomiting/diarrhea) are uncommon by some reports(<10%), but not by others (>30.0%). 12
    • May take 9-12 days from onset of symptoms to severe disease
  • Labs 1
    • Lymphopenia is common (up to ~80%)
    • Abnormal liver function (AST and ALT) is found in about 1/3 of patients
    • C-reactive protein (CRP) is usually elevated (~80% of severe cases)
    • Procalcitonin is usually normal
  • Treatment: Supportive for now. Candidate drugs include remdesivir, lopinavir/ritonavir, chloroquine phosphate, ribavirin and several others.4
  • Mortality: Reported mortality among mostly symptomatic hospitalized cases is ~2.0% (0.9% without comorbidities, 5-10% in those with comorbidities, 50% among critically ill). Overall mortality rates will likely drop as more patients without symptoms or with mild disease are tested. In contrast, 2 other coronavirus diseases, SARS and MERS, have mortality rates of ~9.0% and 36.0%, respectively. 1,4,5

 

Bonus pearl: Did you know that, Covid-19-infected patients shed the virus in their nasopharyngeal secretions on the average for 12 days, some as long as 24 days?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. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of Coronavirus disease 2019 in China. N Engl J Med 2020. First published Feb 28, 220, last updated March 6, 2020. https://www.nejm.org/doi/10.1056/NEJMoa2002032
  2. Holshue ML, DeBolt C, Lindquist S, et al. First case of 2019 novel Coronavirus in the United States. N Engl J Med 2020; 382:929-36. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
  3. Young BE, Ong SWX, Kalimuddin S, et al. Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore. JAMA. Doi:10.1001/jama.2020.3204. Published online March 3, 2020. https://jamanetwork.com/journals/jama/fullarticle/2762688
  4. Wang Y, Wang Y, Chen Y, et al. Unique epidemiological and clinical features of the emerging 2019 novel coronavirus pneumonia (COVID-19) implicate special control measures. J Med Virol 2020. Doi: 10.1002/jmv.25748. https://www.ncbi.nlm.nih.gov/pubmed/32134116
  5. Fauci AS, Lane HC, Redfield RR. Covid-19—Navigating the uncharted. N Eng J Med 2020. DOI:10.1056/NEJMe2002387. https://www.nejm.org/doi/full/10.1056/NEJMe2002387
  6. Del Rio C, Malani PN. 2019 novel coronavirus—important information for clinicians. JAMA 2020, Feb 5. https://www.ncbi.nlm.nih.gov/pubmed/32022836
  7. Lipsitch M, Swerdlow DL, Finelli L. Defining the epidemiology of Covid-19—studies needed. N Engl J Med 2020. Feb 19. DOI:10.1056/NEJMp2002125. https://www.ncbi.nlm.nih.gov/pubmed/32074416/
  8. Morens DM, Daszak P, Taubenberger JK. Escaping Pandora’s box—another novel coronavirus. N Eng J Med 2020. Feb 26. DOI:10.1056/NEJMp2002106. https://www.nejm.org/doi/full/10.1056/NEJMp2002106
  9. She J, Jiang J, Ye L, et al. 2019 novel coronavirus of pneumonia in Wuhan, China: merging attack and management strategies. Clin Trans Med 2020;9:19. https://clintransmed.springeropen.com/articles/10.1186/s40169-020-00271-z
  10. Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020; 395: 497-506. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext
  11. Bai Y, Yao L, Wei T, et al. Presumed asymptomatic carrier transmission of COVID-19. JAMA 2020. Feb 21. https://jamanetwork.com/journals/jama/fullarticle/2762028
  12. Pan L, Mu M, Yang P, et al. Clinical characteristics of COVID-19 patients with digestive symptoms in Hubei, China: a descriptive, cross-sectional, multicenter study. Am j Gastroenterol 2020. https://journals.lww.com/ajg/Documents/COVID_Digestive_Symptoms_AJG_Preproof.pdf
Catch these selected key clinical pearls on coronavirus disease (Covid-19)!

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?

Compared to 2007,1 the 2019 ATS/IDSA guidelines2 have 2 major “Do’s” and 2 major “Dont’s” in the diagnostic approach to CAP in hospitalized patients:

  • DO order sputum and blood cultures in patients empirically treated for methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa—in addition to those with severe CAP as in 2007.  
  • DO order rapid influenza molecular assay—in preference to antigen test— when influenza viruses are circulating in community, irrespective of pneumonia severity
  • DON’T routinely order urine antigens for pneumococcal or Legionella antigens, except in severe CAP or in the presence of suggestive epidemiological factors (eg. Legionella outbreak, recent travel)
  • DON’t routinely order serum procalcitonin to determine need for initial antibacterial therapy

Patients at risk of MRSA or P. aeruginosa include those with prior infection with the same pathogens as well as those with hospitalization and treated with parenteral antibiotics—in or out of the hospital— in the last 90 days; HCAP is no longer recognized as an entity.

The definition of severe CAP is unchanged: 1 of 2 major criteria (septic shock or respiratory failure requiring mechanical ventilation) or 3 or more of the following minor criteria or findings listed below:

  • Clinical
    • Respiratory rate ≥30 breath/min
    • Hypotension requiring aggressive fluid resuscitation
    • Hypothermia (core temperature <36 ᵒC, 96.8 ᵒF)
    • Confusion/disorientation
  • Radiographic 
    • Multilobar infiltrates
  • Laboratory 
    • Leukopenia (WBC <4,000/ul)
    • Thrombocytopenia (platelets <100,000/ul)
    • BUN ≥20 mg/dl
    • Pa02/FI02 ratio ≤250

Keep in mind that these guidelines focus on adults who are not immunocompromised or had recent foreign travel and are often based on expert opinion but low or very low quality evidence due to the dearth of properly designed studies.

Bonus Pearl: Did you know that the urine Legionella antigen only tests for L. pneumophila type I, with an overall sensitivity ranging from 45% to 100%!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. Mandell LA, Wunderink RG, Anzueto A. Infectious Disease Society of America/American Thoracic Society Consensus Guidelines on the Management guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44:S27-72. https://www.ncbi.nlm.nih.gov/pubmed/17278083
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
  3. Blazquez RM, Espinosa FJ, Martinez-Toldos CM, et al. Sensitivity of urinary antigen test in relation to clinical severity in a large outbreak of Legionella pneumonia in Spain. Eur J Clin Microbiol Infect Dis 2005;24:488-91. https://www.ncbi.nlm.nih.gov/pubmed/15997369
  4. Marlow E, Whelan C. Legionella pneumonia and use of the Legionella urinary antigen test. J Hosp Med 2009;4:E1-E2. https://www.ncbi.nlm.nih.gov/pubmed/19301376

 

 

What changes should I consider in my diagnostic approach to hospitalized patients with community-acquired pneumonia (CAP) in light of the 2019 guidelines of the American Thoracic Society (ATS) and Infectious Diseases Society of America (IDSA)?

How well does procalcitonin distinguish bacterial from viral causes of community-acquired pneumonia in hospitalized patients?

Not extremely well! Although a recent multicenter prospective study in adult hospitalized patients reported that the median procalcitonin (PCT) concentration was significantly lower for community-acquired pneumonia (CAP) caused by viral compared to bacterial pathogens, normal PCT values at  <0.1 ug/ml and <0.25 ug/ml  were also found in 12.4% and 23.1% of typical bacterial cases, respectively1

This means that we could potentially miss about a quarter of CAP cases due to typical bacterial causes if we use the <0.25 ug/ml threshold (<0.20 is ug/ml has often  been used to exclude sepsis2). Based on the results of these and another study3, no threshold for PCT can reliably distinguish bacterial from viral etiologies of CAP.4  Clinical context is essential in interpreting PCT levels!

Can PCT distinguish Legionella from other atypical bacterial causes of CAP (eg, caused by Mycoplasma or Chlamydophila)? The answer is “maybe”! Legionella was associated with higher PCT levels compared to  Mycoplasma and Chlamydophila in one study1, but not in another3

For a related pearl on P4P go to https://pearls4peers.com/2017/07/01/should-i-order-serum-procalcitonin-on-my-patient-with-suspected-infection   

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. Self WH, Balk RA, Grijalva CG, et al. Procalcitonin as a marker of etiology in adults hospitalized with community-acquired pneumonia. Clin Infect Dis 2017;65:183-90. https://www.ncbi.nlm.nih.gov/pubmed/28407054
  2. Meisner M. Update on procalcitonin measurements. Ann Lab Med 2014;34:263-73.
  3. Krüger S, Ewig S, Papassotiriou J, et al. Inflammatory parameters predict etiologic patterns but do not allow for individual prediction of etiology in patients with CAP-Results from the German competence network CAPNETZ. Resp Res 2009;10:65. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2714042/pdf/1465-9921-10-65.pdf
  4. Bergin SP, Tsalik EL. Procalcitonin: the right answer but to which question? Clin Infect Dis 2017; 65:191-93. https://academic.oup.com/cid/article-abstract/65/2/191/3605416/Procalcitonin-The-Right-Answer-but-to-Which?redirectedFrom=fulltext
How well does procalcitonin distinguish bacterial from viral causes of community-acquired pneumonia in hospitalized patients?

Should I order serum procalcitonin on my patient with suspected infection?

Two things to ask before you order procalcitonin (PCT): 1. Will it impact patient management?; and 2. If so, will the result be available in a timely manner ie, within hours not days?

Whatever the result, PCT should always be interpreted in the context of the patient’s illness and other objective data. Not surprisingly then, as a “screening” test, PCT may be more useful in patients with low pre-test likelihood of having bacterial infection, not dissimilar to the use of D-dimer in patients with low pre-test probability of pulmonary embolism1.  

Several potential clinical uses of this biomarker have emerged in recent years,  including:1,2

  • Helping decide when to initiate antibiotics in patients with upper acute respiratory tract infections and bronchitis. A normal or low PCT supports viral infection.
  • Helping decide when to discontinue antibiotics (ie, when PCT normalizes) in community-acquired or ventilator-associated pneumonia.
  • Helping monitor patient progress with an expected drop in PCT of about 50% per day (half-life ~ 24 hrs) with effective therapy.

Few caveats…

  • PCT may be unremarkable in about a third of patients with bacteremia (especially due to less virulent bacteria, including many gram-positives)3.  
  • PCT levels are lowered by high-flux membrane hemodialysis, so check a baseline level before, not after, hemodialysis4.
  • Lastly, despite its higher specificity for bacterial infections compared to other biomarkers such as C-reactive protein, PCT may be elevated in a variety of non-infectious conditions, including pancreatitis, burns, pulmonary edema or aspiration, mesenteric infarction (ischemic bowel), cardiogenic shock, and hypotension during surgery2.

 

References:

  1. Schuetz P, Muller B, Chirst-Crain M, et al. Procalcitonin to initiate or discontinue antibiotics in acute respiratory tract infections (review). Evid-Based Child Health (A Cochrane Review Journal) 2013;8:4;1297-137. http://onlinelibrary.wiley.com/doi/10.1002/ebch.1927/pdf
  2. Gilbert GN. Use of plasma procalcitonin levels as an adjunct to clinical microbiology. J Clin Microbiol 2010;48:2325-29. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2897488/pdf/0655-10.pdf
  3. Yan ST, Sun LC, Jia HB. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria. Am J Emerg Med 2017;35:779-83. https://www.ncbi.nlm.nih.gov/m/pubmed/27979420/#fft
  4. Grace E, Turner RM. Use of procalcitonin in patients with various degrees of chronic kidney disease including renal replacement therapy. Clin Infect Dis 2014;59:1761-7. https://www.ncbi.nlm.nih.gov/pubmed/25228701
Should I order serum procalcitonin on my patient with suspected infection?