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Ask a Librarian: post-COVID-19 condition (long COVID)

Last updated: October 22, 2021

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CMA Joule’s Ask a Librarian team is committed to curating free evidence-based resources related to the COVID-19 pandemic. We continue to update the Ask a Librarian: COVID-19  and the Ask a Librarian: COVID-19 vaccines and the immunization roll-out posts with current clinical summaries, article collections, guidance and more.

Here we focus on information sources specific to post‒COVID-19 condition — also known as long COVID, long-haul COVID, post-acute COVID-19 (PACS), post-acute sequelae of COVID-19 (PASC), long-term effects of COVID, or chronic COVID. On October 6, 2021 the World Health Organization (WHO) published a clinical case definition based on Delphi methodology that was developed in consultation with hundreds of patients, researchers, external experts and WHO staff. The standardized definition includes 12 domains to help clinicians in all settings identify patients more easily and to advance recognition and research:

Post COVID-19 condition occurs in individuals with a history of probable or confirmed SARS CoV-2 infection, usually 3 months from the onset of COVID-19 with symptoms and that last for at least 2 months and cannot be explained by an alternative diagnosis. Common symptoms include fatigue, shortness of breath, cognitive dysfunction but also others and generally have an impact on everyday functioning. Symptoms may be new onset following initial recovery from an acute COVID-19 episode or persist from the initial illness. Symptoms may also fluctuate or relapse over time.

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Clinical summaries


(Included with membership. Access now)  – COVID-19 (Novel Coronavirus) – see Post-acute COVID-19 Syndrome (PACS) in Complications section. Updated Oct 21, 2021.


Post-acute COVID-19 Syndrome (PACS)

  • PACS is also known as "long-COVID" or "post-acute sequelae of COVID-19" (PASC) and patients are commonly referred to as "long-haulers" in general media
    • reported persistent symptoms after recovery include
      • fatigue
      • joint pain
      • chest pain
      • palpitations
      • shortness of breath
      • worsening quality of life
      • cardiopulmonary symptoms
      • neurologic and psychiatric symptoms including
        • anxiety
        • depression
        • headache
        • vision changes
        • hearing loss
        • loss of taste or smell
        • impaired mobility
        • numbness in extremities
        • tremors
        • myalgia
        • memory loss
        • cognitive impairment
        • mood changes
  • Reference - NIH COVID-19 Treatment Guideline (NIH 2021 Apr 21)


BMJ Best Practice

Coronavirus Disease (COVID-19). Under “Complications” see “post COVID-19 syndrome”. Updated October 14, 2021.



COVID-19: Evaluation and management of adults following acute viral illness. Literature review current through: Sep 2021. Topic last updated: Oct 21, 2021. 


Evidence reviews

American Family Physician

Coronavirus Disease 2019 (COVID-19) Daily Research Briefs

Research updates

Persistent Symptoms Common Even after Mild COVID-19 Eight Months Later. Written by Mark H. Ebell MD, MS, on April 11, 2021. (Source: Haverall S, Rosell A, Phillipson M, et al. Symptoms and functional impairment assessed 8 months after mild covid-19 among health care workers [published online April 7, 2021]. JAMA. 2021.

Neurologic and Psychiatric Consequences after COVID-19 Are More Common Than with Other Respiratory Illnesses and Influenza. Written by Henry C. Barry, MD, MS, on April 8, 2021. (Source: Taquet M, Geddes JR, Husain M, et al. 6-month neurological and psychiatric outcomes in 236 379 survivors of COVID-19: a retrospective cohort study using electronic health records [published online April 6, 2021]. Lancet Psychiatry. 2021.  


Canadian Agency for Drugs and Technology in Health (CADTH)

An Overview of Post‒COVID-19 Condition (Long COVID). Updated September 24, 2021.

Post‒COVID-19 Condition: A Condition-Level Review. Published September 14, 2021


COVID-19 Evidence Synthesis Network



McMaster University

COVID-END – Care Models for Long COVID - A Rapid Systematic Review. Date of Literature Search: May 27, 2021.COVID-19 Evidence Alerts – weekly update of high-quality clinical studies with free email notifications. Search “long COVID” and/or other synonyms.

Recent reviews

Characterising long COVID: a living systematic review. Michelen M, Manoharan L, Elkheir N, et al. BMJ Glob Health. Reviewed October 8, 2021.

More than 50 long-term effects of COVID-19: a systematic review and meta-analysis.
Lopez-Leon S, Wegman-Ostrosky T, Perelman C, et al.  Sci Rep. Reviewed August 16, 2021

Whole of population-based cohort study of recovery time from COVID-19 in New South Wales Australia.
Liu B, Jayasundara D, Pye V, et al.   Lancet Reg Health West Pac. Reviewed July 9, 2021

Assessment of the Frequency and Variety of Persistent Symptoms Among Patients With COVID-19: A Systematic Review. Nasserie T, Hittle M, Goodman SN JAMA Netw Open. Reviewed June 9, 2021

Cardio-Pulmonary Sequelae in Recovered COVID-19 Patients: Considerations for Primary Care.
Sarfraz Z, Sarfraz A, Barrios A, et al.  J Prim Care Community Health. Reviewed June 14, 2021

Post-acute effects of SARS-CoV-2 infection in individuals not requiring hospital admission: a Danish population-based cohort study. Lund LC, Hallas J, Nielsen H, et al.  Lancet Infect Dis. Reviewed May 24, 2021.

The occurrence of long COVID: a rapid review. Iwu CJ, Iwu CD, Wiysonge CS. Pan Afr Med J. Reviewed May 4, 2021.


Articles and article collections

CMAJ articles

Unpacking “long COVID”. Terry Murray. CMAJ March 01, 2021 193 (9) E318-E319; DOI:

Even mild COVID-19 may have long-term brain impacts. Diana Duong. CMAJ August 30, 2021 193 (34) E1360-E1361; DOI:


Guidelines and other information


Centers for Disease Control and Prevention – Post-COVID Conditions: Information for Healthcare Providers. Updated July 9, 2021.

Centers for Disease Control and Prevention – Evaluating and Caring for Patients with Post-COVID Conditions: Interim Guidance. Updated June 14, 2021.

National Institute for Health and Care Excellence (NICE) – COVID-19 rapid guideline: managing the long-term effects of COVID-19. December 18, 2020.

World Health Organization – A clinical case definition of post COVID-19 condition by a Delphi consensus. Updated October 6, 2021.

World Health Organization – Post COVID-19 condition (Long COVID). Updated October 16, 2021.



CMA Joule – CPG Infobase: Clinical Practice Guidelines on Long COVID. Updated October, 2021.

Center for Effective Practice – COVID-19: Clinical Guidance for Primary Care Providers - Long-term symptoms / Post-acute sequelae of COVID-19 (PASC)

Government of Canada – COVID-19 for health professionals: Post COVID-19 condition. Updated August 20, 2021.

Viral Neuro Exploration, COVID Long Haulers Support Group Canada, and Neurological Health Charities Canada – Report on Pan-Canadian Long Covid Impact Survey. June 8, 2021.



British Columbia

Provincial Health Services Authority – Post-COVID-19 Care. No date.


Alberta Health Services – Recovery & Rehabilitation After COVID-19: Resources for Health Professionals. Updated September 30, 2021.


Saskatchewan Health Authority – Long-COVID information repository to support Saskatchewan decision-makers during the COVID pandemic. Updated October 5, 2021.


Ontario COVID-19 Science Advisory Table – Understanding the Post COVID-19 Condition (Long COVID) and the Expected Burden for Ontario. Updated September 14, 2021.

Nova Scotia

Nova Scotia Health. My COVID Recovery – your source of health information after having COVID-19. Updated October 6, 2021.


Patient information

CanCov – Patient resources to help people cope with the disease. No date.

Government of Canada – Post COVID-19 condition. Updated September 24, 2021.

Johns Hopkins Medicine – COVID ‘Long Haulers’: Long-Term Effects of COVID-19. Published April 1, 2021.

Long Covid Canada. Includes Long COVID information, patient stories and provincial supports. No date.

Mayo Clinic – COVID-19 (coronavirus): Long-term effects. Published October 22, 2021.

University Health Network. Health Science Information Consortium of Toronto. Long COVID: COVID-19 Resources for Patients and Families. Updated October 7, 2021.


Pre-populated literature searches

Long COVID search – LitCovid is a curated literature hub for tracking current scientific information about the 2019 novel Coronavirus. Updated daily.

Long COVID search – COVID-19 Portfolio - NIH’s comprehensive, expert-curated source for publications and preprints related to COVID-19 and the novel coronavirus SARS-CoV-2.

Need more information or have a more focused clinical question on Post‒COVID-19 Condition or any other clinical topic of interest? Contact the Ask a Librarian team to request a literature search.

This material is for informational purposes only. It is not intended to be a substitute for professional medical advice and should not be relied on as health or personal advice. The opinions stated by the authors are made in a personal capacity and do not necessarily reflect those of the Canadian Medical Association and its subsidiaries including CMA Joule.

About the author(s)

CMA Joule’s medical librarians are the professionals behind “Ask a Librarian”, a service for all CMA members looking for clinical search expertise. This experienced team of librarians can support you by searching on your behalf, teaching you effective search strategies or training you to use our clinical resources.