The U.S. Centers for Disease Control and Prevention (CDC) is working closely with international partners to respond to the coronavirus disease 2019 (COVID-19) pandemic. CDC provides technical assistance to help other countries increase their ability to prevent, detect, and respond to health threats, including COVID-19.

This document is provided by CDC and is intended for use in non-US healthcare settings.

1. Overview

This document provides guidance on the identification or screening of healthcare workers (HCWs)[1] and inpatients with suspected COVID-19. Rational, requirements, and considerations will be discussed for three broad case identification strategies:

  • Passive strategies: Reporting/alerts are initiated by the data source (e.g., healthcare worker or treating clinician) based on a known set of rules or regulations.
  • Enhanced passive strategies: Reporting/alerts are initiated by the data source with an added mechanism to prompt data collection, review, and/or reporting.
  • Active strategies: Reporting/alerts are initiated by the centralized health authority (e.g., Ministry of Health, facility infection preventionist, facility administration) using a known set of rules or regulations.

To support the activities for these strategies, this document provides an initial discussion on the importance of defining the signs/symptoms of persons with COVID-19, general best practices, and surveillance capacities.

 2. Signs and Symptoms Consistent with COVID-19

Uncertainty remains in defining a generalizable set of characteristic signs and symptoms for COVID-19. At best, current evidence suggests substantial variability ranging from mild to severe and based on only partially described patient-level factors. The most commonly reported signs and symptoms in the current literature include:

However, additional non-specific or atypical symptoms include:

Further, elderly patients may present differently than younger populations.

3. General Best Practices

In addition to a specific strategy for the identification of suspected COVID-19 cases, there are general best practices that will improve both healthcare worker and inpatient COVID-19 screening. Some examples include:

Train and Educate Healthcare Workers

Monitor and Manage Ill and Exposed Healthcare Workers

Establish Reporting within and between Healthcare Facilities and to Public Health Authorities

4. Surveillance Capacities

Facility-based surveillance for healthcare-associated infections (HAIs), including infections in healthcare workers and inpatients, is one of the WHO’s eight core components of infection prevention and control.  While surveillance is a critical component of providing safe healthcare, it is important to recognize that it requires expertise, good quality data, and an established infection prevention and control (IPC) program and thus, may require time to set up[2].  For this reason, during public health emergency response, healthcare facilities are encouraged to initially implement facility-based suspect COVID-19 patient case finding (surveillance) feasible with existing surveillance capacities.

Health facility surveillance capacity varies greatly even within health systems.  A realistic appraisal of capacity can help identify the best strategy for a given context.  A general description of surveillance capacities based on existing HAI surveillance activity is provided for guidance.

5. Identification of Healthcare workers with suspected COVID-19

Objective:  Prevent exposure of at-risk patients and staff to symptomatic COVID-19 positive healthcare workers.

Passive strategy

All healthcare workers self-assess for fever and/or a defined set of newly present symptoms indicative of COVID-19.  If fever or respiratory symptoms are present, healthcare workers:


Establishes mechanisms for the identification of healthcare workers at increased likelihood of infection with minimal resource requirements.



Enhanced passive strategy

In addition to passive strategy, establish a plan to remind or prompt workers to self-assess for symptoms consistent with COVID-19.  Common reminders include automated text messages or phone calls.


Evidence suggests that simple automatic reminders can increase adherence.


Requirements (Automated System):

Requirements (Manual System):


Active strategies

In-person active strategy

All healthcare workers present for in-person evaluation of symptoms and fever prior to each shift.  If symptoms consistent of COVID-19 are reported or observed, healthcare workers are provided with immediate follow-up actions.

Remote active strategy

All healthcare workers report (e.g., by call or text) the absence or presence of symptoms consistent with COVID-19 remotely each day.  Staff that fail to report or report symptoms are followed up.


While there is limited evidence for the benefit of active healthcare worker monitoring, active strategies will theoretically result in increased healthcare worker adherence to self-evaluation of symptoms, thus enhancing patient protection.

Requirements (In-person active strategy):

Requirements (Remote Active Strategy):


6. Identification of Inpatients with suspected COVID-19

The development of acute respiratory infection and healthcare-associated pneumonia are common complications of hospitalization. However, it is important that clinicians maintain a high level of suspicion for COVID-19 when there is a compatible presentation.  Because healthcare facilities often represent a gathering of individuals at higher risk of infection and adverse outcome, the potential of outbreak and harm to patients requires special effort to ensure any inpatient COVID-19 cases are identified.

A goal of identifying inpatients with suspected COVID-19 is to guide infection prevention and control (IPC) strategies to prevent or limit transmission in healthcare setting.  See interim WHO guidance hereexternal icon7.

Figure: Passive strategy for identification of inpatients with suspected COVID-19

Figure: Passive strategy for identification of inpatients with suspected COVID-19

Passive Strategy:

Clinicians are kept informed8 on:

  • Current COVID-19 case definitions
  • Latest description of COVID-19 clinical presentation
  • Relevant local epidemiology, including at risk groups and association with travel or area of residence
  • Facility COVID-19 admission triage, and cohorting practices

Clinicians are also made aware of what to do if they suspect COVID-19 in a hospitalized patient, including isolation precautions, PPE use, reporting/informing IPC focal point at the facility and public health authorities, and how to obtain testing, if available

Recommended Surveillance Capacity Level:

Applicable at all HAI surveillance capacity levels (i.e., Very Low to High)


Minimal disruption of existing clinical practice and no requirement for standardized data collection or form completion. Strategy seeks to encourage recognition and reporting by astute clinicians.


  • Regular and up-to-date educational materials/job aids provided to and accessible by clinicians
  • COVID-19 case definitions9
  • Standard operating procedure (SOP) for response to identified suspect case patients (e.g., isolation, cohorting, PPE). See WHO interim guidance (hereexternal icon) for recommendations
  • Acceptable reporting/communication channels to hospital administration and public health authorities


  • Strategy is dependent on participation and skill of available clinicians and an understanding of local epidemiology and clinical presentation of COVID-19, which may differ in different populations.
  • Limited to no access for viral testing will complicate this effort with the most conservative strategy being to treat all suspect cases as confirmed cases (empirical case determination) – potentially wasting resources, and if cases are cohorted, mixing positive and negative patients for extended periods.
    • The degree of resource waste and case patient mixing will depend on the accuracy of empirical case determination.
    • Supporting empirical case determination through clinician education and job aids (as described) can help improve accuracy of clinical diagnosis of COVID-19.
Figure: Enhanced passive strategy for identification of inpatients with suspected COVID-19

Figure: Enhanced passive strategy for identification of inpatients with suspected COVID-19

Enhanced Passive Strategy:

Enhancement of the passive strategy can be achieved through establishing systems that prompt or require clinicians to regularly review all patients as to their likelihood of harboring COVID-19.  Example enhanced passive strategies might include:

  • Incorporating consideration of COVID-19 into sign out reporting
  • Requiring units to provide a daily clinician-generated list of suspected cases, including if there are zero cases
  • Specific daily request to clinicians to report and discuss encountered patients with symptoms/history consistent with COVID-19

Recommended Surveillance Capacity Level:

Applicable in most HAI surveillance capacity levels (very low to high)


Dialog and accountability for case finding and reporting can improve empirical case determination, ensure patient evaluations are not missed, and help avoid clinician complacency over the long term


  • All requirements of Passive Strategy
  • Strategy to prompt and/or ensure clinician review – Requirements will depend on selected strategy


  • Effective strategies will be context specific – requiring thought and effort in design and implementation
  • May represent changes in current practice limiting acceptability
Figure: Active strategy for identification of inpatients with suspected COVID-19

Figure: Active strategy for identification of inpatients with suspected COVID-19

Active Strategy:

Active case identification involves targeted data collection and review of patient information by groups specifically responsible for the identification of suspected COVID-19 cases.  Examples of groups responsible for case identification and active case identification may include:

  • Ministries of Health
  • Sub-national/local public health authorities
  • Facility infection prevention and control teams

Recommended Surveillance Capacity Level:

High existing surveillance capacity or medium capacity with the provision of additional resources


Smaller more centralized team responsible for case identification can increase overall quality through dedicated training, improved engagement, limiting of competing priorities, and standardization of methods


  • Team with the information access, resources, and experience necessary for systematic review of patient information in order to appropriately apply standardized suspect case definitions
  • Group(s) with availability and responsibility for data collection, analysis/presentation, and information sharing
  • Group(s) with availability and responsibility for review of case-finding information with the authority and willingness to take appropriate action


  • Highly resource intensive
  • Teams with the requisite skills can be difficult to build during outbreak response periods
  • Separates case finding activities from patient care activities, which can decrease acceptability and impact sustainability
  • Value of active inpatient case finding, especially the context of limited viral testing, should be carefully considered

7. Case Definitions


Suspected Case Definitions

See: icon for details.

Confirmed Case Definition

Currently, a confirmed case is a person with laboratory confirmation of infection with the COVID-19 virus, irrespective of clinical signs and symptoms.


  • If testing is unavailable or severely limited, confirmed case counts will not reflect the true burden of disease. In this situation, caution should be used in using case counts for decision making.
  • Suspected Case Definition C. (Severe Symptoms) is applicable for inpatient case finding but may identify a substantial proportion of false positives. Especially when viral testing is limited, the value of assessing travel history and epidemiological links/contact may be of value.


CDC would like to acknowledge April Baller, MD, Infection Prevention and Control Lead, World Health Emergency Programme and Maria Clara Padoveze RN, PhD, Technical officer, IPC unit at the World Health Organization.

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