Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.
UPDATE
Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

Appendices

Appendices
Updated Aug. 11, 2022
PAGE 13 of 13

View Table of Contents

Summary of Changes

Revisions made on August 11, 2022

  • Updates made to the public health recommendations for the close contact definition.

Revisions made on January 4, 2022

  • Updates made to the public health recommendations listed under the close contact definition.

Revisions made on October 19, 2021

  • Based on evolving evidence, CDC recommends fully vaccinated people get tested 5-7 days after close contact with a person with suspected or confirmed COVID-19.
Appendix A – Glossary of Key Terms

Term

Term

Term

Definition

Definition

Definition

Case Investigation & Contact Tracing

Term

Case Investigation & Contact Tracing

Fundamental activities that involve working with a person with COVID-19 (index case) who has been diagnosed with an infectious disease to identify and provide support to people who may have been infected (close contacts) through exposure to the person with COVID-19. This process prevents further transmission of disease by separating people who have (or may have) an infectious disease from people who do not.

Definition

Fundamental activities that involve working with a person with COVID-19 (index case) who has been diagnosed with an infectious disease to identify and provide support to people who may have been infected (close contacts) through exposure to the person with COVID-19. This process prevents further transmission of disease by separating people who have (or may have) an infectious disease from people who do not.

Close Contact

Term

Close Contact

Close Contact through proximity and duration of exposure: Someone who was less than 6 feet away from an infected person (laboratory-confirmed or a clinical diagnosis) for a total of 15 minutes or more over a 24-hour period (for example, three separate 5-minute exposures for a total of 15 minutes). An infected person can spread the virus that causes COVID-19 starting 2 days before they have any symptoms (or, for people without symptoms, 2 days before the positive specimen collection date).

Public Health Recommendations:

People who are identified as close contacts should follow CDC recommendations to protect themselves and others from COVID-19.

Additional Information:

This definition is for use by public health officials performing case investigation and contact tracing activities as part of outbreak response activities. It may also be useful in certain settings where officials may choose to do contact tracing or investigational activities, such as high-risk congregate settings. This definition does not represent all the ways someone may be infected with the virus that causes COVID-19. A number of factors can influence a person’s risk of getting COVID-19, including the type, proximity, frequency, and duration of their exposure, environmental factors (such as crowding and ventilation), vaccination status, recent COVID-19 infection, circulating variants, and mask use.

Definition

Close Contact through proximity and duration of exposure: Someone who was less than 6 feet away from an infected person (laboratory-confirmed or a clinical diagnosis) for a total of 15 minutes or more over a 24-hour period (for example, three separate 5-minute exposures for a total of 15 minutes). An infected person can spread the virus that causes COVID-19 starting 2 days before they have any symptoms (or, for people without symptoms, 2 days before the positive specimen collection date).

Public Health Recommendations:

People who are identified as close contacts should follow CDC recommendations to protect themselves and others from COVID-19.

Additional Information:

This definition is for use by public health officials performing case investigation and contact tracing activities as part of outbreak response activities. It may also be useful in certain settings where officials may choose to do contact tracing or investigational activities, such as high-risk congregate settings. This definition does not represent all the ways someone may be infected with the virus that causes COVID-19. A number of factors can influence a person’s risk of getting COVID-19, including the type, proximity, frequency, and duration of their exposure, environmental factors (such as crowding and ventilation), vaccination status, recent COVID-19 infection, circulating variants, and mask use.

Confirmed COVID-19 Case

Term

Confirmed COVID-19 Case

Report of person with COVID-19 and meeting confirmatory laboratory evidence.

Definition

Report of person with COVID-19 and meeting confirmatory laboratory evidence.

Contact Elicitation Window

Term

Contact Elicitation Window

The timeframe when the case was likely infectious and not under isolation. This is the time period for which possible contacts should be elicited.

Definition

The timeframe when the case was likely infectious and not under isolation. This is the time period for which possible contacts should be elicited.

Critical Infrastructure Worker

Term

Critical Infrastructure Worker

Exposure

Term

Exposure

Having come into contact with a cause of, or possessing a characteristic that is a determinant of, a particular health problem. Principles of Epidemiology in Public Health Practice.

Definition

Having come into contact with a cause of, or possessing a characteristic that is a determinant of, a particular health problem. Principles of Epidemiology in Public Health Practice.

First-responder

Term

First-responder

Law enforcement, fire services, emergency medical services, and emergency management officials. EMS Guidance.

Definition

Law enforcement, fire services, emergency medical services, and emergency management officials. EMS Guidance.

Healthcare personnel

Term

Healthcare personnel

All paid and unpaid people serving in healthcare settings who have the potential for direct or indirect exposure to people with COVID-19 or infectious materials, including body substances; contaminated medical supplies, devices, and equipment; contaminated environmental surfaces; or contaminated air. Potential Exposure at Work.

Definition

All paid and unpaid people serving in healthcare settings who have the potential for direct or indirect exposure to people with COVID-19 or infectious materials, including body substances; contaminated medical supplies, devices, and equipment; contaminated environmental surfaces; or contaminated air. Potential Exposure at Work.

Incubation period

Term

Incubation period

Period of time between exposure to an infection and onset of symptoms

Definition

Period of time between exposure to an infection and onset of symptoms

Isolation

Term

Isolation

The separation of a person or group of people known or reasonably believed to be infected with a communicable disease and potentially infectious from those who are not infected to prevent spread of the communicable disease. Isolation for public health purposes may be voluntary or compelled by federal, state, or local public health order.

Definition

The separation of a person or group of people known or reasonably believed to be infected with a communicable disease and potentially infectious from those who are not infected to prevent spread of the communicable disease. Isolation for public health purposes may be voluntary or compelled by federal, state, or local public health order.

Multigenerational Household

Term

Multigenerational Household

Households that consist of more than two generations living under the same roofExternal. Many researchers also include households with a grandparent and at least one other generation.

Definition

Households that consist of more than two generations living under the same roofExternal. Many researchers also include households with a grandparent and at least one other generation.

Probable COVID-19 Case

Term

Probable COVID-19 Case

Report of person meeting clinical AND epidemiologic evidence of COVID-19 but without confirmatory laboratory evidence. More about Probable COVID-19 Case Pdf[252 KB, 10 Pages]External.

Definition

Report of person meeting clinical AND epidemiologic evidence of COVID-19 but without confirmatory laboratory evidence. More about Probable COVID-19 Case Pdf[252 KB, 10 Pages]External.

Quarantine

Term

Quarantine

The separation of a person or group of people reasonably believed to have been exposed to a communicable disease but not yet symptomatic from others who have not been so exposed to prevent the possible spread of the communicable disease. Quarantine may be voluntary or compelled by federal, state, or local public health order.

Definition

The separation of a person or group of people reasonably believed to have been exposed to a communicable disease but not yet symptomatic from others who have not been so exposed to prevent the possible spread of the communicable disease. Quarantine may be voluntary or compelled by federal, state, or local public health order.

Appendix B - Tips for Locating COVID-19 Cases and Contacts

When the locating information provided for a person with COVID-19 or close contact is insufficient, case investigation and contact tracing may come to an abrupt halt. The following list includes additional resources that may be used to obtain missing locating information and keep the investigation moving forward.

  • State DMV records
  • Online people search engines (may incur additional costs)
  • Health department records
  • Social media/mobile apps
  • Following up with the index case to ask for additional locating information on a contact
  • Jail and other correctional facility records
  • Property tax records
  • Frequent shopper cards
  • Women Infants and Children Program, Food Stamps and other social services records
  • Online white pages
  • Google maps
  • Employment records
Appendix C - Data Elements for Case Investigation and Contact Tracing Forms
Data Element Type Codes Notes
Case Investigation
Locating Information
Investigator Open Text Name of investigator
Investigator ID Numeric
Date Assigned for Investigation Date
Index case ID Numeric Autogenerated
Lot Number (to link related cases and contacts) Numeric To track clusters
Index case Last Name Open Text
Index case First Name Open Text
Index case Preferred Name Open Text
DOB Date
Gender Categorical M/F/Other/Unk
Primary Language Open Text/Categorical
Interpreter used Categorical Y/N/U/R
Residential Street Address Open Text
City of Residence Open Text
County of Residence Open Text
State of Residence Open Text
Zip code Numeric
Tribal Affiliation Open Text
Born in the United States Categorical Y/N/U/R
Phone Number 1 Numeric
Phone Number 2 Numeric
Email 1 Open Text
Email 2 Open Text
Ok to Text Categorical Yes, No, Partial, Refused
Ok to Email Categorical Yes, No, Partial, Refused
Race Categorical Check all apply Use Census Pdf[454 KB, 4 Pages]External or HHSExternal categories
Ethnicity Categorical Check box Use Census Pdf[454 KB, 4 Pages]External or HHSExternal categories
Date of interview Attempt 1 Date
Interview 1 occurred Categorical Yes, No, Partial, Refused
Date of interview Attempt 2 Date
Interview 2 occurred Categorical Yes, No, Partial, Refused
Date of interview Attempt 3 Date
Interview 3 occurred Categorical Yes, No, Partial, Refused
Symptoms and Clinical Course
Fever Categorical Check Box (Y/N/U/R)
Cough Categorical Check Box (Y/N/U/R)
Shortness of Breath Categorical Check Box (Y/N/U/R)
Diarrhea/GI Categorical Check Box (Y/N/U/R)
Headache Categorical Check Box (Y/N/U/R)
Muscle ache Categorical Check Box (Y/N/U/R)
Chills Categorical Check Box (Y/N/U/R)
Sore throat Categorical Check Box (Y/N/U/R)
Vomiting Categorical Check Box (Y/N/U/R)
Abdominal Pain Categorical Check Box (Y/N/U/R)
Nasal congestion Categorical Check Box (Y/N/U/R)
Loss of sense of smell Categorical Check Box (Y/N/U/R)
Loss of sense of taste Categorical Check Box (Y/N/U/R)
Malaise Categorical Check Box (Y/N/U/R)
Fatigue Categorical Check Box (Y/N/U/R)
Other symptom Categorical
Other symptom description Open Text
Date of symptom onset Date
SARS-CoV-2 testing Categorical Check Box (Y/N/U/R)
Date of first SARS-CoV-2 test Date
Results of first SARS-CoV-2 test Categorical Pos/Neg/Equi/Unk
Date of last SARS-CoV-2 test Date
Results of last SARS-CoV-2 test Categorical Pos/Neg/Equi/Unk
Hospitalized Categorical Yes, No, Partial, Refused
Pneumonia Categorical Yes, No, Partial, Refused
ECMO
ICU Categorical Yes, No, Partial, Refused
Death Categorical Yes, No, Partial, Refused
Stroke Categorical Yes, No, Partial, Refused
MI Categorical Yes, No, Partial, Refused
Pre-existing conditions
Chronic lung disease Categorical Yes, No, Partial, Refused
Diabetes Categorical Yes, No, Partial, Refused
Severe Obesity (BMI>=40) Categorical Yes, No, Partial, Refused
CVD Categorical Yes, No, Partial, Refused
Chronic renal disease Categorical Yes, No, Partial, Refused
Chronic liver disease Categorical Yes, No, Partial, Refused
Immunocompromised Categorical Yes, No, Partial, Refused
Pregnant (if Female) Categorical Yes, No, Partial, Refused
Risk Factors
Contact with confirmed COVID case Categorical Y/N/U/R
Employed Categorical Yes/No-unemployed/No-retired/No-unable to work/No-student
If employed, what occupation Open text
If employed, what kind of workplace Open text
HCP Categorical Y/N/U/R Work or volunteer in a healthcare setting
If HCP, what kind of setting
Hospital Categorical Check box
Ambulatory care Categorical Check box
EMS/Fire/Law Enforcement/1st responder Categorical Check box
Urgent care Categorical Check box
Long term care Categorical Check box
Hospice Categorical Check box
Name of HCP setting Open Text
Address of HCP setting Open Text
Congregate setting Categorical Y/N/U/R Do you live or work in congregate setting
If Congregate, what kind
Corrections Categorical Check box
Dorm Categorical Check box
Group home Categorical Check box
Multi-family household Categorical Check box
Multi-generational household Categorical Check box
Name of congregate setting Open Text
Address of congregate setting Open Text
Contact Tracing (during contact elicitation window)
Any household contact Categorical Y/N/U/R
Total Number of household contacts Numeric
Can you isolate Categorical Y/N/U/R Add in script what this means (use of bedroom and bathroom away from others)
Do you need assistance to isolate Categorical Y/N/U/R
Any intimate partners Categorical Y/N/U/R Partners you do not reside with
Total Number of Intimate Partners Numeric
Any other people in close contact with, including coworkers Categorical Y/N/U/R
Contact Elicitation Investigation
Data Element Type Codes Notes
Index Information Collected on the index
Investigator Open Text Name of investigator
Investigator ID Numeric
Date Assigned for Investigation Date
Index case ID Numeric Autogenerated
Lot Number Numeric To track clusters
Date of contact elicitation Date
Start date of Contact Elicitation Window Date
End date of Contact Elicitation Window Date
Information about contacts Ask for each identified contact
Contact Last Name Open Text
Contact First Name Open Text
Contact AKA Open Text
Contact Phone 1 Open Text
Contact Phone 2 Open Text
Contact email 1 Open Text
Contact email 2 Open Text
Contact social media handle 1 Open Text Twitter, Grindr, etc.
Contact social media handle 2 Open Text
Contact Address Open Text
Contact setting Check all that apply
Home Check box
School Check box
Day Care Check box
Workplace Check box includes people with COVID-19 and coworkers
Place of Worship Check box
Shelter Check box
Hospital/Medical Care Check box
Travel or Transit Check box
Retail setting Check box includes, supermarkets, gas stations, farmers markets, etc.
Duration of Exposure (minutes) Numeric
Pre-existing conditions If known
Chronic lung disease Categorical Y/N/U/R
Diabetes Categorical Y/N/U/R
Severe Obesity (BMI>=40) Categorical Y/N/U/R
CVD Categorical Y/N/U/R
Chronic renal disease Categorical Y/N/U/R
Chronic liver disease Categorical Y/N/U/R
Immunocompromised Categorical Y/N/U/R
Pregnant (if Female) Categorical Y/N/U/R
Risk Factors If known
HCP Categorical Y/N/U/R Work or volunteer in a healthcare setting
If HCP, what kind of setting
Hospital Categorical Check box
Ambulatory care Categorical Check box
EMT/Fire/1st responder Categorical Check box
Urgent care Categorical Check box
Long term care Categorical Check box
Hospice Categorical Check box
Congregate setting Categorical Y/N/U/R Do you live or work in congregate setting
If Congregate, what kind
Corrections Categorical Check box
Dorm Categorical Check box
Group home Categorical Check box
Multi-family household Categorical Check box
Multi-generational household Categorical Check box
Community Settings
Travel risk Categorical Y/N/U/R Train, plane, public transit
Specify travel Open Text List specific flights, routes, etc.
Workplace Categorical Y/N/U/R
Specify workplace Open Text Specific work locations
Retail Categorical Y/N/U/R
Specify retail Open Text
Large community social event Categorical Y/N/U/R
Specify Open Text
Recreational activity Categorical Y/N/U/R
Specify Open Text
Places of Worship Categorical Y/N/U/R
Specify Open Text
Data Element Type Codes Notes
Contact Investigation
Locating Information
Investigator Open Text Name of investigator
Investigator ID Numeric
Date Assigned for Investigation Date
Index case’s ID Numeric Autogenerated
Lot Number Numeric To track clusters
Close contact ID Numeric
Contact Last Name Open Text
Contact First Name Open Text
Contact Preferred Name Open Text
DOB Date
Gender Categorical M/F/Other/Unk
Primary Language Open Text/Categorical
Interpreter used Categorical Y/N/U/R
Residential Street Address Open
City of Residence Open Text
County of Residence Open Text
State of Residence Open Text
Zip code Numeric
Tribal Affiliation Open Text
Born in the United States Categorical Y/N/U/R
Phone Number 1 Numeric
Phone Number 2 Numeric
Email 1 Open Text
Email 2 Open Text
Ok to Text Categorical Yes, No, Partial, Refused
Ok to Email Categorical Yes, No, Partial, Refused
Race Categorical Check all apply Use Census Pdf[454 KB, 4 Pages]External or HHSExternal categories
Ethnicity Categorical Check box Use Census Pdf[454 KB, 4 Pages]External or HHSExternal categories
Date of interview Attempt 1 Date
Interview 1 occurred Categorical Yes, No, Partial, Refused
Date of interview Attempt 2 Date
Interview 2 occurred Categorical Yes, No, Partial, Refused
Date of interview Attempt 3 Date
Interview 3 occurred Categorical Yes, No, Partial, Refused
Any household contact Categorical Y/N/U/R
Total Number of household contacts Numeric
Can you isolate Categorical Y/N/U/R Add in script what this means (use of bedroom and bathroom away from others)
Do you need assistance to isolate Categorical Y/N/U/R
Symptoms and Clinical Course
Fever Categorical Check Box (Y/N/U/R)
Cough Categorical Check Box (Y/N/U/R)
Shortness of Breath Categorical Check Box (Y/N/U/R)
Diarrhea/GI Categorical Check Box (Y/N/U/R)
Headache Categorical Check Box (Y/N/U/R)
Muscle ache Categorical Check Box (Y/N/U/R)
Chills Categorical Check Box (Y/N/U/R)
Sore throat Categorical Check Box (Y/N/U/R)
Vomiting Categorical Check Box (Y/N/U/R)
Abdominal Pain Categorical Check Box (Y/N/U/R)
Nasal congestion Categorical Check Box (Y/N/U/R)
Loss of sense of smell Categorical Check Box (Y/N/U/R)
Loss of sense of taste Categorical Check Box (Y/N/U/R)
Other symptom Categorical
Other symptom description
Date of symptom onset Date
SARS-CoV-2 testing Categorical Check Box (Y/N/U/R)
Date of first SARS-CoV-2 test Date
Results of first SARS-CoV-2 test Categorical Pos/Neg/Equi/Unk
Date of last SARS-CoV-2 test Date
Results of last SARS-CoV-2 test Categorical Pos/Neg/Equi/Unk
Pre-existing conditions
Chronic lung disease Categorical Yes, No, Partial, Refused
Diabetes Categorical Yes, No, Partial, Refused
Severe Obesity (BMI>=40) Categorical Yes, No, Partial, Refused
CVD Categorical Yes, No, Partial, Refused
Chronic renal disease Categorical Yes, No, Partial, Refused
Chronic liver disease Categorical Yes, No, Partial, Refused
Immunocompromised Categorical Yes, No, Partial, Refused
Pregnant (if Female) Categorical Yes, No, Partial, Refused
Risk Factors
Contact with confirmed COVID case Categorical Y/N/U/R
Employed Categorical Yes/No-unemployed/No-retired/No-unable to work/No-student
If employed, what occupation Open text
If employed, what kind of workplace Open text
HCP Categorical Y/N/U/R Work or volunteer in a healthcare setting
If HCP, what kind of setting
Hospital Categorical Check box
Ambulatory care Categorical Check box
EMS/Fire/Law Enforcement/1st responder Categorical Check box
Urgent care Categorical Check box
Long term care Categorical Check box
Hospice Categorical Check box
Name of HCP setting Open Text
Address of HCP setting Open Text
Congregate setting Categorical Y/N/U/R Do you live or work in congregate setting
If Congregate, what kind
Corrections Categorical Check box
Dorm Categorical Check box
Group home Categorical Check box
Multi-family household Categorical Check box
Multi-generational household Categorical Check box
Name of congregate setting Open Text
Address of congregate setting Open Text
Appendix D – Tool for Estimating the Number of Contact Tracers Needed

Once states have lower COVID-19 case rates for at least 14 days, widely available testing, and adequate medical/hospital resources, contact tracing becomes an important strategy to eliminate transmission of SARS-CoV-2, the virus that causes COVID-19.  Contact tracing involves multiple steps, including case investigation of COVID-19 clients, notification of close contacts, and daily monitoring of close contacts. This process can be labor-intensive, and communities have different circumstances that affect contact tracing activities. These factors include the number of persons diagnosed with COVID-19 each day, number of close contacts per index case, and the amount of time and resources needed to reach and follow the clients and contacts. The number of contact tracers needed is large and will vary by community. Each community will need to examine local case load and other factors to estimate how many contact tracers will be needed.

Mathematical modeling tools can be used to help estimate the number of contact tracers needed. These models require data to quantify each part of the process. The data used may differ among communities and over the course of the pandemic, which may lead to large differences in estimates from different models – or from the same model if using different values. Each community will need to determine some key parameters to be in the model. Local tuberculosis / sexually transmitted disease contact tracers are likely familiar with community-specific “inputs” regarding the average number of contacts per case and how difficult contacts are to find.

CDC does not endorse the use of a specific model; however, these tools may be used to guide planning and calculate resources needed under different scenarios. Each community should carefully incorporate as much knowledge about its situation as possible to estimate the number of contact tracers needed.

Content describing non-CDC tools in this document is provided for informational purposes only and is not intended to indicate endorsement, actual or implied, of the tools. Additionally, information on this site is provided “as is,” for users to evaluate and make their own determination as to their effectiveness.

Example using an available tool: Contact Tracing Staffing Tool – Resolve to Save LivesExternal

This model is built into an Excel workbook and requires input on the following values:

  • # new COVID-19 clients / day
  • # close contacts / COVID-19 case
  • Proportion of people who are easy / hard / hardest to reach (and never reached). The amount of time needed to arrange and conduct the initial interview with the index person with COVID-19 can vary.
    • Average time needed for case investigation for each patient category
  • Proportion of contacts who are household / easy / hard / hardest to reach (and never reached). Some close contacts might live with the person with COVID-19; other contacts might lack contact information and require fieldwork to identify.
    • Average time spent on contact notification for each contact category
  • Proportion of people who can be followed in a mostly automated way versus those who need more staff time. For instance, contacts self-reporting their symptoms via email or text messages require much less time than contacts requiring daily telephone calls.
    • Average amount of time spent on contacts for each day in each category
  • Days spent following contacts (for example, 14 days after exposure)
  • Staffing considerations:
    • Hours of daily productive work per contact tracer
    • Number of workdays per week per contact tracer
    • Number of contact tracers per manager

Changing the parameters in the model will change the estimated total staffing needed, even when keeping the number of daily new COVID-19 cases constant.  (Note that this model does not specify overall population size. The total amount of work is proportional to the number of COVID-19 clients and contacts identified in each community rather than the total number of people living in the community.)

Estimates of contact tracers needed based on different assumptions in the model
Model developed by Resolve to Save Lives Assumed daily COVID-19 Incidence/ 100,000 persons Contact tracing staff needed / 100,000 persons Notes or assumptions
Contact Tracing Staffing Calculator -Lower estimate (See below) 9* 33 5 contacts per case; contact tracers work 8 hours/day; contacts easy-to-reach; many contacts use app/email to report daily.
Contact Tracing Staffing Calculator – Higher estimate (See below) 136** 3,739 20 contacts per case; contact tracers work 7-hour days; contacts harder to reach, take longer to interview, most require calls each day.

*Between April 15-23, 2020, the daily incidence of COVID-19 in the United States ranged between approximately 8 and 9 per 100,000 (between 25,858 and 29,916 new COVID-19 cases per day; assume US population of 328M).

**Approximate peak daily incidence of COVID-19 in New York City (approx. 11,400 incident new cases on 4/15/2020, assume NYC population of 8.4M).

Additional Considerations for Estimating Contact Tracing Resources

There are numerous factors that could affect contact tracer staffing needs that should be accounted for when estimating contact tracer needs:

  • These estimates do not necessarily include all managers or additional professions needed.
  • Increased case finding and testing efforts, as well as relaxing mobility restrictions could lead to more daily reported COVID-19 cases and/or close contacts, which would require tracing resources.
  • Effective contact tracing could reduce the number of new people with COVID-19 and contacts over time.
  • Time from diagnosis to isolation for the index patient with COVID-19 will affect the number of people exposed to COVID-19 and needing follow-up.
  • Use of digital contact tracing tools Pdf[391 KB, 2 Pages] could improve workflow efficiency or allow automated messages/contact self-report of symptoms to save contact tracer effort.
  • These models do not necessarily apply to special populations such as people in prisons or long-term care facilities.

This information will be updated as more tools become available.

Parameter values used for high and low estimates

(these are for illustrative purposes only)

Low Estimate Values—daily incident cases based on approximate average national daily incidence

Low Estimate Values—daily incident cases based on approximate average national daily incidence

High Estimate Values—daily incident cases based on peak daily incidence from NYC (approx. 11,400 cases among 8.4M persons)

High Estimate Values—daily incident cases based on peak daily incidence from NYC (approx. 11,400 cases among 8.4M persons)