Yale COVID-19 Statistics

Updated August 4, 2020

These tables and graphs provide the confirmed number of COVID-19 tests and cases at Yale University based on data gathered by Yale Health, which serves university employees, students, and retirees, and their dependents, including nearly 80% of Yale faculty and staff. Symptomatic testing is available to Yale Health members who present with COVID-like symptoms. Asymptomatic testing has been offered on a rolling basis as employees and students return to campus: as of August 3, 2020, 19,879 employees and students have been invited to this testing program.

The data on this page do not include members of the Yale community who were tested by health care providers outside of Yale Health. State of Connecticut statistics by county are included to help place Yale’s data into a broader local context.

Yale Data

Connecticut Data by County


Yale Data


At a Glance

The table here shows the numbers of tests and positive results (cases) for COVID-19 since March 10, 2020, when symptomatic testing began at Yale Health, through July 14, 2020. The table also includes total tests and cases, from May 20, 2020, when the asymptomatic testing program began, through August 2, 2020.

COVID-19 Testing and Positive Cases at Yale
  Total Tests
since March 10
total cases
since March 10
Cumulative % Positive
since March 10
Recent tests
since May 20
Recent Cases
Since May 20
Recent % Positive
Since May 20
Symptomatic 4442 216 4.9% 3327 43 1.3%
Asymptomatic 4396 7 0.2% 4396 7 0.2%
Total 8838 223 2.5% 7723 50 0.7%
The data in the table are based on COVID-19 tests completed by Yale Health. Symptomatic testing refers to testing of Yale Health members (including dependents and retirees) who presented with COVID-like symptoms. Asymptomatic testing refers to gateway and screening testing of Yale students and employees who are present on campus. Asymptomatic testing began on May 20, and the earliest results became available on May 22. Symptomatic testing was first ordered on March 10, with earliest results available on March 13. Totals for tests refer to tests that have been collected, while totals for cases refer to positive results.

Testing at Yale

This graph provides an overview of how many tests Yale has administered through Yale Health by group and testing type, from March 10, 2020 through August 2, 2020. Most tests have been administered to Yale employees, including faculty, staff, and trainees; over half of those tests have been via the asymptomatic screening program (which has been offered to 19,879 employees and students as of August 3, 2020). The majority of tests administered to students, including graduate and professional students, have been through asymptomatic testing; the majority of student tests so far are for Graduate School students invited ahead of the upcoming term. All testing of dependents of Yale Health members and of retirees has been symptomatic testing.

Yale testing by group, overall

Testing completed by Yale Health. Symptomatic testing refers to testing of Yale Health members (including dependents and retirees) who presented with COVID-like symptoms. Asymptomatic testing refers to gateway and screening testing of Yale students and employees who are present on campus and who certified that they were not experiencing symptoms. The “Others” group includes fee-for-service members of Yale Health and asymptomatic tests that are not linked to a Yale employee or student.
View “Testing at Yale” data in a text-based table

Positive Cases at Yale, Counts

COVID-19 cases at Yale have followed a trend similar to the rise and fall of cases in Connecticut as a whole, albeit at a much smaller volume. Cases rose quickly in late March, peaking in early April with approximately 5 to 6 newly-reported positive tests per day. Cases dropped in May, and in recent weeks the university has been averaging fewer than 1 new case per day. Note that although these graphs include both symptomatic and asymptomatic testing, they do not include members of the Yale community who were tested by health care providers outside of Yale Health.

Daily new cases at Yale

Yale new cases by group

Testing completed by Yale Health. Symptomatic testing refers to testing of Yale Health members (including dependents and retirees) who presented with COVID-like symptoms. Asymptomatic testing refers to gateway and screening testing of Yale students and employees whose work requires their presence on campus. The “Others” group includes fee-for-service members of Yale Health. Symptomatic testing began March 10, 2020 at Yale Health. The Yale Health asymptomatic testing program began May 20, 2020.
View “Positive Cases at Yale, Counts” data in a text-based table

Positive Cases at Yale, %

Positivity rate, or the proportion of positive tests out of all COVID-19 tests for a certain group, is a helpful metric for assessing whether there are enough tests being administered among a given population. An early baseline goal based on WHO recommendations was 10% positive tests; on May 12, 2020, WHO recommended 5% as a revised goal. While early positivity rates quickly rose to over 20%, since mid-May positivity rates have fallen to well below 5%. Note that although these graphs include both symptomatic and asymptomatic testing, they do not include members of the Yale community who were tested by health care providers outside of Yale Health.

Testing Positivity Rate at Yale

Yale positivity rate by group

Testing completed by Yale Health. Symptomatic testing refers to testing of Yale Health members (including dependents and retirees) who presented with COVID-like symptoms. Asymptomatic testing refers to gateway and screening testing of Yale students and employees whose work requires their presence on campus. The “Others” group includes fee-for-service members of Yale Health; due to the small size of this group, their positivity rate may look more volatile than that of other groups. Symptomatic testing began March 10, 2020 at Yale Health. The Yale Health asymptomatic testing program began May 20, 2020.
View “Positive Cases at Yale, %” data in a text-based table

Connecticut Data by County


Positive Cases in Connecticut

The number of COVID-19 cases in Connecticut grew dramatically from mid-March and peaked in mid-April. Fairfield County experienced the fastest and most dramatic increase in cases, followed by New Haven County and Hartford County; Fairfield County peaked with nearly 500 cases per day in mid-April, as compared to a peak of around 300 cases per day for New Haven County. Since April, the number of cases has decreased, though at a slower rate than the initial growth.

Connecticut daily new cases overall

Connecticut daily new cases by county

Data primarily sourced from Connecticut Department of Public Health, with data prior to March 24 sourced from the New York Times. Beginning in July, Connecticut began to report data only on weekdays. On July 23, Connecticut reported 440 previously-unreported positive tests administered by an out-of-state lab, and on July 28, Connecticut reported an additional 384 such cases. These backlogged cases have been excluded from rolling averages.
View “Positive Cases in Connecticut” data in a text-based table

Hospitalizations in Connecticut

The number of patients hospitalized due to COVID-19 grew dramatically from mid-March and peaked in mid-April, with the highest numbers of patients in Fairfield County (peaking at 797 patients on 4/17), New Haven County (peaking at 638 patients on 4/18), and Hartford County (peaking at 495 patients on 4/22). Since April, the number of hospitalizations has decreased rapidly, though at a slower rate than the initial growth. On August 2nd, New Haven County had 23 patients hospitalized, out of 56 hospitalized patients in Connecticut overall.

Connecticut hospitalizations overall

Connecticut hospitalizations by county

Data primarily sourced from Connecticut Department of Public Health, with data prior to March 24 sourced from the New York Times. Beginning in July, Connecticut began to report data only on weekdays.
View “Hospitalizations in Connecticut” data in a text-based table

Deaths in Connecticut

Deaths due to COVID-19 increased rapidly in April, peaked in late April in most counties, and have slowly decreased since the beginning of May. Hartford County and Fairfield County experienced a similar death rate due to the virus, both peaking at over 30 COVID-related deaths per day in late April; in the same time period, New Haven County was reporting over 20 deaths per day. As of August 2nd, all counties are reporting fewer than 5 deaths per day due to COVID-19.

Connecticut daily deaths overall

Connecticut daily deaths by county

Data primarily sourced from Connecticut Department of Public Health, with data prior to March 24 sourced from the New York Times. Beginning in July, Connecticut began to report data only on weekdays.
View “Deaths in Connecticut” data in a text-based table