“Testing is the lynchpin to all public health measures put in place,” Johns Hopkins Assistant Professor of Emergency Medicine Lauren Sauer said on “Bloomberg Surveillance” this week. On February 27 there were 2 people tested in the U.S. for COVID-19. On March 27, total tests were 665,689 tested and on April 27 there were 5,593,495 tested with a capacity to test more than 200,000 per day in place. Of those more than 5.59 million tests, 981,134 were positive with 4,077 pending. As of April 27, 50,327 deaths have been reported from the virus across the U.S. and its territories.

You can see daily totals for testing each state and across the U.S. at covidtracking.com.

Here are some key dates in the federal government’s plan to ramp up testing:

March 13: FDA issues an EUA for Roche’s cobas COVID-19 test within 24 hours of receiving the application.

March 18: FDA issues the first emergency use authorization for a point-of-care COVID19 diagnostic test (Abbott).

April 21: FDA authorizes the first COVID-19 diagnostic test with a home collection option (LabCorp).

As of April 27: FDA has issued 70 Emergency Use Authorizations (62 for molecular tests and 8 for serological tests).

The charts below show some of the progress made in the U.S.

Cumulative COVID-19-associated hospitalization rates since March 1 are updated weekly. The overall cumulative hospitalization rate is 20.0 per 100,000, with the highest rates in people 65 and older (63.8 per 100,000) and 50-64 (32.8 per 100,000).

California testing priorities

When standardizing for population differences per 1 million people, California ranked 48th with 6,550 tests processed in the first week of April. Rhode Island ranked first with the most tests processed at 29,037, and Virginia ranked 51st with just 5,740 tests processed.California has been lagging in processed COVID-19 tests for the last three weeks, ranking 50th on April 3, up to 45th the second week and back down to 48th the third week.Gov. Gavin Newsom says California is improving.

“We are seeing substantially larger numbers tested on a daily basis. A little over 18,800 (April 12) yesterday. A little over 12,500 today. We are seeing those numbers increase compared to even a week ago. We want to get to 25,000 tests per day in the next few weeks,” Newsom said. As of April 19, testing for COVID-19 is becoming more readily available at hospital, academic, commercial and public health laboratories across California.There are four priorities for testing for now:Priority 1:Hospitalized patients.Symptomatic health care workers.People identified for testing by public health contact investigations and disease control activities in high-risk settings, including both residents and staff (congregate living facilities, correctional facilities).Priority 2:Screening of asymptomatic residents of congregate living facilities prior to admission or re-admission (a hospitalized patient will be screened for COVID-19 prior to discharge to a congregate living facility).Screening of asymptomatic health care workers (skilled nursing facility workers, hospital workers).Symptomatic people in essential health and public safety occupations.(first responders, law enforcement, congregate living facility workers).Symptomatic people >65 years of age or with chronic medical conditions.

Priority 3:Symptomatic people in essential infrastructure occupations (utility workers, food supply workers, other public employees).Priority 4:Community-based testing of all low-risk symptomatic people.Surveillance testing of asymptomatic people.People should stay home and away from others until they have had no fever without the use of fever-reducing medications; they have seen improvement in respiratory symptoms for at least 3 days; and it been at least 7 days since their symptoms first appeared, i.e., the minimum length of time will be 7 days.

These priorities are subject to change as testing availability increases.

Where testing occurs

Tests can be done in a hospital, a clinic, a community testing site or through a home kit authorized by the FDA this week. There is no test that can be done completely at home to date. However, on Monday, the FDA authorized the first COVID-19 test for home collection of specimens to be sent to a laboratory for processing and test reporting. This authorization is only to the home collection test that has been issued the Emergency Use Authorization for LabCorp’s COVID-19 RT-PCR Test. If you think you have symptoms, you must contact your health care provider or physician first.Hospitals focus on significantly ill patients and health care workers. It is important to keep hospitals and emergency departments as free as possible to treat critically ill people.Clinics focus on people with other medical problems, and it is important to avoid infecting people with other conditions.l Community testing sites can provide professionally managed testing for mildly symptomatic or asymptomatic people. There are several drive-up sites in California, but these are by appointment only.Home testing is being developed but not widely used to date.Type of test: Nasopharyngeal swabs, which are placed in the back of the person’s nasal cavity, have been the most widely recommended because they test a location that is known to have large quantities of the SARS-CoV-2 virus. If the swab doesn’t reach the back of the nasal cavity, the virus may not be detected, even if the person is symptomatic and infected.

To open the country

In the White House’s guidelines to open the country again, testing has an important role. Health officials have created a three-phased approach. These steps will help state and local officials when reopening their economies, getting people back to work and continuing to protect American lives. The following criteria must be met to reach phase 1:SYMPTOMSDownward trajectory of influenza-like illnesses reported within a 14-day period and downward trajectory of COVID-like cases reported within a 14-day period.

CASESDownward trajectory of documented cases within a 14-day period or downward trajectory of positive tests as a percentage of total tests within a 14-day period (flat or increasing volume of tests).HOSPITALSTreat all patients without crisis care and robust testing program in place for at-risk health care workers, including emerging antibody testing.