Testing for COVID-19
SciLine reaches out to our network of scientific experts and poses commonly asked questions about newsworthy topics. Reporters can use these responses in news stories, with attribution to the expert.
What are Quotes from Experts?
April 3, 2020
Why is testing important for pandemic response?
“Testing is critically important for pandemic response, as a tool for gathering information on who is infected, where, and when. Accurate estimates of the number of people infected within a population are the cornerstone of evidence-based public health decision-making during an epidemic, and can help hospitals and other frontline services plan, prepare, and more effectively respond.” (Posted April 3, 2020)
“Testing is critical to understand the pattern of virus spread in order to develop strategies to mitigate spread.” (Posted April 3, 2020)
Would more aggressive and widespread testing help stop or slow the pandemic?
“While the extent of testing will always have to be balanced against practical and logistical considerations, such as the availability of trained personnel to run the tests as well as tools and reagents to collect and process samples, widespread testing can help identify mild or asymptomatic cases early, and prevent those individuals from unknowingly spreading the disease further. Aggressive testing and intensive case management, when conducted hand in hand, can be effective at limiting (although not always stopping completely) community transmission, as has been demonstrated in Singapore. Even once community transmission is widespread, testing can still be a valuable tool, for example to assess whether physical distancing or other non-pharmaceutical interventions are having the intended impact, and as source data for predictive modeling.” (Posted April 3, 2020)
“Yes. Aggressive, widespread testing would help identify and quarantine infected individuals in order to prevent further community spread.” (Posted April 3, 2020)
What’s the difference between tests for the virus and tests for antibodies against the virus?
“The most common tests that look directly for the virus are based on identifying the virus’ genetic material, its RNA. These tests usually rely on a swab from deep within a patient’s nasal cavity to detect live virus, and if the test is positive, indicate that the person is actively infected with the virus, and could possibly transmit it to others.
“Another type of test, which will prove critical to identifying possible “exit strategies” for countries in various levels of lockdown, does not look directly for the virus, but rather looks for specific proteins that a person’s immune response produces after being infected. These proteins are called antibodies, and circulate in the blood, allowing for the potential development of easy-to-use, fingerprick-based tests that could even be done by people at home. However, we know from previous experience with other coronaviruses, as well as preliminary data from countries in East Asia, that antibodies are only usually produced in sufficient levels to be detected a week or more after the onset of symptoms. As such, antibody tests are not effective diagnostic tools to look for active cases of COVID-19, but will be extremely useful in identifying those who have previously been infected, and have since recovered. A study from China has suggested that 100% of the patients infected with SARS-CoV-2 had detectable levels of virus-specific antibodies in their blood two weeks after symptom onset.
“Widespread deployment of these types of antibody tests (often referred to as serological tests) will allow public health authorities to better understand the extent of viral transmission in the community. Knowing how many people have been exposed and have recovered will greatly improve predictive modeling efforts and help determine potential “exit strategies” from current lockdown measures.” (Posted April 3, 2020)
“There are two types of tests being discussed in the news. The CDC-based test that is primarily being conducted across the nation is testing for the presence of coronavirus RNA. This was an easier test to rapidly deploy based on the gene sequence being determined and made available to the public in mid-January.
“The other test being discussed in the news is a serological test, which tests for antibodies against the virus in the blood of a person that has been exposed and infected with the coronavirus. Typically, if a person has been infected, it takes about a week or longer for antibodies against the virus to appear in the blood.
“Each test serves a different purpose, and both are important.
“There is an urgent need to test right now as this information will provide vital data in each state of the number of people infected.
“Also, tests that can provide a rapid result without being sent to a lab to analyze would help quickly determine if someone is infected.” (Posted April 3, 2020)
Who should get tested?
“Many public health departments recommend a tiered approach to COVID-19 testing. Persons with symptoms severe enough to be hospitalized, fever, cough and trouble breathing, and healthcare workers with fever, cough or other COVID-19 compatible symptoms are the highest priority. Symptomatic persons 65 years old or older, or with other chronic medical problems such as heart or lung disease, and symptomatic persons in long-term care facilities are the next priority, as are first responders—police, fire fighters—with symptoms. Other persons with appropriate symptoms should be tested as capacity allows. Individuals without symptoms are not recommended to be tested at this time.” (Posted April 3, 2020)
“At this moment, the decision to test for COVID-19 in the United States depends on both the patient’s clinical status and symptoms (including fever, cough, and difficulty breathing) and what is happening in a particular geographic location. Initially history of travel, especially international travel to one of the most affected areas, was felt to be most important but this has evolved as the outbreak grows domestically and there is now extensive community associated spread across the US. Certain individuals also have higher priority for tests (for example, healthcare workers, first responders).” (Posted April 3, 2020)
“Testing should be for people who have symptoms or have had significant exposure to someone who tested positive for COVID-19, making sure that there is enough time to see if the person was infected or not. Figuring this out is hard sometimes, but using the Coronavirus Checker that Emory developed is a good starting place.” (Posted April 3, 2020)*
“Widespread testing would be extremely helpful in many states to better understand the degree of community spread, which can alert public health and medical professionals of high numbers of infected people in a region (city, county, etc).
“Alcohol-based sanitizers are useful when soap and running water are not available or out of convenience when you need to clean your hands quickly. Alcohol-based hand wipes can also help remove viruses from hands but need to be used carefully to cover all the hand/finger surfaces.” (Posted April 3, 2020)
* Links included in quotes were supplied by the expert.
What should I do if I think I have the virus but can’t access a test?
“Anyone with fever, cough, or COVID-19 compatible symptoms should speak with their healthcare provider about testing. If the healthcare worker does not recommend COVID-19 testing at this time, you should stay home until your symptoms have gone away and you have no fever for at least 24 hours off any fever-reducing medications such as acetaminophen. If you develop any trouble breathing, you should call your healthcare provider right away to be evaluated.” (Posted April 3, 2020)
“With continued limitations on testing capacity (and health systems that are overwhelmed with patients that need hospitalization), some patients who do not have severe symptoms will not be tested at this time, especially if a test result will not change management. The recommendation is that these individuals follow the same guidance as those who are confirmed to have COVID-19. Specifically, staying at home, keeping in touch with your doctor, and avoiding close contact with others. Continue washing your hands, covering your cough and if available, wearing a facemask. These same guidelines can be followed while waiting for a test result.” (Posted April 3, 2020)
“If you think you have the virus but cannot access testing stay at home and isolate yourself so you don’t infect others in the household.” (Posted April 3, 2020)
What should I do while I’m waiting for my test results?
“Persons waiting for their COVID-19 test results should stay home, preferably in self isolation away from others in the house if possible, until notified of your test results. If the COVID-19 test is positive, you should remain in self-isolation until your fever has gone away for at least 72 hours (3 days) off any fever-reducing medications such as acetaminophen. If you never had fever, or only a few days of fever, you should remain in self-isolation for at least 7 days. If you develop any trouble breathing, you should call your healthcare provider right away to be evaluated. If the COVID-19 test is negative, you should stay home until your symptoms have gone away and you have no fever for at least 24 hours off any fever-reducing medications such as acetaminophen.” (Posted April 3, 2020)
“It is critical that you remain isolated until you receive your results. Consulting the CDC website is a good place to get information on how to do this.” (Posted April 3, 2020)*
* Links included in quotes were supplied by the expert.
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Dr. Claire Standley, Assistant Research Professor, Center for Global Health Science and Security at Georgetown University, said:
“I have no competing financial interests or any other relevant disclosures related to this topic.”
Dr. Louis Mansky, Professor and Director, Institute for Molecular Virology, University of Minnesota – Twin Cities, said:
“I have no conflicts to disclose.”
Timothy Brewer, MD, MPH, Professor of Medicine and Epidemiology, University of California, Los Angeles (UCLA), said:
“No known conflicts of interest to disclose for this topic.”
Carlos del Rio, MD, Distinguished Professor of Medicine (Infectious Diseases) at Emory University School of Medicine and Professor of Epidemiology and Global Health at the Rollins School of Public Health, said:
Preeti N. Malani, MD, Chief Health Officer and Professor of Medicine, University of Michigan, said: