COVID-19 Testing

HouseCall MD administers 3 types of COVID tests in your home:

The first two tests,Viral RNA (RT-PCR/RNA) and the Rapid Antigen Test (RAT), are obtained by a nasal swab. The Serum Antibody Test requires a blood draw. Each test is appropriate at different times after the date of the potential exposure. The timing of the test matters for each of the three tests as well as if symptoms are present or not.

• A.
  This is the time from the date of exposure until the time the virus begins replicating inside the body. This can be as quick as 3 days, or take as long as 14 days, though the average incubation period of COVID-19 is 5.6 days. All of the tests are likely to be negative in the incubation window.
• B.
  The time when someone is actively shedding the virus is the Infection Window. This typically starts between 5-7 days after initial exposure, and lasts up to 2 or 3 weeks. This is the period of time where people will have symptoms which may be mild to severe. This is also the time where someone is contagious and can infect others. The RT-PCR/RNA and the Rapid Antigen Test (RAT) are both appropriate choices in this time window after exposure. However, presence or absence of symptoms determines which test would be more appropriate (read below for more information).
• C.
  The Immune Response Window is the period that begins after your body begins to develop antibodies to the infection. This response time takes about 14-24 days on average from the time of first exposure. Antibodies are necessary to fight and eliminate an infection, though they do not necessarily prevent an infection. The Serum Antibody Test is appropriate at this time to determine if you have developed antibodies and have developed immunity.

Symptomatic Patients: Patients experiencing fever, shortness of breath, cough, new loss of taste or smell, or other common COVID-19 symptoms. If you have symptoms, there are two options for testing: the Rapid Antigen Test (RAT) or the Viral RNA (RT-PCR/RNA) test. The RAT has same-day results, while the RT-PCR/RNA test takes a bit longer. Although the RAT results are quicker, the RT-PCR/RNA test is much more accurate. The Rapid Antigen Test has a high false negative rate (~20%). The best and more accurate test is the RT-PCR/RNA, and is preferred over the RAT.

Asymptomatic Patients: The only appropriate test for screening patients without any symptoms is the RT-PCR/RNA test. Remember, the timing of the test after initial exposure is important (see above). For this test, results are currently returning in 2-3 days on average. This test is appropriate for those who have been exposed to someone with COVID-19 but have no symptoms, want to visit a high-risk family member, are returning to work, or need to be tested for travel purposes. The Rapid Antigen Test should NEVER be used for asymptomatic screening. It is only to be used for patients with symptoms (those with a high pre-test probability).

For those who need to document whether they have immunity to COVID-19 (prior infection or immunization), the Serum Antibody Test can be used. While it is good to have peace of mind, this test still doesn’t have much clinical application (though it may help determine if you need a booster of the COVID-19 vaccine). It is important to note, this test is not always covered by insurance, so the cost of the test may be out of pocket.

Schedule an appointment with one of our medical providers. They can discuss which test is the most appropriate based on timing of exposure, potential symptoms, accuracy of each test, and whether the test is needed for travel or employment purposes. If you aren’t sure, schedule a telemedicine appointment, and the medical provider will discuss which option is best, and we can then send a technician to obtain a sample at your home.