Witman News
Coronavirus Testing | Rise in Coronavirus cases
Sweet Potato and Black Bean Tacos

June 28, 2020
All About Coronavirus Testing
There is a lot of confusion about Coronavirus testing - should I get tested? When? How often? Which test? What do the results mean?

One reason for so many questions is that we still don't know very much about COVID-19, although we're learning new information every day. So I've tried to explain testing and what it does (AND DOESN'T) tell us.


Virus Test - The test for active Coronavirus infection is done by PCR (polymerase chain reaction) which picks up even very tiny amounts of viral RNA. This is usually done by deep nasal swab. Yes, this can be uncomfortable, but that's where the virus lives in large amounts, so it is the best place to sample. Throat swabs are less sensitive so you might get a negative result but still be infected.

  • Rapid test - Results within 15-30 minutes. This requires an expensive machine to run, so it's often only available in ER or hospitals.
  • Standard test - Is done by most labs, turnaround is usually 2-5 days

Antibody test - this test tells is if we've been infected in the past. These antibodies develop about 4 weeks after the acute infection. This test requires a routine blood draw and turnaround time is about 1-2 days.


We've heard a lot about various tests with some being better than others. The FDA has given Emergency Use Authorization to a number of tests and click here for a good explanation of their findings. All of the tests they've "approved" are performing reasonably well, so I've personally decided not to get lost in this discussion (sensitivity, specificity, positive predictive value, negative predictive value, etc).


For this discussion, I'm assuming the test is accurate. But remember that no test is always 100% accurate.

Virus test (nasal swab):

  • a positive test means there is virus RNA in your body - you are actively infected, even if you don't have symptoms. You are infectious to other people and should self quarantine. There is a caveat here - people who get infected with COVID-19 can remain positive on this test for up to 12 weeks. Since we do not believe people are infectious this long, it may be that the test is picking up dead virus. But this remains an area of significant uncertainty.

  • a negative test means there is no virus RNA present - you are not actively infected. You are not infectious

Antibody test (blood test):

  • A positive test means you've been infected with Coronavirus at some point in the past. This is very helpful to Public Health professionals to know what percentage of the population has been infected and how close we are to "herd immunity". It is less helpful for a specific individual and questions remain:

  • it doesn't tell us when you were infected.
  • We do not know how long these antibody tests remain positive - a few months, a few years or forever?
  • We do not know if these antibodies protect us from getting infected again. With some viruses (e.g. cold viruses), antibodies protect us for a short while, but we can get infected again and again. With some viruses (e.g. chicken pox, measles) antibodies protect us and we only get infected once in a lifetime. And with other viruses (e.g. herpes, HIV), having antibodies doesn't help at all - we remain chronically infected.

  • A negative test means you've not been infected with Coronavirus in the past. One caveat: If you're recently infected with Coronavirus, the antibody test will not become positive for about 4 weeks.


With symptoms - Always test if you have symptoms suggestive of Coronavirus.

After an exposure - Not everyone gets infected even if exposed. But when (and if) to test is an area of debate . The incubation period of Coronavirus is 2-14 days. If you test negative on day 2, unfortunately you can still turn positive on day 3, 4, 5 up to day 14. So regardless of the results, you should self isolate for 14 days. One recommendation is to test on day 14 - if negative you can safely return to life.

Before visiting a high risk person - Ideally get a rapid viral test right before you're planned visit. A negative result means you can visit Grandma without concern you'll spread it to her. This is limited by the availability of the rapid test (see "where to get tested" below). If you are planning on visiting Grandma for a week, however, you'll need to test every day which is often not feasible.


  • I offer standard virus and antibody testing in my office. I do not have rapid virus testing.
  • County testing sites can be found here. These sites are free and some require an appointment.
  • Scripps is only testing patients with symptoms. If you are a Scripps patient, Call the Scripps Nurse line (888-261-8431) to get scheduled. They offer standard virus testing, they are not doing rapid virus testing.
  • Many CVS locations offer standard virus testing with 2-4 day turnaround. Cost is usually covered by insurance. Register in advance at CVS.com
  • CovidClinic.org in downtown San Diego offers rapid virus testing and antibody testing for about $150
  • QuestDirect allows people to request an antibody test and pay for it online ($130). An appointment is then made for a blood draw at a Quest lab.

At Home testing - this is a rapidly expanding area with many unknowns currently. I will provide more information in the next newsletter.
Increasing Coronavirus Cases
The physical and economic health of our community depends on us!

If you're like me, you've been hearing about the spike in Coronavirus cases in the US, including California. Regardless of the cause, it's happening. And it's not just due to increased testing.

San Diego County has a detailed plan for monitoring the situation and what would prompt a change in the current "re-opening" plan. CLICK HERE for more information. Below is the Dashboard as of 6/26/20 and its updated frequently.
New orders from Public Health (e.g. possible re-closures) will be triggered if San Diego County exceeds any of the following:

  • Community Outbreaks (item #2) - 7 or more new outbreaks in community settings in a 7-day period - Currently at 6
  • ICU Capacity (item #7) <20% availability of ICU beds. Currently 31%
  • PPE Supply (item #9) ≤50% of hospitals have at least 15-day supply of PPE - currently 88%

Right now, none of these has occurred, but we are close on the number of outbreaks.

Alternatively, changes could occur if one or more of the remaining criteria in at least two of the categories (Surveillance, Healthcare, Public Health) is met.

Right now, we've hit one of these - item #6 >10% increase in hospitalization . If we hit a second criteria in one of the other columns, it will trigger a change in Public Health Orders and possible re-closures. I fear we are close to hitting
item #1 - Increase new case counts of at least 10% for five consecutive days above a stable baseline without substantial increase in testing .

It is VITAL that we redouble our efforts at reducing the spread of Coronavirus. Here's three great reasons to wear a face mask:

  1. Humility - we don't know if we have COVID since people can spread the disease before they have symptoms
  2. Kindness - we don't know if the person we are near has a child battling cancer or cares for their elderly mom. While you might be fine, they might not.
  3. Community - We want our community to thrive, businesses to stay open, employees to stay healthy. Containing Coronavirus helps us all!
Sweet Potato and Black Bean Tacos
Smoky roasted sweet potatoes, hearty black beans, and a variety of toppings make this a satisfying meat-free dinner.

It’s also is ready to go in about 30 minutes!

Prep: 10 minutes. Cook: 30 minutes
Yield: 4 servings


  • 1 to 2 medium sweet potatoes (about 1.5 pounds)
  • 1 15-ounce can black beans
  • Your favorite store bought salsa
  • Olive oil
  • Chili powder or taco seasoning
  • Avocado
  • Feta cheese crumbles
  • Hummus
  • corn tortillas


  • Preheat oven to 425°F.

  • Peel and chop sweet potatoes into 1/4-1/2" cubes.

  • Place chunks in medium bowl, drizzle with olive oil, and combine with your favorite spice (chili powder, taco seasoning, etc)

  • Spread seasoned chunks on parchment lined rimmed baking sheet, bake for 20 min or until tender.

  • When sweet potatoes have about 10 min left, drain and rinse black beans. Combine with salsa in large frying pan and simmer.

  • Prep avocados by cubing or slicing

  • Put tortillas in oven to warm

  • Assemble tacos starting with a spoonful of hummus on the corn tortilla (holds everything in)

  • Layer with sweet potatoes and black beans.

  • Serve with avocado and Feta cheese


Serving Size: 2 tacos with avocado
Per serving: Calories: 436; Total Fat: 11g; Saturated Fat: 1g; Sodium: 127mg; Sugar: 11g; Protein: 15g
Office Hours M-F 9 am – 5 pm
Same day visits usually available
12395 El Camino Real, Suite 115.
San Diego, CA 92130
Phone: 858-724-1313
Fax: 858-724-1314