Case Study -- From A Reader -- October 8, 2020

There should be a lot of case studies coming out of the pandemic but we will never hear about them. There will be way too many. 

But here's one that's interesting and probably commonplace. 

Extended family of six, three adults, three children.

One of the adults -- the index case --  comes down with mild respiratory symptoms (normal oxygen sats) and moderate fever. Covid-19 test taken four to five days after initial symptoms but results would not be known for three to five days after that.

During the three-to-five day wait, one of the other three adults and one child get "rapid" Covid-19 testing. They are asymptomatic and test negative. I don't know why they would have asked to be tested; the results of the index case were not yet known.

The "three-to-five" day test for the index case came back positive. At the time the index case tested positive he had been symptomatic for six days. The other extended family members remain asymptomatic and, as noted, two of them tested negative with a rapid Covid-19 test. The original adult -- the index case -- was probably most infectious two days before he became symptomatic through the next five days. 

On the day the two others tested negative was the eighth day of the infectious period of the index case.

Time Line

NOTE: timeline starts with day -1.

That is the day before day 0.  The reader tells me that they are considering their 14-day quarantine to have begun on day 1; and at the time of the post, they were into day 8 of the fourteen-day quarantine. Using their "8" as the starting point, I take it back to day 0, the day before the index case was symptomatic. However, I feel strongly that the index case was infected at least a day before that, but was perhaps not infections whereas on day 0 was probably infectious. Yes, it's confusing, but I wanted to do it like NASA does their countdowns and Ike did his D-Day invasion. It adds a little gravitas to the post. 

Index case:

• day -1 -- asymptomatic; probably infected, but perhaps not infectious;
• day 0 -- asymptomatic; day before first symptoms; possibly infectious
• day 1 -- symptomatic; very, very minor; most likely infectious;
  
• day 2 -- symptomatic: definitely worse but did not need to seek medical attention
  
• day 3 -- very symptomatic with cold-like symptoms; no loss of smell; no fever; eats dinner with extended family
  
• day 4 -- low-grade fever; definitely ill; calls for appointment; can't be seen "same-day"; needs to wait one day
• day 5 -- definitely ill, but minimal (perhaps no) respiratory distress; just the "flu"; Covid testing but results won't be back for three to five days
• day 6 - 8: not much worse; on no meds (not even Tylenol; able to keep working from home in a high-stress 12-hour day job)
• day 8: Covid test comes back positive; index case feeling better; improved; on no therapeutic meds; other extended family members remain asymptomatic;
• day 9: index case afebrile; oxy says normal (always have been); blood pressure lower than usual at 100 / 60; probably a bit dehydrated; at bed rest for seven days; normally with history of high blood pressure for which he takes meds;
• day 10: index case afebrile; back to normal (?); never took any meds; much like seasonal flu; probably less severe;
• day 11: index case back to normal; maybe a bit tired; eating, afebrile
  
• day 12: index case back to normal; back to full-time work;
  
• day 13:

Using same timeline for the second adult and a 14-year old student:

• days 0 - 8: asymptomatic
• day 7: rapid Covid-19 testing comes back negative for both; same-day testing; negative
• day 8: both remain asymptomatic; all extended family members asymptomatic;
  
• day 9: all extended family members living in household remain asymptomatic;
• day 10: all extended family members living in household remain asymptomatic; 
• day 11 - 12: all extended family members living in household remain asymptomatic;
  

Comments:

• the type of testing is incredibly important; see this post;
• the index case probably had the 40-cycle testing: but it's definitely not a false positive; patient has symptoms consistent with Covid-19, although possibly, though unlikely, some other viral illness;
• the second adult and student would have had 30-cycle testing; less sensitive

So, for the reader that sent me the timeline that's where they are now: day 9. 

Except for the index case not one of the other five shows any symptoms. The index case is pretty much back to normal on day 9.

Is it possible the second adult and the student would have tested positive had they had the 40-cycle test? But again, they remain asymptomatic. 

Should the other three be tested even though asymptomatic?

It will be fascinating to watch this play out, assuming the reader stays in touch.

But you can see how complicated this gets very, very quickly.