Adolescent to Adult COVID Transmission

TLDR: Transmission from adolescents to adults: not the answer we'd hoped for, but there is some good news here too!

A recent publication from the Centers for Disease Control and Prevention (CDC) discussed an outbreak of COVID which resulted from a family gathering.

During July and August 2020, CDC investigated a COVID-19 outbreak that occurred during a 3-week family gathering of five households in which an adolescent aged 13 years was the index and suspected primary patient; 11 subsequent cases occurred.

The article provides details about the home in which the gathering occurred, who attended, etc. Interestingly, none of the “day visitors” became infected. Those who visited during the day maintained physical distancing outdoors during visits of 10 and 3 hours, the latter of which occurred when 6 members of the family were potentially infectious.

Three types of tests are listed in the table below. Additional details are available from the CDC at this link.

Ab: blood test for antibody. This is useful for demonstrating prior (but not current) infection. Results are typically available within 48 hours.

Ag: nasal swab for viral antigen. Sometimes called rapid antigen tests (RAT). These tests are the most common “rapid” tests and have sensitivities (the ability to detect the disease when present) between 84 and 98%. Results are typically available within 15 minutes or so.

PCR: polymerase chain reaction or nucleic acid amplification (PCR or NAAT) test for viral RNA. These are the most sensitive tests for the detection of the virus that causes COVID. Results are typically available within 48 hours.

Lessons Learned

For our purposes, the “lessons learned” are important:

  1. Children and adolescents can transmit COVID-19 to adults, even when they have minimal or mild symptoms (in this case, the index patient had only nasal congestion).

  2. Physical distancing appears to have been very effective in preventing the spread of coronavirus in these families. Of the 6 people who remained outdoors and maintained physical distancing, 4 had negative PCR tests and 2 were not tested; none developed symptoms.

  3. RAT tests have sensitivity lower than that of PCR and a negative RAT may need to be confirmed with NAAT testing if the level of suspicion is high. In this case, the index patient had a negative RAT two days before the gathering began.

  4. Group contact and indoor gatherings should be avoided when physical distancing and face mask use is not possible.

It is likely that we are closer to the “end” of our experience with COVID-19 than to the “beginning.” We’ve gotten better at treating severe illness, and vaccines are on the way, but we must remain vigilant in our efforts to prevent this disease. The good news from this report is that physical distancing seems very effective in preventing disease spread.