1/ Here's another quiz for budding epidemiologists
The Guandong Delta outbreak was meticulously investigated. Initial report of 1000x viral load came from there
A finding that hasn't been discussed much is the seeming shorter incubation period (panel b)
virological.org/t/viral-infect…
The Guandong Delta outbreak was meticulously investigated. Initial report of 1000x viral load came from there
A finding that hasn't been discussed much is the seeming shorter incubation period (panel b)
virological.org/t/viral-infect…
2/ In 2021 delta it was only 3.7 days (vs 5.6 days for 2020 outbreak).
This would have an impact on a key transmission dynamic factor we often look for: "serial interval periods" (time between symptom onset for index case vs subsequent case in a contact tracing investigation)
This would have an impact on a key transmission dynamic factor we often look for: "serial interval periods" (time between symptom onset for index case vs subsequent case in a contact tracing investigation)
3/ What you are trying to estimate from observable symptom intervals is underlying mean generation time.
tangent: If you find negative serial intervals as in COVID, it's a sign of asymptomatic and presymptomatic spread.
tangent: If you find negative serial intervals as in COVID, it's a sign of asymptomatic and presymptomatic spread.
4/ (A household transmission study in Singapore didn't find a difference between delta and wild type covid strains, but was so teeny in sample size that I don't think it really counts as evidence one way or another)
5/ Here's the quiz.
If Delta's incubation period is 34% shorter, and cycles through faster from generation to generation, what would that mean for our estimates of R0?
If Delta's incubation period is 34% shorter, and cycles through faster from generation to generation, what would that mean for our estimates of R0?
6/ A plurality of us (34%) got the right answer- If generation time is faster, than means that a lower Ro would explain the growth dynamics
It might seem like a distinction without a difference but it means that a smaller change in behavior (or vaccinations) would reverse trends
It might seem like a distinction without a difference but it means that a smaller change in behavior (or vaccinations) would reverse trends
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