Portage County - January 13, 2021

Effective Reproduction Number (Rt)

A series of reporting gaps/lags beginning in late-December creates some instability in estimates during that period.  However, the most recent data suggests an Rt spiking well above 1.0 in late December and early January.  Significant volatility in estimates remains.  Whether the recent increase in Rt signals the beginning of a sustained trend remains to be seen.

 

Projected Incidence

Because of the significant reporting gaps/lags described above, we modeled what the missing numbers most likely would have been during this period and project future cases over a two-week period based on a combination of these and more recent actual case numbers. It is expected that daily incidence will trend upward over the coming weeks. Because these projections assume continued social mixing at levels seen in recent weeks, a post-holiday decline in mixing could portend lower-than-projected case levels.

 

Asymptomatic to Symptomatic Ratio

Data issues again complicate estimation, but the ratio of asymptomatic to symptomatic cases appears slightly increased since late December. A low ratio of asymptomatic to symptomatic cases facilitates mitigation efforts.