California Covid Cases Make Biggest One-Day Jump of 2021 As Delta Fuels Surge

·3 min read

California tallied 10,356 newly reported confirmed cases of Covid-19 on Friday. That number had skyrocketed up from just 7,457 reported on Thursday, a 39% jump in one day. It’s the biggest 24-hour jump in cases the region has seen this year, according to the state Covid data dashboard.

The jump, while still surprisingly large, makes more sense when one takes into account the surging number daily of cases per 100,000. On July 4, the seven-day average number of cases per 100,000 was 4.6. On Wednesday, that number had risen to 12.7. Just 48 hours later, it had pushed to 14.9, an average of one point per day.

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Increasing cases are largely among unvaccinated populations, according to state officials. For the week of July 14-20, the average case rate among unvaccinated Californians is 20.7 per 100,000 per day and the average case rate among vaccinated Californians is significantly lower at 3.5 per 100,000 per day. The vast majority of new cases are among the unvaccinated with 600% higher case rates among the unvaccinated than for those who are vaccinated.

The state’s seven-day test positivity rate — another trusted indicator of spread — was up over 20% in 7 days, from 5.1% to 6.2% on Thursday. It rose to 6.4% on Friday. On June 15, the day the state threw off Covid restrictions, the seven-day test positivity rate was .9%. What’s more, the line on the graph charting test positivity is becoming increasingly vertical.

Los Angeles County is driving much of the surge, with the raw number of daily cases up 17% in the past week, as of Thursday (numbers for Friday are not yet available). On Thursday, the number of new cases in L.A. was 3,248. That’s roughly half of the 7,458 cases recorded in California on Thursday, even though Los Angeles County’s population accounts for only roughly 25% of the state’s residents.

Driving the rise, according to Los Angeles County Public Health Director Barbara Ferrer, have been more affluent communities on the West Side including Beverly Hills, Bel-Air, Beverly Crest, Venice, Studio City, Sherman Oaks and Encino. The winter surge was led by higher case rates in Central L.A.

The rise in cases in those communities — and across the state — coincides with the rise of the more transmissible Delta variant, which a report released by the CDC on Friday indicated may be even more effective at breaking through the protection afforded by vaccination than previously thought.

Los Angeles officials announced this week that Delta’s share of tests sequenced genomically to determine causal variants had risen from 84% last week to 96% this week.

Hospitalizations in the state, a lagging indicator, have been rising steadily in the past few days. While nowhere near the near 23,000 Covid-related patients seen in January of 2021, the number of infected people in California hospitals topped 4,000 for the first time in four months on Friday.

There have been 73,566,888 tests conducted in California. This represents an increase of 185,144 during the prior 24-hour reporting period.

There have been 63,935 Covid-19 deaths in the state since the start of the pandemic.

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