Los Angeles County on Friday reported 1,355 new Covid cases, continuing an upward trend that began about a week ago as the more infectious BA.2 subvariant continues to spread.
Last week, the 7-day average daily number of new cases in the county was 878. Yesterday, the county had an average of more than 1,000 new Covid cases a day.
Increasing even more than the daily case numbers is the 7-day average daily rate of people testing positive for the virus, a data point that is considered a more accurate indication of spread because, in addition to being an average, it accounts for increasing and decreasing test numbers. That rate had remained constant below 1%, but rose to 1.7% on Thursday and hit 2.4% on Friday. The price is still low overall, but more than double what it was a week ago and roughly tripled what it was two weeks ago. That’s a big increase for a number that is a 7-day average.
The rising case numbers have not yet translated into an increase in hospitalizations and deaths, which is something optimists continue to point to as the region tries to return to normal after the winter’s Omicron wave. The number of Covid-positive hospital patients in Los Angeles County actually dropped today, and it has evolved that way.
Last Friday, the number of Covid-positive hospital patients was 275. Today, the number was 228. That is a decrease of 17% in one week. Of these patients, 31 were treated in intensive care, down from 32 on Thursday. A further 13 virus-related deaths were also reported on Friday.
The BA.2 subvariant, a more infectious offspring of the Omicron variant that caused a winter increase in cases, is now the dominant virus strain in the county, according to public health officials. The latest data show that it accounts for 67% of new infections, but these data are over two weeks old, so the variant probably accounts for a much larger percentage of new cases now.
There has been speculation that BA.2, although more transmissible, is also less virulent. In some regions, an increase in BA.2-related cases has not been followed by an increase in hospitalizations and deaths. This difference from winter’s Omicron wave gives rise to cautious optimism. But it is still too early to say that it is quite clear on BA.2.
Throughout the pandemic, increases in admissions have generally followed increases in daily cases by about 2 weeks. Part of BA.2’s increased ability to infect humans is thought to be a shorter incubation period, which means that admissions have increased more rapidly, from between 10-14 days. So given that the number of cases only started to increase in earnest in the last week, any resulting increase in hospitalizations is likely to show up at the end of next week or in the last week of April.
While some regions appear to have avoided an increase in hospital admissions, the UK – which has often warned of trends from the state – has recently seen an increase in both hospital admissions and deaths.
Closer to home, New York is beginning to see a consistent increase in hospital admissions following an increase in infections and test positivity. The 7-day average number of hospital admissions in the state was about 2,000 at the end of March, according to data from Johns Hopkins University. That was over 5,600 from Wednesday, the most recent day, for which data is available.
A variable in the mix is whether daily testing, which is at one of the lowest ebb in about a month, accurately captures the current wave of new cases. The difference between the increase in 7-day average test positivity and 7-day average case numbers seems to support this suspicion.
In addition, a new state study suggests that the number of people in Los Angeles County who have been infected with Covid-19 during the pandemic is far greater than the number confirmed through standard tests. This is largely due to the number of people who never developed symptoms and therefore were never tested, or who could not access tests, or who tested positive at home and never reported the results.
City News Service contributed to this report.