The highly-infectious BA.2 subvariant of the coronavirus has contributed to a dramatic increase in the number of cases in Los Angeles County over the past several days, although hospitalizations have remained low.
On Thursday, the L.A. County Public Health Director Dr. Barbara Ferrer reported 2,335 new cases. The daily average over the past seven days rose to 1,764, up from 1,261 the previous week, she said.
The daily average case number is roughly triple the number it was a month ago.
According to Ferrer, the infectious BA.2 subvariant is now responsible for 88% of the local cases that underwent special testing to identify variants. BA.2 has been blamed for increasing infection numbers locally and nationally, with officials saying it is exponentially more transmissible than the Omicron variant that fueled the winter surge in cases.
The number of COVID-19 patients in L.A. County hospitals increased to 249 Thursday, up from 235 on Wednesday, according to state numbers.
Ferrer noted that those numbers are still relatively low when compared to the winter surge numbers that topped 8,000 hospitalizations in early January. She credited widespread vaccination, therapeutics and immunity from prior infection for preventing people who are getting infected from winding up hospitalized.
Health officials have warned in recent weeks that the rising case numbers may actually be bigger than the figures reflected by testing results since many people are testing at home and may not be reporting results to the county. And many others may not be getting tested at all because they are not becoming seriously ill.
In hopes of countering those lapses, the county monitors concentrations of COVID in four wastewater systems across the area. The most recent results show that the average concentration of the virus found in most of those systems has risen sharply, with two of them showing nearly double the rate from two weeks ago, and a third showing a sharp upward rise. But the fourth system monitored actually showed a small decrease.
“This suggests that community transmission is increasing in the areas covered by these sewage systems,” Ferrer said.
There is also another variant to worry about. Experts had previously identified an offshoot of BA.2 that has been dubbed BA.2.12.1, and it is now rapidly increasing its grip. That new offshoot was detected in 7% of L.A. County infections that underwent testing during the week that ended April 9, up from 3% the previous week.
It’s still unknown of BA.2.12.1 causes more severe illness or might be more resistant to vaccines.
Eight more virus-related deaths were also reported Thursday, lifting the county’s death toll from the virus to 31,959.
The average daily rate of people testing positive for the virus was 1.8% Thursday.