For the second week running, Los Angeles County Public Health Director Barbara Ferrer has noted a plateau in the levels of Covid detected in the county’s wastewater system. While a plateau in itself is not worrying, the fact that the numbers had been going down and now have stalled is of concern to officials.
“This plateau…is likely to indicate that transmission in L.A. County is no longer decreasing,” said Ferrer. “The most recent observations at these four wastewater plants, along with the small increase we reported in a couple of the early alert metrics, highlight the need to carefully monitor the early alert signals in the weeks ahead to see if we have any additional signs that suggest changes in our transmission patterns or illness severity.
Wastewater analysis is becoming more and more important in identifying Covid outbreaks as many people now take at-home tests and do not report the outcomes. As a result, Ferrer has said she believes that the raw case numbers reported daily are an undercount.
Los Angeles County reported 1,336 new infections today, along with 11 more deaths. That’s roughly in line with the average for the past week. Another indicator of new infections has begun to rise, however.
One week ago, the 7-day average test positivity was 4.1%. Yesterday, the county reported it at 5%. That’s a long way from the 17+% the county saw during the last surge, but a ~25% uptick in a number that is a 7-day average is worth noting. It’s also the first significant jump in the number in months.
Ferrer said numbers overseas have begin to rise, a condition which, in 2020 and 2021, presaged a rise in the U.S.
“I think we need to be prepared for some increases that are associated with that colder weather and subvariants that have some advantages,” she warned.
“The new sublineages are increasing very slowly. And they’re not yet crowding out BA.5. This is no assurance that in the weeks ahead there will not be an acceleration and proliferation of these strains because they appear to have mutation…There is hope that with increased uptake in the fall boosters — which are well-matched to what is circulating now — and the use of common sense precautions as we move into cooler weather months, we can blunt the impact of the anticipated increases in transmission that may be associated with these strains.”
Recent testing has shown a small but discernible increase in a number of new variants of the virus, most notably a variant known as BA.4.6, which represented 5% of tested samples, up from 3% a week ago. The county has also now detected three samples of BA.2.75.2, which has been spreading in parts of Asia and Europe and appears to be able to avoid current vaccinations. Samples of a variant known as BF.7 have also been detected. Health officials have long warned that as long as the COVID continues spreading, the more likely it is that mutations, or variants, will develop that could spread more quickly or cause more severe illness.
Ferrer said the county will be closely watching new variants, noting that while the increases thus far are small, they could potentially spread more as people spend more time indoors during the winter,” she said. “With more people mingling inside, “a variant that has an advantage in transmission and evades protections more easily will flourish.”
City News Service contributed to this report.