Wastewater readings in Gilroy show a rise of Covid-19 that is outpacing other areas of Santa Clara County, possibly indicating a post-Thanksgiving surge in cases to come.
The quantity of SARS-CoV-2 genes, the virus that causes Covid-19, has doubled in Gilroy over the past two weeks, according to samples taken from the South County Regional Wastewater Authority, which serves a population of 110,338. The SCRWA facility collects and processes waste from municipal sewer systems in Gilroy and Morgan Hill.
Since mid-2020, a team led by Stanford University has been regularly testing wastewater in San Jose, Palo Alto, Sunnyvale and Gilroy to reveal local trends of disease spread.
The virus can be found in human stool, according to health officials, even among those who are asymptomatic.
Researchers have determined that as virus levels rise in the region’s wastewater, so too do the number of reported cases. Wastewater information is available sooner than clinical testing, making such research critical in predicting spikes of Covid-19 infections, according to the county.
The data shows that the level of virus detected in Gilroy’s wastewater is currently on par with the end of November 2020, and in late July of this year, when the Delta variant was beginning to take hold.
Between Nov. 14-Dec. 4, the 95020 zip code reported 38 new cases among 931 tests, according to county data. In Santa Clara County, which averaged 21 to 215 new cases over the past week, 290 cases were reported on Nov. 29, the highest since the 333 recorded on Sept. 3.
Vaccines, and the subsequent booster shot, remain the most important tool to reduce the chances of serious illness or death, especially as the new Omicron variant has been discovered in San Francisco, county health officials said.
First found in South Africa, Omicron was designated as a “variant of concern” by the World Health Organization on Nov. 26, and the first known case in the United States was reported in San Francisco on Dec. 1. It is not yet clear if the variant is more transmissible or deadly than the other variants, according to WHO.
Dr. Jennifer Tong, associate chief medical officer for Santa Clara Valley Medical Center, said as of this week, Omicron has not been detected in the county, but said health officials have a “high level of suspicion” that it will be found eventually.
County officials are encouraging those eligible to receive their booster shots in anticipation of a holiday surge in cases.
Booster shots are now available to everyone over the age of 18 who received their second dose of Pfizer or Moderna at least six months ago, or who received their Johnson & Johnson dose at least two months ago.
Roughly 78% of eligible county residents ages 5 and older have completed their vaccination, according to county data, with that number jumping to 90% for those 12 and over.
Tong said the demand for booster shots is high in most parts of the county, but so far is not as strong in South County.
“It’s easy to say ‘why should I get the vaccine if I can get sick even after I get it?” she said. “What we’re seeing in people who are getting infected after being vaccinated is that the infection is much less severe. There are much less hospitalizations and deaths.”
The county last reported four deaths on Nov. 8, with 111 Covid-positive patients hospitalized in the county as of Dec. 2, including three at St. Louise Regional Hospital.
The county is working to raise awareness of its two vaccination sites in South County at the San Martin Animal Shelter and DePaul Health Center in Morgan Hill. With the Hispanic population making up the majority of Gilroy, Tong said the county has a team of “promotoras” who reach out to monolingual Spanish-speaking residents to answer questions about the vaccine and reserve appointments.
The San Martin vaccination site operates as a drive-thru, while DePaul is a more traditional clinic-type setting for inoculations.
No proof of insurance or identification is required at the vaccination sites. Appointments are recommended.
To make an appointment, visit sccfreevax.org. Pop-up vaccination locations are also listed on the website, and county officials expect South County sites to be added soon.