AUSTIN (KXAN) — COVID-19 case numbers and hospitalizations are continuing to trend upward in Central Texas. Several counties in KXAN’s viewing area have been moved to the Centers for Disease Control and Prevention’s “high” COVID-19 risk level as of Thursday.

According to the University of Texas at Austin COVID-19 Modeling Consortium, projections show the trend will continue until the fall.

“In the case that the BA.4 and BA.5 [subvariants] are highly transmissible… we expect that the number of cases will keep growing and reach a peak around October. That’s what our model suggested,” Dr. Oluwaseun Egbelowo, a postdoctoral researcher with the UT COVID-19 Modeling Consortium, said.

In the most optimistic scenario, Egbelowo said this surge could last until mid-August. That would require people’s immunity from the original omicron surge to last a significant amount of time, and as always, “it depends on our behavior,” he said.

Either way, it’s clear from the current models “we are not at the peak yet.”

Severity of BA.4 and BA.5

Egbelowo noted the BA.4 and BA.5 subvariants might not be as severe as previous strains of COVID-19, but also said when case numbers go up, hospitalizations follow. There are 163 people in the hospital with COVID-19 locally, according to Austin-Travis County’s COVID-19 key indicators dashboard. During her last update before Travis County commissioners, Dr. Desmar Walkes, the local health authority, said roughly half of those people are there for a primary diagnosis of COVID-19.

Dr. Ogechika Alozie with the Texas Medical Association’s COVID-19 task force told KXAN last week he’s seeing more mild symptoms in his patients who likely have BA.4 and BA.5, especially for people with immunity through vaccination or previous infection.

“It’s the scratchy throat, the rhinitis, that runny nose, itchy eyes, a general feeling of unwell, what we’d call malaise or lethargy,” Alozie said.

Meanwhile, the local health authority for Austin-Travis County has noted the two new subvariants are causing more disease to lung tissue than what was circulating in December and January. She has also said getting re-infected could lead to more serious disease.

When Travis County could hit CDC’s ‘high’ risk level

To hit the CDC’s highest risk level, which recommends masking, the CDC looks at the seven-day rolling average of new COVID-19 cases per 100,000 people, the seven-day rolling average of new COVID-19 hospital admissions per 100,000 people and the seven-day rolling average of the percentage of staffed inpatient beds taken by COVID-19 patients.

Right now, in the early stages of the surge, it’s the case numbers metric that’s driving Travis County’s “medium” level designation. As of Thursday, there’s a seven-day rolling average of 290.8 new COVID-19 cases per 100,000 people in the county.

Both hospital metrics are on the lower end of the risk scale independently, however. New hospital admissions are at a week average of 9.6. The threshold is 10 for medium risk and 20 or more for high risk in that category alone.

The percentage of staff inpatient beds taken by COVID-19 patients sits at a seven-day rolling average of 4.1%. The threshold for medium risk on that metric alone is 10%-14.9% for medium and 15% or higher for high risk.

Wastewater testing

While case numbers are trending upward, health leaders said those are not an entirely accurate depiction of our current situation. Many people are turning to at-home tests, the results of which are not widely reported to health authorities.

“We know case counts are underreported nationwide. At-home rapid tests are readily available, and there isn’t a state or federal requirement to collect, track or investigate self-reported tests,” a spokesperson for Austin Public Health said.

That’s where other indicators like wastewater testing come into play. Since early March, wastewater data from Biobot shows more COVID-19 traced in wastewater in Travis County. There were 39 copies of the virus/mL of sewage reported on March 9, at its lowest recorded point since before the original omicron surge. As of July 6, there were 528 copies.

Wastewater testing was paused in Travis County for some time due to lack of funding, so current levels cannot be compared to levels detected in previous surges.

The wastewater shows it’s the BA.5 subvariant that is responsible for most COVID-19 cases in Travis County. As of the latest update, nearly 60% of the samples sequenced were BA.5. An additional 14% were BA.4.