COVID-19 infection model predicts additional surge in cases

Dozens of people wait in line to be tested for COVID-19 on Aug. 17 at Lokahi Park in Hilo. (Kelsey Walling/Tribune-Herald)
Subscribe Now Choose a package that suits your preferences.
Start Free Account Get access to 7 premium stories every month for FREE!
Already a Subscriber? Current print subscriber? Activate your complimentary Digital account.

All signs are pointing toward a worsening COVID-19 surge in Hawaii, according to statistical models.

Researchers for the Hawaii Pandemic Applied Modeling Group, a network of data scientists, epidemiologists and medical professionals developing models of the potential future spread of the novel coronavirus, told the Senate Special Committee on COVID-19 Friday that the test positivity rates throughout the state indicate another surge of cases in the near future.

University of Hawaii at Manoa mathematics professor Monique Chyba said that at the current rates of vaccinations and COVID-19 transmission, daily infections in Hawaii County are predicted to plateau at about 175 by mid-September.

However, the worst-case scenario for Hawaii County, which assumes an increase in transmission rates — the sort that could be caused, for example, by large gatherings over a three-day weekend — predicts that there could be well more than 200 new COVID cases a day in the county within a week.

On Friday, the county had 131 new cases.

HiPAM’s worst-case scenario also predicts more than 100 people in the county a day would require hospitalization for COVID-19 within a week but, because the county’s hospital capacity has already been reached, any further hospitalization predictions would be inaccurate, Chyba said.

The worst-case scenario also predicts that daily infections in the county will peak on Oct. 4 at about 240 cases. However, Chyba cautioned that HiPAM’s models become highly uncertain more than two weeks into the future because of the uncertainty of human behavior and the lag before receiving updated data.

HiPAM’s more optimistic scenarios have both daily infections and hospitalizations quickly stabilizing within a week, but those best-case scenarios are based on a 20% increase in the number of vaccines administered daily and an 8% drop in COVID-19 transmission rates.

Chyba said HiPAM foresees similar trends for Oahu and Maui.

On all three islands, she said, test positivity rates have spiked since July, which is a leading indicator for an exponential surge in cases in the future.

Tom Blamey, UH-Maui biostatistics professor, told the committee Friday that the current models predict an overwhelming strain on the state’s hospital capacity, without taking into account the upcoming flu season and an impending liquid oxygen shortage.

Hilton Raethel, president and CEO of the Healthcare Association of Hawaii, said the state was anticipated to run short of liquid oxygen by Monday, because of the increased demand for liquid oxygen around the globe. However, he said, hospitals have activated oxygen conservation strategies and are in the process of procuring additional oxygen generators and tanks, so the shortage has been averted for the time being.

Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.