Hawaii has the fastest-growing infection rate in the country, according to several statistical models that try to estimate how many people an infected person will spread the virus to.

While public health experts warn of the limitations of some of these models, they also say other data points — including a rising number of new daily cases and the percentage of COVID-19 tests that come back positive — point to Hawaii being in an alarming new phase of the pandemic.

“We’re in a very dire situation,” said Dr. Tim Brown, an epidemic tracking expert with the University of Hawaii at Manoa’s East-West Center. “We’re seeing COVID spread out throughout the population.”

The state has recorded more than 1,300 new cases since the beginning of August. The 7-day average of new cases is at 166.71 currently, compared with 1.71 two months ago. And the percentage of tests that come back positive has jumped from roughly 1% in June to 5.8% last week.

“Clearly, Hawaii has taken a turn,” said Dr. Cyrus Shahpar, director of Prevent Epidemics, a research team at Resolve to Save Lives, a public health organization headed by a former federal Centers for Disease Control and Prevention director.

Months ago, Hawaii could have been an example for effective virus control, but new data — however limited — is showing a resurgence, he said. “In order to understand why these things are happening, we need to have better information.”

In July, Prevent Epidemics released a report saying the U.S. lacks federal guidance on what data should be reported across states on COVID-19 to create optimal virus control plans, making the data “inconsistent, incomplete and inaccessible in most locations.” That was also the case for Hawaii.

Soaring Infection Rate

The state has been reporting fewer numbers of cases in the past few days. On Tuesday, there were 140 new cases, compared to Friday when there were 231 new cases.

The state Department of Health said in a news release that the lower numbers could be due to a decrease in the number of tests that were being conducted. It also said there are daily fluctuations in test counts and that there was no specific reason for the decrease that it could point to.

Meanwhile, a metric that has gained a lot of attention is something called the effective reproduction rate, or Rt. It’s otherwise known as the infection rate.

It’s a mathematical model for how many more people a person is predicted to spread the virus to, says Thomas Lee, an assistant professor of epidemiology at the University of Hawaii Manoa and a modeler with the Hawaii Pandemic Applied Modeling Work Group.

Statistical models that calculate this metric generally show Hawaii as currently having the highest or one of the highest rates in the country.

The rates are calculated using other COVID-19 data, such as active case counts, how long somebody is infectious and the strength of the pathogen. If the value is above 1, then it means COVID-19 is likely to spread quickly and that the area should expect to see many more cases.

One model — Rt.live, which was created by Instagram co-founders Kevin Systrom and Mike Krieger — shows that Hawaii has a mean value of 1.4 as of Tuesday afternoon, higher than any other state.

Another model from Covid Act Now calculates Hawaii’s infection rate to be at 1.42, while Covid-19 Projections estimates 1.02. This is why reproduction rates should be looked at with caution, Lee and Shahpar of Prevent Epidemics both said.

“There’s no standard way to measure it, so you will see different estimates,” Shahpar said.

Hawaii is unusual in many ways from other states, Lee of UH said — geographically, demographically and socioeconomically.

“No statistical or mathematical formula can accurately capture all of the nuances when it comes to Hawaii,” he said.

Nick Redding, executive director of the Hawaii Data Collaborative, said his team decided not to include this reproductive or rt rate in their COVID-19 dashboard because of the amount of uncertainty associated with the rates.

Instead of focusing too much on the rankings or any specific model, it’s more prudent to pay more attention to what the trend line or shape shows, Lee and Shahpar both said.

Hawaii’s trend line definitely shows that there’s cause for concern, the epidemiologists said. Cases are rising and COVID-19 is a serious threat in Hawaii.

Despite the growing number of cases, the public does not seem to have a sense of urgency about the worsening pandemic, Brown of UH, who has also served on a COVID-19 advisory task force for Hawaii, said.

Some people are still not convinced that they should wear masks, he said. And some think it’s perfectly okay to gather as long as the group is smaller than 10 people, even if they’re all from different households, which he says is absolutely not the case.

“People have to understand we are not in normal circumstances right now,” he said. “We are in a once-in-a-century pandemic.”