The “exposure notifications” alert that some Connecticut iPhone owners saw flash across their screens Thursday could soon help state health officials trace people who came in close proximity to someone with COVID-19.

The app, which is available for iPhone and Android, uses Bluetooth to tell whether a phone’s owner has been in contact for a long enough period with someone who tested positive for the coronavirus and had been notified by state health officials.

Rolled out by Gov. Ned Lamont, it’s the latest tool to go with advancements in drug therapies, hospital treatment and contact tracing as the number of cases rises and the temperature falls, threatening more spread as people head inside.

The new app comes as this state, like many others, is almost entirely in the danger zone. Red-alert communities, with an average of at least 15 new cases for every 100,000 people in the two weeks that ended Saturday, now account for 100 of the 169 towns and cities, the state’s new COVID-19 map showed. That’s about 80 percent of the state population, Lamont said in his regular media briefing.

In a good news-bad-news assessment, Dr. Scott Gottlieb, the Westport resident and former head of the U.S. Food and Drug Administration, said the nation is in “the eighth inning” of the battle against coronavirus. After this winter, he said, we should see cases abate helped by warmer weather, the natural decline of the virus, broader immunity, better treatment techniques and perhaps by a vaccine.

Gottlieb is on the board of directors at pharma giant Pfizer, which on Monday said its COVID-19 vaccine exceeded expectations in early assessments of clinical trials.

The app announcement came as Connecticut reported 1,158 new cases on Thursday, or 32 for every 100,000 people. The daily positivity rate was 4.8 percent, calculated from 24,001 new tests in the last 24 hours. The seven-day average is 4.4 percent.

Hospitalizations were also up, with a net increase of 33 patients, bringing the total to 617. On March 31, there were 608 hospitalizations.

“We’ve doubled the number of people in the hospital related to COVID over the last two weeks,” Lamont said. Over the next week, the governor said, he will decide whether the increase in hospitalizations should prompt him ask the Connecticut National Guard to again set up the field hospitals.

Connecticut never needed to use the field hospitals, set up quickly throughout the state, because the number of people being treated in hospitals peaked at 1,972 on April 22. The summer low in was 42 on August 17.

Despite the latest surge, Lamont said he doesn’t see the need to return to the massive closures of the early spring. “We’re going to have to take other precautions as needed,” he said.

Bridgeport has surpassed Norwalk and New London with the largest number of daily infections per 100,000 people in the recent two-week period, an average of 53, the new map shows. Those two cities remain close behind. Lamont said Mayor Joe Ganim has properly clamped down on restaurants that tried to ignore limits on operating hours and capacity.

Privacy guaranteedLamont assured that the new mobile phone app, which is voluntary, has anonymity guaranteed. It has been rolled out in recent weeks with mixed results among phone owners in New York, New Jersey, Pennsylvania and Delaware, some of whom have balked out of privacy concerns.

“It provides immediate notification if you’ve been near someone who tested positive in the last 14 days,” Lamont said, adding that Connecticut is the first state in New England to adopt the technology. “You’ll be notified on an anonymous basis. I think that’s really important to give you confidence that you want to download this app. If you do get an alert that you’ve been in contact with somebody, you’ll get instructions on testing, quarantine, where you can get tested and reach out to a contact tracer, or they’re reach out to you to get a little more information from you.”

The new app, which has been tested in recent weeks in state universities, is only triggered if the user was within 6 feet of a person with COVID-19 for a total of 15 minutes or more in one day — the same standard the U.S. Centers for Disease Control and Prevention uses for contact tracing.

Apple users have the option to sign up for the alerts through tapping on the “exposure notifications” selection in their iPhone’s settings menu. Android users will need to download the app from Google Play. “It’s not that tough,” Lamont said about downloading the tool. “Even I could do it. I urge you to do it now. It is exponentially more-effective if each and every one of you download this app.”

Dr. Jaime Meyer, an infectious disease specialist at Yale Medicine, said that the app can remove the guesswork for people.

“It’s one thing if your best friend who you just had lunch with got infected, told you… or the Department of Public Health told you you were in their immediate a contact and therefore you knew you had to get tested and quarantine,” Meyer said.

But what often happens is a person might not know when and how they came in contact with someone who had the virus? That's where the app comes in.

“The phones do the work of pinging each other without you having to do the work of having to think about who your potential contacts were,” Meyer said.

Dr. David Banach, head of infection prevention at UConn Health, said the app will not replace traditional contact tracing, but said it “has the potential to be helpful.”

“A person performing contact tracing can reach a certain amount of people,” Banach said. “The app has the ability to expand that even further.”

‘We’re in that winter’Lamont reported 10 more fatalities attributed to the illness, bringing the statewide death toll to 4,726.

Gottlieb, the former head of the federal Food and Drug Administration, predicted that the pandemic should peak in late January nationally. “We’re in for a very difficult two to three months,” Gottlieb said.

“The Northeast is doing well relative to other parts of the country, but we have a situation right now where we have a lot of spread everywhere across the country,” Gottlieb said. “We’re going to have a dense epidemic right now and I think the question is how long will it last and where will we peak-out? As we get into the spring and summer, we’re going to not only be coming down the epidemic curve, but we’re going to be entering the season when a coronavirus typically doesn’t circulate.”

The virus, which became evident in New York and Connecticut in March, then spread south and now throughout the country, where is is setting infection and hospitalization records as the national death toll closes in on 225,000.

“This is really the sort of eighth inning, if you will,” Gottlieb said. “I think this is the final stage of the acute phase of this pandemic that we need to get through. We always thought that the fall and the winter would be the most-difficult period with this virus. This is a respiratory pathogen that would typically spread in the wintertime. Now, we’re in that winter.”

“I need you to be cautious a little bit longer,” Lamont said, after Gottlieb noticed that Connecticut has been about a month behind Europe’s infection outbreaks. He said that those over-60 should stay home as if it were the early spring again.

“I’m a baseball fan, so I took to heart the ‘eighth inning,’” Lamont said. “That means something to me. I know some innings are longer than others and I know a lot of games are won and lost in the eighth and ninth inning. This is the time you buckle down.”

Earlier this week, a study of 69 infection clusters in the state concluded 20 of them began in restaurants, according to a report from the state Department of Public Health. The largest other groups of clusters were workplaces and private homes.

The announcement came as New Haven officials said several key staffers, including Director of Public Health Maritza Bond and Gage Frank, the mayor’s spokesman, are quarantining after coming in close contact with someone who tested positive for the disease.