ZIP code tracking data has shown Arizona’s surge in COVID-19 cases is hitting some of its most populous areas, according to the Arizona Department of Health Services.

Downtown and South Phoenix ZIP code, 85006, reported a cumulative total of 1,321 active cases on Tuesday, ADHS said.

ZIP codes close to the Downtown metropolitan area, 85003 and 85004, now have more than 300 to 400 cases. The rate of positive COVID-19 tests has also increased to 10%, ADHS said.

“We are definitely experiencing what I would say for Arizona is a second wave,” said Dr. Heather Ross, a member of Arizona State University’s Modeling and Epidemiology Team, describing the state’s surge in COVID-19 cases recently.

Arizona’s daily COVID-19 cases have been fluctuating between 700 and 1,000 since Oct. 19, ADHS said. Ross said that the high volume of cases is due to businesses and schools reopening.

The ZIP code tracker is not just for reporting total COVID-19 cases. The tracker also has data on how COVID-19 is affecting different demographics.

Here is how COVID-19 impacts different ages, genders and ethnicities:

• Arizona has reported over 242,000 COVID-19 cases, and 20-44-year-olds make up more than 115,000 of that total.

• People 65 and older make up for 27,000 of total cases, and around 4,000 have died.

• 52% of COVID-19 cases are female.

• Males make up for 57% of deaths.

• Hispanic and Latinos make up for 31% of cases, which is 5% higher than Whites.

Dr. Timothy Lant, leader of ASU’s Modeling and Epidemiology Team, said that individuals can use ZIP code data to stay alert.

“If there are a lot of cases in the ZIP code that you are in, or in the ZIP code surrounding you, that’s the perfect opportunity to make a decision about making sure you have fewer contact with other people,” Lant said.

Lant said with ZIP code data, Arizona will have a better chance of containing COVID-19.

ZIP code tracking could help government officials enforce or remove policies for limiting transmission, Lant said.

“Scottsdale, for example, doesn’t currently have the mask ordinance and Tempe does,” Lant said. “If Scottsdale ZIP codes start showing higher case counts, which they have several times, we can see which policies work.”

However, Lant said that ZIP code data needs to be used more. The data alone is just a valuable science tool.

Ross said she agrees ZIP code tracking is not an effective way to track COVID-19.

“The state reports cumulative cases at the ZIP code level for Arizona,” Ross said. “I need to know how many new cases are being reported each day.”

She said that she looks at the ADHS website every day but focuses on the epidemic (epi) curve. An epi curve can show the distribution of cases over time, outliers and the magnitude of the outbreak, according to the Centers for Disease Control and Prevention.

Ross said the epi curve is a better alternative for ZIP code data, because its tracking method is day-by-day.

The Arizona epi curve visually displays the total number of COVID-19 cases since Jan. 27. The state hit 5,460 cases on July 29, which was the highest total cases reported.

Lant said the epi curve is “a foundational tool” the public can use along ZIP code data. His team looks at epi curves based on the nation, the state, county and ZIP code. This helps them notice specific trends and patterns that the virus creates.

Observing the epi curve has helped Lant realize that COVID-19 cases transmit between neighboring ZIP codes.

“In 85282, our experience is pretty closely tied to 8528l, even though none of the people are the same,” Lant said.

Lant said that transportation between ZIP codes for work and school could be a cause for the new surge in COVID-19 cases. He said that on the ZIP code map, an individual can see that correlation.

“The places that are closest to each other, the places that have high density and the places that have higher interaction are the places that our theoretical disease models suggest will have faster transmission,” Lant said.