"I was the most vocal about it. I was telling the grocery lady bagging my groceries. I told my entire second grade class," Lewis tells PEOPLE.
"He told everyone," adds Julie. "It was kind of comic relief for our family because you didn't know when Ryan was going to bring it up or what he was going to say. I liked it because he kind of broke the stigma a little bit."
Julie, 55, contracted the virus in 1984 from a blood transfusion due to complications after giving birth to her first daughter, Teresa.
She wasn't officially diagnosed until 1990 after she had two more children – including Ryan. Her biggest fear was that she had passed the virus on to them. Fortunately, Lewis, 26, and his two older sisters were not infected.
"I was very lucky to have a 25 percent chance of infection and to not be infected," says the Grammy Award-winning producer behind Macklemore & Ryan Lewis.
"It was just excruciating waiting for their tests, and when they all came back negative, I felt like 'Okay, I can handle this,' because it could've been just so much worse," Julie says.
Lewis and his family were living in Spokane, Wash., at the time, where Julie spent 10 years as an HIV/AIDS educator.
"There was a family with a similar story to ours. They had three kids and the youngest was my age and infected by birth," says Lewis. "My first time feeling the reality of what HIV was was when she died two days before we started second grade and then her mom died a few years later. When you're that young and you know your mom has a really bad disease and she could be gone, you're just fearful."
Courtesy Ryan Lewis
Julie was told she would only have three to five years to live, but as drugs improved she was "maintaining and living life much longer than expected," says Lewis.
"I cherish [every milestone]," Julie says. "It's a miracle that I've been so lucky to not only be at their graduations and weddings, but this past year, my two daughters both had babies and I was there for delivery. It's really been a huge blessing."
To commemorate Julie's 30 years of living with the disease, they announced the 30/30 Project, an initiative that will raise funds to build health centers around the world. Their first project is to raise $100,000 to build the first center in Malawi. Donations are being accepted on the project's website.
"It gives me chills. It's surreal to think that I am here talking to the world," Julie says.
For more on Lewis, including a personal family photo, pick up this week's issue of PEOPLE, on stands Friday