Three-month-old Thiago is meeting all of his milestones, and that makes his mother, Cecilia Calderon, very happy.
Months before Thiago was born, Calderon was tested for and diagnosed with cytomegalovirus, or CMV, a congenital infection that is generally harmless to the mother, but potentially deadly to baby.
"I never heard of CMV," Calderon said. "I had asked people after they told me I had it, and nobody had heard of it either."
Calderon is not alone.
"It actually affects more babies than Down syndrome and spina bifida combined. It's just not that well known because most of the babies don't have symptoms at birth," said Dr. Brenna Anderson of Women & Infants Hospital.
So how is it spread?
"It's just like a cold virus. Most of the time they catch it from children. It's very commonly passed in day cares or even in hospitals. So, if a pregnant woman is around a young child, she acquires the infection. If she acquires it for the first time during her pregnancy there's a 40 percent chance of passing it on to her fetus," Anderson said.
Calderon said she does social work with children from the ages from 3 to late teens and that it's possible she got it from one of them.
It is because the virus is so common and easily spread that Women and Infants Hospital and 13 other sites are enrolling people like Calderon during pregnancy.
"The way that we are testing to find out whether or not they have it is by a blood test," Anderson said.
The national study is being led by Anderson at Women & Infants because there's an efficient and reliable screening test for CMV and there are promising treatments should the baby become infected.
"It can lead anywhere from a mild asymptomatic infection all the way to a very severe infection, developmental disabilities, even still birth and death," Anderson said.
Thiago tested positive, but he's asymptomatic. He'll be watched closely until he's 2.
"I'm just passing the word around for a lot of women to get tested," Calderon said.
The goal is to screen 150,000 pregnant women nationwide and enroll those who test positive for first-time exposure to CMV. Those women will be randomized into a treatment trial.
All babies, whether they test positive or not, will be followed for two years, which is when any hearing or developmental delays would likely develop.