The rate of circumcisions in the United States has dropped significantly in the last three years, from 56 percent in 2006 to 33 percent in 2009, according to a recent review of data from the Centers for Disease Control and Prevention (CDC).
For the past 10 years, the American Academy of Pediatrics has remained neutral on the issue, recommending that "parents should determine what is in the best interest of the child."
The AAP cites studies that there are medical complications in only 0.2 to 0.6 percent of all circumcisions.
When the AAP changed its guidelines, Medicaid and insurance companies in some states stopped covering the procedure.
"Inactivists" like Wilson have been told they helped convince parents that circumcision is psychologically traumatizing and serves no medical purpose, despite at least three randomized control trials in Africa that have suggested it can help prevent the spread of HIV/AIDS.
Other experts say that the decrease may be because of the increase in the Latino population.
Parents choose or decline the procedure for cultural norms, religious and health reasons, according to Dr. Ari Brown, an Austin, Texas, pediatrician and author of the pregnancy guide, "Expecting 411."
"Statistically, as far as the Latino population, they tend not to circumcise and that has not changed," said Brown, who has practiced medicine for 15 years. "African Americans are a mixed bag. The biggest change is in Caucasians. They do it a bit less now."
Some make their choice based on family: "I want to look like Dad, or I want my kid to fit in to the locker room," she said.
"It's a personal decision what to do with the child's penis," said Brown. "You give the parents the rationale for why they should from a health perspective, and then the risks caused by the surgical procedure. It boils down to what you choose."
Other than emerging data on HIV transmission and other sexually transmitted diseases, there are other "small benefits" to circumcision, she said.
Boys who are circumcised have lower risks for bladder infections and penile cancer. "Both are extremely rare," said Brown. "Is it worth circumcising?"
As for Mario Viera, now five weeks old, Brown says he had no choice.
"It's like cutting off the wrong leg when someone has surgery," said Brown. "That shouldn't happen. They should have checked the wrist bands with the consent forms. That medical error should never have happened for an elective procedure. Shame on them."