In his series "Encerrados," he is committed to humanizing the continent's exploding prison population.
"It is an anthropological study to help understand the detained," Bispuri said. "We know very little about them. We don't know about their daily lives, what they do. My job as a journalist is to show a reality that is rarely shown."
Bispuri's photos, just published in a book
, span 74 prisons over 10 years. They show inmates crammed in small cells. Some share their space with decaying animals. Some sleep over leaking sewage.
"Prison mirrors the realities of (the) outside world," Bispuri said. "Everything that takes place in a prison reflects what is happening in that very country. Each prison said a lot about what nation they were in."
In Brazil, for example, Bispuri said correctional officials quickly acknowledged who ruled the prisons in Rio de Janeiro.
"They told me up front: If you want to go there, you have to get permission from the Red Command, a viciously dangerous drug gang that has ruled parts of the city," Bispuri said. "Most prisons have a social organization, like a pyramid style."
When a camera enters a prison, it often upsets the prison's dynamic, presenting challenges for the photographer himself. Such was the case in Peru, when an inmate nearly stabbed Bispuri with a syringe filled with contaminated blood.
"I was saved by an Italian inmate who grabbed me just in time," Bispuri said. "I often think of how he saved my life."
Bispuri has also had bags of urine thrown at him during his project. But no threats or harassment dissuaded him from his mission, which took an interesting twist in Mendoza, Argentina.
There, he was denied access to a maximum-security area of the state prison.
"They claimed it was too dangerous and that the most violent inmates were there," Bispuri recalled. "But the prisoners from that pavilion kept telling me through the windows: 'Valerio, please come see this, we are not dangerous. We are living in terrible conditions.' "
Finally, the prisoner director gave Bispuri the go-ahead while making him sign a document stating he was allowed to go in but at his own risk -- and without any police escort.
"I finally entered alone. There were 90 inmates crammed together," Bispuri said. "I started to talk to them, and they began to tell me their stories. Their situation was terrifying. There were dead animals in the cell, filthy water everywhere, men with infected, untreated wounds."
After Bispuri's photos were published, Amnesty International Argentina succeeded in shutting down the gruesome area.
"Photography can change things," Bispuri said.
Bispuri's photos also show very human moments in places that are often anaesthetized by violence, poverty and despair.
"I photographed (prisoners) during leisure time as they tried to mimic the world outside by playing football, pretending they are in a bar, lifting weights at a gym," Bispuri said. "Some were born into the delinquent world, others were there for a lapse of judgment at some point in their lives. Others were mentally ill, but a great number were there because of drugs.
"What they all had in common is that they are human beings deprived of liberty. It was important to show, in an in-depth kind of way, what life is like for a detainee."
While "Encerrados" receives international acclaim, Bispuri said his work with prisoners is actually only beginning. He said he is still committed to his mission: to humanize prisoners and help find a universal element that connects us all.
"When I went to present the book in a prison of Palermo, (Italy,) the prisoners began to cry," Bispuri said. "They asked me, 'Valerio, please come here and photograph our reality.' I answered, 'Here in Europe it is not so easy due to the bureaucracy.' "
Immersing yourself into a subject, however difficult, is the only way to work, said Bispuri, who warns his students against what he sees as a trend in today's photography.
"For me, photography is about depth," he said. "It's not all about aesthetics. It has to have content.
"That depth can only be attained once you have lived a situation with all your heart and soul."