Mr Bennet went under the scalpel in January as the first person to receive a heart transplant from a genetically-modified pig. This surgery was conducted at the University of Maryland Medical Centre.
Sadly, the handyman died two months after undergoing this landmark operation.
Doctors at Maryland Medical Centre thought there was “no obvious cause identified at the time of his death” at first.
However, the lead surgeon has now suggested the heart might have been infected with porcine cytomegalovirus.
This virus is thought to be a pathogen, targeting domestic pigs.
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Mr Bennett suffered from heart failure prior to the transplant.
After he died, the hospital explained that his condition simply worsened but they didn’t provide an exact cause of death.
However, Bartley Griffith, Bennett’s transplant surgeon, shared that the pig’s heart might have been infected with a pig virus.
Mr Griffith detailed the virus and attempts to treat it in a webinar hosted by the American Society of Transplantation on April 20, according to the MIT Technology Review.
“We are beginning to learn why he passed on,” said Griffith during the webinar.
He added that the virus might have been what “set this whole thing off”.
“If this was an infection, we can likely prevent it in the future,” Griffith noted.
Revivicor, the biotech firm that raised and engineered the pigs, declined to comment to MIT Technology Review and has not made a public statement about the claims.
According to experts, the transplant was a “major test of xenotransplantation”, which describes a process of transferring tissues between different species.
They think that the experiment came across an “unforced error”, as pigs that are bred to provide organs are supposed to be free of viruses.
Genetically-engineered pigs are created using a special technology that produces altered pig cells.
These are then used to make pig embryos, who are raised in an controlled environment.
After the pig grows up, the organ is removed and transplanted into a human.
The patient with the transplant needs to take immunosuppressant drugs to prevent their organism from rejecting the foreign organ.
Mr Bennett’s son, David Jr, shared he hoped that the transplant would “be the beginning of hope and not the end”, according to news agency AP.
“We are grateful for every innovative moment, every crazy dream, every sleepless night that went into this historic effort,” he added.