There has been a dramatic shift in how doctors use donated kidneys infected with hepatitis C that used to be thrown away.

More transplant centers are willing to use kidneys infected with hepatitis C. That might sound risky, but with advances in treatment for hepatitis C, a new study finds the organs are viable and won't make a recipient ill.

The study published in Journal of the American Society of Nephrology on Thursday found a threefold increase in the number of transplant centers using hepatitis C-infected kidneys.

Hepatitis C is a viral infection that causes liver inflammation, sometimes leading to serious damage. Prior to 2018, most of the infected organs went to patients who already had hepatitis C. Since 2018, most of these infected kidneys, about 75%, went to patients who did not have the virus.

Patients who received infected kidneys had nearly the same function as those who received uninfected kidneys, the study said.

"The key thing about hepatitis C is that millions of Americans have this infection and most don't know that they have it, it's mild and takes many years for it to progress," said Dr. Vishnu Potluri, the lead author on the study and a nephrology fellow at the University of Pennsylvania.

Until a few years ago, there weren't really good options to treat hepatitis C. Now, there are drugs with high cure rates, Potluri said. The transplant community realized that you could transplant a kidney from someone with hepatitis C and start treating them right away, Potluri said, and the early trials found the infection could be cured after the transplant.

With the massive shortage of organs -- there are more than 100,000 people in the United States waiting for a donated kidney -- that will come as good news to patients with kidney failure. More than 37 million Americans have chronic kidney disease and roughly 5,000 die each year while on the kidney transplant waiting list; that's about 12 people each day. Kidney disease is the ninth leading cause of death in the United States. One-fifth of the spending of all of Medicare dollars pays for kidney care.

But nearly 40% of the hepatitis C-infected kidneys donated between January 2018 and March 2019 were discarded.

The study authors say this need not be the case.

"We think there is quite a bit of missed opportunity here for sure," said Potluri.

He and his coauthors argue that the Kidney Donor Profile Index Calculator needs to be updated to better reflect modern science and take into consideration the evidence that organs from infected donors work just as well as uninfected organs.

Earlier studies have shown that the United States is throwing away at least 3,500 donated kidneys every year for a wide variety of reasons.

The small number of organs available for kidney failure patients is a major public health problem and one that President Donald Trump addressed in July when he signed an executive order promising to transform kidney care in the United States. His goal is to double the number of kidneys available for transplant by 2030.

Potluri said the next phrase of the research will be to monitor how these kidneys function long-term. The research has only been tracking patients for a few years.

"We will keep an eye on how a patient's immune system is reacting and what other effects may be happening. We need to be cautious and take a careful approach," Potluri said.

"I do think this is a small victory, but there are still many many organs that are being thrown away and we need to find other ways to prevent them from being discarded. That said, I think this is an important victory. If we could make even one extra kidney work and prevent it from being discarded, we think this is important for this community."