Preventable bloodstream infections related to kidney failure treatment are more common in U.S. Blacks and Hispanics than in whites, according to a report from the Centers for Disease Control and Prevention (CDC) released on Monday.

Use of neck veins for administration of hemodialysis was the most important risk factor, but not the only one, researchers said in the CDC’s Morbidity and Mortality Weekly Report.

Using data from multiple national databases collected between 2017 and 2020, they estimated that potentially deadly Staphylococcus (or S.) aureus bloodstream infections occurred in 4,751 of every 100,000 Black patients receiving hemodialysis and 4,500 of every 100,000 Hispanic patients compared with 3,866 of every 100,000 white late-stage kidney disease patients receiving these treatments.

Roughly 40% of the infections were resistant to treatment with the antibiotic methicillin, the report found.

Patients whose kidney function falls below a certain level require a dialysis machine periodically to do the organs’ work of cleansing the blood.

The most significant risk factor for the serious and potentially deadly infection was administration of dialysis though a large “central vein” catheter in the neck.

Use of a central venous catheter for hemodialysis conferred a six-times-higher risk for S. aureus bloodstream infection compared to use of a port in the arm known as a fistula, the researchers found.

The highest use of central venous catheters was seen in Black patients ages 18 to 49.

Ideally, as kidney function deteriorates and patients get closer to needing dialysis, doctors recommend a surgical procedure to create the fistula, with an artery connected to a vein.

Without the fistula, dialysis must be administered via a catheter in a large central vein in the neck, which is associated with higher rates of complications, including infections, and should only be used temporarily.

Even after accounting for use of these catheters, the risk of S. aureus bloodstream infections was still higher in Hispanics than in whites.

“Central venous catheter use was the most important risk factor but didn’t entirely explain the higher risk in Hispanic patients,” said study leader Dr. Shannon Novosad, team lead for Dialysis Safety in CDC’s Division of Healthcare Quality Promotion.

There were also more S. aureus bloodstream infections in areas with higher poverty, crowding, and lower education levels.

“Overall these are complex relationships that deserve additional study,” Novosad said.

Her team called for research to help minimize central venous catheters use, address possible barriers to use of safer routes for hemodialysis access, and improve education of patients and healthcare providers.

“We need to focus interventions that we know work to prevent infections, specifically in these (high-risk) groups,” Novosad said.