In a new report, researchers from the Centers for Disease Control and Prevention and the Georgia Division of Public Health describe what may be the first cases of West Nile virus infection transmitted through dialysis machines.

Two of the patients, men from the same county, received dialysis from the same machine on the same day in late August 2003. Several days after dialysis, both men began experiencing fever, chills, and mental confusion.

Both patients were later confirmed as having West Nile virus disease, according to an article in the CDC’s Morbidity and Mortality Weekly Report.

In October, the Georgia Division of Public Health was brought in to investigate the cases.

In reviewing the dialysis center’s records, health officials uncovered another patient who had been dialyzed on the same machine between the other two patients on the same day. Although this woman never experienced any symptoms, blood testing revealed that she had been infected with West Nile virus recently.

“From what I understand, these are the first cases of West Nile virus infection possibly related to dialysis,” Richard Quartarone, a communication officer with the Georgia Division of Public Health, told Reuters Health. “Since then, no further cases have been identified.”

Despite the seemingly strong links between the cases, Quartarone believes the likelihood that transmission occurred through dialysis is low.

First, for the virus to be passed from one patient to another via the dialysis machine, the equipment would have to be improperly cleaned between uses. The DPH’s investigation “failed to uncover any breaches in infection control practices at the dialysis center,” Quartarone noted.

Second, the subjects shared another factor that may have explained the association - they all lived in relatively close proximity to each other.

“The properties of the two symptomatic patients actually butted up against each other” and the asymptomatic patient lived about a mile away, Quartarone noted. Moreover, “there was a very high concentration of West Nile virus in their community.”

He commented, “There’s still a greater risk of contracting the disease from geography than from something like dialysis.”

SOURCE: Morbidity and Mortality Weekly Report, August 20, 2004.