HIV transmission in a dialysis center -- Colombia 1991-1993.

Health personnel must adhere to strict infection control practices during dialysis to prevent the patient-to-patient transmission of HIV. The finding of HIV-seropositive blood samples in May 1993 from three patients of a dialysis center in Colombia prompted the subsequent testing of blood specimens from all dialysis center patients which had been stored during January 1988-December 1993 as part of an affiliated kidney transplant program. A retrospective cohort study among all patients dialyzed in the center from January 1992 through December 1993 was launched subsequent to HIV antibody testing of the specimens. Blood specimens were available for 59 of the 84 patients treated during January 1988 to December 1993. 22% of these individuals were HIV-seropositive including ten who were HIV seroconverters. All HIV seroconverters had undergone ten or more dialysis sessions. Of the nine who seroconverted during the epidemic period of January 1992 through December 1993 seven were male two had a history of paying for sex and five had received blood products within six months before seroconversion. None reported IV or illicit drug use or receiving unscreened blood products and none of the males reported having had sex with other men. The center had no written policies about reprocessing patient access needles dialyzers or blood lines. Interviews with staff nurses however revealed that all dialyzers and blood lines were labeled appropriately and individually reprocessed with 5% formaldehyde while still attached to the machine placed in separate labeled containers and stored for reuse only on the same patient. In contrast patient access needles were reprocessed through the use of a 0.16% solution of benzalkonium chloride with the pairs of access needles for two-four patients placed unlabeled in a common soaking pan for disinfection and the disinfectant changed only every seven days. As a result of the investigation patient care equipment is no longer reprocessed at the dialysis center and HIV counseling is provided to all infected patients. Furthermore national surveillance was initiated for HIV infection among patients undergoing dialysis and the Ministry of Health has banned the use of quaternary ammonium compounds for disinfecting intravascular devices.