SIMIAN IMMUNODEFICIENCY VIRUS (HUMAN HIV-II) TRANSMISSION IN ALLOGRAFT BONE PROCEDURES

Study Design. Infection of rhesus monkeys (Macaca mulatta) with simian immunodeficiency virus (SIV, HIV-II) was used to study disease transm ission in allograft bone. Four allograft bone processing techniques-fr esh, fresh frozen, double freeze-thaw, and double freeze-thaw with che mical decontamination-were evaluated. Objectives. To determine if SIV could be transmitted in allograft bone and if processing techniques co uld be used to eliminate the potential for disease transmission. Summa ry of Background Data. Although the risk of HIV transmission in bone a llograft was reported to be low, HIV transmission had occurred. In all cases, frozen allograft was used. Donor screening and serologic testi ng significantly reduced the risk of transmission, although a window o f time existed in which an individual was infected but had not serocon verted. Experimental infection of rhesus monkeys with SIV induced a di sease syndrome similar to AIDS and provided an ideal model to study di sease transmission. Methods. Corticocancellous cylinders were obtained aseptically from SIV-infected rhesus monkeys. The grafts were randoml y placed into one of four processing groups and implanted into noninfe cted animals. The presence of SIV antibody was monitored by serologic testing. After the monkeys were killed, the graft sites were studied b y histology. Results. All animals receiving fresh allograft or allogra ft bone that had been subjected to either single or double -70 C freez e-thaw cycles became infected with SIV. Animals receiving allograft th at had been subjected to a double freeze-thaw cycle and chemical decon tamination were disease-free after 26 weeks when the animals were kill ed. Conclusions. The results show that SIV (HIV-II) can be transmitted in bone allograft procedures. Although freeze-thaw cycles and lavagin g to remove blood elements can reduce the infectivity of a graft, it a ppears chemical decontamination is necessary to provide a high level o f confidence in its safety.