Retesting of bone donors 2 months after donation guarantees sufficient safety of bone allografts

Risk of virus transmission through femoral head allografts: A Belgian appraisal

BACKGROUND

To evaluate the incidence and the risk of transmitting a virus through a bone allograft from a living donor.

MATERIAL AND METHODS

A total 7032 femoral heads have been collected from 24 Belgian institutions. The tissue along with the screening blood tests were systematically sent to the bank. Serological screening included: for HIV, a HIV1-2 antibody test; for HBV, a HBS antigen and HBS and Hbcore antibodies; for HCV, a HCV antibody test. Syphilis was also screened with a non-specific and a specific assays. HTLV1-2 screening was recommended but not obligatory.

RESULTS

From the 7032 femoral heads, 1066 (15.2%) implants were definitively excluded. Hundred forty-six femoral heads, representing 2.1% of all grafts and 13.9% of the excluded ones, were discarded for positive serological testing associated with a risk of disease transmission. There were 2 donors who tested positive for HTLV1-2. The prevalence of HIV in the femoral head donor population was six times lower than in the general one. The prevalence of hepatitis B and C was similar but far higher than HIV. The risk was computed to be 0.54 out of 1 × 10(5) for HIV and HCV without quarantine or tissue processing. For HBV, the risk was 0.77 out of 1 × 10(5).

CONCLUSION

Current standards of tissue banking incorporated safety and quality as their main features. This policy is now regulated at the European level. With a multi-step screening-policy, stringent donor selection guidelines, the risk of viral transmission trough a tissue is minimized.

[Sporadic transmission of hepatitis C in dental practice]

Percutaneous contact with contaminated blood is the principal mode of transmission of the hepatitis C virus (HCV). However, the diagnosis of infection in patients in whom no parenteral risk factor can be identified allows speculation on the existence of other routes of transmission. In the field of dentistry, the role of saliva has still not been defined as a potential vehicle for infection nor the role of dental treatment as a possible occult factor in the sporadic transmission of hepatitis C. HVC-RNA is detectable in the saliva of over 50% of patients with chronic hepatitis C. The infectivity of the HVC particles detected in the saliva has not been determined, though it may be deduced from epidemiological studies that their potential for transmission, if it exists, is extremely limited. There has been no documented case of HVC transmission in a dental clinic. Studies which propose a history of dental treatment as a risk factor for HVC infection have not achieved conclusive results. The age distribution of the prevalence of HVC could indicate that a risk of iatrogenic transmission existed in the past, before the systematic application of universal barriers. The transmission of HVC in dental clinics may be considered a very infrequent occurrence as long as the norms for the control of cross-infection are respected.

Cefuroxime, rifampicin and pulse lavage in decontamination of allograft bone

The risk of bacterial infection through allogenic bone transplantation is one of the major problems facing tissue banks. Different screening methods and decontamination procedures are being used to achieve a safe surgical result. The purpose of this study was to investigate the contamination rate in fresh frozen bone allografts after treating them with different decontamination methods. The allografts were contaminated by rubbing on the operating theatre floor for 60 min, after which they were rinsed either with sterile physiological saline, cefuroxime or rifampicin solution or they were washed with low-pressure pulse lavage of sterile physiological saline. Our findings show that low-pressure pulse lavage with sterile saline solution is very effective in removing bacteria from bone allograft, when compared with the antibiotic solutions tested.

High-pressure saline washing of allografts reduces bacterial contamination

60 fresh-frozen bone allografts were contaminated on the operating room floor. No bacterial growth was detected in 5 of them after contamination. The remaining 55 grafts had positive bacterial cultures and were processed with three methods: soaking in saline, soaking in antibiotic solution or washing by high-pressure saline. After high-pressure lavage, the cultures were negative in three fourths of the contaminated allografts. The corresponding figures after soaking grafts in saline and antibiotic solution were one tenth and two tenths, respectively. High-pressure saline cleansing of allografts can be recommended because it improves safety by reducing the superficial bacterial bioburden.