Analysis of predisposing factors for contamination of bone and tendon allografts

Abstract

Bone and tissue allografts are widely used in transplantation. The increasing demand for safe allografts must be met, while minimizing disease transmission. We analysed the incidence and potential risk factors of allograft contamination and the effectiveness of disinfection, by reviewing 22 years of tissue bank activity and 474 donor procurements. We also compared different disinfection procedures used over the 22 years. The overall contamination rate was 10.1%. Risk factors were related to the donor or procurement method. Immediate culture at the tissue recovery site diminished the rate of false positives by reducing later sample manipulation. High-virulence allograft contamination was mainly related to donor factors, while low-virulence contamination was related to procurement methods. Analysis of donor-related risk factors showed no statistical differences for age, sex, or cause of death. An intensive care unit stay was associated with less contamination with high-virulence microbes. Procurement in a setting other than an operating theatre was associated with higher contamination rate. Team experience reduced contamination. Pelvic and tendon allografts were most frequently contaminated. Proper disinfection considerably reduced the contamination rate to 3.6%. We conclude that procurement must be performed under aseptic conditions, with short delays, and by trained personnel. Grafts should be disinfected and packed as soon as possible.

Disinfection of human musculoskeletal allografts in tissue banking: a systematic review

“…A number of studies performed tests on tissues that were contaminated by researchers following recovery to assess the efficacy of their decontamination methods. Similar to the recovered contaminating microorganisms observed in Schubert et al (2012), the most commonly inoculated organisms in these studies were Staphylococci and Bacillus species. Seven studies sought to test various decontamination methods on tissues infected with viruses, such as HIV2, pseudorabies virus (PRV), bovine virus diarrhoea virus (BVD), hepatitis A virus (HAV), and porcine parvovirus (PPV).…”

“…In Schubert et al (2012), the presence of a number of contaminating bacteria and fungi were observed. These included species, in descending order of prevalence, such as coagulase negative Staphylococcus , Micrococcus , Bacillus cereus , Corynebacterium , Penicilium , Alcaligenes , Lactobacillus , Eschericcia coli , Acinetobacter , Enterococcus , Pseudomonas aeruginosa , Pneumococcus , and the fungus, Candida.…”

“…Recovery of tissues was performed in operating theatres for organ donors(Haimi et al 2008; Schubert et al 2012) and autopsy rooms for cadaveric donors (Lomas et al 2004; Pruss et al 2002), when reported. Two studies indicated recovery of cadaveric tissues in processing labs (Guo et al 2012; Kaminski et al 2012).…”

“…Prior to intervention, the contamination rate ranged from 0 to 10.1 % in three studies that reported the initial bioburden (Dunsmuir and Gallacher 2003; Parker and Maschke 2008; Schubert et al 2012). A method to describe the cleaning of the musculoskeletal allograft was reported in 32 laboratory studies, and six clinical studies.…”

“…These included species, in descending order of prevalence, such as coagulase negative Staphylococcus , Micrococcus , Bacillus cereus , Corynebacterium , Penicilium , Alcaligenes , Lactobacillus , Eschericcia coli , Acinetobacter , Enterococcus , Pseudomonas aeruginosa , Pneumococcus , and the fungus, Candida. These authors noted that of these species, Streptococcus , Acinetobacter , and Escherichia are highly virulent (Schubert et al 2012). A number of studies performed tests on tissues that were contaminated by researchers following recovery to assess the efficacy of their decontamination methods.…”