Evaluation of post-mortem heart blood culture in a Chinese population

Background: Post-mortem blood cultures have been used in a wide variety of research studies. However, their significance is still a matter of dispute among medico-legal experts. This study was aimed to determine the factors which influenced post-mortem blood culture results and to assess their value in determining the cause of death.

Methods: We retrospectively investigated 76 post-mortem cases with suspected infection and correlated pathological findings with heart blood culture results.

Results: We found that survival time after onset of illness was significantly associated with positive heart blood cultures (P=0.014). Blood culture results were not influenced by age, gender, prior antibiotic therapy, interval time from death to store or interval time from death to autopsy (P>0.05). In those who had heart blood cultures taken, 49 cases (64.5%) including four cases with mixed growth, showed positive results, and approximately one-third of blood cultures were sterile. The positive predictive value (PPV) was 77.6% (38/49) including two cases with mixed growth; most were genuine pathogens according to the clinical and pathological findings. However, the negative predictive value (NPV) was 59.3% (16/27). Escherichia coli, Streptococcus spp., Staphylococcus aureus, Streptococcus pneumoniae and Klebsiella spp. were isolated most often.

Conclusion: These findings suggest that the results of post-mortem heart blood cultures, when combined with clinical and pathological findings, strengthen the understanding of the cause of death.