Reliability of minimally invasive tissue sampling (MITS) for cause of death determination up to 72 h postmortem

Minimally invasive tissue sampling (MITS) is a postmortem technique that involves percutaneous needle sampling of key organs and fluids, offering a practical alternative to complete autopsy for determining cause of death (CoD), a critical factor in reducing mortality. In low- and middle-income settings, autopsies are rarely performed, particularly in the first hours after death. To assess the impact of postmortem interval (PMI) on MITS diagnostic performance, we compared CoD determinations from repeated MITS procedures at different PMIs in the same individuals and analyzed changes in histological and microbiological findings over time. We conducted serial MITS at 24, 48, and 72 h after death in nine adults who died at Maputo Central Hospital, Mozambique, between June 2017 and January 2018. The process included thorough histological and microbiological analyses. Results showed that MITS maintained consistent diagnostic accuracy across all PMIs. While histological findings showed minor changes over time, these did not significantly affect CoD determination. Microbiological analyses revealed a substantial increase (p < 0.0001) in Enterobacteriaceae isolation with longer PMIs, whereas fungal and parasitic detection remained stable, and viral isolations declined. These findings highlight that MITS remains reliable for postmortem diagnosis even when performed up to 72 h after death, offering crucial utility in settings where immediate autopsies are unfeasible.