Last September, in the Italian seaside province of Chieti, a 41-year-old Ukrainian man and his friend went for a dip in the sea. Sixteen hours later, he was dead from drowning. A sad tale, but no medical mystery. Except for the fact that, for nearly six full weeks after his death, his body tested positive no fewer than 28 times for COVID-19 – a discovery that the researchers involved say is of “fundamental importance for pathologists.”

Even weirder is the fact that, before death, the man had been “completely asymptomatic,” the team wrote in a study now published in the BMC Journal of Medical Case Reports, and is likely to have had a pretty low viral load when he died.

This “reflect[s] the importance of postmortem swabs in all autopsy cases, and not only in potential [COVID-19]-related death,” the report notes – and shows that pathologists should test for the presence of COVID “a long time after the moment of death, even if a low initial viral load was assessed.”

Although his death was confirmed to be from drowning, Italian guidelines required that a COVID test be performed regardless. Once he had been tested and an autopsy had been carried out, the body was moved to the local morgue, where it was stored in a sealed and disinfected waterproof bag at a cool 4 °C (39 °F).

So far, so standard – but a delay in receiving burial authorizations meant the body would stay there a little longer than expected. Forty one days, to be exact.

“Twenty-eight nasopharyngeal swabs were performed on the corpse” during that time, the case report explains, and “always … by the same team, adequately prepared and with standardized procedures as per international guidelines and established protocols.” That’s the same type of COVID test you’re used to having: a long swab straight up the nose – although hopefully with less sneezing in this case.

Every single test came back positive – the team even retested each of them with a reagent kit from another supplier, just to be sure.

And not only were the COVID viral particles detectable for nearly six weeks after death, but by the end of the testing period they were the only detectable particles. See, when researchers test for COVID, they can also run a control test at the same time to verify that test results really are coming from the samples they want. They do this by testing for human cellular RNA which get swept up with the viral particles when a swab is taken – if no human RNA is found, then it probably didn’t come out of a human nose.

But by the time 41 days had passed, these tests weren’t picking up human RNA anymore. The COVID tests were still coming up positive, but the human cells had become undetectable.

This is more than just a mildly morbid curiosity: the case report has real implications for how corpses are treated in the age of COVID. As the study authors point out, while we have a lot of good research about the behavior of the virus in living bodies and in the environment, “there is a lack of data on virus persistency on dead bodies and on the risk of contagion from cadavers.” That’s a problem, as “execution of … autopsies puts various categories of workers (pathologists, technicians, and so on) in contact with a possible source of biological risk, with implications not only from a health point of view but also from a medicolegal one.”

Although most COVID transmission occurs due to large droplet respiration, that’s not the only possible vector: “transmission via contact with contaminated body excretions, air, and fecal–oral route has also been suggested,” the report notes. While no scientifically-verified data yet has surfaced of the living being infected by the dead, at least one study has shown that corpses can stay infectious for up to 35 hours after death – important information for those tasked with the care and preparation of bodies before burial or cremation.

While the authors note that their study was by its nature limited – ethics committees tend to look unfavorably on efforts to proactively recruit people for post-mortem studies – they hope that their findings will spur future research. And as for the Ukrainian man – his burial authorization came through in the end, which, along with what the authors describe as “the putrefactive state of the body,” finally brought an end to the study.