5 February 2000
The dead can kill!
by Kate Melville
This story wins this weeks Weird Science award.
Morticians and related post-death and pre-bone yard staff can catch tuberculosis (TB) from a cadaver.
Now while TB is not something most people worry about (except maybe in Russian hospitals) it is as far as infectious diseases go the second leading cause of death (2 million deaths each year and 7-8 million new cases)! The way TB spreads is through infectious aerosols in the air , these tiny particles enter the body through the mouth or nose and lodge deep in the lungs. Treatment is notoriously difficult and relies on complex and very expensive multi-drug treatment.
Now a new report from Johns Hopkins University documents the first case of TB transmitted from a cadaver to an embalmer.
"Aerosols can be generated by the injection of fluids, or by the frothing and gurgling of fluids through the mouth and nose. Before this study, the transmission of TB from a cadaver to an embalmer had never been demonstrated, says Timothy Sterling, M.D., assistant professor of infectious diseases at the Johns Hopkins School of Medicine. "Previous studies had shown that funeral home workers had unexpectedly high rates of TB infection and disease, but it was not known if this was due to exposure in the workplace. In addition, the cadaver can spasm during the embalming process, which can cause the release of respiratory secretions."
The new study identified an individual with active TB whose exposure TB was via embalming a cadaver which was infected. The embalming process involves blood removal after which fluids are injected into the body with the aim of preserving it. The usual procedure for embalming fluids after the process is completed is that they are flushed down a drain and this may release the infectious aerosols.
This discovery was made after doctors thought they has seem an unusual transmission route during an ongoing tuberculosis surveillance program. After finding two cases with similar DNA signatures, researchers became worried. In Baltimore each new case of TB is reported to the city health department and these cases are then DNA fingerprinted by Johns Hopkins researchers. After seeing this anomaly researchers then started to look for possible coincidences in exposure between the patients - the vital clue turned out to be the death certificates which had been signed by the same mortician.
In a very strange outcome it turns out that the guidelines from the Centers for Disease Control and Prevention designed to prevent the spread of TB are apparently not applied to funeral homes! This incident would seem to suggest they had better change their protocols ASAP unless they want more exotic and hard to identify case.