Transmission of infection requires the presence of an infectious agent, exposure to that agent, and a susceptible host. It is, therefore, possible to characterise the infectious risk from dead bodies following a natural disaster by considering these elements.

The human body is host to many organisms, only some of which are pathogenic. When the body dies, the environment in which pathogens live can no longer sustain them. However, this does not happen immediately, and transmission of infectious agents from a cadaver to a living person may occur.

Infectious hazards for individuals who routinely handle cadavers include tuberculosis, group A streptococcal infection, gastroenteritis, transmissible spongiform encephalopathies (such as Creutzfeldt-Jakob disease), hepatitis B, hepatitis C, HIV infection, and possibly meningitis and septicemia (especially meningococcal). Micro-organisms involved in the decay process (putrefaction) are not pathogenic.

Do victims of natural disasters have these infections when they die? Usually disaster victims die from trauma, burns, or drowning, and they are no more likely than the local population to have acute infections (meningitis and septicemia) or rare diseases (eg Creutzfeldt-Jakob disease).

Instead, where disease is present, it is far more likely to be due to chronic infections with blood-borne viruses (hepatitis B virus, hepatitis C virus, and HIV), enteric pathogens, and possibly Mycobacterium tuberculosis.

Historically, epidemics resulting in mass casualties have only occurred from a few diseases, including plague, cholera, typhoid, tuberculosis, anthrax, and smallpox. As previously noted, such infections are no more likely to be present in disaster victims than in the general population.

Furthermore, although some of these diseases are highly contagious, their causative agents are unable to survive long in the human body following death. It is, therefore, unlikely that such epidemics will result from contact with a cadaver.

Indeed, survivors present a much more important reservoir for disease. Where dead bodies have contaminated water supplies, gastroenteritis has been the most notable problem, although communities will rarely use a water supply where they know it to be contaminated by dead bodies.

Source: PAHO