One of the most useful studies that come from studying Zombies is the nature of how diseases spread. Either by airborne means, carried by water, physical contact, etc. However the latest phenomenon in Greece has been self-inflicted infections of the HIV virus.
According to this article from the Mirror, about half of all the new HIV infections Greece are self-inflicted. A poor economy with poor job prospects have driven many to get infected on purpose in order to get monthly benefits and access to treatments.
Lessons learned from these incidents is that disease, and disaster for that matter, can spread by unforeseen means, and how one seemingly unrelated event can become the trigger for yet another disaster.
Preparing for the outbreak means being flexible, adaptable, and being open to consider the possibility of the extremely unlikely.