[MUSIC] While you are doing your work in your healthcare facility, public health is doing their part. If not for public health, the following historical outbreaks would not have been contained. Our first example is plague, also known as the black death. Even as far back as the 14th century, caregivers recognized the need to protect themselves. This is a drawing of the plague doctor. He is essentially wearing an antique version of personal protective equipment. Notice the mask in the shape of a beak. In addition to providing protection, the doctor would place herbs or perfumes in the beak to mask the smell of the sick and dying patients. The gown was made of heavy fabric or leather, and was waxed so that liquids would be repelled. And finally, the pointer was used to keep patients at a distance. One of the more significant outbreaks that occurred at the end of World War I was the 1918 influenza pandemic. Pandemics occur when a novel virus is introduced to a population that is completely susceptible. Although I would consider the eradication of smallpox one of the public health's greatest successes, it has certain features that made it a good candidate for eradication. Even though that took 13 years. First, it didn't have a reservoir in nature. Meaning that there were no animal or vector populations that would harbor the virus even though we stopped all human transmission. The second reason it was more easily eradicated was that it was a very distinguishable disease as you can certainly tell by this photo. Public health didn't need a laboratory test to confirm the infection. It was obvious who had smallpox. It was also obvious who had recovered from the disease based on the severe scarring that was left after recovery. Meaning they had immunity and would be a perfect candidate to care for active cases. So once the logistics of establishing people in the field who could scout out the cases. Implement some quarantine, and ring vaccinate all the folks who were exposed to the case. The eradication program was well on its way to success. Interestingly enough, one field investigator found that he had the most success finding cases if he took pictures to the schools and showed them to the children. School children come from all corners of the villages and towns and were likely to have seen someone with this distinct disease. Because this was such a successful strategy, the World Health Organization developed a brochure for field workers around the world to use in the same way. The last reason it was a good candidate for eradication was based on the fact that one could use the vaccine even after someone was exposed to smallpox to prevent that person from getting the disease. This is an unusual phenomenon, and not the case for most vaccine preventable infectious diseases. The last endemic case of smallpox was in 1978 in Somalia, and this young man recovered. The last actual case was in England in 1979, where a medical photographer contracted the infection from a laboratory exposure. In 1980, smallpox was declared eradicated globally. And the world celebrated the end of a era where millions of people died of this horrible infection. Today there are only two places where we have securely stored smallpox virus. The debate on whether to destroy these samples continues, but that's a story for another time. Not all attempts to eradicate an infectious disease are successful. And now that you know the features that make an infection easier to eradicate, you probably understand why that may be the case. Not all eradication programs are as successful as smallpox. Polio is one such example. Let's hear about this from an infectious disease expert. >> Polio has been a longstanding pathogen that has had neurologic sequelae in people so it's been of great interest. I remember growing up and being told not to go to swimming pools. And in the 50s the first polio vaccine appeared, and it had a dramatic impact and it was quite safe. And as a result, by the 1990s, polio was virtually eradicated from the US and the Western Hemisphere. Because of this and because of the past experience with smallpox, the decision was made to try to eradicate polio globally. And that has not quite worked out yet. There are a number of reasons. But perhaps the most important is that as with smallpox you have to go back into the remote corners of countries that are difficult to get to, undeveloped countries in Asia and Africa. And make sure everybody is vaccinated. Unlike smallpox, in the case of polio, you can have people that carry the polio virus and are asymptomatic. Whereas with smallpox people have a dramatic illness. They're easy to identify and easy to do ring vaccinations. I think so, but it can be rather stubborn and it wouldn't surprise me if five or ten years from now we're still having the same discussion. >> As you can see, epidemics and pandemics have existed for centuries. In the next module, we'll explore more recent examples of disease containment. [MUSIC]
