Wednesday, October 15, 2014

If You're Afraid of Ebola. . .

It bothers me to agree with Ruth Marcus but get your damned flu shot.

Influenza kills countless thousands of people in the United States every year. The CDC doesn't even know how many because nobody is actually checking; it's just a part of the natural background of people who die every year.

We just got our flu shots today.  It took about 10 minutes at our doctors office, with no co-payment. And my arm is already starting to get a little sore. But it's worth not getting the flu for.

That's not to say the Ebola is something to sneeze at.  The news from Texas, that a second healthcare worker has been found to be infected is not good news.  It shows, that despite (and I will argue because of) all our medical knowledge and technology, Ebola in the US is spreading as fast or faster than it has in Africa, where it typically has an "R0" of 1-2 (one sick patient infects one to two more). Our patient zero has already infected 2, that we know of.

Why is it spreading so fast here, and how can I blame  medical science and technology?
Values of R0 of well-known infectious diseases[1]
PertussisAirborne droplet12–17
SmallpoxAirborne droplet5–7
PolioFecal-oral route5–7
RubellaAirborne droplet5–7
MumpsAirborne droplet4–7
HIV/AIDSSexual contact2–5
SARSAirborne droplet2–5[2]
(1918 pandemic strain)
Airborne droplet2–3[3]
(2014 Ebola outbreak)
Bodily fluids1-2 [4]

Consider two cases of Ebola. A villager in Africa comes home from hunting in the jungle, where he has contracted Ebola from eating "bush meat".  This is our patient zero or "index" patient.  Soon after as he gets noticeably sick (the point at which Ebola allegedly becomes infectious), he stays home, and his wife and or mother will begin to care for him and very few others will come in contact with him, because of the lack of health care services. If, as is likely, he dies, his body may be a source of infection for those who deal with it, but even then, it's restricted to a fairly small circle. Little material is used to become infectious waste.

Consider what happened in Texas.  Patient zero arrived on a plane from Liberia without symptoms (probably), but shortly afterwards, went to the emergency center, where he interacted with several healthcare providers and likely a few people in the waiting room. He was given a fever reducer and sent home to be with his family, and out in public. The fever reducer did nothing to stop the Ebola (in fact, a fever is part of the bodies response to help clear viruses, so it may have hurt), and he came back to the hospital after a few days with his family with full blown obvious Ebola, too late to treat effectively.  In the hospital, he was treated by, one figure I saw was 77 healthcare providers, at this point all, or mostly at least, decked out in biohazard style suits. However, these people were not, in fact, well trained in the use of these suits and how to avoid exposure to suits. It's not sufficient to wear the suit, you have to take it off in such a way as to not touch anything on the outside of the suit while doing so. Try taking off your clothes without touching the outside, with the knowledge that failing to get it right could kill you.  At the same time, all the material used in his treatment, all the bedding, etc, have now become biohazardous waste, which need to be handled as if deadly; because it could be, and the people who dispose of it need to handle it appropriately. A case of Ebola in the US may cost millions of dollars to treat, success or not, whereas a case in Africa may only cost a life.

Healthcare workers in Africa have developed, and implemented a relatively cheap and simple methods of dealing with Ebola using plastic bags and other light, cheap and available materials. The trick is not the expense of the gear, it is the training in how to avoid the infection using them that makes the difference.

So is it hopeless?  No, but we need to get over the notion that our superior knowledge and technology in the United States can save us from Ebola. What will save us from Ebola will be learning how to trace infections and their contacts (which we do pretty well already), and the hard won knowledge of healthcare workers on how to avoid infection. The question is how many will need to die to learn how.

Let me end with a fable:
The story goes that the ruler or India was so pleased with one of his palace wise men, who had invented the game of chess, that he offered this wise man a reward of his own choosing.

The wise man, who was also a wise mathematician, told his Master that he would like just one grain of rice on the first square of the chess board, double that number of grains of rice on the second square, and so on: double the number of grains of rice on each of the next 62 squares on the chess board.

This seemed to the ruler to be a modest request, so he called for his servants to bring the rice. How surprised he was to find that the rice quickly covered the chess board, then filled the palace! Let's stop here, and see just how many grains of rice this is.
The number of grains of rice on the last square can be written as "2 to the 63th power", which looks like this:


This means: 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2 times 2

. . . or "2 times itself 63 times". Which can be written as approximately: 18,446,744,070,000,000,000 (I can't write this more accurately as I have only 10 spaces on my TI-34 calculator!)

A grain of rice is approximately .2 inches long. Converting .2 inches to feet (divide by 12 inches to a foot) and then dividing that number by 5,280 feet in one mile, we get the length of the grains of rice, placed end-to-end, to be approximately 60,000,000,000,000 miles. How far is that? Alpha Centauri, the nearest star, is located 25,000,000,000,000 miles from Earth. Placed end to end, these grains of rice would reach farther than from the Earth, across space to the nearest star, Alpha Centauri, and back to Earth again!
Replace the chess squares with 2 week intervals. . .

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