# Time machines - easy way to trigger an epidemic? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 10, 2011, 8:30pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218 "2011-10-10T20:30:11Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Arrogance\_Ex\_Machina](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/arrogance_ex_machina/32/192_2.png) [@Arrogance\_Ex\_Machina](https://boards.straightdope.com/u/Arrogance_Ex_Machina)\ **Post date:** [October 10, 2011, 8:30pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/1 "2011-10-10T20:30:11Z")
So with all the SDMB sanctioned time travel going on, has anybody thought about the disease angle? Wouldn’t one of us venturing back in time both trigger a potential epidemic in that era and in the other hand also get a potentially lethal dose of local germs? Assuming the person was just visiting the past to check out the sights, maybe see a gladiator game, and then returned, that’d be possibly two epidemics for the price of one. Or maybe two complete sets of them with a bunch of different diseases on rampage both in the past and in the present. Smallpox, anyone? Or some Black Death? ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [October 10, 2011, 8:31pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/2 "2011-10-10T20:31:26Z")
You can mitigate the consequences of this if you purchase the right protection. Is anyone here in insurance? ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [October 10, 2011, 8:55pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/3 "2011-10-10T20:55:58Z")
I think it’s more likely that someone from the future traveling into the past will catch something nasty than vice-versa. Our herd immunity to several icky diseases has dropped hugely in the past century, not to mention a lack of broad vaccination for smallpox. I’d be sure to get up to date on all vaccinations prior to leaving for the past. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [October 10, 2011, 11:19pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/4 "2011-10-10T23:19:06Z")
Some viral stuff and nasty parasites would certainly be an issue. Ordinary bacteria could be resolved with a pocketful of antibiotics. That and we’d at least have some idea of “rest, good hygene, clean water, good nutrition” = better chance of surviving the nasty stuff. And unless you’re stupid enough to say “Oh hey, I’m still fighting off Yellow Fever from my visit to Ancient China, but nevermind, I need to hop of a jet to London by way of the Atlanta airport”, you’re probably not going to spread it too far. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [October 11, 2011, 12:16am UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/5 "2011-10-11T00:16:59Z")
Meh, Navy gave me vaccinations for Yellow Fever, Black Plague and whatever else is in their full overseas package. Which reminds me, it is getting time for a tetanus booster. ---
**Author:** ![Alan\_Smithee](https://avatars.discourse-cdn.com/v4/letter/a/2acd7d/32.png) [@Alan\_Smithee](https://boards.straightdope.com/u/Alan_Smithee)\ **Post date:** [October 11, 2011, 3:56am UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/6 "2011-10-11T03:56:33Z")
Of course, even if you’ve been vaccinated for Yellow Fever and Black Plague, there’s an excellent chance that it’s mutated somewhat over time. You’re vaccine might not be too effective against whatever form was around back then. And we’re not even completely sure what the Black Pague was. If the OP’s right, it might have been something that hasn’t even evolved yet! ---
**Author:** ![Hypno-Toad](https://avatars.discourse-cdn.com/v4/letter/h/b2d939/32.png) [@Hypno-Toad](https://boards.straightdope.com/u/Hypno-Toad)\ **Post date:** [October 11, 2011, 12:40pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/7 "2011-10-11T12:40:52Z")
> [@Broomstick](#): > > I’d be sure to get up to date on all vaccinations prior to leaving for the past. That won’t help. You need to get the old, out of date vaccinations to fight off that ancient stuff. ---
**Author:** ![chrisk](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@chrisk](https://boards.straightdope.com/u/chrisk)\ **Post date:** [October 11, 2011, 1:50pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/8 "2011-10-11T13:50:30Z")
> [@Alan\_Smithee](#): > > Of course, even if you’ve been vaccinated for Yellow Fever and Black Plague, there’s an excellent chance that it’s mutated somewhat over time. You’re vaccine might not be too effective against whatever form was around back then. And we’re not even completely sure what the Black Pague was. If the OP’s right, it might have been something that hasn’t even evolved yet! > [@Hypno-Toad](#): > > That won’t help. You need to get the old, out of date vaccinations to fight off that ancient stuff. This gives me a possible sci-fi story idea - the time-travel corp employees whose job it is to go visit the Black Plague and collect samples to whip up a vaccination before tourists can be allowed into the era. And the sample-collector would get quarantined when he returns to the future, to see if he comes down with it. ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [October 11, 2011, 2:56pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/9 "2011-10-11T14:56:01Z")
I think the fact that smallpox hasn’t re-emerged since it was eradicated in the 70’s is another piece of evidence that time travel will never be possible. With time travel, the worst threat might not even be smallpox. With smallpox, at least we know what it is and have a vaccine for it. If someone time traveled and brought back a disease like [sweating sickness](http://en.wikipedia.org/wiki/Sweating_sickness), which vanished before modern medicine could figure out what it was, we’d be in even more trouble. > [@Chimera](#): > > And unless you’re stupid enough to say “Oh hey, I’m still fighting off Yellow Fever from my visit to Ancient China, but nevermind, I need to hop of a jet to London by way of the Atlanta airport”, you’re probably not going to spread it too far. This kind of thing happens with sick people today, and it would happen with time travelers. Airlines generally won’t give you a refund if you don’t want to travel because you’re sick. With that kind of incentive to travel when you are sick, people are going to do it. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [October 11, 2011, 10:19pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/10 "2011-10-11T22:19:36Z")
> [@Broomstick](#): > > I think it’s more likely that someone from the future traveling into the past will catch something nasty than vice-versa. Our herd immunity to several icky diseases has dropped hugely in the past century, not to mention a lack of broad vaccination for smallpox. > > I’d be sure to get up to date on all vaccinations prior to leaving for the past. That’s not logical. Viruses & bacteria evolve at rapid rates. The diseases of the past? We’d be utterly immune to all but a few. Today’s diseases **in the past**? Even mild flu would be deadly. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [October 11, 2011, 10:43pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/11 "2011-10-11T22:43:42Z")
> [@chrisk](#): > > This gives me a possible sci-fi story idea - the time-travel corp employees whose job it is to go visit the Black Plague and collect samples to whip up a vaccination before tourists can be allowed into the era. And the sample-collector would get quarantined when he returns to the future, to see if he comes down with it. But I thought the Plague still exists today and is treatable with antibiotics > **[Bubonic plague](https://en.wikipedia.org/wiki/Bubonic_plague)** > > Bubonic plague is one of three types of plague caused by the bacterium Yersinia pestis. One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and vomiting, as well as swollen and painful lymph nodes occurring in the area closest to where the bacteria entered the skin. Acral necrosis, the dark discoloration of skin, is another symptom. Occasionally, swollen lymph nodes, known as "buboes", may break open. > The three types of plague... Or has it mutated so much that the plague known today is not the same in terms of vaccination? And, since it’s a bacterium and not a virus, a vaccination may be more difficult. ---
**Author:** ![robert\_columbia](https://avatars.discourse-cdn.com/v4/letter/r/e79b87/32.png) [@robert\_columbia](https://boards.straightdope.com/u/robert_columbia)\ **Post date:** [October 11, 2011, 10:46pm UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/12 "2011-10-11T22:46:51Z")
> [@Bosda\_Di\_Chi\_of\_Tricor](#): > > … > > The diseases of the past? We’d be utterly immune to all but a few… Do we inherit antibodies from our parents (or just our mother)? I didn’t think this was the case. So if great-great-great-great-great-great-great-grandma had some now dead virus whose surviving descendants mutated after everyone became immune to the old form, do I have immunity from birth by virtue of being a descendant of a survivor? ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [October 12, 2011, 12:09am UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/13 "2011-10-12T00:09:21Z")
> [@robert\_columbia](#): > > Do we inherit antibodies from our parents (or just our mother)? I didn’t think this was the case. So if great-great-great-great-great-great-great-grandma had some now dead virus whose surviving descendants mutated after everyone became immune to the old form, do I have immunity from birth by virtue of being a descendant of a survivor? Natural selection gives us many immunities. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [October 12, 2011, 12:13am UTC](https://boards.straightdope.com/t/time-machines-easy-way-to-trigger-an-epidemic/599218/14 "2011-10-12T00:13:40Z")
> [@robert\_columbia](#): > > Do we inherit antibodies from our parents (or just our mother)? I didn’t think this was the case. So if great-great-great-great-great-great-great-grandma had some now dead virus whose surviving descendants mutated after everyone became immune to the old form, do I have immunity from birth by virtue of being a descendant of a survivor? Genetic traits that prevent certain diseases can be selected for. For example, it is believed that the [sickle cell trait is useful in fighting off malaria](http://sickle.bwh.harvard.edu/malaria_sickle.html) and humans have evolved in such a way that they are not susceptible to the feline leukemia virus. Some people of Northern European descent have a [gene that makes them resistant to HIV](http://www.pbs.org/wgbh/evolution/library/10/4/l_104_05.html). It is hypothesized that this may have made their ancestors immune to the plague. So it could be the case that your great-great-…-grandma only survived to have children because she had a gene that allowed her to fight off some deadly disease of the time. Just like \*\*Bosda Di’Chi of Tricor \*\* said faster than I did.