Could terrorists use New York rats to release Bubonic plague?

Forgive me fellow dopers for asking a seemingly dreadful question. I honestly ask the question out of genuine concern, not as some sort of troublemaker.

In the last week, by accident, I’ve watched two seemingly separate documentaries which when you link them add up to a potentially frightening possibility.

The first documentary related to rats - New York City rats to be specific. It seems that NYC has the most genetically designed super rats on the planet. They’re bigger and craftier in NYC than anywhere else - and why? Apparently NYC is the ultimate perfect evolutionary laboratory for rats. They prosper in direct proportion to the amount of human garbage left lying around and that, in combination with NYC’s extraordinary subterranean underworld allows for the biggest baddest monster rats you’ve ever seen.

The second documentary related to the history of the bubonic plague in Europe from the Dark Ages through to England’s attack of 1665. I was astonished to learn that fully 25% of Europe’s population was killed in 1447 and that it’s population levels didn’t return to pre ‘black-death’ levels until a remarkable 400 years later. Modern knowledge is now aware of course that the “pestilus versis” bacterium is carried by fleas and that it’s the fleas which act as the conduit of the disease from rats to humans and so on. However, there is a more fatal strain of bubonic plague called “pneumonic plague” which is effectively the airborne version of the disease which humans share with one another via airborne airosol saliva and that version is apparently 90% fatal if left untreated!

Accordingly, my questions are as follows… I’m just a humble Aussie guy with a good heart and not a mean bone in my body. Surely, if I have linked the two together, there must be some horrible folks out there who would be planning such an atrocity. How effective could a deliberate release of bubonic plague ridden fleas into New York’s rat population be in terms of spreading the Black Death? Would the concentratoin of NYC’s population be sufficient to also induce the airborne version as well? Also, it’s common knowledge now that because “pestilis versis” is a bacterium, that antibiotics work against it. However, in 1998 in Madagascar, the first ever strain of bubonic plague which was resistant to every known antibiotic appeared on the scene. How well would Atlanta’s Center for Disease Control react to such a deliberate release of THAT particular strain?

Most importantly, what are you, my lovely American cousins doing to look for such threats on a daily basis? Out there somewhere, some real baddies have gotta be planning this sort of shit. How would you look for such a threat, let alone fight one?

*Originally posted by Boo Boo Foo ***
How effective could a deliberate release of bubonic plague ridden fleas into New York’s rat population be in terms of spreading the Black Death? Would the concentratoin of NYC’s population be sufficient to also induce the airborne version as well? **

My understanding is that the pnuematic form of pestis versis is the form the US govt fears (see above link). I think, thier thinking is that it is is easier to breed and aereolize(sp) bacterium than infected fleas. Also on delivery :You can just spray a subway car vs. breeding a bunch of rats n’ fleas, let them go and hoping they catch on someone.

It is an ugly thing & I hope nothing like it ever happens. Bioterrorism is so over the top … I just hope thats all …

Releasing plague-infected rats would be an almost entirely ineffective way of infecting people in the modern-day USA. Plague was a threat during the medieval period because people lived in constant close proximity to rats and (more importantly) fleas. While there’s no shortage of rats and fleas in NYC, most of the population isn’t bitten by fleas on a regular basis. Hence, there’s no way for the bacterium to get from the rats to humans.

A more promising avenue, as the second poster notes, would be to weaponize the plague bacteria directly and then use it to cause pneumonic plague. However, I’m not sure there’s anything about plague that makes it a more likely/lethal biological weapon than, say, anthrax (which seems to have been the favorite bio-agent of both sides during the Cold War.)

Poking around the CDC link jimmy provided reveals why anthrax is more commonly mentioned as a bio-weapon than plague. Antrhax spores are quite hardy, and can survive for years in the soil:

Plague is quite fragile, as jimmy’s link shows. A couple hour’s expose to sunlight will kill it. That no doubt makes plague much harder to weaponize than anthrax.

Thanks guys. Scary stuff to be sure. Correct me if I’m wrong here, but after reading the above links and taking on board your post Wumpus, have I got it right that for Bubonic Plague to work at the human/rats/fleas level that it requires fleas to constantly bite humans, then bite rats (who are immune) and then bit humans again. It has to be a two way transmission for the bacteria to spread I see? Accordingly, if the flea bite rate between rats and humans is low enough, the threshold isn’t met and a plague won’t kick in? So really, it comes down to methematics, doesn’t it? How interesting…

I think the scenario has been addressed. Just thought I might add a tidbit of epidemiology trivia. Y. Pestis is usually treatable with readily available antibiotics, quite successfully, but as with so many other little bugs she has been developing resistance lately and a Madagascar strain of the bacteria is on the watch list for reemerging disease.

Once again Y. Pestis is pretty hard to spread without host carriers, so resistant or not she might not prove the most efficient weapon, but still.


Yersinia pestis is already resident in the U.S. in a variety of native reservoirs ( for example Beechey Ground Squirrel colonies in the Sierra Nevada of CA ) and periodically explodes out into epizootics. I believe the figures are about 16 human cases a year with ~18% mortality ( probably inflated a bit by doctors not recognizing what they are dealing with at first diagnosis ). It is not a big threat, especially as by far the most efficient transmission vector, the Oriental Rat Flea, is rare in the United States.

Just as an aside I’ll also note that there remains a low-level controversy over whether or not the Black Death was in fact Plague. Some biologists hold out for Anthrax or some other unidentified culprit, based on analysis of the historical distribution of appropriate animal vectors.

  • Tamerlane

Oh and Boo Boo Foo, the rats and other rodents generally aren’t immune. What happens is that periodically you have epizootics that will badly decimate the rodent populations, causing the starved fleas ( starved by both by lack of the favorite “food” and by the effect of the bacterium itself, which forms a gooey mass in the proventriculus, preventing the flea from actually ingesting the blood ) to search for other warmblooded prey - i.e. humans.

  • Tamerlane

At the start of the London plague of 1665 the Lord Mayor ordered all dogs and cats destroyed in the belief that they spread the disease. Naturally this aided the rat population no end. One of history’s great bad calls.

Wasn’t the plague carried by black rats, which were driven out by the larger Norway Brown rat?

(I can’t vouch for the veracity of this - I don’t know why a flea would prefer one family of rat over another. Also, one place I read this was in a book by Paul Theroux, the same fellow who wrote that Pacific Islanders eat so much spam because it reminds them of human flesh).

Boo Boo, I think you may have meant 1347 vice 1447. Actually, the mid 1340’s to 1350’s were the peak years for that plague. But try Procopuis for an earlier outbreak in Constantinople, ca 542. Apparently the Emperor Justinian himself got it but recovered.

The first US outbreak IIRC was in San Francisco in 1900 (brought from Asia via Hawaii), where the city officials, fearful of what it would do the the city’s image and business, said it wasn’t really plague but rather syphilis and of course it was spread by the Chinese (the available villian). The story didn’t wash for long, and the next outbreak ('04?) was treated more effectively.

I ask Dopers please not to speculate about the most effective way for terrorists to attack us. This is knowledge that can all too easily be misused.

Can anyone explain just what role fleas play in the food chain? Is there an animal out there who lives entirely on fleas as it’s main form of food intake?

Hypothetical question - if we could design some form of germ which killed the entire world population of fleas, would the food chain or environment suffer?

Coz I gotta tell ya! I hate fleas!

Wildest Bill? 'zat you?

Oh dear… I just read your threadlink “Ino” and poor “Wildest Bill” - he copped a hounding there at the end didn’t he?

Forgive my ignorance my friends. I most certainly am not “Wildest Bill”. It sounds as though he’s asked if you could obliterate a number of species in his time!

  1. I don’t expect that a lot of terrorists read the SDMB.
  2. The answer to the OP’s question seems to be “not easily.”
  3. If the Centers for Disease Control can talk about it publicly, so can we.

moderator GQ

Boo Boo Foo, the snippet of info that I liked most in that documentary was that 184 New Yorkers claimed to been bitten by rats, while in the same year 1,200(+/-) New Yorkers claimed to have been bitten by other New Yorkers. :smiley:

By the way, drop in and meet the locals @ G’Dope!

Originally posted by Boo Boo Foo
Hypothetical question - if we could design some form of germ which killed the entire world population of fleas, would the food chain or environment suffer?

Boo Boo may or may not recall that years ago in his own Australia they tried to do this very thing to rabbits (an introduced and ecologically disruptive species). There was a dramatic but brief drop in the rabbit population as the rabbits quickly developed an immunity to whatever rabbit fever was introduced.

Were fleas to disappear, something else would fill their niche. Ticks, mites, biting flies, mosquitoes; who knows?

Hot off the presses of the latest historical research . . .

The latest issue of the American Historical Review *(unfortunately, issue, title, and author are not readily at hand) had a VERY interesting article on the history of plague with some relevance here.

First, some disease killed a quarter of the European population in the mid 1300s. There’s some question, though, whether that disease was what is today known as the bubonic plague. Lots of the specific symptoms and patterns of transmission were NOT the same as the disease today called bubonic plague.

If it IS the same causative organism (which the author doubts), then it has changed its activity a great deal over the last 600-700 years. That’s not unheard of, but suggests that an outbreak of bubonic plague today would not be a rerun of the Black Death.

In particular, recent epidemics of absolutely, positively no doubt bubonic plague (India around the turn of the century, Manchuria a little later) show surprisingly and relatively slow rates of transmission and mortality, especially compared to what Europe experienced in the 1300s.

The key issue is that the rat-flea-human cycle seems to be a poor way of running an epidemic. Human-human transmission is much better, and (at least according to the article), the pneumonic variant of the plague develops quite rarely.

For a good early treatment of this topic, check The Black Death:A Biological Reappraisal by Graham Twigg ( 1984, Batsford Academic and Educational ). Note this is still a hotly debated topic, so Twigg’s hypotheses shouldn’t be taken as definitive. Still I think he makes a pretty convincing argument that the modern Plague bacterium lacked the vectors necessary to devastate medieval Britain to the extent it did.

  • Tamerlane