bubonic plague

bubonic plague - The Bubonic Plague to}...

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Unformatted text preview: The Bubonic Plague to} "'l" at bacterial disease carried by fleas that feed as rate. it has aflictea‘ human beings for more than Lilfltl years. The factors responsible for its alternate rise and fall remain a mystery. CuliJ'l MeEeedy February. 1533 nearer parts of the Middle East had a total popu- lation of approximately lflit million people. In the course of the next few years a fourth of them died. victims of a new and terrifying illness that spread throughout the area. killing most of those unfortunate enough to catch it. The disease put an end to the population rise that had marketi the evolution of medieval society: within four years Eu- nJ-pc alone suffered a loss of roughly Ill million people. The disease responsible for such grim statis- tics was the bubonic plague. and this particular eut- brea it. lasting from 13-16 to 1352. was known as the Great Dying or the Great Pestilence. Later it was appropriater referred to as the Elaclt Death. a name that has come down through history. Although the effects of the Elaclc Death may have been particularly catastrophic. strilting as it did after a long period in which the disease had been un- ltnown in the West. this was not the first time the plague had ravaged Europe- Some Elli] years earlier. during the reign of the emperor Justinian in the 15th century. there was an epidemic of similar propor- items. There were also repeated. if less widespread, epidemics in the two emu-dries following the plague In the year I345 Europe. northern Africa and of Justinian‘s time. and for four centuries after the Black. Death. The disease has undergone a precipi- tous decline since that time. but it still occurs spo- radically in various parts of the world today. includ- ing the U5. From Tr'tl to tilt] percent of those who contracted the plague Ln the 14th century died from it. Indeed. the symptoms usually presented themselves with a ferocity that presaged death within five days. The name. bubonic plague. derives from one of the early signs of the disease: the appearance of large. painful swellings called bubom in the lymph nodes of the armpit. neck or groin of the victim. Three days after the appearance of the buboes people were charac- teristically overwhelmed by high fever. became de- iirious and broke out in intact: splotches that were the ruult of hemorrhaging under the shin. As the disease progressed. the buboes continued to grow larger and more painful; often they burst- The bursting is said to have been particularly ago- nieing. capable of arcntsing even the most moribund patients to a state of frenzy. ‘t'et physidans always regarded the bursting as a good signr if only because it indicated that the patient was still capable of put- ting up a fight a week or so after the onset of the EPI'J-sottfir 4 * [El-Lilli HCEVED't' illness. {if these who were going to die. probably half were already dead by this stage. In some cases a person's bloodstream was directly infectedr which led to septic shock. mam've hemor- rhaging and rapid death. a form of the disease lrnown as septicemia gee. In other cases plague was bansrfilflfi'is‘fpltype of neurnonia: in pneu- monic plagur the victims cella , spr lood and were almost always dead within a few days. Strange as it may seem. in 1rte-w of the frequency of the disease and the tell it exerted on the popula- tion. no one at the lime had an inkling of its funda- mental naturer its ultimate muse or how it was spread. During the period of the Iliad: Death people were inclined to attribute the disease to unfavorable astrologij combinations or malignant atmospheres {“miasmasmt, neither of which could be translated bite a public-health program of any kind. More paranoid elaborations blamed the disease on delib- erate contamination by witches. h-‘Iesiems [an idea proposed by Christiane-l. Christians {proposed by Iails-loslemsfl and laws {proposed by betlt groups]. t was not urtlil 135” that the French bacteriolegtst Alexandre 't'ersln discovered lhrlt bubonic plague is caused by a gram-negative bacteriumr 't’ersim's pearls. belonging to a group of bacteria known as rod-shaped bacilli.r many of which are pathogenic. Plague bacilli are found at low frequency in many wild rodent populations throughout the world and are transmitted from one rodent to another by fleas. _ In the case of the bubonic plague the flea often responsible for unnsmitdng the disease is the orien- tal rat flea. liesopsylla cbropis. 1When a flea bites an infected rat, it 'mgesls the bacilli. which proceed to replicate within its digestive tract, formh'tg a solid mass that obstructs the Elea's gut; the flea is unable to ingest blood and becomes ravenoust hungry- In a feeding frenzy it repeatedly bites its animal host. regrngitat'rng plague bacilli into the host's blood- stream every time it does so. These infection sites then act as loci for the spread of bacilli. If the host animal dies. as it is likely to do. the flea moves to the nest available litre rodent- The disease spreads rap- idly in this manner; as the number of live rats de- creases, the fleas more to warm-blooded hosts on which they would not normally feed, such as human beings and their domesticated animals, and so an epidemic is launched. Gnce the disease enters the human populalion it can sometimes spread directly from human to human through the inhalation of infected l'EE-Fllis tory droplets. The normal mode of spread is by the bite of rat fleas. however; the disease fines 3t per; ' ' Mgmmdgnm. which are the primary hosts for both the plague FaEIllus and the rat flea The essean requirement for an epid ' {gn_ o tbroalr in a human population} is a rodenflgtl ' {an outbreak in an animal population}- This is necessary both to initiate and to sustain the disease in human beings. IEll courser the two populations must be in close contact fer the transmission to be sneeessfpl, but it is unliirely that this was ever a significant eariable in medley-a1 times. in rural as well as urban areas humans lived surrounded by rain. The Black Death is thought to have migrated along the Sills Road. the trans-Asian route by which Chinese sill: was brought to Europe [see Figure 1.1}. There are two reasons for belie-ring this was the case. The first is that outbreaks of the plague were recorded in tars in Astralrhan and horny, both car— avan stations on the tower 1|Ir'olga Riser irt what is new the H-553. The second is that during the years 1341? and lilili the Arab traveler and scholar Ibn Battuta. returning along the Spice Route from a stay in India. first reported hearing news of the plague when he reached Aleppo in northern Syria. not before. That clue erreludes transmission by way ol‘ the Indian Queen and Persian (3qu ports. est lilot‘ly the disease erupted first among marrnots. large rodents native to central Asia lithey are related to woodchuclrs but belong to a different spedesi whose for was an important arti- cle of trade throughout that part of the world. Ac- cording to this historical reconstruction. trappers coming across dead or dying animals collected their fora. delighted to find such an abundant supply. and sold them to dealers who in turn {withqu wor- rying about reports. of illness. among the fur trap— per-s] sold them to buyers from the Ir‘iest. 1II'lII'hen the bales of marrnet furs sent west along the Bill: Read were first opened in Astralrhan and Satay. hungry fleas lumped from the for; seeking the first available blood meal they could find. From Saray the disease is thought to have traveled down the Don River to Ital-fa. a major port on the Black Sea. where a. large rat population presided the perfect breeding ground for the plague bacillus. Because many of the rats in Haifa were living on sailing 1.u'e-ssels bound for the ports of Europe. the disease had a ready means of transport to that part {if the world. .- lndeed. it would be dificull te desigt a more Figure 1.1 steel: DEATH tame hum meat Jul: in Eu- rape 1th the Silk Raid. mil-ling in Haifa in about: 1313?. Fran! there it wil carried by ehlp In the main].- parla at Eltmpe and flflrthem Africa. Hunt at Eura-pe w" affected efficient means at disseminating the plague than a medieval ship. The hat-ids at' these ships were gener- ally crawling with rats; when the new slept. the rats teal: aver. running thtaugh the rigging and drap- pirtg fleas untu the tied-cs hetaw. The cycle at infer:— liun. Frnrn flea ta :rat and rat Ina flea. wauld be main— tained until the rat papulatian was 5:: reduced by the disease that it cauld nu ledger sustain the fleas and the plague bacteria they were carrying- Hungry I'Ieae. seeking any hast they cauld find, waulti then carry the disease inta the human populatiua. It is small wander that by the end at I34? plague had braked out in meat parts an the mute. Linking Haifa ta lEeneta in nurthern Iiely. he twu meat impaatant pee'ts alang thisr mute were Peta. a art-I‘Dth at Constanli'smple. and - I -_ .J .. Itttrt sting " 'JIF' AHTIHEPLE It. H .l. T a: L | .t. I. HEDI‘TEPMAHEAH SEA. THE BUM}le PLAGUE ‘ 5 lit? 'It .3” If. Hut-El a. T- ma 5"“ last Ly list f ta || it: WWII“ I I / ASTIAHHAH ‘ $.- hefctre the epidemltt fittiIly Iulflidrd. In 1352.. Milan, the largest city ta Henge the plague. is believed he have time in: team it 1:! the tar-then tutti“ cit-,- tmn It" Ifl. Mesah‘la in Sicily. Bath places Were stapayer pahtfi for ships email-lg the Mediterranean and became maiar idei far fitrther dissemination at the plague. The initial impact an the papulau'an at Canetlnth nepie was graphically deaa'ihed try the emperar Cantaeuaemts, wha last a Sun ta the disease in 134?. He recatmts haw it spread thruugheut the Greet: islands and alang the canals af Anataiia and the Balkan, hitting “meat at the hi hie-s- sirta the that authreal: was recanied in Detaber at 134?. launching an epidemic that quickly spread be include the entire island. Frat-n there in early 1343 the Black Death massed ever ta Tunis en the earth cues: of Africa and then spread by way at Sardinia ta Spain. By the time it reached Spain the Black DEath had alsa spread. ten the heart at Eat-ape. a fact that can be blamed at Figure 1-1 Huanfllt DF TH'E PLAGUE h uprated in thin lath—mature Faint- [regI he l'ielat: Brueghel the Elder. ‘Trlumplt at Death," “It!!! flit-“ll. ll! lht' alreletom, overwhelm: .t. kingdom ut the living. hing wllir his pllea 11! gold net the I'l'fl-III'IE revelers at their ub‘te can Help! the re'll'nIJ-efl Ira-t1.- at the dead. Behind lite hing a snap! el skeletent putt-ea eietl-ttu. into :- water-fitted man grave; a turret: lend-ape already retitled of tile out be seen in the diatanet. Apenntyptlr ririem at this tried were romaine in the cenlurlfi when the plague I'l'lu'lfltd. Europe and the hflllhieal could he term at ming trip-ed rrul In a [He darn. least in part an the fleneeae, who are said he have I'LeartJe-aah].r hinted away-I ah'lp-fi [Turn the east ean'yirtg their aiei'. muntry'men. Not only tilt! surh hardheart- edneas have liltle effect {the C“? Iwas as badly hit as any in Eurepe} but also the diversion el‘ ships to ether pet-ta, such ea Marseilles and Pisa, hastened Ihe spread at the plague threughmtt Eurupe. iiy thia time the epidemic was mgLng throughoul the Mediterranean. Ship-a taming siiltr slaeea and fur brought it to Alexandria heiete the end of 1311?: From there it apread south te IKaine. east to Gaza. ileum and Dames-ma and finall}.r along the nerth @335: of Africa in Meroceh- By 13-13 the Black Death had jumped them the Mediterranean region he the Atlantic eeaat et' Eu- rope. it created aeuthweatem Franee by way of the Neither lite regional capital. Touleuae. and rapidly pasaed dawn the Liarortne River to Berdeaua on the wee-t eeast- Fret-n there it is like]? that one o-F Ihe ships loading elaret fer the lith market hreught the Hlaek Death to lGreat Britain. In 1343 it was first reeerded at 1II"'.I'negl-nturnuth on the south coast of England, and it is believed to have spread to- Ireland Erin-n Eli-late]. Frnm England the plague chased the Hurth Sea to envelop Scandinavia in its deadly grasp. flit-certi- ing to one file-w, the invasion oi Scandinavia can. be blamed. en a ehip that Jelt lmdot'l in May. lit-W. hound ler Bergen with a full crew and u eargo oi wetell. The ship is rep-erred. ttJ have been seen flame days Later. drifting nail“ the man of Norway. Loea] people who towed ant to ineeatiga te found the crew dead and returned Io shere. E'flTTjElItfi the wee! and —un1.e1ttjngl3,' — the plague rtuttttt them- That started a chain reaelien as village after village aleng the Nemeg'tan euast ment'umhed ten the disease. The feline-int; year the Blade Death ravaged the pepulatiene uf Denmark and German]; bet'ere e11- tering Peland in 135i .md Eusiia 1n lEI-EI. This in Elfl'tft rumpleted the eite[e; tau-t mil}: had the disease rIL'l'urI'HI'IEl TD within a let-1' hundred mjlee uf Its enrr'tr int-t1 Eurepe en the 1't'unltga steppe but .3150 after t'nur lung and devastating y'eai'ti mettality rates in west- em Europe had finally returned ten num-Lal. he .eureietj.r that emerged from the period at the Elarlt Death became quite [tempt-rune; the aur— I-r'tenrs heel inhen'ted the fortune-a at their deeeeaed releti'r'ee tutti Tl'lfll'ljr were able te muee :intn peeitiune el pmminenee enee eleeed tu them. TheLr gee-rd flu-1'- l'uE'IE did I'lfll neeeeearite laet fur Icing. hat-mean In 135$ a seeund uuth-realt at the plague appeared in Genmtny and epread rapidly thteughtJut Eumpe. tt exacted a partieuta El].-' heavy tell flmL'IEI'LE the ehtletren hem stifle the end {It the Elect: Death. "mere-alter the plague returned tn Ell'l'flFli" with muumful regularity; it‘tdtted. the {'{If‘lljl'tE'fll‘ never Seemed lI'IE'E' [IF it fut mere than .3 [eye were. at a time. Allhtlltgl'l the litter epidemics nearer matched the Blaelt Death in llL'HTui- elf ever-all mortality. they nnnetheleee eentlnued tIJ ha are a negative impact an PfiP'L-ll-il-llfll‘l gre‘wth in Eu tape thmugh the end [at the I-Hh century- Figure 1.2 illustrates an artist's tren- eeptien rat the lflh'afiflfi el' plague tn the Iath eentu rgr'. At this pit-int" an equilibrium was reached between H ‘ Cit—FUN MEE't-‘litil‘r plague and people, and 1'11. the 15th century the Impulafiun [mgfin In teetwer. [11 particularly hard- l'til regluns it mink mnre than :1 I'.'L':|'|.ll'l.ll."!|" lt'IT numberh rn return tu their nr'tglnel lurch. but 11‘]: HI? end Hf the 16th century [Inpulntiune .1['.' ever wene higher than they»: had been print tt: Ihe nnfiel ni Ithe Hlaeh Death. Strangely. when the plague did reappear (which it continued tn do, albeit int-.15- “PW—1F. ntly']. I'l. UHL'J'I. tilt! 50 with a Fetnc'thr' equal. in: an}; hecnrded in Frfl‘r'l'illlfr nutbrealt-s. In The lee: epidemi-t :11 France, hum 11’2” LL: 1 22. halr' rat the pupuiatimt L11 Ihe fit? “If Mat- fiflllL‘fi med. mgerher 'l-'.'|.l:l‘l EIEI pct-WW L'IIc the pupuln mm m nelphh—nfing TtJuIL‘In. H pett't-Int at Arlee- and Ell]l Perm-n1 at Ah: and eh'igntan [see Figure 1.13. "t'e: the epidemw did 11m ep‘rflflt‘l. I‘JE'FHTIEI Fmvcncu. and the I-L'I-IZJII. number at death; was lei-15 than lflfl'fifl'fl' B 1..- the Hath century it was widely hulle'fiutl 1h!“ plague spread as a result {Elf utlntagiun. a hu'll' Iqrttn' that amid he: transferred Fmrn the =.1-:k W Hill I'Ll'fll1lf'l}'. Hunmn-m-i'luman lmnt'atTI-is‘ilnn was Figure [.1- |'H'!t'5lf]hh"h {LIFE 1th was warn during a plague uul'hnak in Marseiler in NM. The hledhhe testumE. made Elf Ellfllfi'lfl'. em-ered I15 Henri iwm head 1|! +ue and WM: l'rL-l'LL-vEd It: pen-tida- pmrertiml [mm cunt-1- giu-n The Ia.ng her-IE rnnlaiuerl sweet-smufling herb-t. Eu HILEE dill barn: :nntafiiml; Hit Inf-1nd ED11- [alt-Ind. incense Hut was tlmugltl [[1 ward off impurities. Eve-I1 lhr eye- hetn. whit]: held :nntelnne Ilene-e5, Ian-rt: prulectit'u. thought to take place either directly through physi- cal contact with a aiclc peraon or hidhectly by the flflfltfl- or bed aheelra. In response, many towns and villager inatituted quarantine regulations. The au- thorities in England. for example. recommEnded that plague airline be locked up in their homes or tranet'etrod to special "th hUIJSE'E.” An extreme example of adherence to public policy is the famous nae of Mompeaaon, rector in the email vil- lage oflEyarnlin who peieuaded the entire munity to enter into quarantine III-vtthllro the plague erupted there in 1ddo. fine by one the pa- rishioners. who remained faithful to their contenti- naled hearthr. fell victim to the disease. .t'i mortality figure 1.! PHUGHEI'DH [IF THE PLAGUE through i medieval houaehold could be very rapid once the black retl thal Ila-ed there became inflicted. Ari inlet-lied rat. [allied with a colored due on day ‘1r it. II'IID'II'II to die from the diaeue by day 5 and it: lieu ten-e, carry-ingthe plague Iiltl'lth them to other rate in lhe honoe. By lily Ill thine nta THE BUB-DNIC HAGUE * 9 rate of F2 percent indicate-a that the community probably had a morbidity {infection} rate of ltltl percent. an extraordinary price to pay for a miscon- ceived theory- Locking people in their homes is. of eoeme, one of the worst poasibte ways to light the plague. The plague is a disease of r‘Iot:a.iity.“ moat lilter to roan- ifeat itself when rain. fleas and peopie are kept in clue-e contact with one another {see Figure 1.4}. To confine people is to maximize their chance of being bitten by a plagueecarrying flea or infected though close contact with another human hiring. flifieiale recognized that quarantinea were dan- Etta-nus to healthy individuals confined with etch EIM' 'Ii lure Iii-fl- died and lhe lieu Iuro In human hinge. interle— irig almocl t5 parent of them. By day 15 approximater half of III! htuame ll't lhe home will have died from lhe elem-Ir; I fourth either: will have recovered. from it and a fourth will have eeceped iL Ill * C-D'Llhl MCE‘v’ED't' relatives. but they inersed them nonetheless in the belief that some lives must be sacrificed in order to stop further spread of the disease- Because it is rats that carry the plague {and the rats were free to travel). the entire quarantine effort was a waste of time—and fives- ittteinpts were also made to quarantine passen— gers and goods arriving in boats from oversms. 1i‘li'hen sickness suggestive of the plague was ob- served among crew members or passengers. the strips were diverted to laaarettos {quarantine sta- tionsi until the authun't'les deemed it safe to release them. At Marseilles in May of 15"2tl. for example. the sailing ship Grand Sairit Antoine was placed in quarantine for three weeks because eight of its crew had died in the course of the voyage from the Near East- In spite of these efforts to limit the spread of the plague. the disease broke out in Marseilles— tiist among the doclrworlrers who unloaded the ship’s cargo when it was released from quarantine and then in the population at large- There is little evidence that quarantines of this type were over very effective- 1lien-ice was one of the first seaports to introduce quarantine regulations. early in the 15th century. enforcing them by impose ing the death penalty on anyone who broke the rules. ‘t‘et 1|i'enice suffered from the plague as much as any city in ltaly. presumably because it was bri- posslhle to prevent rats aboard quarantined ships from jumping ashore. carrying the plague with them. inal-ly. afte: influme‘rable cycles of onslaught and retreat. the plague disappeared from Eu— rope. London’s last experience with the disease. the 'Great PlagueJ began in iii-55 and ended in spectacu- lar fashion with the lGreat Fire of 1666. hit that time it was natural of Londoners to believe they owed their deliverance to the purifying conflagration- Later it was suggested Iondoners owed their resis- tance to the plague to the reconstruction that fol~ lowed the tire and the fact that the rebuflt clty boasted brick houses and wider rubbish-free streets in place of the higgledy-piggledy structures and maludorous alleys of medieval times. ‘lhis explanation is attractive but does not hold up under scrutiny. I{lite reason is that the fire destroyed only the central part of londcm. the area least af— fected by any of the outbreaks of plague earlier in the century. leaving untouched the overcrowded suburbs that had provided the disease with its main lodging in presrious times. it second reason is that other cities in Europe. such as Paris and sinister— dam. became plagueufree during the same period— a phenomenon that could not be linlred to the Great Fire of London- a somewhat more convincing [but still flawed} theory sugests that the disappearance of the plague coincided with a slow rise in prevailing stan— dards of health and hygiene- Although hygiene cannot be eliminated as a factor. it does not explain why subsequent outbreaks followed the standard course. complete with high rates of mortality. but were farther and farther away from the center of Europe each time they appeared. It was almost as if Europe were developing some form of resistance to the plague that lcept the infection from propagating in the usual way. In the north the path of retreat was to the east.- in the Mediterranean it was to the south. The later the epidemic. the less it seemed to be capable of spreading. This. moreover. was at a time when. according to every available index. traf- fic by land and by sea was increasing. When the role of rats was finally established late in the 19th century. it was suggested that the subsi— dence of the plague could he explained by changes in the population dynamics of the blaclr. rat. Ratios rattvs- During the 13th cen tury it had been observed that the black rat. the historic carrier. had been largely displaced by a NEW species. the brown rat {Ratios aomrgicas]. which would have been a much poorer vector of the plague: the brown rat is as susceptible to the plague bacillus as the blaclr rat but does not nun-sally live in close pinidndty to humans- Brown rats typically live in dark cellars or sewersr whereas hlaclt rats overrun the upper rooms and rafters of a house. Because the oriental rat flea has a maximum jump of fill millimeters {a little more than 3.5 inches]. the difference in preferred habitats may have been enough to isolate humans from plague—infested fleas- The brown-rat theory seems plausible but does not fit the geography: the brown rat spread across Europe in the 13th century from east to west, whereas the plague retreated from west to east. The brown rat was in Moscow long before the city expe- rienced a particularly severe epidemic of the plague in the ll'l'll's; it did not reach England until l'fl'fi, more than fill years after that country's last bout of the plague. he late Andrew B. hppleby of San Diego State University suggested an alternative theoryr namely that a certain percentage of black rats be carne resistant to the plague over the course of the l'l'th century and that the resistant animals would have increased in number. spreading across Europe during the next Itltl years. Although these rats might still be infected by the plague bacillus. they would not die from it and therefore onu]d support a large population ul fleas. rendering it unnecessary for the fleas to seelt other hosts- This theory. how— ever. does not conform to what is ltnown about resistance to plague in animal populations. As [taut Stack of the University of Oxford has pointed out. rat populations ot'ten develop resistanoe when ex- posed to a pathogenic battalions or virus. but such resistance is short-lived and is therefore unlikely to have been ruponsilrle for broad-based immunity to the plague. A more plausible theory suggests that a new spe cies of plague bacillus. ‘r’rrsr'sia arm's. may have evolved that was less vinilent than the previous strain- lining Iess virulent. it might have acted as a vaccine. conferring on infected animals and humans a relative immunity to more virulent strains of the bacterium. The bacteriological theory is acceptable on several grounds. First. it conforms to the dictum. pmpcnsd by the American pathologist Theobold Smith. that "pathological Manifestations are only incidents in a develo ' rasitisrn.” so that in the long run nil-Elm % of disease tend to displace more viru- lent ones. Second. it explains why the decline of the plague is associated with a failure to spread beyond local outme a disease caruiot travel far when the number of people susceptible to it is low. Third. it is supported by the resistance pf a close relative of the plague badllusmrpiwg] liildi5..'|-t"l'tlt'J't does not irfluce visible illness in ra t ocs confer on them a hi h of immunity to the plague. Did 't'. pseudott-tberctriosis or a relative with simi- population of early modern Europe. making it im- possible for l"- prstis to gain a foothold therei' Al- though no direct evidence exists- to support that hypothesis. it seems more reasonable than any other. The discovery and widespread use of antibiotics has conferred on human beings a different form of protection from the plague. Although the disease still occurs with regularity throughout parts of Africa. South America and the southwestern LLE. [in Wild. ill cases were reported in the U.5.}. it is never again lilter to reach epidemic levels now that we lrnow how it spreads. what public-health mea- TH'E ELI'EDNIE PLAGUE * ll sures are appropriate and how to treat plague Eases as they occur. Nevertheless. many questions about the plague are as yet unanswered- For example. the mode of transmission in rural areas. where rat pop Ltlattor'te ate discontinutsas. is entirely unclear. And what explains the distribution of the plague throughout the world today? Why are only certain rodent populations reservoirs of the disease whereas others are entirely free of ltlI PDETSCRl-FT Although the word "plague" is often used generally to refer to any human atfiiction. bubonic plague is a specific disease caused by a specific bacterium named ‘t’rrsinic prstt‘s- One of the most feared dis eases. the name Blaclt Death is Iinited to a :cnaior epidemic of bubonic plague that decimated the civi- lized world in the years between litter and 1352. Although human society had certainly been rav- aged by infectious disease earlier. the Blaclt Death was the first widespread epidemic for which suffi- cient records exist so that its extent and course can be tracked. Coming at a time when human society was wrapped up in the superstitions of the Middle Agm. the Blaclc Death was linked with all manner of fanciful causes. or with minority groups. For in- stance. a woodcut of the times shows Jews bring rounded up and bumed because it was thought :h‘g‘tuda ___,_,.t-"‘ they were guilty of spreading the plague. :2, From an ecological viewpoint. plague is one of the most interesting infectious diseases because norv mally it is not a disease of humans at all—'l'he Black Death and the later episodes of bubonic plague were the unfortunate result of accidental association of humans with rats and with the fleas that accom- pany rat's. Although the plague was a mild disease of rats. when it spread to humans in the Middle Ages it assumed a new and particularly malevolent form- Why was it the "blank" Icleathill We now lrnow that the bactefluni that causes plague produces a toxin that muses the destruction of blood vessels. As the blood oozes from the capillaries into the surrounding tissues. hernorrhage and fluid accumu- lation occur. resulting in oedornatous swellings- Ga-ngrene develops. especially in the extremities. with vicious-looking blade lesions on the hands and legs- Although the worldwide epidemics of the plague have long since ceased. the disease is still found in numerous countries in Africa. Asia. North America and South America. in the first lit years of 12 ' CDLIN' MCE‘H'ED‘I" the 20th centmy, user 12 miliicm peeple died at the plague in India alune. There are still uccasiunal cases in the United States. generally cuncentrated in the Sunthwest and Recity Mauntain regions. asse- ciated net with ram but with wild redents. Amung the mere interesting ideas is the sugges- tiun that the bacterium which causes plague, t’er- st'm'e testis; may have changed its virulence in the centuries since the great sceurge at the Black Death. it is theu theught that the must successful disease- causing mumrgWs are these that liye in “har- many" with their husts. Elf what advantage is it In the pathogen tu lull its heat? Eeulutiunary success fur a pathugen requires that it multipIy and pruduce numeraus offspring and since enly when it is. in a living hust is the pathogen ahle tu grew and repre- duee. mmmen sense will dictate that killing the “grease that laid the gelden egg" :is net the prayer thing in tin. Many ecelegisls believe that in the early stages cut“ the deeelupment et a disease, the paths:- gen may he unusually virulent, but gradually re duces its trinilence as it hecumes :rnure '“adapteti'r in its hust. This type uf adaptatiun may have hap- pened. with Tersiuis pestist and. if set, this weltld explain why yiulent epidemics, such as that at the Black Death. nu lenger uccur. As with ether bacterial diseases. the advent all antihietics has changed. the whale medieai picture- Diagnusecl in time, therapy at plague is almust uni- versally successful- The must effective antihiutic is streptomycin, hut tetracycline, Itanarnyc'tn and sul- fadiaaine can else be used. Althuugh vaccines [see Sectiun II} fer plague are available. they are uniy used with people in high~rlslt areas, such as Iatiura- tery persennel wurlting with yinilent culhires. Fertunately, plague is primarily at histcirical inter- est thay. althflugh it was at cine lime censidered as a biulugical warfare agent {see Chapter 12}, but it teaches 1.IE much ahuut epidemics {see Chapter 11] —-huw they spread and hats they are centre-He'd. ...
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bubonic plague - The Bubonic Plague to}...

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