Blockchain Papers

Esteban Ortiz‐Prado, María Paz Cadena, Jorge Vasconez-Gonzalez, Juan S. Izquierdo-Condoy

Latin America and the Caribbean are a global hotspot for emerging and re-emerging infectious diseases, yet regional One Health preparedness remains uneven and incompletely operationalized. This narrative Mini Review synthesizes evidence published mainly between 2015 and 2026 on One Health preparedness for emerging infectious diseases in the region, emphasizing how environmental disruption and climate change shape zoonotic and vector-borne spillover risk. Available regional surveys suggest broad professional familiarity with the One Health concept but limited operational implementation, with environmental health frequently identified as the least-integrated domain. We argue that spillover risk—and the failure to detect and contain spillover once it occurs—should be understood as a system-level outcome shaped by ecological disruption, socioeconomic vulnerability, surveillance capacity, and governance, rather than as an isolated biological event: deforestation, agricultural and extractive expansion—including illegal mining and logging—unplanned urbanization, and climate variability generate new human–animal–vector interfaces, while fragmented governance, uneven and poorly decentralized laboratory capacity, and limited reservoir and environmental surveillance leave these interfaces unmonitored. Environmental and climatic drivers are robustly linked to spillover, although the pathways are disease-specific rather than universal, and socioeconomic vulnerability concentrates the resulting burden in Indigenous, rural, and marginalized populations. We identify priority gaps in integrated surveillance, decentralized diagnostics, genomic capacity, reservoir ecology, governance, financing, and equity, and propose an agenda for anticipatory, climate-informed, and context-sensitive preparedness.

Robert E. Lerner

Added to the list of scathing historiographical epithets we now have: “plague denier.” The opprobrium arises from a controversy about the biological nature of the pandemic of 1348–1349 commonly known as the Black Death. Was it bubonic plague? My present intention is to review this controversy with attention to fleas, literal and figurative. In a later part of this essay I then will pursue some fleas that infest other areas of current Black Death historiography. The plague controversy pits a majority of traditionalists, who believe that modern clinical descriptions of bubonic plague fit the epidemiology of the Black Death as reconstructed from fourteenth-century evidence, against a minority of rebels who propose that the modern plague and the medieval pandemic were different diseases. The traditionalists bask in certainty. John Aberth writes that “we know exactly” how the Black Death was spread because we know that it was caused by a bacterium that produces bubonic plague; John Kelly concludes: “about one thing we can be certain … the Black Death was an outbreak of plague.”1 And yet as a “denier” I will insist that such assurance is unwarranted. We are fully informed about the nature of modern bubonic plague. During a plague epidemic sweeping India, an officer of the British army compiled detailed hospital data in 1896–97. Then, in 1905, the British government established an “Indian Plague Research Commission” to gather clinical findings toward the aim of fighting the disease. Detailed reports were published regularly in The Journal of Hygiene in the years between 1906 and 1914. Traditionalists and deniers agree that these reports represent a “medical revolution in the understanding and nature of epidemic disease” as well as “models of interdisciplinary and comparative research.”2 This evidence demonstrates beyond dispute that the modern plague is a bacterial disease of rats communicated to humans by fleas. An apothegm to this effect, voiced in 1901 by one of modern science's greatest bacteriologists, Robert Koch, was quoted with approval in the first report of the Indian Plague Research Commission: “plague is a disease of rats in which men participate.”3 Humans, however, do not participate as a result of rat bites. Rather, it is the rat flea, forced to depart from the infected dying rat, which carries the plague bacteria to humans by means of a bite that regurgitates the bacteria into the human bloodstream. Once a human being is infected, the bacilli are carried by the lymphatic system to the lymph node nearest the site of the bite, where they multiply. After three to eight days the colonies of bacteria are large enough to cause swellings known as buboes, and three or four days after that the infection reaches other organs, usually causing death. The bubo, of course, is the most obvious symptom of eponymous bubonic plague. Because fleas find it easiest to bite around the ankles, the preponderance of buboes grow from the lymphatic node nearest the bite, namely the groin. According to the British records, between 55 and 75 percent of plague buboes were located in the groin, followed by 10 to 20 percent in the armpits and some 10 percent forming in other glands. Whether in the groin or elsewhere, in 94 percent of cases the buboes were found in only one location.4 The modern literature on bubonic plague often refers to a sibling, “pneumonic plague,” a disease of the lungs that results in frightful coughing. Here misunderstanding often arises because of the lack of proper distinction between “secondary” and “primary” forms. Secondary pneumonic plague is simply bubonic plague that has reached the lungs. Victims have buboes but also start coughing, and because they frequently cough blood they are likely to die from that. Modern research shows this happening in between 10 to 25 percent of bubonic plague cases. Before such victims die, however, they can infect others with their coughing, and recipients so infected may infect still others in the same manner. In other words, this is the primary form: true pneumonic plague, transmitted by coughing directly from human to human. Primary pneumonic plague is highly lethal, but in fact “too lethal for its own good.” Many of those infected die within a day, before having time to develop any cough at all, and those who do cough usually die within a day after they start coughing. Consequently human-to-human infection by means of coughing is minimal: the most serious incidence of primary pneumonic plague recorded by the British during the Indian bubonic pandemic of the early twentieth century resulted in a death rate of 0.4 percent of the population.5 This leads to one more salient point about the modern plague: contrary to common belief, bubonic plague as known since the nineteenth century is not highly contagious. In this regard it falls well behind other epidemic diseases such as measles, smallpox, or scarlet fever. An initial outbreak of plague in nineteenth-century China traveled extremely slowly, moving at about ten to twenty miles a year; observers in India noted that the disease seldom infected doctors or nurses; malaria there killed ten times as many people as the plague.6 It will already be evident that great discrepancies exist between the clinical evidence regarding modern bubonic plague and the numerous medieval accounts of the mid-fourteenth-century pandemic most familiarly known as the Black Death.7 For these reasons, clear-sighted twentieth-century historians had difficulty reconciling the modern and medieval data. To take one example, the prominent American medievalist David Herlihy conceded in an essay of 1974 that bubonic plague as known from modern observations is not highly contagious, whereas numerous medieval descriptions and the documented rate of spread of the Black Death leave no doubt of extraordinary contagion. To account for this, Herlihy offered the stand-in of the pneumonic which spread directly the In fact Herlihy not to have that the pneumonic is lethal to account for of but was not to a different to the pneumonic from coughing is most in but the medieval epidemic spread more in in the this as a and not from that the medieval disease was bubonic plague. in a in a of of published as a around to that true nature of the great medieval of historians the plague but it is one of who in has be its death In a of one by it can be that has the To this for we are not about not not not system be that is at is an of historiography. I have to a who has it be for I and as in one account and the Black Death of bubonic and pneumonic in I find most are the extraordinary in which different traditionalists to their of their and these are some of the fleas I to I will from literal fleas, to literal to we that the fourteenth-century disease was bubonic plague, then it had to have transmitted by rat fleas because we have that pneumonic plague account for and pneumonic plague in its and primary at any rate on infection by the bubonic plague fleas were the of they to have in that were not to The lack of between for fleas and incidence of the Black Death for and In the incidence of the disease during the and the fact that the rat has difficulty the as well as the of those the Black Death plague carried by fleas, its incidence have in areas with the and of and early to the for the first of the Black Death but for later that it in and John Aberth to account for this by the of around this this will not for as Aberth then in a is some about the was part of this may be an for the has not only that the in the but may also have had in the century one were to for the of that were during Black Death in it still be to account for the early to the of the lack of between the Black Death and the known of rat fleas at the other of the the of the is fleas do not in that are any more they do the And yet in of the Black Death in the of that the in around and most between and this is the of in a no in in and in In the of the Black Death on of Aberth that is no to a on the that fleas may in we have no about in medieval from modern it may to be in the of fleas that by the not be to cause a is the fact that Aberth to that areas have we on the of a incidence of a around and that of and were to be For this the only evidence is a noted report of the of the of which that was it to have however, this report was in of John Kelly to the rat with an the fleas were not rat fleas but human fleas. first this to be a because medieval people not and human fleas may have to whereas the rat in its and with the rat, the human is a This flea, that not on humans or in their but around and at to and this not with humans and be an of epidemic disease. plague was after in were for and that human fleas in not a of of plague by the human was against the Black Death as bubonic plague is on the of According to modern clinical records, as we have the preponderance of plague buboes is located in the groin. In buboes in armpits still lymph and the buboes only in a In the medieval evidence a different often large in the groin, they only more often they have in groin and and in three groin, and behind the or on the or that the groin, and are the of human lymph it is to believe that the Black Death was a lymphatic disease. the to buboes in or more is at with the modern evidence about a and the to armpits and the groin is not one about infection by it is can but they to do so a The incidence of buboes in the groin in modern plague cases is by the fact that rat fleas a are most likely to bite on or who a in the that are most likely to for the first the are not to of the medieval incidence of buboes on armpits or was so great that it leads to medieval people were to evidence in The has this to have that to be into account are for obvious reasons, were in fourteenth-century have before medieval who at into it will to some a of or some with the and to the bubonic plague I to to to be the greatest that or the lack of the that modern plague is disease of rats in which men and the that the plague will only spread from fleas to humans the death of one find many to of rats in medieval accounts the medieval pandemic had plague. in fact there are The first arises as to rats during the in some of the where the Black Death the human that they in on the of that rats do not in a that to a that the disease in was bubonic plague. the Black Death in in the and of its incidence in and data for to the of any that rats in but that they were not present in the that the of the Black Death in the evidence to the that plague in was bubonic plague transmitted by rat The is that this on a that rats rats do not on the Black with some The this is because to only the initial incidence of the Black whereas the was from that first to the evidence of of the epidemic in from or the of rats in in the to do all, regarding the of rats in the for a that but no of I to The of the in for rats in of was the Black Death. rats from this have found by and lack of rats are of is a of the by a from which that many exist in but no the other is an account published in that rats at only one and then to that they had on a may that of or have followed a in the is by that the of an in The The only had one of any are to be with the as that this to a on the of by one I have found it to the and In The of into from the and published in the but that there are no fleas in According to on the is with … the only thing of the are … where is a great many will gather about … no other of are also has a that are a great many in this for as are to a of in their the find not a about have To the in of “plague is the lack of any in the to rat of the fourteenth-century Because rat fleas will only leave their the rats have there have of rats in mid-fourteenth-century and but no The we is a from a about the spread of the Black Death on the not men but many with and by and and the of the rats that to within the of the can be this is not a to rat the human or to the of large of rats any more of large of or the death of rats the death of humans and the report is which is it the plague for modern observations have that and are to the bubonic plague in being for rat an by a of the Black Robert who that of the reports the medieval disease with a of and enough the as with John who that to rat are John on the to that of medieval … rat in with the of three one is the and a that of the Aberth refers to a from in which in refers to the by a And we find a list of that the had on and To on this as with the plague is not only because of the of rats with and but also because in fact is of rat is from the of can to this within and there they will find the to that in some is which is an of some as as eight and with some and some … and those who against the to their will this as a account of a also from the in and so do the of account is more for the is is that an of as large as a having eight by the on those who to the bubonic plague now to the of In a of published the results of a on of from found in human in where of epidemic victims had located from the the To they that to that of the modern plague was found in of their and that “we have the of the disease at the of the century in After the report was on the the in This time they located a fourteenth-century and found results from from one and to “we believe that we can the medieval Black Death was in of this time from in from in fourteenth-century and found no of the plague According to the of this “we plague as the cause of the Black but now there is no evidence for to that the are being now but the is by the of a that after the British with from research in and as well as and the this is to an between modern and a pandemic that before the twentieth there are I have not with but it that no was the epidemic disease that so in the who of the plague to be they can this to to be the a early was to that the epidemic disease was it was but because those who then to the of that the disease was not plague. for are the that medieval were not and that most had a for the in the that their reports often in The medieval evidence only to be that the Black Death was extremely contagious, extremely and by of swellings of lymph to have but not and many other and were also may and that we had clinical data from the we still not be to the or that caused the Black for as diseases David Herlihy was to that is not at certain that the diseases we are the same that one of the for such a about the Black Death was plague: that for the is that of people a I the to for the are no one the that in the century was and had the in the and but around had reached its the was such as and to have in the first of the but these not the to any And then to as great one to with the of the Black Death was to the disease had bubonic plague, that be for such plague be an An from the of infected rats have at any time some and a where the disease had then more the of the The is by no means to and The evidence, to be is a between and the great a that who was by to the of the was a not about a century after the to be on that at the time of the plague was with people it had the by to a of the that to the plague by believe that no more twenty of a had or any and those who had people on and the of … and the was of people who around how their were discrepancies in incidence between and one noted that and were the of the and that the and common people die in great such are to be as an data. from on the and in an of the the was about for or who to the bubonic plague is to the of of and on the I do not propose that the is in of the of the Black Death after the first great incidence be a it to that historians of the bubonic plague they pursue the of and as to great with more they have To now from epidemiology to one of to the plague was David Herlihy refers to writes that of to in and John Kelly refers to and in the the exist but it is to to of the of evidence with which we are from the of in the of The for the Black Death the During the time of the of were on a of to they to an where they men and to the of and and into the for this, they were that the plague has not we that will it and this is we are the traveled their and to the same where they found with the had they the the of in a … so that some people were killed by it and others of not where to or which to this be but a for by And yet John Aberth that it to a in that and was by an who in the we are and their and or and had to The of a on the on and its may be that it is in of this of and and that is by as In the same we find by the John of about in After of during the of the in people to in but and no the of the who to a of For they that not their or their about men with as as a from as well as or who and and the this not To that the Black Death in the David Herlihy the to the … to the most and … they in their into the of into and they into this not in for other and of the the same or as has is a with of to the point a is of Herlihy also refers to in in the of a site on by the in to for and the Black Death the Herlihy as evidence is a of of on the and And since the from it of in the caused by a epidemic of some It is to about for historians the to this great as one of the most accounts of to the Black Death on which we can According to some people in to the of the epidemic by and but others the and that an of this was to to the around and as and the thing as an and they they to the of their historians to in is that whereas at to be the offered as a of We to be of that be at in a so to the to do not account of to the Black Death to be For plague in the the of in of the of the of Robert to of in that will be the of a and and that the at was in a as was at the same for the is the of a which from not to at to the as well as of to be or to in with To be we are not to of the to and any more we are to the as an of but we do to of as and in this the that people by the of death by their as John Kelly from to For the of and after the Black Death of a that only a had so so for for to into an to and and The not be for a of only Kelly had for of the only however, is the in the the Black a in a that is a The of to from later as they were of the Black Death is not Because for the of the pandemic often find for a they to it with the one and then caused In the of this often is to that the Black Death to an with death and and that it to the the it be conceded that large of and evidence do an with death and in the The is that one can find of the same of evidence the century and more of the same in the An for the is the of three and the three of this to which three men on are with the of their own in of is found in a of in the in the great this the of the in with account of and in in and after the Black a has that the was And not only the three and the three can be in numerous other of the Black a in the of in the of the In to who simply in others to evidence they know well from later the century in to how the Black Death an of with death. of the on the The Black the by the on their an of death on an at an This fit the Black Death were it not for the fact that the was to a century after the Black at a time of the had in but still is the of a with the The Black The of which shows death as a on in an from the from about it is often are not for the of but John the of the with the evidence to the to the pandemic of that the first known of the of was in and that from but still to that such how of Death to the of the Black to the a of a from to the same Aberth also on namely that with or that the of these from the and from this who intention in to those that the first outbreak of the Black Death in not be from the and later had evidence of the same from the of the it be that of the to to an of is to of the and as to the I that on or in to a may well have some with the in the was not that after the which was not that after the it is to in an extremely that had to do with the at in of a it may be still more to that because of of the Black Death in from the time of the initial the early one well an so one that the is a that in we to one is of the most is the lack of and after the greatest in a different of the Black Death is to be Here is the by Black Death to have the of the that it not into the Modern The one be more can be at by that there was more there have more a in was already in the of the century any for the refers not only to more but also to a on and that the also a in from to with the of of it is to how to the have had any on such to John to a Black Death of which to have by the of with of The is that around at the time of and followed its own as in the of with no obvious to the incidence of Aberth that a between an of and highly in of of medieval and in the years during and after the Black David Herlihy a not found to the Black Death with of of and on the Herlihy four between and but one of because Herlihy have was in as For the is only had no at between and and between and there to a toward the is for the for the of the of in this is and because the Black Death may not have it that only after the of Herlihy as a for the of but this on the of a that was not into that other were in the and early the in the of the no in and at these in were often Herlihy the in were at any rate to the after at the of the of in this was by the in that in was its by the the such as or and was a of the with the more is so that it to be in but for the of it For the Black Death a in the of and was for an of in at the that in a in the at in an to the not to its medieval but to its The of was a to the In other more more the The is yet more the Black and since the is one of the of the to and since of a in the plague the for then the is not but toward the in the common there may have the that the Black Death was the of the of the It was time to on with the and that it is time to this doubt a of the Black Death is still that it is it will the bubonic plague and some common into the of