tag:blogger.com,1999:blog-3492197469143963742.post4671704258549886012..comments2023-06-13T04:45:22.434-04:00Comments on Infection Landscapes: PlagueMichael Walshhttp://www.blogger.com/profile/05038031388622939797noreply@blogger.comBlogger44125tag:blogger.com,1999:blog-3492197469143963742.post-83552358957794611442016-03-18T10:56:48.803-04:002016-03-18T10:56:48.803-04:00I found the discussion regarding how fleas jump qu...I found the discussion regarding how fleas jump quite fascinating. Hey, I never even thought of fleas as jumping, let alone did i ever wonder if they used their knees or feet to jump.Shmuelhttps://www.blogger.com/profile/16321894818345397249noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-27102169802901565572016-03-18T10:54:36.088-04:002016-03-18T10:54:36.088-04:00First, I enjoyed the introduction, which I ask why...First, I enjoyed the introduction, which I ask why you call it a hyperbole? Its important! Albeit not characteristic of the other article I read on Landscapes. <br />I found it interesting that with the spread of goods comes the spread of evils. As soon as humans started traversing the globe to new locations, disease was brought with them. Perhaps one can argue the really “vector” is trade (business)! <br />I also found the relationship between the fleas and the Y. pestis interesting in that it is an antagonistic relationship for the fleas and they end up dying from Y. pestis if they don’t clear it. It is the very harm that requires the flea to infect humans. If the flea would not be effected by Y. pestis, it wouldn’t have to regurgitate the blood and mix its own blood with that of the human. <br /><br />Shmuelhttps://www.blogger.com/profile/16321894818345397249noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-76323907383161011082016-01-27T21:25:59.610-05:002016-01-27T21:25:59.610-05:00Hi Edith,
I chose this post because I just finish...Hi Edith,<br /><br />I chose this post because I just finished the book "Rats" by Robert Sullivan and he makes a number of arguments in favor of vector borne Y. pestis as the culprit for those plagues attributed to it. One interesting one is the correlation of surplus crop years to outbreaks of plague. This would be related to an increase in the rat population.<br /><br />While pneumonic transmission and other diseases (anthrax seems to be a popular alternative theory) could have played a role in the high death rates, it's worth remembering just how many rats there are living anyplace that humans do. The CDC still today does surveys of the NYC rat population to check for, among other things, plague infections.Max Mecklenburghttps://www.blogger.com/profile/18413082131755339117noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-90708706642936200372016-01-27T17:01:40.200-05:002016-01-27T17:01:40.200-05:00But wasn't the Black Death the plague in its p...But wasn't the Black Death the plague in its pneumonic form? Since people lived in such close quarters during that era, it would have been easy for a pathogen manifesting in lung secretions to be passed to someone else via coughing or talking. The pneumonic form of the plague is very contagious and with people not practicing or even knowing about proper hygiene practices back then, it is quite conceivable that pneumonic plague could have spread so quickly, to so many people. Anonymoushttps://www.blogger.com/profile/13872756155519670878noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-45642982043680633522016-01-22T19:51:46.361-05:002016-01-22T19:51:46.361-05:00I am convinced that there are two different diseas...I am convinced that there are two different diseases here. Y pestis causes bubonic plague which is still around, but the Black Death had different symptoms, different transmission and very different mortality rates. I think this is very important to clarify because we should know exactly what caused a third of humanity to be wiped out.<br /><br />A Journal of a Plague Year was written by Daniel Dafoe about living through the 1665 outbreak in London. I read this during the recent Ebola outbreak and I couldn't help associating the two. I think the Black Death was far more likely to be a viral hemorrhagic fever spread through human contact than Bubonic plague. I have also read that researchers have studied early Parish records in England to understand the mortality patterns which fit more with a human contact disease than a vector-borne.<br />Anonymoushttps://www.blogger.com/profile/07792996651771706535noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-80541509344907570002016-01-22T12:35:23.716-05:002016-01-22T12:35:23.716-05:00From a genetic standpoint, are there any known mec...From a genetic standpoint, are there any known mechanisms/genes that allow the reservoir, i.e. the rat, to survive while the bacterium flows in its bloodstream? Anonymoushttps://www.blogger.com/profile/13872756155519670878noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-77098723864180982112015-11-20T01:58:59.800-05:002015-11-20T01:58:59.800-05:00As Rukhsana suggested, I also reviewed the case i...As Rukhsana suggested, I also reviewed the case in Colorado in which a girl with disseminated intravascular coagulopathy due to severe Yersinia pestis infection survived as a result of re-interviewing the family into her risk factors. Knowing that septicemic plague is extremely severe and is fatal if not treated, her survival can be attributed to the medical staff diligence and the benefits that come as a result of advanced medical support. I was also wondering why there are not more cases in the US, more than the 10 or so a year? In contrast, what makes the Democratic Republic of Congo so vulnerable? The WHO reports that the Médecins sans Frontières is actively working to assess the situation and provide support. Despite isolation wards, contact tracing and chemo-prophylaxis of close contacts, control measures have been difficult to implement because of security concerns in the area. (http://www.who.int/mediacentre/ factsheets/fs267/en/) I was thinking that one solution could be to vaccinate the communities that are at high risk, similar to the way vaccines are used to protect high risk laboratory personnel. Anonymoushttps://www.blogger.com/profile/06851929241182903843noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-73383610843770786992015-09-18T12:14:15.653-04:002015-09-18T12:14:15.653-04:00This was definitely an interesting read that has c...This was definitely an interesting read that has changed my perception of what the plague actually is and how it works; from the primary reservoir host and their fleas to humans. Prior to reading this post, when I heard the word “plague,” I immediately thought bubonic plague where the Y. pestis invades the lymphatic system and people get the “signature characteristic” of the swelling of the lymph nodes (buboes). Nonetheless, I did not consider that there are actually three distinct clinical manifestations of plague (bubonic, septicemic and pneumonic plague). The septicemic plague (bacteria enters the blood) requires treatment within 24 hours of infection since it can lead to an extraordinarily rapid death and the pneumonic plague, which is “extremely contagious directly between humans via airborne transmission,” has a case-fatality similar to that of septicemic plague (close to 100%). Another interesting point I was not aware of is that in order to comprehend the epidemiology of plague, the geographic distribution of enzootic disease must be examined. It is crazy to know that the plague represents some of humanity's first experiences with pandemics, from the Justinian Plague to the Black Death, which affected more than 100 million people. Even today we can see how deadly the plague can be where even though few cases are reported yearly, there are still unexpected ones such as the Taylor Gaes case, where the 16 year old contracted the septicemic plague from fleas on a dead rodent or another animal on the family's land and died. However, there are other cases, such as that of a Michigan resident that contracted the rare life-threatening bubonic plague, who is thankfully recovering after hospitalization and diagnosis (first ever bubonic plague case confirmed in Michigan). According to the CDC’s MMWR from August 28, 2015, there have been 11 cases of human plague reported in residents of six states since April 1st, including: “Arizona (two), California (one), Colorado (four), Georgia (one), New Mexico (two), and Oregon (one)” (2015). The links for these two cases and the CDC’s MMWR are: http://www.freep.com/story/news/2015/06/20/officials-say-rare-form-plague-killed-poudre-student/29031569/, http://www.freep.com/story/news/health/2015/09/14/bubonic-plague-case--michigan/72273070/, and http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6433a6.htm. <br />Anonymoushttps://www.blogger.com/profile/10812728419197385223noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-30680422490066028992015-09-17T23:11:35.802-04:002015-09-17T23:11:35.802-04:00I have always found the Plague to be a fascinating...I have always found the Plague to be a fascinating disease. Like this post states, it brought millions of people to death, and at one point, it wiped out 25% of the global population. As of late, there have a been a smattering of cases of human plague reported in West/Southwest in the US. According to an MMWR in late August of 2015, 11 cases were reported since April 2015 in the US. The WHO has also declared an outbreak of the plague in Madagascar with 14 reported cases and 10 deaths as of August 30th of 2015. It seems like there are these satellite outbreaks of the plague which tend to fizzle out. This seems to be in direct relation to how it’s relatively rare. Unfortunately, like many infectious diseases, this disease is closely related to poverty and poor living conditions. While I’m assuming that elimination is impossible for a disease like this, if public health officials and policy implement interventions to reduce disease risk through proper sanitation, house disinfection, and vector control, could the disease burden be reduced to virtually nothing?Anonymoushttps://www.blogger.com/profile/14455301455977148925noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-20211216215005660042015-09-11T16:36:00.024-04:002015-09-11T16:36:00.024-04:00This article is informative and I also found the p...This article is informative and I also found the points you listed to be interesting too. I am not sure if they are listed in a particular order, but what you listed as number one stood out to me the most. Other comments to this article also include fascination about the history of plagues.<br />Plagues are beyond detrimental compared to typical pandemics and devastating morbidity and mortality. History is important when understanding the first occurrence of a human pandemic which was considered a plague. The article mentions that one of the first pandemic disease, were the wide trade routes across extremely large geographic landscapes bringing their goods and disease. It is interesting to see a reoccurring theme. The second plague pandemic known as the “Black Death” was also due to movement of people along trade routes. Also, it is stated that the current plague pandemic was widely distributed as bubonic plague by shipping routes, and rats carried aboard transported the plague bacteria to various ports. Although there are other modes of transmission, it is a good demonstration of how history repeats itself with the first few plagues. <br />CassandraDhttps://www.blogger.com/profile/11409445804775833571noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-86962991527679916192015-09-10T23:27:28.737-04:002015-09-10T23:27:28.737-04:00I would add this for the black death that swept Eu...I would add this for the black death that swept Europe in the 14 century:<br /><br />"This dramatic fall in Europe’s population became a lasting and characteristic feature of late medieval society, as subsequent plague epidemics swept away all tendencies of population growth. Inevitably it had an enormous impact on European society and greatly affected the dynamics of change and development from the medieval to Early Modern period. A historical turning point, as well as a vast human tragedy, the Black Death of 1346-53 is unparalleled in human history." <br /><br />http://www.historytoday.com/ole-j-benedictow/black-death-greatest-catastrophe-ever#sthash.vgTIEonH.dpufAnonymoushttps://www.blogger.com/profile/01959289654941672974noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-24558432829353599972015-09-10T23:15:56.816-04:002015-09-10T23:15:56.816-04:00I would add that it's because the fall of Ital...I would add that it's because the fall of Italian city states and the depopulation of southern and central Europe, the ottomans were able to invade Constantinople, and the Spaniards Andalusia. These 2 events are very significant to shaping the world as we know it now. Anonymoushttps://www.blogger.com/profile/01959289654941672974noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-37751981040524867932015-09-03T13:52:08.190-04:002015-09-03T13:52:08.190-04:00Very informative article! I did not know that the...Very informative article! I did not know that the second pandemic plague claimed the lives of approximately 1/2 and 1/3 of the populations of China and Europe, respectively.<br />A few things I found interesting were:<br />1. The historical context surrounding the first and second pandemic plagues.<br />2. The animated graphic showing the spatial-temporal spread of the Black Death.<br />3. The detailed description of how fleas transmit Y. pestis and the explanation of the antagonistic relationship between the flea and Y. pestis.<br />4. The clip about the life cycle of a flea.NBhttps://www.blogger.com/profile/07062917683379409807noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-9321654327163088112015-07-23T08:41:51.547-04:002015-07-23T08:41:51.547-04:00I too find this worrisome especially if pneumonic ...I too find this worrisome especially if pneumonic plague reaches the prevalence it did in the 15th century. A fundamental aspect of identifying an outbreak is gaining a handle on clinical manifestations and if physicians are unable to differentiate between traditional pneumonia infections (typically treatable in otherwise healthy individuals with access to healthcare) and pneumonic plague it can be quite problematic. Generally physicians won't have the time or means to exhaust all tests and take unnecessary cultures to rule out plague when it is not endemic of a region.Anonymoushttps://www.blogger.com/profile/16624706820510231248noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-65430199412589999722014-11-14T10:12:35.851-05:002014-11-14T10:12:35.851-05:00Hi Ashley,
It's really hard to distinguish be...Hi Ashley,<br /><br />It's really hard to distinguish between the two. If the local doctors are not used to seeing plague, odds are they will not be able to identify it (like many other diseases). It seems that the only way to fully determine the presence of pneumonic plague is to conduct a culture - which unfortunately may prove to be too late for the infected individual and many of the potential secondary transmissions. <br /><br />Establishing control measures is also extremely difficult. With the proliferation of fleas among sylvan and domestic animal hosts, control becomes damn near impossible. The best thing we can hope for is making sure no areas have enormous population densities and individual based rodent control (e.g you set up traps and prevent infestations). Which is why, I think. even though the United States has the most number of foci, it has a minimal incidence of disease. The specific parts of Africa mentioned above, however, are not as fortunate. Richard Shttps://www.blogger.com/profile/07809743197514220377noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-67377683553618780682014-10-22T16:39:20.538-04:002014-10-22T16:39:20.538-04:00How can one distinguish between normal cases of pn...How can one distinguish between normal cases of pneumonia and pneumonic plague out side of its initial transmission through infected rodent contact. Based on the secondary transmission from human to human from droplet transmission, how is one able to tell? Also, I was shocked to see that there have been recent cases this past summer, one in Colorado and in China. What measures have been taking or may be currently in development, in preventive from more cases from spreading? Anonymoushttps://www.blogger.com/profile/09151898896031061829noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-74305727377661015722014-09-19T13:55:33.558-04:002014-09-19T13:55:33.558-04:00I am interested in how several waves of this disea...I am interested in how several waves of this disease outbreak had a major impact on the course of European and world history and the rise and fall of different empires.<br /><br />Looking through some online resources, mostly Wikipedia☺ I read some about that and here is a sample of what is out there,<br />“The plague's long-term effects on European and Christian history may have been enormous. As the disease spread to port cities around the Mediterranean, the struggling Goths were reinvigorated and their conflict with Constantinople entered a new phase. The plague weakened the Byzantine Empire at a critical point, when Justinian's armies had nearly retaken all of Italy and the western Mediterranean coast; this evolving conquest would have reunited the core of the Western Roman Empire with the Eastern Roman Empire. Although the conquest occurred in 554, the reunification did not last long. In 568, the Lombards invaded northern Italy, defeated the small Byzantine army that had been left behind, and established the Kingdom of the Lombards. This began the fragmentation of Italy, which lasted until the Risorgimento of the 19th century.”<br />I will do a more detailed research regarding the effect of major disease outbreaks on history of the world and keep you posted ☺<br /><br />Usama Wissanoreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-36125626214134922142014-07-24T13:01:09.371-04:002014-07-24T13:01:09.371-04:00Hi Mohammad,
I just read this article too and was...Hi Mohammad,<br /><br />I just read this article too and was going to make similar comments on the handling of the situation by the Chinese government. Like you mentioned the man didn't die from the pneumonic plague infection which can spread from person to person and this precaution of quarantining those infected will not help with the actual prevention of the bubonic plague. I think there is a political aspect to this case in particular since it does involve China and this response is more to alleviate fears and the mention that they are providing supplies is to show that they are providing for these people. However, looking at it in the public health prospective, this man was in contact with a dead marmot which he fed to his dog and there is no additional cases. I think its interesting like you mentioned how even today that there is still this fear of just the mention of the "plague" to cause such a response <br /><br />http://www.huffingtonpost.com/2014/07/22/china-bubonic-plague-death-yumen_n_5609908.htmlAnonymoushttps://www.blogger.com/profile/13004424672438793997noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-49303662591402733782014-07-23T16:31:16.936-04:002014-07-23T16:31:16.936-04:00I found this article especially interesting in lig...I found this article especially interesting in light of the report of a man dying from the bubonic plague in China recently (1). As Professor Walsh mentions in the article, there is an overwhelming visceral response to hearing about the plague. Chinese authorities have blockaded the town where the case occurred in attempts to stem mass panic as occurred in India’s epidemic in the 1990s. The town has enough basic food supplies to last a month and is setting aside 1 million yuan ($161,200) for an emergency program to vaccinate citizens (2). They have also quarantined the 151 people who had direct contact with the man. As professor Walsh mentioned, such exaggerated responses may be costly if the man did not die of pneumonic plague, the type that is able to be transmitted between humans. Of more concern to authorities ought to be controlling the threat of human transmission from rodents, or in China’s case, marmots (a large squirrel). <br /><br />(1) http://sinosphere.blogs.nytimes.com/2014/07/23/town-in-northwest-china-sealed-after-man-dies-of-plague/ <br />(2) http://www.dailymail.co.uk/news/article-2701641/Parts-Chinese-city-quarantined-resident-dies-BUBONIC-PLAGUE-bitten-rodent.html<br />Mohammad Raohttps://www.blogger.com/profile/07745537034237857591noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-4715644876827931932014-07-23T04:42:55.136-04:002014-07-23T04:42:55.136-04:00I heard about the plague, but didn’t realize how s...I heard about the plague, but didn’t realize how severe it was. Reading this article and taking note of the statistic, that is, wiping out 25% of the human race is beyond belief. <br />I want to add a little with respect to diagnosis and treatment because as I was reading, I wanted to know, apart from identifying symptoms, how can we confirm that it is the plague and once confirmed or suspected, what is the treatment? <br />For diagnosis, specimen should be taken directly from the suspected source for culture (including blood, sputum, bronchial/tracheal washings and lymph node aspirate). <br />Staining and direct visualization under a microscope is mostly used. “Visualization of bipolar-staining, ovoid, Gram-negative organisms with a "safety pin" appearance permits a rapid presumptive diagnosis of plague.” <br />Serologic testing may also be done to confirm diagnosis. <br />For treatment – given that it is a gram negative bacteria, antibiotics that target gram negatives should be used. The drugs of choice are Streptomycin or Gentamycin. However, if these are not available, tetracyclines, fluoroquinolones and chloramphenicol may be used. The usual course is 10 days. <br /><br />Reference: CDC: Plague – Resource for Clinicians. Accessed at http://www.cdc.gov/plague/healthcare/clinicians.htmlHarry Persaudnoreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-49600225455359552014-07-23T04:18:01.284-04:002014-07-23T04:18:01.284-04:00Sarah and Wen D, I do agree with both of you in re...Sarah and Wen D, I do agree with both of you in regards to how the US suppress this disease. The availability of a wide range of laboratory testing and antibiotics is a huge contributor when compared to countries without these luxuries. <br />From the stand point of a medical provider, I must say that on initial assessment of a patient with the plague, it would be very difficult to diagnose for two main reasons: 1. without the pathognomonic lesion, the symptoms are very similar to many other diseases; 2. given that the disease is so rare (in this current age), one would not think about the plague as the initial diagnosis. <br />Especially in the emergency room, when the source of infection is unknown, most patients are started on broad spectrum antibiotics to cover for both gram positive and gram negative bacteria, until they have full workup. With this in mind, I wonder if the prevalence is higher in the US, but are just masked by the way we practice medicine. <br />Another factor to note is that for most part, the US has a good sanitation system leaving little room for rodents to breed and live. In addition, most other host animals such as dogs and cats are domesticated (and not wild) with good hygiene, leading to a significant decrease in flees. Harry Persaudnoreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-72882517306999956902013-11-14T20:34:14.220-05:002013-11-14T20:34:14.220-05:00Wen I think your suggestions as to why the US main...Wen I think your suggestions as to why the US maintains such a low incidence are spot on! We have the advantage of having advanced medical knowledge and technology that help quickly identify the disease and media coverage allows people to become aware of what is going on.Sarah Celestinhttps://www.blogger.com/profile/07678443321439290649noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-51690780207813614612013-10-11T15:23:05.701-04:002013-10-11T15:23:05.701-04:00I think the “Black Death” seems more deadly compar...I think the “Black Death” seems more deadly compared to the modern plague because 1) pneumonic plague (based on the article) facilitated the rapid spread of the disease among populations; 2) many deaths resulted from the lack of proper treatments as the case-fatality of pneumonic plague is very close to 100% if untreated. While reading the article, I was wondering how the US is able to maintain human cases of plague at a lower number even though it has “the largest enzootic foci of Y. pestis in the world”. But I think in addition to the environmental factors and advanced medical knowledge, the readily available resources and the full media coverage of an re-emerging case as Rukhsana mentioned earlier help the control of the disease. Anonymoushttps://www.blogger.com/profile/17602518758241358960noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-7947998546675507062013-10-02T20:39:53.487-04:002013-10-02T20:39:53.487-04:00Sheaba Daniel
I am shocked, like other readers, th...Sheaba Daniel<br />I am shocked, like other readers, that the plague is a still present disease. The way that it was taught in history class, it seemed as if the Plague was a disease of the past.<br />It is interesting to note that Y.pestis has changed very little over 600 years. <br />I wonder if there is any scientific evidence as to why the "Black Death" strain was so deadly compared to the modern strain. other than changes in hygienic and environmental factors.SDanieltkhttps://www.blogger.com/profile/09452298091227184564noreply@blogger.comtag:blogger.com,1999:blog-3492197469143963742.post-88508261502424907332013-09-11T23:11:28.326-04:002013-09-11T23:11:28.326-04:00From what I have read it appears that Y. pestis ca...From what I have read it appears that Y. pestis causes a blockage essentially starving the flea. The bacteria is regurgitated by the flea while feeding on the host and that is how it enters the body. For the most part fleas die from starvation and dehydration, but it has been found that when the temperature rises, the blockage is less likely to occur in the first place which might be why some fleas survive.Sarah Celestinnoreply@blogger.com