scholarly journals The Influence of Time-Limited Immunity on a COVID-19 Epidemic: A Simulation Study

2020 ◽  
Author(s):  
Robert J. Kosinski
Keyword(s):  
Simulation Study ◽  
Recurrent Disease ◽  
Disease Outbreaks ◽  
Disease Prevalence ◽  
Epidemic Disease ◽  
One Year

AbstractA series of spreadsheet simulations using SEIS, SEIR, and SEIRS models showed that different durations of effective immunity could have important consequences for the prevalence of an epidemic disease with COVID-19 characteristics. Immunity that lasted four weeks, twelve weeks, six months, one year, and two years was tested with pathogen R0 values of 1.5, 2.3, and 3.0. Shorter durations of immunity resulted in oscillations in disease prevalence. Immunity that lasted from three months to two years produced recurrent disease outbreaks triggered by the expiration of immunity. If immunity “faded out” gradually instead of persisting at full effectiveness to the end of the immune period, the recurrent outbreaks became more frequent. The duration of effective immunity is an important consideration in the epidemiology of a disease like COVID-19.

scholarly journals Plague and the Fall of Baghdad (1258)

2021 ◽  
Vol 65 (2) ◽  
pp. 157-177
Author(s):  
Nahyan Fancy ◽  
Monica H. Green
Keyword(s):  
Fourteenth Century ◽  
Thirteenth Century ◽  
Disease Outbreaks ◽  
Epidemic Disease ◽  
Late Medieval ◽  
Western Asia ◽  
Abbasid Caliphate ◽  
Historical Accounts ◽  
A Minor

AbstractThe recent suggestion that the late medieval Eurasian plague pandemic, the Black Death, had its origins in the thirteenth century rather than the fourteenth century has brought new scrutiny to texts reporting ‘epidemics’ in the earlier period. Evidence both from Song China and Iran suggests that plague was involved in major sieges laid by the Mongols between the 1210s and the 1250s, including the siege of Baghdad in 1258 which resulted in the fall of the Abbasid caliphate. In fact, re-examination of multiple historical accounts in the two centuries after the siege of Baghdad shows that the role of epidemic disease in the Mongol attacks was commonly known among chroniclers in Syria and Egypt, raising the question why these outbreaks have been overlooked in modern historiography of plague. The present study looks in detail at the evidence in Arabic sources for disease outbreaks after the siege of Baghdad in Iraq and its surrounding regions. We find subtle factors in the documentary record to explain why, even though plague received new scrutiny from physicians in the period, it remained a minor feature in stories about the Mongol invasion of western Asia. In contemporary understandings of the genesis of epidemics, the Mongols were not seen to have brought plague to Baghdad; they caused plague to arise by their rampant destruction. When an even bigger wave of plague struck the Islamic world in the fourteenth century, no association was made with the thirteenth-century episode. Rather, plague was now associated with the Mongol world as a whole.

The Leclerc Expedition to Saint-Domingue and the Independence of Haiti, 1802–1804

2019 ◽  
Author(s):  
Philippe Girard
Keyword(s):  
Yellow Fever ◽  
Black Population ◽  
Great Difficulty ◽  
Epidemic Disease ◽  
Napoleon Bonaparte ◽  
Saint Domingue ◽  
Toussaint Louverture ◽  
One Year

In December 1801, First Consul Napoléon Bonaparte sent a massive expedition to the French colony of Saint-Domingue (today: Haiti). His goal was to restore direct French rule and overthrow Toussaint Louverture, a former slave who, as governor general of Saint-Domingue, had been suspected of plotting independence. Bonaparte’s secondary goal may have been to reinstate slavery, which France had abolished in 1793–1794. Bonaparte’s brother-in-law, General Victoire Leclerc, headed the expedition. After landing in Saint-Domingue in February 1802 with 20,000 troops, he managed, with great difficulty, to defeat Louverture’s army. He then deported Louverture to France, where he died in exile. In August 1802, however, resistance intensified as plantation laborers became convinced that the French intended to restore slavery. Leclerc, who lost much of his army to yellow fever, embraced increasingly murderous tactics against the black population until he died in November 1802. For one year, Leclerc’s successor, General Donatien de Rochambeau, battled Louverture’s successor, General Jean-Jacques Dessalines, in a brutal conflict with genocidal overtones. The bravery of Dessalines’s troops, lack of support from France, epidemic disease, and the renewal of Britain’s war with France eventually doomed the French effort. After the departure of the last remnants of the Leclerc expedition, Dessalines declared the independence of Saint-Domingue, now known as Haiti, on January 1, 1804, and then put to death most of the remaining French planters.

Utility of neutrophil to lymphocyte ratio in predicting colorectal cancer prognosis at a VA hospital: Do stage and sidedness matter?

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16110-e16110
Author(s):  
Kee-Hwan Michael Kim ◽  
Darren Gemoets ◽  
Maithao N. Le
Keyword(s):  
Colorectal Cancer ◽  
Recurrent Disease ◽  
Disease Free Survival ◽  
Free Survival ◽  
Lymphocyte Ratio ◽  
One Year ◽  
Stage 1 ◽  
Disease Free ◽  
Worse Prognosis ◽  
Time Of Collection

e16110 Background: Pretreatment neutrophil-lymphocyte ratio (pNLR) has been shown to associate with prognosis in patients with colorectal cancer (CRC). We asked if pNLR equally predicted prognosis in CRC regardless of stage and tumor location. We also asked if pNLR changed with time, especially within one year of diagnosis. Methods: Retrospective clinical data including age at diagnosis, pathological stage, location of tumors, treatments, disease free survival, NLR at one week, three months, and one year (if available) pretreatment of 934 veterans treated for CRC at one Veteran Affair Medical Center between July 1995 and December 2011 were collected. Disease-free survival (DFS) were analyzed using Kaplan-Meier analysis and compared using the log-rank test. pNLRs were grouped into three categories: less than or equal to three, greater than three and less than or equal to five, and greater than five. Univariate and multivariate Cox regression analyses were used to identify the prognostic value of pNLR. Boxplot analysis was used to evaluate the changes in pNLR over time. Results: In patients with stage 1 or stage 4 CRC, pNLRs of more than 5 and not between 3 and 5 predicted worse prognosis. In patients with stage 2 or 3 CRC, pNLRs did not correlate with prognosis. Interestingly, for patients with recurrent CRC after curative treatment, NLRs obtained prior to treatment of recurrent disease of more than 3 associated with worse prognosis. In subgroup analysis, we found that in patients with stage 1 or 4 left side colon or rectal cancer (LCRC), pNLRs of more than 5 but not between 3 and 5 predicted worse prognosis. In patients with stage 2 or 3 LCRC, NLRs obtained prior to treatment of recurrent disease did not correlate with prognosis. Similarly, for patients with recurrent LCRC after curative treatment, NLRs obtained prior to treatment of recurrent disease of more than 3 associated with worse prognosis. pNLRs did not correlate with prognosis in patients with right side colon cancer (RCC) regardless of stage. When comparing NLRs obtained at 1 year, 3 months, and 1-week pretreatment, boxplots showed a gradual increase leading up to the time of treatment suggesting that NLR changes according to the time of collection. Conclusions: In our large retrospective study, the role of pNLR in predicting oncologic prognosis differed according to the stage and the sidedness of the CRC. In addition, the value of pNLR varied depending on the time of collection. These findings suggested a complex relationship between immunologic parameters and oncologic survival.

scholarly journals Farmers' perception of the epidemic of African Swine Fever in Nigeria

2021 ◽  
Vol 29 (2) ◽  
pp. 217-225
Author(s):  
K. Adebayo ◽  
O. S. Sorungbe
Keyword(s):  
Significant Relationship ◽  
Disease Outbreaks ◽  
African Swine Fever ◽  
Sampling Technique ◽  
Primary Data ◽  
Extension Agents ◽  
Epidemic Disease ◽  
Chi Square ◽  
Pig Farms ◽  
Chi Square Analysis

Livestock diseases constitute a great threat to protein availability in Nigeria. It is thus necessary to eramine how much farmers know about some deadly diseases prevalent in their stock as it would afford the farmer a timely re-adjustment to prevent foreseeable losses. The focus of this study was to determine farmers' level of awareness of African Swine Fever (ASF) in Agege Area of Lagos State, Nigeria. Primary data were collected with the use of a questionnaire administered to one hundred and twenty (120) respondents selected using the purposive sampling technique. Twenty seven (27) pig farms were also visited to obtain 017-farm data on pig mortality during the ASF epidemic. It was revealed that there was inadequate awareness of the early symptoms and characteristic signs of ASF among the respondents. As such mortality of about 95 percent was recorded. The Chi square analysis showed no significant relationship between farmers' level of awareness of ASF and the location of their pig farms. There was also no significant relationship between pig stock population and farmers' contact with Extension agents. The study then concluded that extension services to pig farmers are currently inadequate. It therefore recommends that it be developed to ensure institutional support in cases of epidemic disease outbreaks. More so, possible ways should be sought to ensure a steady flow of agricultural information from the research institutes and universities to the ultimate users. Preventive measures should however be taught to farmers to avoid the incidence of future disease outbreaks. Lastly, pig farmers are also advised to form associations that could serve as a pressure group in such cases of sector specific emergencies. 

Mississippi's Infectious Disease Hotline: A Surveillance and Education Model for Future Disasters

2009 ◽  
Vol 24 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Andrew M. J. Cavey ◽  
Jonathan M. Spector ◽  
Derek Ehrhardt ◽  
Theresa Kittle ◽  
Mills McNeill ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Hurricane Katrina ◽  
Surveillance System ◽  
Respiratory Infections ◽  
Disease Outbreaks ◽  
Health Concern ◽  
Watery Diarrhea ◽  
Epidemic Disease ◽  
Infectious Disease Outbreaks ◽  
Telephone Hotline

AbstractIntroduction:The potential for outbreaks of epidemic disease among displaced residents was a significant public health concern in the aftermath of Hurricane Katrina. In response, the Mississippi Department of Health (MDH) and the American Red Cross (ARC) implemented a novel infectious disease surveillance system, in the form of a telephone “hotline”, to detect and rapidly respond to health threats in shelters.Methods:All ARC-managed shelters in Mississippi were included in the surveillance system. A symptom-based, case reporting method was developed and distributed to shelter staff, who were linked with MDH and ARC professionals by a toll-free telephone service. Hotline staff investigated potential infectious disease outbreaks, provided assistance to shelter staff regarding optimal patient care, and helped facilitate the evaluation of ill evacuees by local medical personnel.Results:Forty-three shelters sheltering 3,520 evacuees participated in the program. Seventeen shelters made 29 calls notifying the hotline of the following cases: (1) fever (6 cases); (2) respiratory infections (37 cases); (3) bloody diarrhea (2 cases); (4) watery diarrhea (15 cases); and (5) other, including rashes (33 cases). Thirty-four of these patients were referred to a local physician or hospital for further diagnosis and disease management. Three cases of chickenpox were identified. No significant infectious disease outbreaks occurred and no deaths were reported.Conclusions:The surveillance system used direct verbal communication between shelter staff and hotline managers to enable more rapid reporting, mapping, investigation, and intervention, far beyond the capabilities of a more passive or paper-based system. It also allowed for immediate feedback and education for staff unfamiliar with the diseases and reporting process. Replication of this program should be considered during future disasters when health surveillance of a large, disseminated shelter population is necessary.

Recurrent disease outbreaks in corneous demosponges of the genus Ircinia: epidemic incidence and defense mechanisms

2010 ◽  
Vol 157 (7) ◽  
pp. 1577-1590 ◽  
Author(s):  
Manuel Maldonado ◽  
Luis Sánchez-Tocino ◽  
Carlos Navarro
Keyword(s):  
Defense Mechanisms ◽  
Recurrent Disease ◽  
Disease Outbreaks

scholarly journals Reserves as tools for alleviating impacts of marine disease

2016 ◽  
Vol 371 (1689) ◽  
pp. 20150210 ◽  
Author(s):  
Joleah B. Lamb ◽  
Amelia S. Wenger ◽  
Michelle J. Devlin ◽  
Daniela M. Ceccarelli ◽  
David H. Williamson ◽  
...  
Keyword(s):  
Water Quality ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Anthropogenic Activities ◽  
Coral Disease ◽  
Disease Prevalence ◽  
Run Off ◽  
One Year ◽  
Over Exploitation

Marine protected areas can prevent over-exploitation, but their effect on marine diseases is less clear. We examined how marine reserves can reduce diseases affecting reef-building corals following acute and chronic disturbances. One year after a severe tropical cyclone, corals inside reserves had sevenfold lower levels of disease than those in non-reserves. Similarly, disease prevalence was threefold lower on reserve reefs following chronic exposure to terrestrial run-off from a degraded river catchment, when exposure duration was below the long-term site average. Examination of 35 predictor variables indicated that lower levels of derelict fishing line and injured corals inside reserves were correlated with lower levels of coral disease in both case studies, signifying that successful disease mitigation occurs when activities that damage reefs are restricted. Conversely, reserves were ineffective in moderating disease when sites were exposed to higher than average levels of run-off, demonstrating that reductions in water quality undermine resilience afforded by reserve protection. In addition to implementing protected areas, we highlight that disease management efforts should also target improving water quality and limiting anthropogenic activities that cause injury.

scholarly journals Evaluating the role of otoendoscope in cholesteatoma surgery

2019 ◽  
Vol 5 (3) ◽  
pp. 764
Author(s):  
Nitika Gupta ◽  
Mohinder Lal ◽  
Rohan Gupta
Keyword(s):  
Middle Ear ◽  
Recurrent Disease ◽  
Neck Surgery ◽  
Ear Surgery ◽  
Sinus Tympani ◽  
Microscopic Surgery ◽  
Acquired Cholesteatoma ◽  
One Year ◽  
Cholesteatoma Surgery

<p class="abstract"><strong>Background:</strong> Endoscope assisted ear surgery (EAES) reduces the chances of residual cholesteatomas as compared to the conventional microscopic technique, primarily because of the direct visualization of sites where residual cholesteatoma is common, which is often missed out during the traditional microscopic surgical procedure. The aim of the study was to evaluate the hidden areas of middle ear using endoscopes during the conventional microscopic cholesteatoma surgery.</p><p class="abstract"><strong>Methods:</strong> The present prospective study was carried out in the Dept. of Otorhinolaryngology and Head &amp; Neck Surgery, Shri Mata Vaishno Devi Narayana Superspeciality Hospital, Katra, Jammu for a period of one year during which a total of 20 patients of acquired cholesteatoma who underwent conventional microscopic surgery were followed by oto-endoscope assisted examination were enrolled.  </p><p class="abstract"><strong>Results:</strong> Otoendoscope was used in all the surgeries to look for residual cholesteatoma in the hidden areas like protympanum, sinus tympani and anterior attic. An overall incidence of cholesteatoma observed and removed from hidden areas using otoendoscope was recorded to be 30% in the present study.</p><p class="abstract"><strong>Conclusions:</strong> Microscopic ear surgery assisted with oto-endoscope allows a better visualization of the extent of cholesteatoma and thus improved eradication of residual/recurrent disease from the hidden areas of middle ear such as facial recess, sinus tympani, anterior epitympanic space, protympanum and hypotympanum.</p>

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