scholarly journals Tuberculosis reinfection rate as a proportion of total infection rate correlates with the logarithm of the incidence rate: a mathematical model

2008 ◽  
Vol 6 (30) ◽  
pp. 11-15 ◽  
Author(s):  
Pieter W Uys ◽  
Paul D van Helden ◽  
John W Hargrove
Keyword(s):  
Incidence Rate ◽  
Empirical Data ◽  
Incidence Rates ◽  
Simple Relationship ◽  
A Value ◽  
High Incidence ◽  
Low Incidence ◽  
First Time ◽  
The Relationship ◽  
Range Of Values

In a significant number of instances, an episode of tuberculosis can be attributed to a reinfection event. Because reinfection is more likely in high incidence regions than in regions of low incidence, more tuberculosis (TB) cases due to reinfection could be expected in high-incidence regions than in low-incidence regions. Empirical data from regions with various incidence rates appear to confirm the conjecture that, in fact, the incidence rate due to reinfection only, as a proportion of all cases, correlates with the logarithm of the incidence rate, rather than with the incidence rate itself. A theoretical model that supports this conjecture is presented. A Markov model was used to obtain a relationship between incidence and reinfection rates. It was assumed in this model that the rate of reinfection is a multiple, ρ (the reinfection factor), of the rate of first-time infection, λ . The results obtained show a relationship between the proportion of cases due to reinfection and the rate of incidence that is approximately logarithmic for a range of values of the incidence rate typical of those observed in communities across the globe. A value of ρ is determined such that the relationship between the proportion of cases due to reinfection and the logarithm of the incidence rate closely correlates with empirical data. From a purely theoretical investigation, it is shown that a simple relationship can be expected between the logarithm of the incidence rates and the proportions of cases due to reinfection after a prior episode of TB. This relationship is sustained by a rate of reinfection that is higher than the rate of first-time infection and this latter consideration underscores the great importance of monitoring recovered TB cases for repeat disease episodes, especially in regions where TB incidence is high. Awareness of this may assist in attempts to control the epidemic.

scholarly journals Incidence Of Diarrheal Infections In Ukraine: Epidemiological Peculiarities

2019 ◽  
Author(s):  
Nina Malysh ◽  
Oksana Chemych ◽  
Roman Rodyna ◽  
Inna Chorna ◽  
Svitlana Doan
Keyword(s):  
Drinking Water ◽  
Food Item ◽  
Analytical Study ◽  
Incidence Rates ◽  
Epidemiological Surveillance ◽  
Statistical Research ◽  
Factors Influencing ◽  
High Incidence ◽  
The World ◽  
Low Incidence

Abstract Background : Diarrheal infections remain relevant for many countries of the world. The processes of globalization, fundamental changes in nutrition and water consumption contributed to the fact that the significance of individual infection sources, etiological structure of diarrheal infections changed. Purpose of the study: on the background of the analytical study of the incidence of diarrheal infections in Ukraine under the current conditions, to determine the factors influencing epidemic situation. Methods: The reports of the Ministry of Health of Ukraine, Main Administrations of Statistics in Kharkiv, Odesa, Zaporizhia oblasts for 2011-2018 are used in the paper. Epidemiological and statistical research methods are applied. Results: The epidemic situation with diarrheal infections in Ukraine is characterized by a low incidence of typhoid fever (from 0.012 to 0.14 per 100 thousand people), shigellosis (from 1.97-6.13 per 100 thousand people), stable incidence rates without the downward trend, salmonellosis (from 17.35 till 24.1 per 100 thousand people), high incidence of diahrreal infections of specified etiology (from 115.5 to141.9 per 100 thousand people) and diahrreal infections of unspecified etiology (from 69.76 to 107.02 per 100 thousand people). The most complicated epidemic situation is observed in economically most developed regions of the country. Most diarrheal infectionsoutbreaks are connected with catering establishments 36.5 % and with children educational establishments 26.1 %. In the region with the highest shigellosis and salmonellosis incidence direct strong correlation relationships are established between the incidence and population, density, natural population movement. The oblasts with the highest diahrreal infections of specified etiology, rotaviral enteritis, diahrreal infections of unspecified etiology incidence are at least provided with water resources and have problems with provision of high-quality drinking water. There is a need to improve the system of epidemiological surveillance over diarrheal infections by extension of the indicators of microbiological study of drinking water quality in the regions of Ukraine, where high diahrreal infections of specified etiology, rotaviral enteritis, diahrreal infections of unspecified etiology incidence is registered; by increasing frequency of food item inspections in the oblasts, where mediana shigellosis and salmonellosis incidence exceeds the average one in Ukraine. Keywords: diarrheal infections, shigellosis, salmonellosis, rotaviral enteritis.

scholarly journals A genome epidemiological study of mycobacterium tuberculosis in subpopulations with high and low incidence rate in Guangxi, South China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Dingwen Lin ◽  
Junning Wang ◽  
Zhezhe Cui ◽  
Jing Ou ◽  
Liwen Huang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Incidence Rate ◽  
South China ◽  
Demographic History ◽  
Lineage Differentiation ◽  
A Genome ◽  
High Incidence ◽  
History Of ◽  
Lineage 2 ◽  
Low Incidence

Abstract Background Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis (Mtb). China is the third in top 8 high TB burden countries and Guangxi is one of the high incidence areas in South China. Determine bacterial factors that affected TB incidence rate is a step toward Ending the TB epidemic. Results Genomes of M. tuberculosis cultures from a relatively high and low incidence region in Guangxi have been sequenced. 347 of 358(96.9%) were identified as M. tuberculosis. All the strains belong to Lineage 2 and Lineage 4, except for one in Lineage 1. We found that the genetic structure of the M. tuberculosis population in each county varies enormously. Low incidence rate regions have a lower prevalence of Beijing genotypes than other regions. Four isolates which harbored mutT4-48 also had mutT2-58 mutations. It is suggested that strains from the ancestors of modern Beijing lineage is circulating in Guangxi. Strains of modern Beijing lineage (OR=2.04) were more likely to acquire drug resistances than Lineage 4. Most of the lineage differentiation SNPs are related to cell wall biosynthetic pathways. Conclusions These results provided a higher resolution to better understand the history of transmission of M. tuberculosis from/to South China. And the incidence rate of tuberculosis might be affected by bacterial population structure shaped by demographic history. Our findings also support the hypothesis that Modern Beijing lineage originated in South China.

scholarly journals Trend of Cutaneous Leishmaniasis in Jordan From 2010 to 2016: Retrospective Study (Preprint)

2019 ◽  
Author(s):  
Mohammad Alhawarat ◽  
Yousef Khader ◽  
Bassam Shadfan ◽  
Nasser Kaplan ◽  
Ibrahim Iblan
Keyword(s):  
Retrospective Study ◽  
Cutaneous Leishmaniasis ◽  
Incidence Rate ◽  
Surveillance System ◽  
Incidence Rates ◽  
Case Definition ◽  
Syrian Refugees ◽  
Annual Incidence Rate ◽  
High Incidence ◽  
Average Annual Incidence

BACKGROUND Cutaneous leishmaniasis (CL) is endemic in the Middle East, with countries such as Syria reporting high incidence rates. OBJECTIVE This study aimed to assess the trends in the incidence of cutaneous leishmaniasis (CL) in Jordan from 2010 to 2016. METHODS This retrospective study included all cases of CL that had been reported to the Leishmaniasis Surveillance System in the Department of Communicable Diseases at the Jordan Ministry of Health during the period from 2010 to 2016. A total of 1243 cases were reported and met the case definition. RESULTS A total of 1243 cases (60.65% [754/1243] males and 39.34% [489/1243] females) were diagnosed during the study period. Of this sample, 233 patients (19.13%) were aged <5 years old, 451 (37.03%) were aged between 5-14 years old, 190 (15.60%) were aged between 15-24 years old, and 344 (28.24%) were aged ≥25 years old. Of those, 646 (51.97%) were Jordanians and 559 (44.97%) were Syrians. The average annual incidence rate of 1.70 per 100,000 people between 2010 and 2013 increased to 3.00 per 100,000 people in the years 2014 to 2016. There was no difference in incidence rates between Jordanians and Syrian refugees between 2010 and 2012. After 2012, the incidence rate increased significantly among Syrian refugees from 1.20 per 100,000 people in 2012 to 11.80 per 100,000 people in 2016. On the contrary, the incidence rate did not change significantly among Jordanians. CONCLUSIONS The incidence rate of leishmaniasis in Jordan has increased in the last three years because of the influx of Syrian refugees into Jordan. A massive effort toward reservoir and vector control, along with actively pursuing diagnosis in endemic foci, will be helpful. Proper and studious reporting of cases is also a necessity for the eradication of this disease.

scholarly journals Investigating the Maturity of Incident Investigations of the Ghanaian Mining Industry and Its Effect on Safety Performance

Safety ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 3 ◽  
Author(s):  
Eric Stemn ◽  
Carmel Bofinger ◽  
David Cliff ◽  
Maureen Hassall
Keyword(s):  
Incidence Rate ◽  
Large Scale ◽  
Mining Industry ◽  
Incidence Rates ◽  
Safety Performance ◽  
Interview Data ◽  
Gold Mines ◽  
Four Dimensions ◽  
High Incidence Rate ◽  
Low Incidence

Effective incident investigations have been recognised as a vital means of improving safety. Nevertheless, there has been little attempt to link incident investigations to actual safety performance. In this study, a framework for assessing the maturity of incident investigations and identifying areas for improvements is described. The framework was developed based on a literature review and interviews with 41 investigators across five large-scale Ghanaian gold mines. The framework consists of 20 elements across four dimensions and five maturity levels. The dimensions (investigator competencies, system of investigation, stages of investigation and post-investigation findings) consider the most relevant aspects of practical investigation and for each dimension, elements that are more specific were defined across five maturity levels. Mapping the interview data collected from five mines into a maturity framework highlighted that the mines occupied different positions on the framework. Some occupied the advanced levels consistently and others consistently occupied the lower levels. Applying the interview data to the framework also identified priority areas for improvement. Finally, the maturity scores derived from mapping interview data onto the framework were correlated with the incidence rates of the mines to determine if any relationship existed between the two variables. The low incidence rate mines had higher maturity scores and the high incidence rate mines had lower maturity scores. It was found that the method was effective in practice, giving clear indications of areas where improvements are needed.

scholarly journals Epidemiological surveillance of Leishmaniasis in Montenegro, 1992-2013

2015 ◽  
Vol 143 (11-12) ◽  
pp. 707-711 ◽  
Author(s):  
Sanja Medenica ◽  
Svetlana Jovanovic ◽  
Ivan Dozic ◽  
Biljana Milicic ◽  
Novak Lakicevic ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Demographic Data ◽  
Coastal Region ◽  
Public Health Problem ◽  
Incidence Rates ◽  
Epidemiological Surveillance ◽  
Notification System ◽  
Significant Public Health ◽  
Low Incidence ◽  
Epidemiological Characteristics

Introduction. The diseases caused by Leishmania are spread worldwide and represent a significant public health problem. Objective. The aim of this study was to present the results of epidemiological surveillance of leishmaniasis in humans in Montenegro in the period from 1992 to 2013. Methods. The study was planned and realized as a descriptive epidemiological study. The sample included patients of leishmaniasis in Montenegro in the period from 1992 to 2013. The health and demographic data were collected from medical records. The disease was microbiologically proven in the patients. For statistical analysis the ?2-test was used, which examined the significance of the incidence rate. Results. During this period, 66 cases of leishmaniasis were identified (40 men and 26 women) aged 0 to 62 (mean 15.61?16.76 years). A visceral form of the disease was diagnosed in 65 (98%) patients, and one patient was diagnosed with cutaneous leishmaniasis. The average incidence rate for the abovementioned period is 0.48 per 100,000 inhabitants. The highest average incidence rate was identified in patients up to seven years of age (3.50 per 100,000 inhabitants). The highest average incidence rates of leishmaniasis were identified in the coastal region of Montenegro, while seasonal distribution indicates that the disease occurs throughout the year with predominance in late spring and summer. Conclusion. The research has shown that Montenegro is among the countries with low incidence of leishmaniasis. Nevertheless, because of leishmaniasis re-emergence in the entire Mediterranean Basin, a comprehensive research of ecological and epidemiological characteristics of leishmaniasis, including better monitoring and notification system, is required.

Incidence of spontaneous intracranial hypotension in a community. Beverly Hills, California, 2006–2020

Cephalalgia ◽  
2021 ◽  
pp. 033310242110485
Author(s):  
Wouter I Schievink ◽  
M Marcel Maya ◽  
Franklin G Moser ◽  
Paul Simon ◽  
Miriam Nuño
Keyword(s):  
Confidence Interval ◽  
Incidence Rate ◽  
Intracranial Hypotension ◽  
Medical Center ◽  
Spontaneous Intracranial Hypotension ◽  
Population Based ◽  
Incidence Rates ◽  
Annual Incidence Rate ◽  
Average Annual Incidence ◽  
First Time

Background Spontaneous intracranial hypotension is diagnosed with an increasing frequency, but epidemiologic data are scarce. The aim of this study was to determine the incidence rate of spontaneous intracranial hypotension in a defined population. Methods Using a prospectively maintained registry, all patients with spontaneous intracranial hypotension residing in Beverly Hills, California, evaluated at our Medical Center between 2006 and 2020 were identified in this population-based incidence study. Our Medical Center is a quaternary referral center for spontaneous intracranial hypotension and is located within 1.5 miles from downtown Beverly Hills. Results A total of 19 patients with spontaneous intracranial hypotension were identified. There were 12 women and seven men with a mean age of 54.5 years (range, 28 to 88 years). The average annual incidence rate for all ages was 3.7 per 100,000 population (95% confidence interval [CI]: 2.0 to 5.3), 4.3 per 100,000 for women (95% CI, 1.9 to 6.7) and 2.9 per 100,000 population for men (95% CI, 0.8 to 5.1). Conclusion This study, for the first time, provides incidence rates for spontaneous intracranial hypotension in a defined population.

Ecological Survey of Plesiomonas Shigelloides

1993 ◽  
Vol 56 (5) ◽  
pp. 444-446 ◽  
Author(s):  
SAM D. ABBEY ◽  
NEDIE P. EMERINWE ◽  
M. PHILL ◽  
EMMANUEL N. AMADI
Keyword(s):  
Incidence Rate ◽  
Plesiomonas Shigelloides ◽  
Fecal Samples ◽  
Ecological Survey ◽  
Port Harcourt ◽  
Microbiological Methods ◽  
High Incidence ◽  
Low Incidence ◽  
Different Origins ◽  
Soil And Water

In order to establish the presence and distribution of Plesiomonas shigelloides in the Port Harcourt area, samples from different origins were examined. Standard microbiological methods were adopted for the analysis. The results showed a relatively high incidence in soil and water which are speculated to be reservoirs of the organism. A low incidence rate occurred in seafoods and humans. No P. shigelloides was detected from cattle and poultry. Although the isolation in humans was low 2.0% (8 of 400), five samples yielded P. shigelloides as the only enteropathogen. Four of the five were from diarrheic fecal samples, thus indicating the involvement of P. shigelloides in diarrhea.

Effect of Thickness in Intermediate Layer on Intensity of Stress Singularity at a Vertex in Three-Dimensional Bonded Joints

2006 ◽  
Vol 324-325 ◽  
pp. 883-886
Author(s):  
Hideo Koguchi
Keyword(s):  
Three Dimensional ◽  
Stress Singularity ◽  
Simple Relationship ◽  
Bonded Joints ◽  
Stress Distributions ◽  
Singular Stress ◽  
Value Analysis ◽  
A Value ◽  
Eigen Value ◽  
The Relationship

In the present paper, singular stress fields at the vertex on the interface in three-dimensional bonded joints are analyzed using BEM. The order of stress singularity is determined solving an eigen equation based on FEM formulation and the stress distribution is expressed using the result of the eigen-value analysis. A simple relationship between the thickness of layer and a value of stress is introduced. Then, stress distributions for various thicknesses of layer are unified using the relationship, and the unified intensity of stress singularity is determined.

scholarly journals Is gastric cancer becoming a rare disease? A global assessment of predicted incidence trends to 2035

Gut ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 823-829 ◽  
Author(s):  
Melina Arnold ◽  
Jin Young Park ◽  
M Constanza Camargo ◽  
Nuno Lunet ◽  
David Forman ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Rare Disease ◽  
Cancer Incidence ◽  
Age Groups ◽  
Cancer Registries ◽  
Global Scale ◽  
Incidence Rates ◽  
Incidence Trends ◽  
High Incidence ◽  
Low Incidence

ObjectivesThe incidence of gastric cancer continues to decrease globally, approaching levels that in some populations could define it as a rare disease. To explore this on a wider scale, we predict its future burden in 34 countries with long-standing population-based data.MethodsData on gastric cancer incidence by year of diagnosis, sex and age were extracted for 92 cancer registries in 34 countries included in Cancer Incidence in Five Continents Plus. Numbers of new cases and age-standardised incidence rates (ASR per 100 000) were predicted up to 2035 by fitting and extrapolating age–period–cohort models.ResultsOverall gastric cancer incidence rates are predicted to continue falling in the future in the majority of countries, including high-incidence countries such as Japan (ASR 36 in 2010 vs ASR 30 in 2035) but also low-incidence countries such as Australia (ASR 5.1 in 2010 vs ASR 4.6 in 2035). A total of 16 countries are predicted to fall below the rare disease threshold (defined as 6 per 100 000 person-years) by 2035, while the number of newly diagnosed cases remains high and is predicted to continue growing. In contrast, incidence increases were seen in younger age groups (below age 50 years) in both low-incidence and high-incidence populations.ConclusionsWhile gastric cancer is predicted to become a rare disease in a growing number of countries, incidence levels remain high in some regions, and increasing risks have been observed in younger generations. The predicted growing number of new cases highlights that gastric cancer remains a major challenge to public health on a global scale.

scholarly journals Epidemiology of Shoulder Instability in the National Football League

2021 ◽  
Vol 9 (5) ◽  
pp. 232596712110077
Author(s):  
Matthew J.J. Anderson ◽  
Christina D. Mack ◽  
Mackenzie M. Herzog ◽  
William N. Levine
Keyword(s):  
Incidence Rate ◽  
Shoulder Instability ◽  
National Football League ◽  
Glenohumeral Joint ◽  
Incidence Rates ◽  
Limited Data ◽  
The Relationship ◽  
Contact Mechanism ◽  
Study Inclusion

Background: Shoulder instability is a common and potentially debilitating injury among collision sport athletes that can lead to long-term damage of the glenohumeral joint. Limited data exist regarding instability among elite athletes in the National Football League (NFL). Purpose: To describe the epidemiology of shoulder instability in the NFL from 2012 through 2017. Study Design: Descriptive epidemiology study. Methods: The NFL’s injury database was reviewed for shoulder instability injuries resulting in missed time during the study inclusion dates. Injuries were classified by type and direction, as well as timing, setting, and mechanism. Median missed time was determined for the different types and directions of instability. Incidence rates for game-related injuries were calculated based on timing during the season and player position. Finally, the relationship between player position and instability direction was assessed. Results: During the 6-year study period, 355 players sustained 403 missed-time shoulder instability injuries. Most injuries occurred during games (65%) via a contact mechanism (85%). The overall incidence rate of game-related instability was 3.6 injuries per 100,000 player-plays and was highest during the preseason (4.9 per 100,000 player-plays). The defensive secondary position accounted for the most injuries, but quarterbacks had the highest incidence rate in games (5.5 per 100,000 player-plays). Excluding unspecified events (n = 128; 32%), 70% (n = 192) of injuries were subluxations and 30% (n = 83) were dislocations; 75% of dislocations were anterior, while subluxations were more evenly distributed between the anterior and posterior directions (45% vs 52%, respectively). Players missed substantially more time after dislocation compared with subluxation (median, 47 days vs 13 days, respectively). When instability direction was known, the majority of instability events among quarterbacks and offensive linemen were posterior (73% and 53%, respectively), while anterior instability was most common for all other positions. Conclusion: Shoulder instability is a common injury in the NFL and can result in considerable missed time. Dislocations occur less frequently than subluxations but lead to greater time lost. While most dislocations are anterior, more than half of subluxations are posterior, which is likely the result of repetitive microtrauma to the posterior capsulolabral complex sustained during sport-specific motions such as blocking. The risk of instability varies by player position, and position may also influence instability direction.

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