Mean Annual Incidence Rate Research Articles

Epidemiological and clinical aspects of Guillain-Barré syndrome and its variants.

Guillain-Barré syndrome (GBS), an acute polyradiculoneuropathy that occurs because of an abnormal inflammatory response in the peripheral nervous system, is clinically characterized by acute flaccid paresis and areflexia with or without sensory symptoms. This syndrome can lead to disabling or even life-threatening sequelae. This study aimed to present the clinical and epidemiological aspects of GBS in patients admitted to a tertiary-level hospital in the Federal District between January 2013 and June 2019. In this observational, cross-sectional and retrospective study, medical records of patients diagnosed with acute inflammatory demyelinating polyradiculoneuropathy, acute motor axonal neuropathy or acute axonal motor-sensitive neuropathy based on electromyographic findings were included, and clinical data were collected retrospectively. A total of 100 patients (63 males and 37 females; ratio, 1.7:1) aged 2-86 years (mean, 36.4 years) were included. The mean annual incidence rate of GBS was 0.54 cases/100,000 inhabitants, with 52 and 49% of the cases occurring between October and March (rainy season) and between April and September (dry season), respectively. The proportions of patients showing each GBS variant were as follows: demyelinating forms, 57%; axonal forms, 39%; and undetermined, 4%. The mean duration of hospitalization was 8-15 days for most patients (38%). During hospitalization, 14% of the patients required mechanical ventilation and 20% experienced infectious complications. The findings indicate that there was an increase in the incidence of GBS during the rainy season. Moreover, we did not observe the typical bimodal distribution regarding age at onset.

Inflammatory bowel disease in Tuzla Canton, Bosnia-Herzegovina: A prospective 10-year follow-up.

BACKGROUNDThe incidence and prevalence of inflammatory bowel disease (IBD) vary between regions but have risen globally in recent decades. A lack of data from developing nations limits the understanding of IBD epidemiology.AIMTo perform a follow-up review of IBD epidemiology in the Tuzla Canton of Bosnia-Herzegovina during a 10-year period (2009-2019).METHODSWe prospectively evaluated the hospital records of both IBD inpatients and outpatients residing in Tuzla Canton for the specified period of time between January 1, 2009 and December 31, 2019. Since all our patients had undergone proximal and distal endoscopic evaluations at the hospital endoscopy unit, we used the hospital’s database as a primary data source, alongside an additional cross-relational search of the database. Both adult and pediatric patients were included in the study. Patients were grouped by IBD type, phenotype, age, and gender. Incidence rates were calculated with age standardization using the European standard population. Trends in incidence and prevalence were evaluated as a 3-year moving average and average annual percentage change rates.RESULTSDuring the 10-year follow-up period, 651 patients diagnosed with IBD were monitored (of whom 334, or 51.3%, were males, and 317, or 48.7%, were females). Of all the patients, 346 (53.1%) had been diagnosed with ulcerative colitis (UC), 292 (44.9%) with Crohn’s disease (CD), and 13 (2%) with indeterminate colitis (IC). We observed 440 newly diagnosed patients with IBD: 240 (54.5%) with UC, 190 (43.2%) with CD, and 10 (2.3%) with IC. The mean annual crude incidence rates were found to be 9.01/100000 population for IBD [95% confidence interval (CI): 8.17-9.85], with 4.91/100000 (95%CI: 4.29-5.54) for UC and 3.89/100000 (95%CI: 3.34-4.44) for CD. Calculated IBD prevalence in 2019 was 146.64/100000 (95%CI: 128.09-165.19), with 77.94/100000 (95%CI: 68.08-87.70) for UC and 65.77/100000 (95%CI: 54.45-74.1) for CD. The average annual IBD percentage change was 0.79% (95%CI: 0.60-0.88), with -2.82% (95%CI: -2.67 to -2.97) for UC and 6.92% (95%CI: 6.64-7.20) for CD. During the study period, 24,509 distal endoscopic procedures were performed. The incidence of IBD was 3.16/100 examinations (95%CI: 2.86-3.45) or 1.72/100 examinations (95%CI: 1.5-1.94) for UC and 1.36/100 examinations (95%CI: 1.17-1.56) for CD.CONCLUSIONTrends in the incidence and prevalence of IBD in Tuzla Canton are similar to Eastern European averages, although there are significant epidemiological differences within geographically close and demographically similar areas.

Clustering of non-leukemia childhood cancer in Colombia: a nationwide study

Background: Childhood cancer is considered one the most important causes of death in children and adolescents, despite having a low incidence in this population. Spatial analysis has been previously used for the study of childhood cancer to study the geographical distribution of leukemias. This study aimed to identify the presence of space-time clusters of childhood of cancer excluding leukemia in Colombia between 2014 and 2017. Methods: All incident cancer cases (excluding leukemia) in children under the age of 15 years that had been confirmed by the National Surveillance System of Childhood Cancer between 2014 and 2017 were included. Kulldorf’s circular scan test was used to identify clusters using the municipality of residence as the spatial unit of analysis and the year of diagnosis as the temporal unit of analysis. A sensitivity analysis was conducted with different upper limit parameters for the at-risk population in the clusters. Results: A total of 2006 cases of non-leukemia childhood cancer were analyzed, distributed in 432 out of 1,122 municipalities with a mean annual incidence rate of 44 cases per million children under the age of 15. Central nervous system (CNS) tumors were the most frequent type. Two space-time clusters were identified in the central and southwest regions of the country. In the analysis for CNS tumors, a spatial cluster was identified in the central region of the country. Conclusions: The distribution of non-leukemia childhood cancer seems to have a clustered distribution in some Colombian regions that may suggest infectious or environmental factors associated with its incidence although heterogeneity in access to diagnosis cannot be discarded.

Incidence of Type 1 Diabetes Among Children and Adolescents During Peace and War Times in Yemen

Background: The incidence of type 1 diabetes (T1D) among children and adolescents has been reported to be steadily increasing worldwide with considerable regional, national and ethnic differences. We aimed in this study to present a 30-year registry-based incidence data on T1D in Yemen, a low-income country, during peace and war times. Methods: A total of 461 children and adolescents aged more than 6 months to 18 years with newly-diagnosed diabetes were registered between1989-2018. We used a standardized registry protocol according to that established in the 155 center WHO Multinational (DiaMonod) Project for childhood diabetes. The registry as with other WHO DiaMond centers was primarily concerned with counting the frequency of new-onset cases of childhood diabetes over time across Sana’a city according to a standard set of specific criteria. Case reports registered were validated on the basis of a physician’s diagnosed diabetes in the records. Eligibility for registration was based on age < 19 years and permanent residence in Sana’a city. The annual incidence rates (cases/100,000 persons/year) were calculated from the numbers of new reported cases for each year (1989-2018) divided by the estimated numbers of person-years ‘at risk’ (population < 19 years) according to age and sex for that year. Completeness of case ascertainment for the identified number of cases was assessed with the use of the 2-source capture-recapture method throughout the study period. Findings: The mean annual incidence rate in children aged 0-14 years over the full observation period was 1.83/100,000/yr with 95% CI: (0.9, 2.74). With the use of 3-year time periods, the mean annual incidence rate was intermediate (5 per 100,000/yr) in the first time-period (1989-1991), low (1.56-2.3/100,000/yr) during subsequent 5 time-periods (1992-2006) and (1.2/100,000/yr) during the next 2 time-periods (2007-2012). Ultimately, there was a precipitous decline in incidence to a very low rate (0.5/100,000/yr) during the last two time-periods (2013-2018) which was the time when Yemen has experienced the conflict and war. The age-specific mean T1D annual incidence rates with the use of 3-year time periods for children aged 0-4 yr, 5-9 yr, 10-14 yr, and adolescents aged 15-18 yr over the full observation period (1989-2018) were 0.83, 1.82, 3.14, and 2.31/100,000/yr, respectively. On temporal trend analysis of incidence rates with the use of 3-years moving average, all trend curves indicated a decline for all participants aged 0-14 years and for other age groups, especially during the last 6 years of the observation period. The mean annual age-specific and sex-specific incidence rates over the full observation period were found to be increasing with increased age in both males and females, peaking at puberty (10-14 year old) with the associated gender effect. A seasonal trend in incidence of T1D was noted with more diagnoses of cases in the winter and autumn months and fewer in the summer months, a feature that was observed in both sexes and in all age groups. Interpretation: The mean incidence rate of T1D in children and adolescents in Sana’a city was found to be low. In children aged 0-14 years in particular, the rate was low during peace time, followed by a precipitous decline to a very low rate during the time of war. Economic destruction, poverty and shortage of food supply to a large sector of children and adolescents were likely associated with decreased incidence of childhood diabetes during war. Undernutrition and low standards of environmental hygiene with exposure to infections very early in childhood might have operated as a protective factor against pediatric-onset autoimmune diabetes. Funding Statement: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors. Declaration of Interests: None declared. Ethics Approval Statement: Patient consent for publication was obtained from patients’ families. Ethical approval statement: This work was approved by the Ethical Committee at the Faculty of Medicine and Health Sciences, University of Sana’a

Assessment of Trends in the Incidence Rates of Central Retinal Artery Occlusion in Korea From 2002 to 2015

Central retinal artery occlusion (CRAO) is associated with and shares common risk factors with cardiovascular diseases. Over the past several decades, the incidence rates of stroke and ischemic heart disease have substantially decreased in high-income industrialized countries. However, little is known regarding current trends in CRAO incidence rates. To estimate trends in the incidence rates of CRAO in Korea. This nationwide population-based cohort study was designed on September 7, 2017, and used data from the Korean National Health Insurance Service from January 1, 2002, to December 31, 2015. Individuals with incident CRAO between 2002 and 2015 were identified using the CRAO diagnostic code (H34.1) from the International Classification of Diseases, Tenth Revision. Unadjusted CRAO incidence rates were calculated using the number of CRAO cases identified and the corresponding midyear population, which was obtained from resident registration data. Standardized incidence rates were calculated based on the 2015 census population, and weighted mean annual incidence rates with 95% CIs were computed based on the Poisson distribution. To identify trends in incidence rates, joinpoint regression analysis was performed using standardized incidence rates, and annual percentage changes (APCs) were calculated across the 12-year study period. Data were analyzed from May 1, 2019, to April 30, 2020. Temporal trends in CRAO incidence rates (measured as cases per 100 000 person-years) and age-standardized APCs in CRAO incidence rates using joinpoint and birth cohort analyses. Among 50 million residents of Korea, 9892 individuals (5884 men [59.5%]) with incident CRAO between 2002 and 2015 were identified. The mean age of Korean individuals diagnosed with CRAO was 62.4 years (range, 0-97 years); among men and women, the mean age was 61.5 years (range, 0-96 years) and 63.6 years (range, 0-97 years), respectively. The mean standardized incidence rate of CRAO was 2.00 cases per 100 000 person-years (95% CI, 1.97-2.04 cases per 100 000 person-years) among the entire population, 2.43 cases per 100 000 person-years (95% CI, 2.37-2.49 cases per 100 000 person-years) among men, and 1.61 cases per 100 000 person-years (95% CI, 1.57-1.66 cases per 100 000 person-years) among women. The highest incidence rate (9.85 cases per 100 000 person-years; 95% CI, 9.10-10.60 cases per 100 000 person-years) was observed among those aged 80 to 84 years (13.74 cases per 100 000 person-years [95% CI, 12.16-15.32 cases per 100 000 person-years] for men and 8.04 cases per 100 000 person-years [95% CI, 7.21-8.86 cases per 100 000 person-years] for women). The incidence rate in the overall study population decreased over time (APC, -3.46%; 95% CI, -4.3% to -2.6%), and this decreasing trend was more evident in women (APC, -4.56%; 95% CI, -5.7% to -3.4%) than in men (APC, -2.90%; 95% CI, -3.9% to -1.9%). The decrease in the incidence rate was more evident among participants younger than 65 years (APC, -6.80%; 95% CI, -8.3% to -5.2%) than among those 65 years and older (APC, -0.57%; 95% CI, -1.5% to -0.4%). Among participants born after 1930, a decrease in the CRAO incidence rate over time was observed in every age group, while the same decreasing trend was not present among those born before 1930. This study found that the CRAO incidence rate has been decreasing among residents of Korea, especially among women, individuals younger than 65 years, and individuals born after 1930. This observed decrease may be associated with the development of a national health care system and the general improvement in chronic disease management.

Age and sex adjusted prevalence and annual incidence of multiple sclerosis in East-Azerbaijan, Iran

BackgroundIncidence and prevalence of multiple sclerosis (MS) is postulated to be rising in recent decades. Therefore, updating and completing the information of patients is essential, especially in high population areas. East-Azerbaijan is the largest and most populous province in the northwest of Iran. This study aimed to determine the prevalence and annual incidence of MS from 2008 to 2017 in East-Azerbaijan. MethodsWe evaluated the data of all patients who had registered at the MS center in the university hospital. The data include nearly all MS patients in the East-Azerbaijan region, because it is the only referral site in the area. All of the reported rates were calculated in 100,000 of the total population. ResultsBy the end of 2017, the number of MS patients was 2995 (residing in the, with 769 (25.67%) men and 2226 (74.32%) women. The prevalence rate was 75.72/100,000 (95 % CI: 73.06-78.48), 38.2 in men (95% CI: 35.5-41.0), and 114.61 for women (95% CI: 109.9-119.4), with a female to male (F/M) ratio of 3:1. The mean annual incidence rate was 7.63/100,000 (95% CI: 5.6-9.3), and this rate was higher in women than men. During the nine years, the incidence rate increased. The patients' mean age was 32.33 ± 8.92, with a peak prevalence in 25-29 years for both genders. In this study, 13.9% of patients had a positive MS family history. ConclusionsThis study showed a high prevalence of MS in the region. There is a significant increase in the incidence of MS during the nine years in East-Azerbaijan. The increment of incidence was more prominent in women. Also, considering the increasing incidence rate, it is concluded that the risk of MS is increasing in this region.

Clustering of childhood cancer in Colombia: a nationwide study.

Background: Childhood cancer is considered one the most important causes of death in children and adolescents, despite having a low incidence in this population. Spatial analysis has been previously used for the study of childhood cancer to study the geographical distribution of leukemias. This study aimed to identify the presence of space-time clusters of childhood of cancer excluding leukemia in Colombia between 2014 and 2017. Methods: All incident cancer cases (excluding leukemia) in children under the age of 15 years that had been confirmed by the National Surveillance System of Childhood Cancer between 2014 and 2017 were included. Kulldorf's circular scan test was used to identify clusters using the municipality of residence as the spatial unit of analysis and the year of diagnosis as the temporal unit of analysis. A sensitivity analysis was conducted with different upper limit parameters for the at-risk population. Results: A total of 2006 cases of non-leukemia childhood cancer were analyzed, distributed in 432 municipalities with a mean annual incidence rate of 44 cases per million children under the age of 15. Central nervous system (CNS) tumors were the most frequent type. Four spatial clusters and two space-time clusters were identified in the central and southwest regions of the country. In the analysis for CNS tumors, a spatial cluster was identified in the central region of the country. Conclusions: The distribution of non-leukemia childhood cancer seems to have a clustered distribution in some Colombian regions that may suggest infectious or environmental factors associated with its incidence.

The cholera risk assessment in Kano State, Nigeria: A historical review, mapping of hotspots and evaluation of contextual factors.

Nigeria is endemic for cholera since 1970, and Kano State report outbreaks annually with high case fatality ratios ranging from 4.98%/2010 to 5.10%/2018 over the last decade. However, interventions focused on cholera prevention and control have been hampered by a lack of understanding of hotspot Local Government Areas (LGAs) that trigger and sustain yearly outbreaks. The goal of this study was to identify and categorize cholera hotspots in Kano State to inform a national plan for disease control and elimination in the State. We obtained LGA level confirmed and suspected cholera data from 2010 to 2019 from the Nigeria Centre for Disease Control (NCDC) and Kano State Ministry of Health. Data on inland waterbodies and population numbers were obtained from online sources and NCDC, respectively. Clusters (hotspots) were identified using SaTScan through a retrospective analysis of the data for the ten-year period using a Poisson discrete space-time scan statistic. We also used a method newly proposed by the Global Task Force on Cholera Control (GTFCC) to identify and rank hotspots based on two epidemiological indicators including mean annual incidence per 100 000 population of reported cases and the persistence of cholera for the study period. In the ten-year period, 16,461 cholera cases were reported with a case fatality ratio of 3.32% and a mean annual incidence rate of 13.4 cases per 100 000 population. Between 2010 and 2019, the most severe cholera exacerbations occurred in 2014 and 2018 with annual incidence rates of 58.01 and 21.52 cases per 100 000 inhabitants, respectively. Compared to 2017, reported cases and deaths increased by 214.56% and 406.67% in 2018. The geographic distribution of outbreaks revealed considerable spatial heterogeneity with the widest in 2014. Space-time clustering analysis identified 18 out of 44 LGAs as high risk for cholera (hotspots) involving both urban and rural LGAs. Cholera clustered around water bodies, and the relative risk of having cholera inside the hotspot LGA were 1.02 to 3.30 times higher than elsewhere in the State. A total of 4,894,144 inhabitants were in these hotspots LGAs. Of these, six LGAs with a total population of 1.665 million had a relative risk greater than 2 compared to the state as a whole. The SaTScan (statistical) and GTFCC methods were in agreement in hotspots identification. This study identified cholera hotspots LGAs in Kano State from 2010–2019. Hotspots appeared in both urban and rural settings. Focusing control strategies on these hotspots will facilitate control and eliminate cholera from the State.

Is the sharp increasing trend of multiple sclerosis incidence real in Iran?

BackgroundSome epidemiologic studies have reported a sharp increase in multiple sclerosis (MS) incidence in different provinces in Iran. This report aimed to investigate more closely the increasing trend of MS incidence in the past 10 years in Iran.MethodsIn this longitudinal study, the data for all MS patients meeting the McDonald criteria were obtained from a national registry, coordinated by the Ministry of Health (MOH). Joinpoint (JP) regression was used for time trend analysis of MS incidence and determine the optimal number of significant joinpoints. Finally, an annual percentage change (APC) in MS incidence for each segment of the trend line was estimated with 95% confidence interval.ResultsThe mean age of the patients and the mean annual incidence rate of MS were 30.9 ± 1.1 and 5.3 ± 1.9 per 100,000 population, respectively. The overall incidence rate of MS had increased significantly from 2.14 in 2006 to its peak (7.5) in 2014, per 100,000 population (APC = 12%, P < 0.001). The first JP was observed in 2011 in both male and female groups. The overall APC in the first segment was 22.6% (17.2–28.2%, p < 0.01). Besides, the corresponding APC values for males and females were 22.1% (14.7–30%, p < 0.01) and 22.5% (17.5–27.8%, p < 0.01), respectively. After 2011, the MS incidence underwent a more or less decreasing trend in both genders.ConclusionContrary to previous studies, the MS incidence trend in Iran was rising just before 2011, and in the recent decade, Iran has a stable rate of MS cases.

Prevalence and incidence of idiopathic subglottic stenosis in southern and central Alberta: a retrospective cohort study

BackgroundSubglottic stenosis (SGS) is a reportedly rare disease that causes recurrent severe airway obstruction. Etiologies reported for SGS include idiopathic, iatrogenic, autoimmune, congenital, and traumatic, with variable ratios among different centres. From empiric observation, southern and central Alberta was hypothesized to have a disproportionate distribution of SGS driven by increased idiopathic SGS (iSGS) compared to previous literature. Identification of causative agents of iSGS will help understand and guide future management options, so this study aimed to characterize the demographics of SGS subtypes, define prevalence and incidence rates of iSGS in southern Alberta, and geographically analyze for clustering of iSGS prevalence.MethodsSGS patients from Alberta census divisions No. 1–9 and 15 were retrospectively reviewed. Patients were subtyped according to etiology of SGS and characterized. Idiopathic SGS prevalence and incidence was assessed; prevalence was further geographically segregated by census division and forward sortation area (FSA). Significant clustering patterns were assessed for using a Global Moran’s I analysis.ResultsFrom 2010 to 2019 we identified 250 SGS patients, who were substantially overrepresented by idiopathic patients (80.4%) compared to autoimmune (10.0%), iatrogenic (7.6%), congenital (1.2%), and traumatic (0.8%). The total iSGS prevalence was 9.28/100,000 with a mean annual incidence rate of 0.71/100,000 per year. Significant clustering was observed (Moran’s index 0.125; z-score 2.832; p = 0.0046) and the highest rates of prevalence were observed in southern Alberta and in rural communities heterogeneously dispersed around Calgary FSAs.ConclusionIn southern and central Alberta, iSGS patients were disproportionately over-represented in contrast to other subtypes with the highest prevalence in southern Alberta. There was a three-fold higher annual incidence compared to previous literature demonstrating the highest rates of disease reported worldwide. Future research aims to expand the geographical scope and to assess for demographic or environmental differences within significant clusters that may contribute to disease pathophysiology.Level of evidenceIII.Graphical

Optimal Design of Paired Built Environment Interventions for Control of MDROs in Acute Care and Community Hospitals.

Our goal was to optimize infection control of paired environmental control interventions within hospitals to reduce methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Enterobacteriaceae (CRE), and vancomycin-resistant Enterococci (VRE). The most widely used infection control interventions are deployment of handwashing (HW) stations, control of relative humidity (RH), and negative pressure (NP) treatment rooms. Direct costs of multidrug-resistant organism (MDRO) infections are typically not included in the design of such interventions. We examined the effectiveness of pairing HW with RH and HW with NP. We used the following three data sets: A meta-analysis of progression rates from uncolonized to colonized to infected, 6 years of MDRO treatment costs from 400 hospitals, and 8 years of MDRO incidence rates at nine army hospitals. We used these data as inputs into an Infection De-Escalation Model with varying budgets to obtain optimal intervention designs. We then computed the infection and prevention rates and cost savings resulting from these designs. The average direct cost of an MDRO infection was $3,289, $1,535, and $1,067 for MRSA, CRE, and VRE. The mean annual incidence rates per facility were 0.39%, 0.034%, and 0.011% for MRSA, CRE, and VRE. After applying the cost-minimizing intervention pair to each scenario, the percentage reductions in infections (and annual direct cost savings) in large, community, and small acute care hospitals were 69% ($1.5 million), 73% ($631K), 60% ($118K) for MRSA, 52% ($460.5K), 58% ($203K), 50% ($37K) for CRE, and 0%, 0%, and 50% ($12.8K) for VRE. The application of this Infection De-Escalation Model can guide cost-effective decision making in hospital built environment design to improve control of MDRO infections.

Kawasaki disease in Latvia 2012–2019: epidemiology and rate of resistance to initial treatment

IntroductionKawasaki disease (KD) is an acute febrile illness of early childhood, characterised by vasculitis of the coronary and medium-sized arteries. The incidence of the disease differs worldwide, but the incidence of KD has not been established in Latvia. The aim of the study was to describe the epidemiological characteristics and estimate the incidence rate and resistance to initial treatment of KD among hospitalised children in Latvia.Material and methodsThe study was a descriptive, population-based study, which used hospital discharge records of patients &lt; 18 years old diagnosed with KD in the years 2012–2019. Incidence rate was calculated using the number of KD patients and corresponding national census data.Resultshere were 36 KD patients in Latvia. The median age at admission was 2.8 years, with 67% of cases under 5 years of age, and the male/female ratio was 1.3 : 1. The mean annual incidence rate was 1.3 per 100,000 children 0–18 years old, and 2.9 per 100,000 for children &lt; 5 years old. The mean length of hospital stay was 14 days. Coronary artery dilatation was recorded in 8% of the patients (all of whom were male). Every patient received intravenous immunoglobulin (IVIG), with a median of 7 days from fever onset to IVIG administration. Refractory treatment was reported in 25% of cases.ConclusionsThis is the first epidemiological study of KD in Latvia. The incidence rates are lower than those reported for other European countries. The percentage of refractory treatment was higher than in other studies.

Identification of Ross River virus hot spots along urban fringes of South East Queensland, Australia

Background/Aim: Ross River virus (RRV) is responsible for the most common vector-borne disease of humans reported in Australia. The virus circulates in enzootic cycles between multiple species of mosquitoes, wildlife reservoir hosts and humans. Despite regular outbreaks, ongoing morbidity and substantial economic costs, the underlying determinants of epidemics remain unclear. Public health concern about RRV has recently increased due to rising incidence rates in Australian urban centres, along with increased circulation in Pacific Island countries. We aimed to provide a detailed analysis of disease trends and explore potential links between disease patterns and transmission pathways of RRV. Methods: We assessed the spatial and temporal distribution of notified RRV cases, and associated epidemiological features in south east Queensland, Australia, from 2001-2016. This included fine-scale analysis of disease patterns across the suburbs of the endemic capital city of Brisbane, and those of 8 adjacent Local Government Areas. Results: The mean annual incidence rate for the region was 41/100,000 with a consistent seasonal peak between February and May. The highest RRV incidence was in adults aged from 30-64 years (mean incidence rate: 59/100,000), and females had higher incidence rates than males (mean incidence rates: 44/100,000 and 34/100,000, respectively). Spatial patterns of disease were heterogeneous between years, and there was a wide distribution of disease across both urban and rural areas of SEQ. Overall, the highest incidence rates were reported from predominantly rural suburbs to the north of Brisbane City, with significant hot spots located in peri-urban suburbs where residential, agricultural and conserved natural land use types intersect. Conclusions: Although RRV is endemic across all of SEQ, transmission is most concentrated in areas where urban and peri-urban environments intersect. The drivers of RRV transmission across rural-urban landscapes should be prioritised for further investigation, including identification of specific vectors and hosts that mediate human spillover.

Trends in the Incidence of Central Precocious Puberty and Normal Variant Puberty Among Children in Denmark, 1998 to 2017

There has been a worldwide secular trend toward earlier onset of puberty in the general population. However, it remains uncertain if these changes are paralleled with increased incidence of central precocious puberty (CPP) and normal variant puberty (ie, premature thelarche [PT] and premature adrenarche [PA]) because epidemiological evidence on the time trends in the incidence of these puberty disorders is scarce. To provide valid epidemiological data on the 20-year secular trend in the incidence rates of CPP and normal variant puberty. This population-based, 20-year cohort study used national registry data for all youth in Denmark registered with an incident diagnosis of CPP, PT, or PA in the Danish National Patient Registry from 1998 to 2017 (N = 8596) using the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10). We applied the maximum diagnostic age limit for precocious puberty (ie, onset of puberty before age 8 years for girls and age 9 years for boys) with and without a 12-month lag to address time from first contact to final registration in the Danish National Patient Registry. Data analysis was conducted in 2019. Diagnosis of CPP, PT, or PA. The age-specific and sex-specific incidence rates of first-time diagnosis of CPP, PT, and PA were estimated using data from the Danish National Patient Registry from 1998 to 2017, and information about the total number of children at risk within the same age groups and sex from Statistics Denmark. Incidences were stratified according to immigration group (Danish origin, first-generation immigrant, second-generation immigrant). Overall a total 8596 children (7770 [90.4%] girls; median [interquartile] age at diagnosis for boys, 8.0 [7.1-9.0] years; for girls, 8.0 [7.6-8.5] years) were registered with an incident diagnosis of CPP, PT, or PA, of whom 7391 (86.0%) had Danish origin (6671 [90.3%] girls), corresponding to 370 new cases in children with Danish origin per year. The 20-year mean annual incidence rates of CPP, PT, PA, and all 3 conditions per 10 000 girls with Danish origin were 9.2 (95% CI, 8.0 to 10.3), 1.1 (95% CI, 0.7 to 1.5), 1.3 (95% CI, 0.9 to 1.7), and 11.5 (95% CI, 10.3 to 12.8), respectively. For boys with Danish origin, the 20-year mean annual incidence rates per 10 000 boys were lower: 0.9 (95% CI, 0.6 to 1.2), 0.2 (95% CI, 0.1 to 0.4), and 1.1 (95% CI, 0.7 to 1.4) for CPP, PA, and the sum, respectively. There was a 6-fold increase in incidence for girls with Danish origin (from 2.6 per 10 000 to 14.6 per 10 000) and a 15-fold increase for boys with Danish origin (from 0.1 per 10 000 to 2.1 per 10 000). The 20-year mean incidence of CPP and PA among girls in the first-generation and second-generation immigrant groups were greater than that of girls with Danish origin. The incidence rate for CPP per 10 000 girls in the first-generation and second-generation groups were 13.7 (95% CI, 9.3 to 18.2) and 14.2 (95% CI, 4.6 to 23.9), respectively; the incidence rate for PA per 10 000 girls in the first-generation and second-generation groups were 2.0 (95% CI, 0.3 to 3.6) and 1.5 (95% CI, -1.6 to 4.7), respectively. No differences associated with immigration status were observed among boys. Our findings suggest that the annual incidence of CPP and normal variant puberty has substantially increased in Denmark during the last 20 years. These findings have implications for short-term and long-term health and potentially for the international classification of the reference age of puberty.

Spatial and temporal patterns of Ross River virus in south east Queensland, Australia: identification of hot spots at the rural-urban interface

BackgroundRoss River virus (RRV) is responsible for the most common vector-borne disease of humans reported in Australia. The virus circulates in enzootic cycles between multiple species of mosquitoes, wildlife reservoir hosts and humans. Public health concern about RRV is increasing due to rising incidence rates in Australian urban centres, along with increased circulation in Pacific Island countries. Australia experienced its largest recorded outbreak of 9544 cases in 2015, with the majority reported from south east Queensland (SEQ). This study examined potential links between disease patterns and transmission pathways of RRV.MethodsThe spatial and temporal distribution of notified RRV cases, and associated epidemiological features in SEQ, were analysed for the period 2001–2016. This included fine-scale analysis of disease patterns across the suburbs of the capital city of Brisbane, and those of 8 adjacent Local Government Areas, and host spot analyses to identify locations with significantly high incidence.ResultsThe mean annual incidence rate for the region was 41/100,000 with a consistent seasonal peak in cases between February and May. The highest RRV incidence was in adults aged from 30 to 64 years (mean incidence rate: 59/100,000), and females had higher incidence rates than males (mean incidence rates: 44/100,000 and 34/100,000, respectively). Spatial patterns of disease were heterogeneous between years, and there was a wide distribution of disease across both urban and rural areas of SEQ. Overall, the highest incidence rates were reported from predominantly rural suburbs to the north of Brisbane City, with significant hot spots located in peri-urban suburbs where residential, agricultural and conserved natural land use types intersect.ConclusionsAlthough RRV is endemic across all of SEQ, transmission is most concentrated in areas where urban and peri-urban environments intersect. The drivers of RRV transmission across rural-urban landscapes should be prioritised for further investigation, including identification of specific vectors and hosts that mediate human spillover.

Detailed epidemiological analysis as a strategy for evaluating the actual behavior of tuberculosis in an apparently low-incidence region

ABSTRACT Tuberculosis control in developing regions with apparent low incidence, like the low-income Mexican state of Michoacán, with mean annual incidence rates below 10/100,000 inhabitants, requires knowledge of the actual behavior of the disease. This can be determined using an epidemiological profile at sub-regional level, allowing disclosure of the clinical and social factors that may be hampering efforts to control tuberculosis. In this work, a detailed epidemiological profile was outlined using data of all new monthly cases registered in the National System of Epidemiological Surveillance Database for Michoacán municipalities from 2000 to 2012. Cases were grouped by gender and age, and sociodemographic data were obtained both from the National Institute of Statistics and Geography and from the United Nations Development Programme. Correlations were calculated by Chi-square, Mann-Whitney U, and Kruskal-Wallis H tests. We observed no statistically significant differences between notification rates for the years 2000, 2005 and 2010 (χ2 = 0.222, p = 0.895). The percentage of cases is similar between all age groups older than 15, while some regions had low notification rates but high proportions of pediatric cases. Higher proportions of cases of extrapulmonary tuberculosis were observed in municipalities in northern Michoacán. No correlation was found between municipal Human Development Index values and municipal notification rates. Michoacán is undergoing an epidemiological transition with three regions having different epidemiological profiles and particular needs for effective prevention and containment of tuberculosis. Our work shows the importance of the spatial scale of epidemiological profiles for determining specific regional needs of surveillance and containment.

Incidence of acute rheumatic fever and rheumatic heart disease in Melbourne, Australia from 1937 to 2013.

Acute rheumatic fever (ARF) most commonly presents in children aged 5-14 years old. Lifelong rheumatic heart disease (RHD) can result. This study investigated time trends in ARF and RHD using inpatient data from the Royal Children's Hospital, Melbourne (RCH). A retrospective cohort study covering the period 1937-2013 was conducted using records from RCH, a quaternary paediatric hospital in Melbourne, Victoria, Australia. Patient data were identified using RCH classification of diseases coding for ARF or RHD for years <1952. For the period 1952-1987, this system was used in addition to identifying International Classification of Disease (ICD) discharge codes that corresponded to ARF or RHD. From 1988-2013, only ICD codes were used to identify patient data. Descriptive epidemiological analyses were performed, including incidence rate calculations using historical census population denominator data. Analyses focussed on children in the peak age group. Among children aged five to 14 years, a total of 4337 RCH admissions with ARF/RHD occurred for 3015 patients. A sharp decline in first ARF/RHD hospitalisations at RCH occurred from 1959, following a peak mean annual incidence rate during 1944-1947 of 40.1/100 000 children (95% confidence interval (CI): 36.6-43.9; P < 0.05). Over 1996-2013, the mean annual incidence rate was 1.6/100 000 (95% CI: 1.3-1.8) and reached 2.3/100 000 (95% CI: 1.3-3.7) in 2005. The burden of ARF and RHD treated at RCH declined following the 1940s, mirroring changes seen in North America and Europe. Despite this, inpatient treatment for these conditions continued to be provided right up until the end of the study period.

Demographic and epidemiological characteristics of scorpion envenomation and daily forecasting of scorpion sting counts in Touggourt, Algeria.

OBJECTIVESThis study was conducted to provide better insights into the demographic and epidemiological characteristics of scorpion envenomation in an endemic area in Algeria and to identify the model that best predicted daily scorpion sting counts.METHODSDaily sting data from January 1, 2013 to August 31, 2016 were extracted from questionnaires designed to elicit information on scorpion stings from the two emergency medical service providers in Touggourt, Algeria. Count regression models were applied to the daily sting data.RESULTSA total of 4,712 scorpion sting cases were documented, of which 70% occurred in people aged between 10 years and 49 years. The male-to-female ratio was 1.3. The upper and lower limbs were the most common locations of scorpion stings (90.4% of cases). Most stings (92.8%) were mild. The percent of people stung inside dwellings was 68.8%. The hourly distribution of stings showed a peak between 10:00 a.m. and 11:00 a.m. The daily number of stings ranged from 0 to 24. The occurrence of stings was highest on Sundays. The incidence of scorpion stings increased sharply in the summer. The mean annual incidence rate was 542 cases per 100,000 inhabitants. The fitted count regression models showed that a negative binomial hurdle model was appropriate for forecasting daily stings in terms of temperature and relative humidity, and the fitted data agreed considerably with the actual data.CONCLUSIONSThis study showed that daily scorpion sting data provided meaningful insights; and the negative binomial Hurdle model was preferable for predicting daily scorpion sting counts.

Long-term monitoring of tick-borne viral encephalitis and tick-borne borreliosis in the Komi Republic

Our study was aimed at analyzing data combining objective epidemiological, zoological and entomological research intended to determine the environmental and epidemiological patterns of tick-borne encephalitis (TBE) and Lyme borreliosis (LB) foci, as well as the role of anthropogenic factors in epidemic manifestations to improve anti-epidemic activities. Long-term data on the abundance of ticks flagged from vegetation in various districts of the Komi Republic (RK) have been analyzed. The prevalence of tick-borne encephalitis virus (TBEV) and Borrelia burgdorferi (agent of LB) in ticks picked from vegetation, humans and domestic animals in various districts of the RK was measured by using enzyme-linked immunosorbent assay and polymerase chain reaction (PCR-ELISA). In addition, the data on 1994–2017 tick-bite incidence in RK, 1970–2017 TBE incidence, and 1997–2017 LB incidence were also examined and correlated with the impact of forest transformation on the TBE incidence. The rise of tick population in the southern districts of RK and its northward expansion were noted. It is also shown that the RK territory, where tick bites are registered, expanded significantly. Mean annual tick-bite incidence rate in 2006–2017 vs. 1994–2005 timeframe was increased by 4-fold. RK regions where deforestation took place, the tick-bite incidence was increased, and the local TBE incidence elevated distinctly. In recent years, there was a rise in TBEV prevalence in ticks, collected either from vegetation or from humans and animals. In 2006–2017 and 1970–1981, mean annual TBE incidence rate increased by a 11- and 36-fold as compared to that one registered in 1982–1993. In recent years, the most severe focal TBE forms began to be recorded. In 1996–2017, the TBE mortality rate was 2.3%. The main features of LB epidemiology mimic those found in TBEV. In particular, the prevalence of Borrelia burgdorferi in ticks flagged from vegetation increased from 9.5% to 34.7% in 2010 vs. 2017, respectively. A sharp rise in LB incidence rate and profound northward shift for bacterial range, where this infection started to be registered only in recent years, were noted. Both TBE and LB demonstrated marked occupation-related pattern. The need in conducting task-oriented prophylaxis of tick-borne infections is necessitated by taking into account geographic specifics. The RK northern regions should be considered as potentially endemic, where tick bites in human population has recently begun to be reported.

Culture-Confirmed Invasive Meningococcal Disease in Canada, 2010 to 2014: Characterization of Serogroup B Neisseria meningitidis Strains and Their Predicted Coverage by the 4CMenB Vaccine.

The molecular epidemiology of culture-confirmed invasive meningococcal disease (IMD) in Canada from 2010 to 2014 was studied with an emphasis on serogroup B Neisseria meningitidis (MenB) isolates, including their predicted coverage by the 4CMenB vaccine. The mean annual incidence rates of culture confirmed IMD varied from 0.19/100,000 in Ontario to 0.50/100,000 in New Brunswick and 0.59/100,000 in Quebec. In both Quebec and Atlantic region, MenB was significantly more common than other serogroups, while in other provinces, both MenB and serogroup Y (MenY) were almost equally common. The majority of MenB cases (67.0%) were in those aged ≤24 years, while most MenC (75.0%) and MenY (69.6%) cases were in adults more than 24 years old. The 349 MenB isolates were grouped into 103 sequence types (STs), 90 of which belonged to 13 clonal complexes (CCs). A large number of 4CMenB antigen genes were found among the Canadian MenB, which is predicted to encode 50 factor H binding protein (fHbp) types, 40 NHBA types, and 55 PorA genotypes. Provinces and regions were found to have their own unique MenB STs. A meningococcal antigen typing system assay predicted an overall MenB coverage by 4CMenB to be 73.6%, with higher coverage predicted for the two most common STs: 100% for ST154 and 95.9% for ST269, leading to higher coverage in both the Atlantic region and Quebec. Higher coverage (81.4%) was also found for MenB recovered from persons aged 15 to 24 years, followed by strains from infants and children ≤4 years old (75.2%) and those aged 5 to 14 years (75.0%).IMPORTANCE Laboratory surveillance of invasive meningococcal disease (IMD) is important to our understanding of the evolving nature of the Neisseria meningitidis strain types causing the disease and the potential coverage of disease strains by the newly developed vaccines. This study examined the molecular epidemiology of culture-confirmed IMD cases in Canada by examining the strain types and the potential coverage of a newly licensed 4CMenB vaccine on Canadian serogroup B N. meningitidis strains. The strain types identified in different parts of Canada appeared to be unique as well as their predicted coverage by the 4CMenB vaccine. These data were compared to data obtained from previous studies done in Canada and elsewhere globally. For effective control of IMD, laboratory surveillance of this type was found to be essential and useful to understand the dynamic nature of this disease.