Age Distribution Of Disease Research Articles

Актуальные проблемы эпидемиологии офтальмологической заболеваемости среди молодежи России и Центрального федерального округа.

Indicators of primary morbidity of the eyes and their appendages in adolescents aged 15–17 years and young people, in particular among students of higher educational institutions, increase annually due to increased visual stress as risk factors. The purpose of the work is to identify current problems in the epidemiology of ophthalmological morbidity among young people in the Russian Federation and the Central Federal District. Materials and methods. A theoretical analysis of the literature on the epidemiology of ophthalmic diseases in young people and a search for statistical data on the epidemiology of ophthalmic diseases was carried out. To assess the dynamics of epidemiological indicators, an increase calculation was carried out. Results. The increase in the incidence of visual organs in adolescents per 100 thousand children aged 15–17 years from 2000 to 2021 was +47.9%, and from 2018 to 2019 the increase in the incidence of myopia was +9.2%. In the structure of diseases for adolescents, it is pathologies of the visual organs that lead, and 40% of students have visual impairments, the detection of which increases by 3–7% annually, while the severity of myopia grows every year by 5–7%. The increase in morbidity of the eyes and adnexa in the Central Federal District for 2019–2021 was +57.5%, however, morbidity statistics do not consider the age distribution of diseases and their structure. The largest (+296.0 +110.1%) increase per 100 thousand population is observed for the Vladimir, Voronezh, Lipetsk, Ivanovo and Kaluga regions. It was revealed that in 2017, the incidence rate of eyes and their appendages in the Voronezh region over 10 years increased from 64.8 to 94.8 per 1000 students, 45.6% of students had impaired visual acuity. In the region, there is a staff shortage of ophthalmologists, insufficient coverage of preventive examinations and a low level of detection of patients at an early stage of disease. Conclusion. The epidemiology of eye diseases on the territory of the Russian Federation and its constituent entities in the young population has not been sufficiently studied. Improving regional analysis tools will help identify factors of variability in the epidemiology of eye diseases across the country’s regions. In regions with a high increase in ophthalmic morbidity, it is necessary to study in more detail the epidemiology of vision diseases in young people.

Impact of variability of reproductive ageing and rate on childhood infectious disease prevention and control: insights from stage-structured population models.

We propose a stage-structured model of childhood infectious disease transmission dynamics, with the population demographics dynamics governed by a certain family and population planning strategy giving rise to nonlinear feedback delayed effects on the reproduction ageing and rate. We first describe the long-term aging-profile of the population by describing the pattern and stability of equilibrium of the demographic model. We also investigate the disease transmission dynamics, using the epidemic model when the population reaches the positive equilibrium (limiting equation). We establish conditions for the existence, uniqueness and global stability of the disease endemic equilibrium. We then prove the global stability of the endemic equilibrium for the original epidemic model with varying population demographics. The global stability of the endemic equilibrium allows us to examine the effects of reproduction ageing and rate, under different family planning strategies, on the childhood infectious disease transmission dynamics. We also examine demographic distribution, diseases reproductive number, infant disease rate and age distribution of disease, and as such, the work can be potentially used to inform targeted age group for optimal vaccine booster programs.

Cost-effectiveness of pneumococcal conjugate vaccination in Croatia

ObjectivePneumococcus is a known cause of meningitis, pneumonia, sepsis, and acute otitis media in children and adults globally. Two new vaccines for children have the potential to prevent illness, disability, and death, but these vaccines are expensive. The Croatian Ministry of Health has considered introducing the vaccine in the past, but requires economic evidence to ensure that the limited funds available for health care will be used in the most effective way. MethodologyCroatia appointed a multidisciplinary team of experts to evaluate the cost-effectiveness of introducing pneumococcal conjugate vaccination (PCV) into the national routine child immunization program. Both 10-valent and 13-valent PCV (PCV10 and PCV13) were compared to a scenario assuming no vaccination. The TRIVAC decision-support model was used to estimate cost-effectiveness over the period 2014–2033. We used national evidence on demographics, pneumococcal disease incidence and mortality, the age distribution of disease in children, health service utilization, vaccine coverage, vaccine timeliness, and serotype coverage. Vaccine effectiveness was based on evidence from the scientific literature. Detailed health care costs were not available from the Croatian Institute for Health Insurance at the time of the analysis so assumptions and World Health Organization (WHO) estimates for Croatia were used. We assumed a three-dose primary vaccination schedule, and an initial price of US$ 30 per dose for PCV10 and US$ 35 per dose for PCV13. We ran univariate sensitivity analyses and multivariate scenario analyses. ResultsEither vaccine is estimated to prevent approximately 100 hospital admissions and one death each year in children younger than five in Croatia. Compared to no vaccine, the discounted cost-effectiveness of either vaccine is estimated to be around US$ 69,000–77,000 per disability-adjusted life-years (DALYs) averted over the period 2014–2033 (from the government or societal perspective). Only two alternative scenarios were borderline cost-effective (US$ per DALY averted less than 3×GDP per capita of approximately US$ 40,000). The first was a scenario based primarily on the WHO 2008 pneumococcal disease burden estimates for Croatia. The second was a scenario that assumed a fairly dramatic drop in the price of the vaccine over the period. Both vaccines would need to be priced at approximately US$ 20 per dose or less to be considered cost-effective under base-case assumptions. PCV10 would be more cost-effective than PCV13 with base-case assumptions, but this is sensitive to the price of each vaccine. ConclusionBased on estimated health and economic benefits in children alone, PCV is unlikely to be cost-effective in Croatia. Both vaccines would need to be priced at less than US$ 20 per dose to be considered cost-effective for children. Further analyses should be conducted to estimate the health and economic burden of pneumococcal disease in older age groups, and to assess the influence on cost-effectiveness results when short-term and long-term indirect effects are included for older individuals. While there are important uncertainties around the price and effectiveness of both vaccines, our analysis suggests there is insufficient evidence to warrant a significant difference in the price of the two vaccines.

Epidemiological Pattern of Scabies and Its Social Determinant Factors in West of Iran

Objectives: Scabies has a different epidemiological distribution among different communities worldwide due to different social factors, management approaches and healthcare policies. The present study came to address outbreaks of scabies according to the social factors in west of Iran. Methods: In a cross-sectional study, using the census sampling method, all consecutive patients with the primary diagnosis of scabies based on clinical manifestations referred to healthcare center throughout the two great provinces of Hamadan and Kermanshah at western Iran between March 2006 and February 2010 were enrolled into the study. The baseline characteristics were collected from recorded files at the healthcare centers or by interviewing with the affected patients. Results: Among 3,625,966 subjects covered by the two studied provinces, 177 cases of scabies (170 cases in Kermanshah and 7 cases in Hamadan) were identified by medical staff at the healthcare centers according to clinical manifestations (85.3%) and laboratory microscopic assessments (14.7%). The highest and the lowest prevalence rates were specified to 2009 (58.2%) and 2008 (1.7%). Regarding gender distribution of disease, 53.1% of men and 46.9% of women suffered from scabies with no significant discrepancy. In respect to age distribution of disease, the highest rates of scabies were revealed in the ages ranged 17 to 30 years (31.6%), followed by younger than 17 years (30.5%). The prevalence of scabies was dependently associated with residency in rural areas, family history of scabies, lower educational level, household density, lower monthly income, low personal hygiene, the existence of livestock or rodents at home, seasonal conditions, and movement to contaminated areas. Conclusion: West region of Iran especially Kermanshah province faced with high prevalence and this high disease burden can be determined by some potential factors such as residency in rural areas, family history of scabies, lower educational level, household density, lower monthly income, low personal hygiene, the existence of livestock or rodents at home, seasonal conditions, and movement to contaminated areas.

The Impact of Truncation and Missing Family Links in Population-based Registers on Familial Risk Estimates

Family history information is often incomplete in population-based disease registers because of truncation and/or missing family links. In this study, the authors simulated complete populations of related individuals with realistic age, family structure, and incidence rates. After mimicking the realities of register-based data, such as left truncation of family history and missing family links due to death, the authors explored recovery of familial association parameters from standard epidemiologic models. Truncation of family history produced almost no bias for a familial risk of 2 and 50 years of follow-up, but it had a dramatic impact when the familial risk was 10. The age distribution of disease and the magnitude of background incidence rates also affected family history loss and thus the magnitude of bias. One can safeguard against bias by starting follow-up later, with the number of registration years to be ignored in the analysis depending on the value of familial risk. The missing familial links due to death had no effect, except when there was differential mortality for cases with and without a family history of disease. In summary, truncation, and to a lesser extent missing family links, induces bias in familial risk estimates from population-based registers.

Clinicopathological findings associated with feline infectious peritonitis in Sydney, Australia: 42 cases (1990-2002).

Objectives To review the clinicopathological findings in naturally‐occurring, histopathologically confirmed cases of feline infectious peritonitis in client‐owned cats in Sydney, Australia, with the purpose of identifying factors assisting in the diagnosis of this complex disease syndrome and to characterise the disease as it occurs in this region. Design Retrospective clinical study: the clinical records of all cats with histopathologically confirmed feline infectious peritonitis at the University Veterinary Centre Sydney and a private cat hospital in Sydney between 1990 and 2002 were reviewed for signalment, history, physical findings, diagnostic test results and the distribution of histological lesions throughout the body at necropsy. Results Forty‐two cats met the inclusion criteria. Significant features of this study that unique to the contemporary literature are i) the over‐representation of certain breeds (Burmese, Australian Mist, British Shorthaired, and Cornish Rex) and the under‐representation of other breeds (Domestic Shorthaired, Persian); ii) the overrepresentation of males; iii) the tendency for effusive disease in Australian Mist cats and non‐effusive disease in Burmese; iv) the even age distribution of disease seen in cats older than 2 years‐of‐age; and v) the presence of fulminant immune‐mediated haemolytic anaemia in two cats in this study. Conclusion The study highlights the diverse range of clinical manifestations and the complexities experienced by clinicians in diagnosing this fatal disease. Some aspects of the epidemiology and clinical manifestations of feline infectious peritonitis appear different to the disease encountered in Europe and North America, most notably the over‐representation of specific breeds and the presence of immune‐mediated haemolytic anaemia.

Epidemiological features of rotavirus infection in Caracas, Venezuela: implications for rotavirus immunization programs.

The epidemiological features of rotavirus infection may be quite relevant for evaluation of the performance of a rotavirus vaccine in different settings, as well as for monitoring its impact during vaccination under routine conditions. This article describes some important issues regarding rotavirus epidemiology in Venezuela, where major field trials of rotavirus vaccine have been carried out. Rotaviruses was significantly more frequently observed in inpatient (43%) than in outpatient (21%) consultations for diarrhea in infants and young children. There was a high prevalence of rotavirus illness, regardless of socioeconomic conditions, but the risk of dehydration was greater among the lower socioeconomic groups. Rotavirus disease occurs year-round, with a slight seasonal pattern. Eighty-five percent of rotavirus-positive diarrheal episodes, as well as 86% of cases of dehydration due to rotavirus, occurred during the first year of life. However, rotavirus illnesses occur less commonly during the first months of life (0-2 months), which may be a result of protection by transplacental antibodies. The pattern of acquisition of rotavirus antibody was consistent with this age distribution of disease and with optimal age for vaccination. Thus, regional epidemiological characteristics of rotavirus infection may affect optimal performance of rotavirus vaccine.

Choosing the limits to life.

How can the world's population be made more healthy? Study of the age distribution of diseases and causes of death in individual countries will enable nationally appropriate research and public-health priorities to be set.

Molecular Epidemiology of Haemophilus influenzae Type b

Ninety-five percent of systemic Haemophilus influenzae infections in childhood are caused by serotype b organisms. The high risk for mortality and serious sequelae and the increase in antibiotic resistance of H influenzae type b are strong arguments for vaccination. Incidences and age distribution of disease caused by H influenzae type b vary considerably among countries. Compiled data for meningitis show the highest incidences to be among Alaskan Eskimos, Navajo and White Mountain Indians, and aboriginals in Australia. High incidences coincide with a peak incidence in a younger age group. This differs from Finland, where 95% of the cases of disease caused by H influenzae type b occur in children older than 7 months of age. In general, incidences are low in industrial and high in nonindustrial areas. For example, in Gambia the highest age-specific incidence is at 4 to 5 months after birth (H.A.B., unpublished data, 1988). This implies that a vaccine and regimen similar to that used in Finland would not be as efficacious if used in Gambia because of differences in demographics and incidence. Vaccines that confer protection at 3 to 4 months of age are, therefore, strongly desired. Outer membrane proteins and lipopolysaccharides of H influenzae type b have been suggested as alternative vaccine candidates in conjugation with the capsular polysaccharide because they apparently can contribute to the virulence of H influenzae type b. The occurrence and immunogenicity of various outer membrane proteins and lipopolysaccharides among H influenzae type b in industrial and nonindustrial countries and their significance as epidemiologic markers for the spread of disease, the type of disease, the age of acquisition, and their association with antibiotic resistance will be reviewed in this article.(ABSTRACT TRUNCATED AT 250 WORDS)

Modeling malaria vaccines II: Population effects of stage-specific malaria vaccines dependent on natural boosting

Population effects of malaria vaccination programs will depend on the stage specificity of the vaccine, its duration of effectiveness, whether it is responsive to natural boosting, the proportion vaccinated, and the preexisting endemic conditions. This paper develops models of infection-blocking (sporozoite), disease-modifying (merozoite), and transmission- blocking (gametic) vaccines. It explores numerically their different effects on prevalence of infection and disease when utilized in different types of immunization programs at various levels of coverage. Simulations show that possible qualitative consequences of malaria vaccination programs include decreased prevalence of infection and disease and decreased prevalence of infection without a corresponding decrease in prevalence of disease. Epidemics, either one-time or cyclical, could occur. These effects could be accompanied by changes in the age distribution of disease. Finally, vaccination could contribute to elimination of transmission. The duration of effectiveness of the malaria vaccine relative to the duration of natural immunity could have important consequences for the unvaccinated. The problem of predicting a threshold for elimination of transmission is discussed.

John Brownlee and the Measurement of Infectiousness: An Historical Study in Epidemic Theory

SUMMARY THE development of the germ theory, during the course of the nineteenth century, was a pivotal event in the history of medicine. Its impact was enormous, leading all of the biomedical sciences away from previously held notions of miasmas and humours, towards more rigorous concepts of specific aetiologies and appropriate preventive and therapeutic measures. Though the discoveries of Pasteur and of Koch stand out in any history of the germ theory, its develop- ment involved major contributions by many other workers. Included in the effort were not only microbiologists, but also a number of epidemiologists, notably Panum and Snow, whose detailed studies of population patterns of disease seriously challenged the notion of miasmas and resurrected Fracastoro's idea of a contagium vivum. It is interesting to note that virtually all of the builders of this germ were practical men. Though there were obvious theoretical implications to their work, they were in a very real sense not theorists; and their immediate interests were directed towards practical solutions of specific disease problems. Thus Panum advocated isolation and quarantine against measles, Snow removed the handle of the pump incriminated in cholera transmission, and Pasteur repeatedly applied his researches to the development of vaccines and other control measures. The pure theorists came later, those who generalized and abstracted the information about infectious in order to derive global explanations for the patterns of disease in time, space and populations. There were many problems which lent themselves to such theorizing, which could indeed hardly be approached otherwise: the duration and frequency of epidemics, the relationship between population size and disease pattern, the spatial spread of disease, the age distribution of disease, and so forth. And essential to the building of this body of theory was the development of an appropriate quantitative measure for infectiousness, or infectivity, the fundamental property of those germs which had been found responsible for disease. But this turned out to be a surprisingly difficult problem, whose solution required many years. Furthermore, it raised ancillary problems which had an important influence upon much microbiological and epidemiological work for almost half a century. It is the intent of this paper to discuss the evolution of this quantitative concept of infectivity as it is reflected in the theoretical epidemiology literature. Because he was the first to formulate