Age-specific Case-fatality Rates Research Articles

Age-dependent virulence of human pathogens.

Host age is often evoked as an intrinsic factor aggravating the outcome of host-pathogen interactions. However, the shape of the relationship between age and infection-induced mortality might differ among pathogens, with specific clinical and ecological traits making some pathogens more likely to exert higher mortality in older hosts. Here, we used a large dataset on age-specific case fatality rate (CFR) of 28 human infectious diseases to investigate i) whether age is consistently associated to increased CFR, ii) whether pathogen characteristics might explain higher CFR in older adults. We found that, for most of the infectious diseases considered here, CFR slightly decreased during the first years of life and then steeply increased in older adults. Pathogens inducing diseases with long-lasting symptoms had the steepest increase of age-dependent CFR. Similarly, bacterial diseases and emerging viruses were associated with increasing mortality risk in the oldest age classes. On the contrary, we did not find evidence suggesting that systemic infections have steeper slopes between CFR and age; similarly, the relationship between age and CFR did not differ according to the pathogen transmission mode. Overall, our analysis shows that age is a key trait affecting infection-induced mortality rate in humans, and that the extent of the aggravating effect on older adults depends on some key traits, such as the duration of illness.

Patterns of diarrhoeal disease among under-five children in Plateau State, Nigeria, 2013\u20132017

BackgroundDiarrhoea is the second commonest cause of under-five mortality accounting for over half a million deaths annually. Although the prevalence of diarrhoea in Plateau State is lower than the national figure, the level remains high despite remarkable progress in the reduction of under-five mortality. This study seeks to determine the pattern of diarrhoea disease among under-fives in Plateau State.MethodsWe extracted data from the Integrated Disease Surveillance and Response platform between January 2013 and December 2017 and analysed the trends of diarrhoea, age-specific case fatality rate (ASCFR), and seasonal patterns. We modelled the quarterly pattern of diarrhoea cases using additive time series and predicted the expected cases for 2018–2020.ResultsWe documented 60,935 cases of diarrhoea with age group 12–59 months having the highest number of cases (49.3%). The age group < 1 month had the highest ASCFR of 0.53%. Seasonal variation showed cases peaked in the first and third quarters of each year, except for the year 2016. The time series projection estimated 16,256, 17,645 and 19,034 cases in the year 2018, 2019 and 2020 respectively.ConclusionSeasonal variation exists, and trends show an increased pattern of diarrhoeal disease among under-fives. There is a need to strengthen the implementation of diarrhoeal preventive and control strategy in the state and to improve the quality of data reporting.

Profile of COVID 19 positive patients of Balochistan, Pakistan

Background: Current study aim to describe epidemiological, clinical and demographic features in patients confirmed to have COVID-19 in Balochistan Methods: This descriptive cross sectional Study was conducted during months of March and April 2020 based on the secondary data available regarding COVID-19 positive patients from the health service records of Government of Balochistan quarantine centers and hospitals during this period. Data was analyzed by using Excel and SPSS version 23. Mean and standard deviations are used for continuous variables like age and duration of stay (of recovered patients), while frequencies and percentages were used to describe age categories, point of entry and current status. Age specific case fatality rate is calculated by keeping deaths in numerator and confirmed cases in denominator. Results: Mean age of respondents was 35.3±16.12 years , two third of the study population i.e,652(76.3%) were males,353 (40.6)% were in the age group 30-49 years and 417(48.9%) had history of contact with COVID-19 case. Overall case fatality rate was 1.87% and Age Specific Mortality Rate was found to be highest (30%) in age group 70 years and above Conclusion: The epidemiologic behavior of COVID-19 infection introduced in Pakistani population from neighboring country has responded differently in community spread among different ethnic groups represented in different provinces of Pakistan. The case fatality ratios among Baloch ethnic group were much lower than international COVID-19 case responses

Monitoring trends and differences in COVID-19 case-fatality rates using decomposition methods: Contributions of age structure and age-specific fatality.

The population-level case-fatality rate (CFR) associated with COVID-19 varies substantially, both across countries at any given time and within countries over time. We analyze the contribution of two key determinants of the variation in the observed CFR: the age-structure of diagnosed infection cases and age-specific case-fatality rates. We use data on diagnosed COVID-19 cases and death counts attributable to COVID-19 by age for China, Germany, Italy, South Korea, Spain, the United States, and New York City. We calculate the CFR for each population at the latest data point and also for Italy, Germany, Spain, and New York City over time. We use demographic decomposition to break the difference between CFRs into unique contributions arising from the age-structure of confirmed cases and the age-specific case-fatality. In late June 2020, CFRs varied from 2.2% in South Korea to 14.0% in Italy. The age-structure of detected cases often explains more than two-thirds of cross-country variation in the CFR. In Italy, the CFR increased from 4.2% to 14.0% between March 9 and June 30, 2020, and more than 90% of the change was due to increasing age-specific case-fatality rates. The importance of the age-structure of confirmed cases likely reflects several factors, including different testing regimes and differences in transmission trajectories; while increasing age-specific case-fatality rates in Italy could indicate other factors, such as the worsening health outcomes of those infected with COVID-19. Our findings lend support to recommendations for data to be disaggregated by age, and potentially other variables, to facilitate a better understanding of population-level differences in CFRs. They also show the need for well-designed seroprevalence studies to ascertain the extent to which differences in testing regimes drive differences in the age-structure of detected cases.

Using Markov Chain Monte Carlo methods to estimate the age-specific case fatality rate of COVID-19

Objectives: The COVID-19 epidemic has swept all over the world. Estimates of its case fatality rate were influenced by the existing confirmed cases and the time distribution of onset to death, and the conclusions were still unclear. This study was aimed to estimate the age-specific case fatality rate of COVID-19. Methods: Data on COVID-19 epidemic were collected from the National Health Commission and China CDC. The Gamma distribution was used to fit the time from onset to death. The Markov Chain Monte Carlo simulation was used to estimate age-specific case fatality rate. Results: The median time from onset to death of COVID-19 was M=13.77 (P(25)-P(75): 9.03-21.02) d. The overall case fatality rate of COVID-19 was 4.1% (95%CI: 3.7%-4.4%) and the age-specific case fatality rate were 0.1%, 0.4%, 0.4%, 0.4%,0.8%, 2.3%, 6.4%, 14.0 and 25.8% for 0-, 10-, 20-, 30-, 40-, 50-, 60-, 70- and ≥80 years group, respectively. Conclusions: The Markov Chain Monte Carlo simulation method adjusting censored is suitable for case fatality rate estimation during the epidemic of a new infectious disease. Early identification of the COVID-19 case fatality rate is helpful to the prevention and control of the epidemic.

A logistic model for age-specific COVID-19 case-fatality rates.

To develop a mathematical model to characterize age-specific case-fatality rates (CFR) of COVID-19. Based on 2 large-scale Chinese and Italian CFR data, a logistic model was derived to provide quantitative insight on the dynamics between CFR and age. We inferred that CFR increased faster in Italy than in China, as well as in females over males. In addition, while CFR increased with age, the rate of growth eventually slowed down, with a predicted theoretical upper limit for males (32%), females (21%), and the general population (23%). Our logistic model provided quantitative insight on the dynamics of CFR.

Impact of mitigation measures on the COVID-19 pandemic in Chile: preliminary data for the period April 14 to May 14

To model disease progression, healthcare demand and case fatality rate attributed to COVID-19 pandemic that may occur in Chile in 1-month time, by simulating different scenarios according to diverse mitigation measures hypothetically implemented. Furthermore, we aimed to estimate the same outcomes assuming that 70% of the population will be infected by SARS-CoV-2, with no time limit assumption. We based on the number of confirmed COVID-19 cases in Chile up to April 14th 2020 (8 273 cases and 94 deaths). For the simulated scenarios we assumed basic reproduction numbers ranging from R0=2.5 to R0=1.5. The estimation of the number of patients that would require intensive care and the age-specific case fatality rate were based on data provided by the Imperial College of London and the Instituto Superiore di Sanità en Italia. If no mitigation measures were applied (R0=2.5), by May 25, Chile would have 2 019 775 cases and 15 068 deaths. If mitigations measures were implemented to decrease R0 to 1.5 (early detection of cases, quarantine, social distancing of elderly), the number of cases and deaths would importantly decrease. Nonetheless, the demand for in-hospital care including intensive care would exceed the available resources. Our age-specific analysis showed that population over 60 years are at higher risk of needing intensive care and death. Our evidence supports the mitigation measures implemented by the Chilean government. Nevertheless, more stringent measures are needed to prevent the health care system's collapse due to shortfall of resources to confront the COVID-19 pandemic.

Low case fatality during 2017 cholera outbreak in Borno State, North Eastern Nigeria.

Background:Cholera is endemic in sub-Saharan Africa, especially in areas affected by natural disaster and human conflict. Northeastern Nigeria is experiencing a health crisis due to the destruction of essential amenities such as health infrastructure, sanitation facilities, water supplies, and human resources by Boko Haram insurgents. In 2017, a cholera outbreak occurred in five local government areas (LGAs) hosting internally displaced persons. The Nigeria Center for Disease Control, World Health Organization, Mĕdecins Sans Frontiĕres International, and several other organizations supported disease containment. An emergency operating center (EOC) established by the State Ministry of Health (SMoH) then coordinated the outbreak response.Methods:We conducted a retrospective analysis of data extracted from the line list utilized by the SMoH to investigate outbreaks. We evaluated the outbreak by time, place, and person. Attack rate by LGA and age-specific case fatality rate (CFR) was calculated based on cases with complete records for age, sex, place of residence, date of symptom onset, and disease outcome.Results:A total of 5889 cholera cases were reported from five LGAs with an overall attack rate of 395.3/100,000 population. Among 4956 cases with documented outcome, the overall CFR was 0.87%, with CFR ranging from 0% to 6.98% by LGA. The age-specific CFR was highest among those aged ≥60 years (1.92%) and least among those aged 20–29 years at 0.3%. The epidemiological curve revealed two peaks that coincided with periods of heavy rain and flooding.Conclusion:This study reports on the largest ever documented cholera outbreak in five LGAs in Borno State. The outbreak was focused in LGA hit hardest by the destructive activities of insurgents and then spread to neighboring LGAs. The low CFR recorded in this cholera outbreak was achieved through timely detection, reporting, and response by the coordinated efforts of the EOC established by the SMoH that harmonized the outbreak response.

Descriptive epidemiology of a cholera outbreak in Kaduna State, Northwest Nigeria, 2014.

IntroductionCholera is an acute gastrointestinal infection caused by Vibrio cholerae, which may lead to severe dehydration and death if not treated. This analysis is aimed at highlighting the magnitude, pattern and trend of cholera outbreak that occurred in Kaduna State in 2014.MethodsWe obtained the 2014 cholera line-list from the Kaduna State Disease Surveillance and Notification officer (DSNO). We described the outbreaks in time, place and person using Epi-info 7 and Health Mapper.ResultsA total of 1468 case-patients and 54 deaths were recorded, giving a case fatality rate (CFR) of 3.68%. Female case-patients were 809(55.08%). The median age for case-patients was 15 years, with an age range of 0.04-90 years. Age specific case fatality rate (ASCFR) is highest among the > 60 years. Seven (30%) out of the 23 local government areas (LGAs) in Kaduna State were affected by the cholera outbreak in 2014. Igabi LGA has the highest attack rate (150.46 per 100,000 population) while Chikun LGA has the lowest attack rate (12.22 per 100,000 population). Chikun LGA records the highest CFR (17.54%). Cholera infection spread across LGAs sharing the same borders. The outbreak started from the first epidemic week of 2014 and lasted over 33 weeks.ConclusionOur analysis revealed a protracted cholera outbreak that gradually increases in magnitude throughout the first half of 2014 and spread within contiguous LGAs. We recommended the strengthening of the state's diseases surveillance system towards timely detection and early response to disease outbreaks in the future.

Impact of pneumococcal conjugate vaccination: a retrospective study of hospitalization for pneumonia in North-East Italy.

Pneumonia remains a common reason for hospitalizing infants and the elderly worldwide, and streptococcal infection is often responsible. The aim of this study was to assess the burden of pneumonia in a large general population. All pneumonia-related hospitalizations from 2004 to 2013 in north-east Italy were identified from the hospital records with a first-listed diagnosis on discharge of bacterial pneumonia, or a first-listed diagnosis on discharge of meningitis, septicemia or empyema associated with a secondary diagnosis of bacterial pneumonia. We identified major comorbidities, calculated agespecific case-fatality rates (CFR), and estimated the related cost to the health care system. Of the 125,722 hospitalizations identified, 96.9% were cases of pneumonia, 2.4% of septicemia, 0.4% of meningitis, and 0.3% of empyema; 75.3% of hospitalizations involved ≥ 65-yearolds. The overall CFR was 12.4%, and it increased with age, peaking in people over 80 (19.6%). The mean annual pneumonia-associated hospitalization rate was 204.6 per 100,000 population, and it peaked in 0- to 4-year-old children (325.6 per 100,000 in males, 288.9 per 100,000 in females), and adults over 65 (844.9 per 100,000 in males, 605.7 per 100,000 in females). Hospitalization rates dropped over the years for the 0-4 year-olds, and rose for people over 80. The estimated overall annual cost of these pneumonia-related hospitalizations was approximately € 41 million. This study shows that the burden on resources for pneumonia-related hospitalization is an important public health issue. Prevention remains the most valuable tool for containing pneumonia, and vaccination strategies can help in the primary prevention of infection, possibly reducing the number of cases in all age groups.

Estimating the number of hand, foot and mouth disease amongst children aged under-five in Beijing during 2012, based on a telephone survey of healthcare seeking behavior.

BackgroundOver the last decade, increases in the number of outbreaks of hand, foot and mouth disease (HFMD) have shifted the disease into the public health spotlight in China. Children under the age of five years are particularly susceptible, with fatalities recorded. However, estimating the burden of HFMD has been difficult to conduct to date.MethodsIn 2012, a cross-sectional survey of healthcare-seeking behaviour for HFMD was undertaken, using computer assisted telephone interviewing (CATI) technology. Sample of telephone numbers was obtained from the Beijing Immunization Information System. Respondents were parents or guardians of children under the age of five. Multiplier model was used to estimate the number of HFMD case, following the telephone survey of healthcare-seeking behavior. The number of laboratory-confirmed cases was also estimated based on the monthly positive rate of each subtype of virus causing HFMD. The age-specific case fatality rate (CFR) was calculated based on the ratio of reported deaths to the estimated number of cases.ResultsFor children under five, the consultation rate of parent-defined cases was estimated at 77.8% ((95% CI = [75.2, 80.4]). Parents or legal guardians of children aged between two and four years were more likely to seek healthcare than those of children aged less than two years. For children under the age of five, we estimated that there were 40,165 (95% CI = [38,471, 41,974]) HFMD cases, with an incidence rate of 5.6%, and 22,166 (95% CI = [21,150, 23,295]) laboratory-confirmed cases in Beijing during 2012. The overall CFR was estimated at 10 deaths per 100,000 cases, while for children aged less than two years it was 15.6 deaths per 100,000 cases.ConclusionsGiven the public health impact of HFMD in China, control measures need to be prioritized for children < 2 years, due to the higher CFR in this age group. Sentinel surveillance approaches could be used to monitor trends and the impact of control measures.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2334-14-437) contains supplementary material, which is available to authorized users.

Should identical CVD risks in young and old patients be managed identically? Results from two models

ObjectivesTo assess whether delaying risk reduction treatment has a different impact on potential life years lost in younger compared with older patients at the same baseline short-term cardiovascular risk.DesignModelling based...

Age-prioritized use of antivirals during an influenza pandemic

BackgroundThe WHO suggested that governments stockpile, as part of preparations for the next influenza pandemic, sufficient influenza antiviral drugs to treat approximately 25% of their populations. Our aim is two-fold: first, since in many countries the antiviral stockpile is well below this level, we search for suboptimal strategies based on treatment provided only to an age-dependent fraction of cases. Second, since in some countries the stockpile exceeds the suggested minimum level, we search for optimal strategies for post-exposure prophylactic treatment of close contacts of cases.MethodsWe used a stochastic, spatially structured individual-based model, considering explicit transmission in households, schools and workplaces, to simulate the spatiotemporal spread of an influenza pandemic in Italy and to evaluate the efficacy of interventions based on age-prioritized use of antivirals.ResultsOur results show that the antiviral stockpile required for treatment of cases ranges from 10% to 35% of the population for R0 in 1.4 – 3. No suboptimal strategies, based on treatment provided to an age-dependent fraction of cases, were found able to remarkably reduce both clinical attack rate and antiviral drugs needs, though they can contribute to largely reduce the excess mortality. Treatment of all cases coupled with prophylaxis provided to younger individuals is the only intervention resulting in a significant reduction of the clinical attack rate and requiring a relatively small stockpile of antivirals.ConclusionOur results strongly suggest that governments stockpile sufficient influenza antiviral drugs to treat approximately 25% of their populations, under the assumption that R0 is not much larger than 2. In countries where the number of antiviral stockpiled exceeds the suggested minimum level, providing prophylaxis to younger individuals is an option that could be taken into account in preparedness plans. In countries where the number of antivirals stockpiled is well below 25% of the population, priority should be decided based on age-specific case fatality rates. However, late detection of cases (administration of antivirals 48 hours after the clinical onset of symptoms) dramatically affects the efficacy of both treatment and prophylaxis.

Mortality from pandemic A/H1N1 2009 influenza in England: public health surveillance study

Objective To establish mortality from pandemic A/H1N1 2009 influenza up to 8 November 2009.Design Investigation of all reported deaths related to pandemic A/H1N1 in England.Setting Mandatory reporting systems established in...

Subarachnoid haemorrhage in Sweden 1987–2002: regional incidence and case fatality rates

Background:Incidence estimates of subarachnoid haemorrhage (SAH) in Sweden vary, which may be caused by regional variations. Reliable estimates of age-specific case fatality rates are lacking. We analysed regional incidence rates...

West Nile fever outbreak, Israel, 2000: epidemiologic aspects.

From August 1 to October 31, 2000, 417 cases of West Nile (WN) fever were serologically confirmed throughout Israel; 326 (78%) were hospitalized patients. Cases were distributed throughout the country; the highest incidence was in central Israel, the most populated part. Men and women were equally affected, and their mean age was 54+/-23.8 years (range 6 months to 95 years). Incidence per 1,000 population increased from 0.01 in the 1st decade of life to 0.87 in the 9th decade. There were 35 deaths (case-fatality rate 8.4%), all in patients >50 years of age. Age-specific case-fatality rate increased with age. Central nervous system involvement occurred in 170 (73%) of 233 hospitalized patients. The countrywide spread, number of hospitalizations, severity of the disease, and high death rate contrast with previously reported outbreaks in Israel.

West Nile Fever Outbreak, Israel, 2000: Epidemiologic Aspects

Abstract From August 1 to October 31, 2000, 417 cases of West Nile (WN) fever were serologically confirmed throughout Israel; 326 (78%) were hospitalized patients. Cases were distributed throughout the country; the highest incidence was in central Israel, the most populated part. Men and women were equally affected, and their mean age was 54±23.8 years (range 6 months to 95 years). Incidence per 1,000 population increased from 0.01 in the 1st decade of life to 0.87 in the 9th decade. There were 35 deaths (case-fatality rate 8.4%), all in patients >50 years of age. Age-specific case-fatality rate increased with age. Central nervous system involvement occurred in 170 (73%) of 233 hospitalized patients. The countrywide spread, number of hospitalizations, severity of the disease, and high death rate contrast with previously reported outbreaks in Israel.

Lethality of firearm-related injuries in the United States population

Study objective: To characterize differences in the lethality of firearm-related injuries in selected demographic subgroups using national representative data on fatal and nonfatal firearm-related injuries. We also characterize the lethality of firearm-related injuries by intent of injury and anatomic location of the gunshot wound. Methods: We analyzed case-fatality rates (CFRs) of firearm-related injuries in the United States by using death data from the National Vital Statistics System and data on nonfatal injuries treated in US hospital emergency departments from the National Electronic Injury Surveillance System. National estimates of crude and age-adjusted CFRs are presented by sex, race/ethnicity, age, intent, and primary body part affected. Results: Each year during the study period (July 1992 through December 1995), an estimated 132,687 persons sustained gunshot wounds that resulted in death or treatment in an ED. The overall age-adjusted CFR among persons who sustained firearm-related injuries was 31.7% (95% confidence interval [CI] 27.7 to 35.6). The age-adjusted CFR for persons who were alive when they arrived for treatment in an ED (11.3%; 95% CI 9.4 to 13.2) was about one third as large as the overall CFR. The age-adjusted CFR varied by sex, race/ethnicity, and age, but these differences depended on intent of injury. For assaultive injuries, the age-adjusted CFR was 1.4 times higher for females (28.7%) than males (20.6%). For intentionally self-inflicted injuries, the age-adjusted CFR was 1.1 higher for males (77.7%) than females (69.1%). For assaults, the age-adjusted CFR was 1.5 times higher for whites (29.5%) than blacks (19.2%). For assaultive and intentionally self-inflicted injuries among persons 15 years and older, the age-specific CFR increased with age. Persons shot in the head (age-adjusted CFR, 61.0%) were 3.3 times as likely to die as those shot in other body parts (age-adjusted CFR, 18.7%). Conclusion: The lethality of firearm-related injuries was influenced strongly by the intent of injury and body part affected. The high lethality of firearm-related injuries relative to other major causes of injury emphasizes the need to continue prevention efforts and efforts to improve access to care and treatment (including emergency medical and acute care services) to reduce the number and increase survivability of firearm-related injuries. [Beaman V, Annest JL, Mercy JA, Kresnow M, Pollock DA. Lethality of firearm-related injuries in the United States population. Ann Emerg Med. March 2000;35:258-266.]

Overcrowding and intensive exposure as determinants of measles mortality.

Data from a 1979 measles epidemic in an urban district of Guinea- Bissau indicate that state of nutrition is not a major determinant of outcome of infection. However, overcrowding increases the risk of early infection and the severity of disease. In instances in which several children have measles simultaneously, the case fatality rate is significantly higher than for isolated cases. This tendency is apparently a result of intensity of exposure; within the same house, secondary cases have a much higher age-specific case fatality rate than index cases. It is suggested that the association between intensive exposure and severity of infection may be due to increase rates of intercurrent infection and/or a greater dose of infection. Since it is not only the malnourished children who die of measles, vaccination may have a greater importance for survival patterns than has previously been assumed.