Case fatality rates of COVID-19 during epidemic periods of variants of concern: A meta-analysis by continents

OBJECTIVES

To calculate the case fatality rates (CFR) of COVID-19 during epidemic periods of different variants of concern (VOC) by continents.

METHODS

We systematically searched five authoritative databases (Web of Science, PubMed, Embase, Cochrane Library, and MedRxiv) for epidemiological studies on the CFR of COVID-19 published between January 1, 2020, and March 31, 2023. After identifying the epidemic trends of variants, we used a random-effects model to calculate the pooled CFRs during periods of different VOCs. This meta-analysis was conducted following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and registered with PROSPERO (CRD42023431572).

RESULTS

There were variations in the CFRs among different variants of COVID-19 (Alpha: 2.62%, Beta: 4.19%, Gamma: 3.60%, Delta: 2.01%, Omicron: 0.70%), and disparities in CFRs also existed among continents. On the whole, the CFRs of COVID-19 in Europe and Oceania were slightly lower than in other continents. There was a statistically significant association between the variant, HDI value, age distribution, coverage of full vaccination of cases, and the CFR.

CONCLUSIONS

The CFRs of COVID-19 varied across the epidemic periods of different VOCs, and disparities existed among continents. The CFR value reflected combined effects of various factors within a certain context. Caution should be exercised when comparing CFRs due to disparities in testing capabilities and age distribution among countries, etc.

Country-based modelling of COVID-19 case fatality rate: A multiple regression analysis

BACKGROUND

The spread of the severe acute respiratory syndrome coronavirus 2 outbreak worldwide has caused concern regarding the mortality rate caused by the infection. The determinants of mortality on a global scale cannot be fully understood due to lack of information.

AIM

To identify key factors that may explain the variability in case lethality across countries.

METHODS

We identified 21 Potential risk factors for coronavirus disease 2019 (COVID-19) case fatality rate for all the countries with available data. We examined univariate relationships of each variable with case fatality rate (CFR), and all independent variables to identify candidate variables for our final multiple model. Multiple regression analysis technique was used to assess the strength of relationship.

RESULTS

The mean of COVID-19 mortality was 1.52 ± 1.72%. There was a statistically significant inverse correlation between health expenditure, and number of computed tomography scanners per 1 million with CFR, and significant direct correlation was found between literacy, and air pollution with CFR. This final model can predict approximately 97% of the changes in CFR.

CONCLUSION

The current study recommends some new predictors explaining affect mortality rate. Thus, it could help decision-makers develop health policies to fight COVID-19.

[Effect of the Omicron variant on cumulative incidence of infection and lethality during the sixth wave of the COVID-19 epidemic in Spain]

The COVID-19 pandemic has strained healthcare systems globally. The successive epidemic waves have shown different characteristics. The Omicron variant of SARS-CoV-2 modified the epidemic behavior that previous variants had followed. The aim of this analysis was to determine the epidemiological characteristics of COVID-19 during the sixth epidemic wave and its differences according to the predominance of the Delta or Omicron variants. The epidemiological data corresponding to the sixth wave of the epidemic published by official organizations were analyzed, and the cumulative incidence of infection (CI-I) and case fatality rates (CFR) were calculated, both for Spain as a whole and for the different Autonomous Communities, in the population as a whole and by age groups. The results showed that the CI-I was higher with the Ómicron variant (10.89% vs 0.75% with Delta) while the CFR was higher with the Delta variant (4.2‰ vs 1.3‰ with Ómicron), as well as a higher rate of hospitalization and ICU admission with the Delta variant.

NIPAH Virus Encephalitis: Unveiling the Epidemiology, Risk Factors, and Clinical Outcomes - A Systematic Review and Meta-Analysis

Objective

This study assessed Nipah virus (NiV) encephalitis epidemiology, clinical outcomes, and risk variables to inform treatment and prevention.

Methodology

In a PubMed systematic search, 929 citations were found. After screening and eligibility, 22 studies were included. This study obtained age, gender, geographic regions, diagnostic methods, data collection methods, and bias risk. The case fatality rate (CFR) and NiV infection risk variables were evaluated by meta-analysis.

Results

Southeast Asia, especially Bangladesh and Malaysia, had the most NiV cases. The major diagnostic method was blood and cerebrospinal fluid IgM and IgG antibody tests, and males predominated. Proxy respondents and matched controls were utilized for risk factor analyses when patients could not answer. The pooled CFR for NiV encephalitis was 61.0%, indicating severity. Risk factors included pigs, nighttime bats near homes, tree climbing, and male gender.

Conclusion

Southeast Asian public health is plagued by NiV encephalitis. The high CFR calls for better diagnosis, treatment, and prevention. NiV's multiple risk factors must be understood for targeted therapy. Future research should fill knowledge gaps and improve NiV infection prevention.

Changes in the intrinsic severity of severe acute respiratory syndrome coronavirus 2 according to the emerging variant: a nationwide study from February 2020 to June 2022, including comparison with vaccinated populations

BACKGROUND

As the population acquires immunity through vaccination and natural infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), understanding the intrinsic severity of coronavirus disease (COVID-19) is becoming challenging. We aimed to evaluate the intrinsic severity regarding circulating variants of SARS-CoV-2 and to compare this between vaccinated and unvaccinated individuals.

METHODS

With unvaccinated and initially infected confirmed cases of COVID-19, we estimated the case severity rate (CSR); case fatality rate (CFR); and mortality rate (MR), including severe/critical cases and deaths, stratified by age and compared by vaccination status according to the period regarding the variants of COVID-19 and vaccination. The overall rate was directly standardized with age.

RESULTS

The age-standardized CSRs (aCSRs) of the unvaccinated group were 2.12%, 5.51%, and 0.94% in the pre-delta, delta, and omicron period, respectively, and the age-standardized CFRs (aCFRs) were 0.60%, 2.49%, and 0.63% in each period, respectively. The complete vaccination group had lower severity than the unvaccinated group over the entire period showing under 1% for the aCSR and 0.5% for the aCFR. The age-standardized MR of the unvaccinated group was 448 per million people per month people in the omicron period, which was 11 times higher than that of the vaccinated group. In terms of age groups, the CSR and CFR sharply increased with age from the 60 s and showed lower risk reduction in the 80 s when the period changed to the omicron period.

CONCLUSIONS

The intrinsic severity of COVID-19 was the highest in the delta period, with over 5% for the aCSR, whereas the completely vaccinated group maintained below 1%. This implies that when the population is vaccinated, the impact of COVID-19 will be limited, even if a new mutation appears. Moreover, considering the decreasing intrinsic severity, the response to COVID-19 should prioritize older individuals at a higher risk of severe disease.

Case fatality rate for Ebola disease, 1976-2022: A meta-analysis of global data

An up-to-date pooled case fatality rate (CFR) for Ebola disease (EBOD) at the global level is lacking. We abstracted EBOD data from 1976 to 2022 for 16 countries and 42 outbreaks to conduct a meta-analysis. The pooled CFR was 60.6% (95% confidence interval (CI) 51.6-69.4; 95% prediction interval 12.9-99.1). Of the four ebolaviruses, Zaire virus was the most lethal (CFR = 66.6%, 95% CI 55.9-76.8), then Sudan virus (CFR=48.5%, 95% CI 38.6-58.4), Bundibugyo virus (CFR=32.8%, 95% CI 25.8-40.2) and Tai Forest virus (CFR= 0%, 95% CI 0.0-97.5). The CFR in sub-Saharan Africa was 61.3% (95% CI 52.8-69.6) and for the rest of the world was 24.5% (95% CI 0.0-67.9%). CFR declined over time but stabilized at 61.0% (95% CI, 52.0-69.0) between 2014 and 2022. Overall, the EBOD CFR is still high and heterogeneous. Accordingly, early diagnosis, early treatment if available, and supportive care are important to prevent significant morbidity and mortality.

Incidence and case fatality of stroke in Korea, 2011-2020

OBJECTIVES

Stroke remains the second leading cause of death in Korea. This study was designed to estimate the crude, age-adjusted and age-specific incidence rates, as well as the case fatality rate of stroke, in Korea from 2011 to 2020.

METHODS

We utilized data from the National Health Insurance Services from January 1, 2002 to December 31, 2020, to calculate incidence rates and 30-day and 1-year case fatality rates of stroke. Additionally, we determined sex and age-specific incidence rates and computed age-standardized incidence rates by direct standardization to the 2005 population.

RESULTS

The crude incidence rate of stroke hovered around 200 (per 100,000 person-years) from 2011 to 2015, then surged to 218.4 in 2019, before marginally declining to 208.0 in 2020. Conversely, the age-standardized incidence rate consistently decreased by 25% between 2011 and 2020. When stratified by sex, the crude incidence rate increased between 2011 and 2019 for both sexes, followed by a decrease in 2020. Age-standardized incidence rates displayed a downward trend throughout the study period for both sexes. Across all age groups, the 30-day and 1-year case fatality rates of stroke consistently decreased from 2011 to 2019, only to increase in 2020.

CONCLUSIONS

Despite a decrease in the age-standardized incidence rate, the total number of stroke events in Korea continues to rise due to the rapidly aging population. Moreover, 2020 witnessed a decrease in incidence but an increase in case fatality rates.

Incidence and case fatality of acute myocardial infarction in Korea, 2011-2020

OBJECTIVES

Cardiovascular diseases are a leading cause of mortality worldwide, and acute myocardial infarction (AMI) is particularly fatal condition. We evaluated the incidence and case fatality rates of AMI in Korea from 2011 to 2020.

METHODS

We utilized data from the National Health Insurance Services to calculate crude, age-standardized, and age-specific incidence rates, along with 30-day and 1-year case fatality rates, of AMI from 2011 to 2020. Age-standardized incidence rates were determined using direct standardization to the 2005 population.

RESULTS

The crude incidence rate of AMI per 100,000 person-years consistently increased from 44.7 in 2011 to 68.3 in 2019, before decreasing slightly to 66.2 in 2020. The age-standardized incidence rate of AMI displayed a 19% rise from 2011 to 2019, followed by a slight decline in 2020. The increasing trend for AMI incidence was more pronounced in males than in females. Both 30-day and 1-year case fatality rates remained stable among younger individuals but showed a decrease among older individuals. There was a minor surge in case fatality in 2020, particularly among recurrent AMI cases.

CONCLUSIONS

Over the past decade, the AMI incidence rate in Korea has consistently increased, with a slight downturn in 2020. The case fatality rate has remained relatively stable except for a minor increase in 2020. This study provides data for continuous surveillance, the implementation of targeted interventions, and the advancement of research aimed at AMI in Korea.

Case fatality rate considering the lag time from the onset of COVID-19 infection to related death from 2020 to 2022 in Japan

Importance

On an ecological scale, the lag time between coronavirus disease 2019 (COVID-19) infection and related fatality has varied between epidemic waves and prefectures in Japan. The variability in lag time across areas of Japan during the seven distinct waves can help derive a more appropriate estimation of the weekly confirmed case fatality rate (CFR) of COVID-19.

Objective

To estimate the 7-day moving average CFR across area block levels in Japan from February 2020 to July 2022 using the lag time between COVID-19 infection and related fatality.

Main outcomes and measures

The 7-day moving average CFR of COVID-19 for area blocks in Japan considering the lag time between infection and death (total and subgroup analysis of elderly).

Results

Lag time was found to vary substantially among prefectures in Japan from the first wave to the seventh wave of the COVID-19 epidemic. The estimated 7-day moving average CFR based on the lag time reflects the Japanese COVID-19 pandemic and related policy interventions (e.g. vaccination of elderly people) rather than other standard CFR estimations.

Conclusions and relevance

The variation in estimated lag time across prefectures in Japan for different epidemic waves indicates that it is inadequate to use the clinical results of the period from the start of infection to death for evaluation of the ecological scale of the CFR. Moreover, the lag time between infection and related fatality was found to be either shorter or longer than the clinically reported period. This revealed that preliminary reports of CFR may be overestimated or underestimated, even if they consider the lag based on clinical reports.

First Molecular Confirmed Outbreak of Malignant Ovine Theileriosis in Sheep from North India

CONTEXT

Malignant ovine theileriosis is a tick-borne disease of sheep and goats, caused by protozoan Theileria lestoquardi. The disease has serious economic implications for small ruminant production around the world.

METHODS

An outbreak of malignant ovine theileriosis in a sheep flock was investigated from Hisar district of Haryana, India, in March 2022. The etiological agent was identified using polymerase chain reaction assay with genus specific primers targeting 18S rRNA gene and subsequently confirmed by sequencing.

RESULTS

The morbidity, mortality and case fatality rate reported in the outbreak were 22.2, 18.8 and 85%, respectively. The phylogenetic analysis clustered the present study T. lestoquardi isolate in the same clade with T. lestoquardi from Iraq, Iran and Pakistan with maximum nucleotide identity of 99.37% with strains from Iraq. The tick vector Hyalomma anatolicum recovered from dead animals was implicated in the disease's transmission.

CONCLUSIONS

Malignant ovine theileriosis resulted in high case fatality rate. This study presents the first molecularly confirmed outbreak of malignant ovine theileriosis outbreak in the North Indian region, with characteristic post-mortem findings.

Clinical burden of invasive Escherichia coli disease among older adult patients treated in hospitals in the United States

BACKGROUND

Invasive extraintestinal pathogenic Escherichia coli disease (IED) can lead to severe outcomes, particularly among older adults. However, the clinical burden of IED in the U.S. has not been well characterized.

METHODS

IED encounters among patients ≥ 60 years old were identified using the PINC AI™ Healthcare Database (10/01/2015-03/31/2020) by either a positive E. coli culture in blood or another normally sterile body site and ≥ 1 sign of systemic inflammatory response syndrome or signs of sepsis, or a positive E. coli culture in urine with urinary tract infection and signs of sepsis. Medical resource utilization, clinical outcomes, and E. coli isolate characteristics were descriptively reported during the first IED encounter and during the following year (observation period).

RESULTS

Overall, 19,773 patients with IED were included (mean age: 76.8 years; 67.4% female; 78.5% with signs of sepsis). Most encounters involved community-onset IED (94.3%) and required hospitalization (96.5%; mean duration: 6.9 days), with 32.4% of patients being admitted to the intensive care unit (mean duration: 3.7 days). Most E. coli isolates were resistant to ≥ 1 antibiotic category (61.7%) and 34.4% were resistant to ≥ 3 antibiotic categories. Following their first IED encounter, 34.8% of patients were transferred to a skilled nursing/intermediate care facility, whereas 6.8% had died. During the observation period, 36.8% of patients were rehospitalized, 2.4% had IED recurrence, and in-hospital death increased to 10.9%.

CONCLUSIONS

IED is associated with substantial clinical burden at first encounter with considerable long-term consequences. Findings demonstrate the need for increased IED awareness and highlight potential benefits of prevention.

The role of universal health coverage and global health security nexus and interplay on SARS-CoV-2 infection and case-fatality rates in Africa : a structural equation modeling approach

BACKGROUND

The Coronavirus Disease (COVID-19) caused by SARS-CoV-2 infections remains a significant health challenge worldwide. There is paucity of evidence on the influence of the universal health coverage (UHC) and global health security (GHS) nexus on SARS-CoV-2 infection risk and outcomes. This study aimed to investigate the effects of UHC and GHS nexus and interplay on SARS-CoV-2 infection rate and case-fatality rates (CFR) in Africa.

METHODS

The study employed descriptive methods to analyze the data drawn from multiple sources as well used structural equation modeling (SEM) with maximum likelihood estimation to model and assess the relationships between independent and dependent variables by performing path analysis.

RESULTS

In Africa, 100% and 18% of the effects of GHS on SARS-CoV-2 infection and RT-PCR CFR, respectively were direct. Increased SARS-CoV-2 CFR was associated with median age of the national population (β = -0.1244, [95% CI: -0.24, -0.01], P = 0.031 ); COVID-19 infection rate (β = -0.370, [95% CI: -0.66, -0.08], P = 0.012 ); and prevalence of obesity among adults aged 18 + years (β = 0.128, [95% CI: 0.06,0.20], P = 0.0001) were statistically significant. SARS-CoV-2 infection rates were strongly linked to median age of the national population (β = 0.118, [95% CI: 0.02,0.22 ], P = 0.024); population density per square kilometer, (β = -0.003, [95% CI: -0.0058, -0.00059], P = 0.016 ) and UHC for service coverage index (β = 0.089, [95% CI: 0.04,0.14, P = 0.001 ) in which their relationship was statistically significant.

CONCLUSIONS

The study shade a light that UHC for service coverage, and median age of the national population, population density have significant effect on COVID-19 infection rate while COVID-19 infection rate, median age of the national population and prevalence of obesity among adults aged 18 + years were associated with COVID-19 case-fatality rate. Both, UHC and GHS do not emerge to protect against COVID-19-related case fatality rate.

Decreased Emergency Cholecystectomy and Case Fatality Rate, Not Explained by Expansion of Medicaid

INTRODUCTION

Population data on longitudinal trends for cholecystectomies and their outcomes are scarce. We evaluated the incidence and case fatality rate of emergency and ambulatory cholecystectomies in New Jersey (NJ) and whether the Medicaid expansion changed trends.

MATERIALS AND METHODS

A retrospective population cohort design was used to study the incidence of cholecystectomies and their case fatality rate from 2009 to 2018. Using linear and logistic regression we explored the trends of incidence and the odds of case fatality after versus before the January 1, 2014 Medicaid expansion.

RESULTS

Overall, 93,423 emergency cholecystectomies were performed, with 644 fatalities; 87,239 ambulatory cholecystectomies were performed, with fewer than 10 fatalities. The 2009 to 2018 annual incidence of emergency cholecystectomies dropped markedly from 114.8 to 77.5 per 100,000 NJ population (P < 0.0001); ambulatory cholecystectomies increased from 93.5 to 95.6 per 100,000 (P = 0.053). The incidence of emergency cholecystectomies dropped more after than before Medicaid expansion (P < 0.0001). The odds ratio for case fatality among those undergoing emergency cholecystectomies after versus before expansion was 0.85 (95% CI, 0.72-0.99). This decrease in case fatality, apparent only in those over age 65, was not explained by the addition of Medicaid.

CONCLUSIONS

A marked decrease in the incidence of emergency cholecystectomies occurred after Medicaid expansion, which was not accounted for by a minimal increase in the incidence of ambulatory cholecystectomies. Case fatality from emergency cholecystectomy decreased over time due to factors other than Medicaid. Further work is needed to reconcile these findings with the previously reported lack of decrease in overall gallstone disease mortality in NJ.

Clinical efficacy of low-dose glucocorticoid therapy for critically ill patients with severe fever with thrombocytopenia syndrome: A retrospective cohort study

BACKGROUND

Glucocorticoid therapy is now recommended as an adjunctive treatment for severe fever with thrombocytopenia syndrome (SFTS). However, no criteria for identifying patients suitable for receiving glucocorticoid therapy, nor recommended regimens to achieve clinical benefit were defined.

METHODS

A retrospective study was performed to include patients with confirmed SFTS from designated hospitals. The effect of glucocorticoids in reducing case fatality rate (CFR) and improving clinical recovery was evaluated by multivariate logistic regression models.

RESULTS

A total of 2,478 eligible patients were analyzed, of whom 331 received glucocorticoids. An integrated parameter (L-index) based on Log₁₀(LDH*BUN/LYM) was constructed to discriminate disease severity. In patients with L-index >3.823 indicating severe SFTS, significantly reduced CFR was observed in patients receiving low-moderate glucocorticoid doses with ≤60 mg daily methylprednisolone or equivalent (OR 0.46, 95% CI, 0.23-0.88), while not in the high dose group. In patients with L-index ≤3.823 indicating mild SFTS, glucocorticoid treatment was significantly associated with increased CFR (OR 3.34, 95% CI, 1.35-9.51), and mainly attributable to high-dose glucocorticoids (OR 2.83, 95% CI, 1.72-4.96). Disaggregated data analysis revealed significant effect only in patients of ≤65 years old, male, and early admission within 7 days after onset, but not in their counterparts.

CONCLUSIONS

Glucocorticoids are not recommended for mild patients defined by L-index<3.823, however, severe SFTS patients may benefit from low-moderate doses of glucocorticoids.

Sex differences in incidence and fatality of severe fever with thrombocytopenia syndrome: a comparative study based on national surveillance data of China

Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne emerging infectious disease with an increasingly global concern. Sex difference in infectious diseases is an important public health problem. A comparative study on sex differences in SFTS incidence and fatality was conducted using all laboratory-confirmed cases in mainland China during 2010-2018. Females had significantly higher average annual incidence rate (AAIR) with a RR of 1.17 (95% CI 1.11-1.22; p˂0.0001), but significantly lower-case fatality rate (CFR) with an OR of 0.73 (95% CI 0.61-0.87; p=0.001). The significant differences in AAIR and CFR were observed in age groups of 40-69 and 60-69 years, respectively (both p<0.05). There was a rising incidence and declining CFR along with epidemic years. After adjusting for age, temporal and spatial distribution, agricultural setting and onset-to-diagnosis interval, the female-to-male difference in either AAIR or CFR remained significant. The underlying biological mechanisms of the sex-based differences that the females are more prone to get the disease, but less likely for a fatal outcome deserve further investigations. This article is protected by copyright. All rights reserved.

High variability of COVID-19 case fatality rate in Germany

BACKGROUND

During the first wave of the COVID-19 pandemic a high case fatality rate (CFR) was noticed worldwide including also Germany where the first European cases have been observed. The WHO recommended immediate intubation for patients with dyspnoea which has since been revised after reviewing the initial clinical outcome. The objective of this study is to analyze CFR and assess if there is an advantage of a more conservative management of COVID-19 induced hypoxemia.

METHODS

PCR confirmed COVID-19 infections and death counts were obtained for all German districts from 27 Jan 2020 until 15 Feb 2021 using official reports of Robert Koch Institute Berlin, Germany. A moving average CFRt was constructed by dividing disease related deaths two weeks after a given index day by the number of infections two weeks prior to that date. In addition to a local comparison also mortality outcomes in other German speaking countries were compared.

RESULTS

The mean CFR is estimated to be 2.92% based on 71.965 fatalities and 2.465.407 cases. There was a large regional scattering of CFRs across the German districts. Differences of the mortality pattern were observed also at state level and preserved across different sex and age groups while being largely independent of case numbers. Although Munich city had higher infection rates, more patients died during the first wave in Hamburg (OR 1.6, 95% CI 1.3-1.9) which was mirrored also by higher death risk at Hamburg intensive care units (OR 2.0, 95% CI 1.3-3.1). While the majority of Munich hospitals favoured a conservative management of hypoxemia including high flow nasal cannula (HFNC), Hamburg hospitals followed a more aggressive scheme of early mechanical ventilation (MV). Austria and Switzerland experienced higher CFRs than Germany during the first wave but after changing their treatment guidelines, both countries experienced lower CFRs during the second wave.

CONCLUSION

Using retrospective public health data, different case fatality rates have been observed across Germany. A more conservative management of COVID-19 induced Adult Respiratory Distress Syndrome (ARDS) is justified also by epidemiological data.

Prevalence and epidemiological trends in mortality due to COVID-19 in Saudi Arabia

OBJECTIVES

This article describes the prevalence and epidemiological trends of COVID-19 mortality in the largest registry in the Kingdom of Saudi Arabia (KSA).

STUDY DESIGN

A prospective epidemiological cohort study using data from all healthcare facilities in KSA collected between March 23, 2020, and April 30, 2022. Data on the number of daily deaths directly related to COVID-19 were gathered, analyzed, and reported.

METHOD

Data analysis was carried out using national and regional crude case fatality rate and death per 100,000 population. Descriptive statistics using numbers and proportions were used to describe age, gender, nationality, and comorbidities. The mortality trend was plotted and compared with international figures. In addition, the most common comorbidities associated with mortality and the proportion of patients who received COVID-19 vaccine were reported.

RESULTS

The total reported number of deaths between March 23, 2020, and April 30, 2022, was 9085. Crude case fatality rate was 1.21%, and death per 100,000 population was 25.38, which compared favorably to figures reported by several developed countries. The highest percentages of deaths were among individuals aged between 60 and 69 years, males (71%), and individuals with diabetes (60%). Only 2.8% of mortalities occur in patients who received COVID-19 vaccine. Diabetes, hypertension, and heart failure had the highest attributable risk of mortality among patients who died due to COVID-19.

CONCLUSION

Case fatality rate and death per 100,000 population in KSA are among the lowest in the world due to multiple factors. Several comorbidities have been identified, namely, diabetes, hypertension, obesity, and cardiac arrhythmias.

Indirect impact of COVID-19 on the incidence rates of vector-borne diseases in Mexico

INTRODUCTION

SARS-CoV-2 infection spatial and temporal distribution overlaps with endemic areas of vector-borne diseases (VBD), whose surveillance in Mexico has substantially changed since the first COVID-19 confirmed case.

OBJECTIVES

To estimate and compare the incidence rates of VBDs before and after the introduction of SARS-CoV-2 in Mexico.

METHODS

Retrospective study of VBD cases from 2014 to 2021. The incidence rates of each VBD in the period before (2014-2019) and after (2020-2021) the introduction of SARS-CoV-2 in Mexico were calculated and compared.

RESULTS

Before the introduction of SARS-CoV-2, the incidence rates of VBDs were high and after the introduction of coronavirus there was a decrease in epidemiological indices; however, there was only statistically significant difference in the incidence rate of malaria (p ≤ 0.05) and other rickettsiae (p ≤ 0.05).

CONCLUSIONS

Some measures to reduce COVID-19 cases, such as social distancing, home confinement, reductions in public transport and working at home (home office), probably temporarily decreased the number of VBD cases; however, there may be a resurgence of VBDs in the near future.

Is the Testing System No Longer Effective for Coronavirus Disease 2019? Elucidating the Policy Change in the United Kingdom

Various studies have reported the vaccine's efficacy against coronavirus disease 2019; however, there has been little discussion regarding the test frequency since the emergence of the Omicron strain. In this context, the United Kingdom has abolished its free testing program. Our analysis revealed that the decrease in case fatality rate was heavily influenced by vaccination coverage rather than the testing frequency. However, the effectiveness of testing frequency should not be underestimated and therefore needs further validation.

Clinical features of Guillain-Barré syndrome and factors associated with mortality during the 2019 outbreak in Peru

INTRODUCTION

Peru has suffered an increase of Guillain Barre Syndrome incidence since 2015, being the biggest outbreak during 2019. We aimed to describe the clinical features, outcomes, and factors associated with mortality among cases reported in the 2019 outbreak.

METHODS

Cross-sectional analysis of data from the National Surveillance of Guillain Barre Syndrome of the National Center for Control Disease and Prevention of Peru. We included all cases that met the Brighton criteria, level 1 to level 3. We used multivariable logistic regression to determinate factors associated with mortality.

RESULTS

Overall, 772 cases were analyzed (58.7% male; mean age, 41.7 ± 20.3). 86.0% of cases aged over 30 years. 71.4% had a respiratory or gastrointestinal infection in the last 4 weeks. Case fatality rate was 4.3% and 32.2% of survivors reported sequelae. Axonal subtypes were identified in 75.6% of cases with an available nerve conduction study (38.7%). Age and impaired function of cranial nerves were independently associated with mortality.

CONCLUSIONS

The 2019 outbreak of Guillain Barre syndrome in Peru was an unprecedented event that affected several regions of the country. Axonal damage was more frequent than demyelinating involvement, which is compatible with findings pointing to Campylobacter jejuni as the triggering agent. The case fatality rate was similar to that reported previously in Peru and other countries, but the high frequency of sequelae is striking.

Geographical distribution of trace elements (selenium, zinc, iron, copper) and case fatality rate of COVID-19: a national analysis across conterminous USA

Severe outcome particularly death is the largest burden of COVID-19. Clinical observations showed preliminary data that deficiency in certain trace elements, essential for the normal activity of immune system, may be associated with worse COVID-19 outcome. Relevant study of environmental epidemiology has yet to be explored. We investigated the geographical association between concentrations of Se, Zn, Fe and Cu in surface soils and case fatality rate of COVID-19 in USA. Two sets of database, including epidemiological data of COVID-19 (including case fatality rate, from the University of John Hopkinson) and geochemical concentration data of Se, Zn, Fe and Cu in surface soils (from the National Geochemical Survey), were mapped according to geographical location at the county level across conterminous USA. Characteristics of population, socio-demographics and residential environment by county were also collected. Seven cross-sectional sampling dates, with a 4-week interval between adjacent dates, constructed an observational investigation over 24 weeks from October 8, 2020, to March 25, 2021. Multivariable fractional (logit) outcome regression analyses were used to assess the association with adjustment for potential confounding factors. In USA counties with the lowest concentration of Zn, the case fatality rate of COVID-19 was the highest, after adjustment for other influencing factors. Associations of Se, Fe and Cu with case fatality rate of COVID-19 were either inconsistent over time or disappeared after adjustment for Zn. Our large study provides epidemiological evidence suggesting an association of Zn with COVID-19 severity, suggesting Zn deficiency should be avoided.

Description and outcomes of patients with eclampsia and severe pre-eclampsia in a rural hospital in North-Eastern Bihar: A retrospective study

Background

Hypertension is one of the most common medical disorders complicating pregnancy. In India, high blood pressure contributes to 7.1% of maternal deaths. This study was carried out to describe the characteristics and pregnancy outcomes of patients presenting with eclampsia or pre-eclampsia to a secondary care hospital in rural India.

Methods

Patients diagnosed with pre-eclampsia or eclampsia between January 2018 and April 2021 were identified and included in the study. Medical records were searched and general patient characteristics, obstetrical history, information about the antenatal period, mode of delivery and outcomes were documented and analysed.

Results

Among the 3651 women who delivered in this hospital during this time period, 2.3% (n = 83) presented with eclampsia and 1.9% (n = 71) with pre-eclampsia. More than 50% of the women delivered by lower segment caesarean section among both the eclamptics and pre-eclamptics. The stillbirth rate among those with either pre-eclampsia or eclampsia was 1 per 1000. The number of low birth weight babies born to those presenting with eclampsia (66.7%) was significantly more than those presenting with pre-eclampsia (48.6%). Eclampsia/pre-eclampsia accounted for 21% of all maternal deaths with a case fatality rate of 2.6%.

Conclusions

This study identified that in this setting the patients presenting with eclampsia were much higher than those presenting with pre-eclampsia which is in stark contrast to the status even in developing countries. This could be an important finding indicating poorer health-seeking behaviour among the population and will need more studies on various interventions to change this status.

Impact of Vaccination and Control Measures on the Fatality of COVID-19: An Ecological Study

Background

During the COVID-19 pandemic, reducing the case fatality rate (CFR) becomes an urgent goal.

Objective

This study explored the effect of vaccination and variants on COVID-19 fatality and provide a basis for the adjustment of control measures.

Methods

This study collected epidemiological information on COVID-19 from January to October 2021. By setting different lag times, we calculated the adjusted CFR. The Spearman correlation coefficient and beta regression were used to explore factors that may affect COVID-19 fatality.

Results

Every 1% increase in the percentage of full vaccinations may reduce the 3 weeks lagging CFR by 0.66%. Increasing the restrictions on internal movement from level 0 to 1, restrictions on international travel controls from level 2 to 3, and stay-at-home restrictions from level 0 to 2 were associated with an average reduction in 3 weeks lagging CFR of 0.20%, 0.39%, and 0.36%, respectively. Increasing strictness in canceling public events from level 0 to 1 and 2 may reduce the 3 weeks lagging CFR by 0.49% and 0.37, respectively. Increasing the severity of school and workplace closures from level 1 or level 0 to 3 may increase the 3 weeks lagging CFR of 0.39% and 0.83, respectively. Every 1-point increase in the Global Health Security (GHS) index score may increase the 3 weeks lagging CFR by 0.12%.

Conclusion

A higher percentage of full vaccinations, higher levels of internal movement restrictions, international travel control restrictions, cancelations of public events, and stay-at-home restrictions are factors that may reduce the adjusted CFR.

Improving access to emergency obstetric care in underserved rural Tanzania: a prospective cohort study

Background

One of the key strategies to reducing maternal mortality is provision of emergency obstetric care services. This paper describes the results of improving availability of, and access to emergency obstetric care services in underserved rural Tanzania using associate clinicians.

Methods

A prospective cohort study of emergency obstetric care was implemented in seven health centres in Morogoro region, Tanzania from July 2016 to June 2019. In early 2016, forty-two associate clinicians from five health centres were trained in teams for three months in emergency obstetric care, newborn care and anaesthesia. Two health centres were unexposed to the intervention and served as controls. Following training, virtual teleconsultation, quarterly on-site supportive supervision and continuous mentorship were implemented to reinforce skills and knowledge.

Results

The met need for emergency obstetric care increased significantly from 45% (459/1025) at baseline (July 2014 – June 2016) to 119% (2010/1691) during the intervention period (Jul 2016 – June 2019). The met need for emergency obstetric care in the control group also increased from 53% (95% CI 49–58%) to 77% (95% CI 74–80%). Forty maternal deaths occurred during the baseline and intervention periods in the control and intervention health centres. The direct obstetric case fatality rate decreased slightly from 1.5% (95% CI 0.6–3.1%) to 1.1% (95% CI 0.7–1.6%) in the intervention group and from 3.3% (95% CI 1.2–7.0%) to 0.8% (95% CI 0.2–1.7%) in the control group.

Conclusions

When emergency obstetric care services are made available the proportion of obstetric complications treated in the facilities increases. However, the effort to scale up emergency obstetric care services in underserved rural areas should be accompanied by strategies to reinforce skills and the referral system.

Decline of onset-to-diagnosis interval and its impacts on clinical outcome of COVID-19 in China: a nation-wide observational study

Background

To quantitatively assess the impact of the onset-to-diagnosis interval (ODI) on severity and death for coronavirus disease 2019 (COVID-19) patients.

Methods

This retrospective study was conducted based on the data on COVID-19 cases of China over the age of 40 years reported through China’s National Notifiable Infectious Disease Surveillance System from February 5, 2020 to October 8, 2020. The impacts of ODI on severe rate (SR) and case fatality rate (CFR) were evaluated at individual and population levels, which was further disaggregated by sex, age and geographic origin.

Results

As the rapid decline of ODI from around 40 days in early January to < 3 days in early March, both CFR and SR of COVID-19 largely dropped below 5% in China. After adjusting for age, sex, and region, an effect of ODI on SR was observed with the highest OR of 2.95 (95% CI 2.37‒3.66) at Day 10–11 and attributable fraction (AF) of 29.1% (95% CI 22.2‒36.1%) at Day 8–9. However, little effect of ODI on CFR was observed. Moreover, discrepancy of effect magnitude was found, showing a greater effect from ODI on SR among patients of male sex, younger age, and those cases in Wuhan.

Conclusion

The ODI was significantly associated with the severity of COVID-19, highlighting the importance of timely diagnosis, especially for patients who were confirmed to gain increased benefit from early diagnosis to some extent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07660-4.

Assessing the impact of temperature and humidity exposures during early infection stages on case-fatality of COVID-19: A modelling study in Europe

Background Although associations between key weather indicators (i.e. temperature and humidity) and COVID-19 mortality have been reported, the relationship between these exposures at different timings in early infection stages (from virus exposure up to a few days after symptom onset) and the probability of death after infection (also called case fatality rate, CFR) has yet to be determined. Methods We estimated the instantaneous CFR of eight European countries using Bayesian inference in conjunction with stochastic transmission models, taking account of delays in reporting the number of newly confirmed cases and deaths. The exposure-lag-response associations between fatality rate and weather conditions to which patients were exposed at different timings were obtained using distributed lag nonlinear models coupled with mixed-effect models. Results Our results show that the Odds Ratio (OR) of death is negatively associated with the temperature, with two maxima (OR = 1.29 (95% CI: 1.23, 1.35) at -0.1°C; OR = 1.12 (95% CI: 1.08, 1.16) at 0.1°C) occurring at the time of virus exposure and after symptom onset. Two minima (OR = 0.81 (95% CI: 0.71, 0.92) at 23.2°C; OR = 0.71 (95% CI: 0.63, 0.80) at 21.7°C) also occurred at these two distinct periods correspondingly. Low humidity (below 50%) during the early stages and high humidity (approximately 89%) after symptom onset were related to the lower fatality. Conclusion Environmental conditions may affect not only the initial viral load when patients are exposed to the virus, but also individuals' immune response around symptom onset. Warmer temperatures and higher humidity after symptom onset were linked to lower fatality.

The hospitalization burden of all-cause pneumonia in China: A population-based study, 2009-2017

BACKGROUND

Pneumonia represents a public health problem of substantial health and economic burden. However, the evidence on the burden of adult pneumonia is limited in China.

METHODS

The China Kadoorie Biobank recruited 512,725 participants aged 30-79 years from five urban and five rural areas during 2004-2008. The current analyses included 506,086 participants who were alive in 2009. Pneumonia hospitalizations were ascertained through the health insurance system until December 31, 2017. Generalized linear models were used to examine the secular trends and regional and population variations in pneumonia hospitalization rate, mean length of hospital stay (LOS), and 30-day case fatality rate (CFR).

FINDINGS

A total of 27,879 participants with 36,567 pneumonia hospitalizations were identified with a mean follow-up time of 8·9 years. The unadjusted hospitalization rate was 8·4 (95% confidence interval [CI]: 8·3, 8·6) per 1000 person-years, with an increase of 15·5% annually from 4·2 (3·9, 4·4) in 2009 to 10·9 (10·6, 11·3) in 2017, after adjusting for age, sex, study area. The mean LOS was 8·8 (95% CI: 8·7, 8·9) days, with a slight decrease of 1·0% annually from 2009 to 2017. The average 30-day CFR remained practically unchanged at 2·4 (95% CI: 2·2, 2·5) deaths per 100 admissions. A clear seasonal pattern of pneumonia hospitalization rate was observed, and the hospitalization rate and CFR differed across regions and subpopulations of different ages and underlying conditions.

INTERPRETATION

There was an increasing hospitalization burden of pneumonia in Chinese adults, especially for adults aged ≥60 years or those with underlying conditions.

FUNDING

The National Natural Science Foundation of China, the Kadoorie Charitable Foundation, the National Key R&D Program of China, the Chinese Ministry of Science and Technology.

TRANSLATED ABSTRACT IN CHINESE

This translation in Chinese was submitted by the authors and we reproduce it as supplied. It has not been peer reviewed. Our editorial processes have only been applied to the original abstract in English, which should serve as reference for this manuscript. :, ., .:(China Kadoorie Biobank)2004-2008555030-79.506,086200911.20091120171231.,30,.:8.9, 27,879, 36,567.8.4 (95% CI:8.3, 8.6)/1000, ,, 20094.2 (3.9, 4.4)201710.9 (10.6, 11.3), 15.5%.8.8(95% CI:8.7, 8.9), 1.0%.30, 2.4(95% CI:2.2, 2.5)/100.;,, 30.:, ≥60.

Geospatial evaluation of COVID-19 mortality: Influence of socio-economic status and underlying health conditions in contiguous USA

Since its outbreak, COVID-19 disease has claimed over one hundred thousand lives in the United States, resulting to multiple and complex nation-wide challenges. In this study, we employ global and local regression models to assess the influence of socio-economic and health conditions on COVID-19 mortality in contiguous USA. For a start, stepwise and exploratory regression models were employed to isolate the main explanatory variables for COVID-19 mortality from the ensemble 33 socio-economic and health parameters between January 1st and 16th of September 2020. Preliminary results showed that only five out of the examined variables (case fatality rate, vulnerable population, poverty, percentage of adults that report no leisure-time physical activity, and percentage of the population with access to places for physical activity) can explain the variability of COVID-19 mortality across the Counties of contiguous USA within the study period. Consequently, we employ three global and two local regression algorithms to model the relationship between COVID-19 and the isolated socio-economic and health variables. The outcomes of the regression analyses show that the adopted models can explain 61%-81% of COVID-19 mortality across the contiguous USA within the study period. However, MGWR yielded the highest R² (0.81) and lowest AICc values (4031), emphasizing that it is the most efficient among the adopted regression models. The computed average adjusted R² values show that local regression models (mean adj. R² = 0.80) outperformed the global regression models (mean adj. R² = 0.64), indicating that the former is ideal for modeling spatial causal relationships. The GIS-based optimized cluster analyses results show that hotspots for COVID-19 mortality as well as socioeconomic variables are mostly delineated in the South, Mid-West and Northeast of contiguous USA. COVID-19 mortality exhibited positive and significant association with black race (0.51), minority (0.48) and poverty (0.34). Whereas, the percentage of persons that attended college was negatively associated with poverty (-0.51), obesity (-0.50) and diabetes (-0.45). Results show that education is crucial to improve socio-economic and health conditions of the Americans. We conclude that investing in people's standard of living would reduce the vulnerability of an entire population.

Impacts of air pollution on COVID-19 case fatality rate: a global analysis

The coronavirus disease 2019 (COVID-19) pandemic is still rapidly spreading globally. To probe high-risk cities and the impacts of air pollution on public health, this study explores the relationship between the long-term average concentration of air pollution and the city-level case fatality rate (CFR) of COVID-19 globally. Then, geographically weighted regression (GWR) is applied to examine the spatial variability of the relationships. Six air pollution factors, including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone (O₃), PM_2.5 (particles with diameter ≤2.5 μm), PM₁₀ (particles with diameter ≤10 μm), and air quality index (AQI), are positively associated with the city-level COVID-19 CFR. Our results indicate that a 1-unit increase in NO₂ (part per billion, PPB), SO₂ (PPB), O₃ (PPB), PM_2.5 (microgram per cubic meter, μg/m³), PM₁₀ (μg/m³), AQI (score), is related to a 1.450%, 1.005%, 0.992%, 0.860%, 0.568%, and 0.776% increase in the city-level COVID-19 CFR, respectively. Additionally, the effects of NO₂, O₃, PM_2.5, AQI, and probability of living with poor AQI on COVID-19 spatially vary in view of the estimation of the GWR. In other words, the adverse impacts of air pollution on health are different among the cities. In summary, long-term exposure to air pollution is negatively related to the COVID-19 health outcome, and the relationship is spatially non-stationary. Our research sheds light on the impacts of slashing air pollution on public health in the COVID-19 pandemic to help governments formulate air pollution policies in light of the local situations.

Clinical characteristics of the first three waves of hospitalised patients with COVID-19 in Japan prior to the widespread use of vaccination: a nationwide observational study

Background

Before widespread coronavirus disease (COVID-19) vaccinations, Japan experienced three COVID-19 epidemic waves. This study aimed to evaluate the characteristics of hospitalised COVID-19 patients and reveal temporal changes.

Methods

This study included 33,554 hospitalised patients with COVID-19 from 553 healthcare facilities. Data were analysed by age group and epidemic wave (first wave, 01/01/2020–05/31/2020; second wave, 06/01/2020–10/31/2020; and third wave, 11/01/2020–03/31/2021).

Findings

By age group, 3% (under 18), 22% (young), 34% (middle-aged), and 41% (older patients) were aged 0-17, 18-39, 40-64, and >65 years; while 16%, 35%, and 49% were in the first, second, and third wave, respectively. The patients’ overall median age (58 years; interquartile range, 39–74) was lowest and highest during the second and third waves, respectively. The frequency of any comorbidity was lowest and highest during the second (44·5%) and third (63·6%) waves, respectively. The symptoms at admission and exposure history differed considerably with age. The overall case fatality rate (5%) was highest among older patients (11·4%). Case fatality rate was highest and lowest during the first (7·3%) and second (2·8%) waves, respectively. Medication use changed over time.

Interpretation

Although the overall case fatality rate remained relatively low, it was more than twice as high among older patients. After adjusting for age and comorbidities, the risk of death was highest in the first wave.

Funding

This work was supported by the Ministry of Health, Labour and Welfare “Research on Emerging and Re-emerging Infectious Diseases and Immunization” 19HA1003].

Correlation between surgical mortality for perforated peritonitis and days of the week for operations: A retrospective study using the Japanese National Clinical Database

BACKGROUND

The association between weekend interventions and poor outcomes is termed the "weekend effect." This retrospective study investigated whether the weekend effect exists in the surgical treatment of acute diffuse peritonitis due to gastrointestinal perforation.

METHODS

Patients (n = 16,209) who underwent operation for acute diffuse peritonitis during 2016-2017 were included and grouped depending on the perforation site. Using 23 variables, we performed hierarchical logistic regression analysis and calculated odds ratios for surgical mortality.

RESULTS

Surgical mortality rates were 8.8%, 15.0%, and 14.1% for patients with gastroduodenal, small bowel, and large bowel perforations, respectively. Unadjusted odds ratios for surgical mortality differed significantly on Wednesdays only for patients with large bowel perforation (odds ratio: 0.772, 95% confidence interval: 0.613-0.972, P = 0.03). However, there was no significant difference in adjusted odds ratios.

CONCLUSION

The quality of emergency surgical treatment is uniform in Japan throughout the week in terms of mortality.

Democracy and case fatality rate of COVID-19 at early stage of pandemic: a multicountry study

Many studies have evaluated factors that influence the course of the COVID-19 pandemic in different countries. This multicountry study assessed the influence of democracy and other factors on the case fatality rate of COVID-19 during the early stage of the pandemic. We accessed the World Health Organization, World Bank, and the Democracy Index 2019 databases for data from the 148 countries. Multiple analyses were conducted to examine the association between the Democracy Index and case fatality rate of COVID-19. Within 148 countries, the percentage of the population aged 65 years and above (p = 0.0193), and health expenditure as a percentage of GDP (p = 0.0237) were positively associated with countries' case fatality rates. By contrast, hospital beds per capita helped to reduce the case fatality rates. In particular, the Democracy Index was positively associated with case fatality rates in a subgroup of 47 high-income countries. This study suggests that enhancing the health system with increased hospital beds and healthcare workforce per capita should reduce case fatality rate. The findings suggest that a higher Democracy Index is associated with more deaths from COVID-19 at the early stage of the pandemic, possibly due to the decreased ability of the government.

Risk factors for COVID-19 severity and mortality among inpatients in Southern Iran

Introduction

COVID-19 is a highly contagious respiratory disease and many factors can affect its severity and mortality. This study aimed to investigate the risk factors associated with the severity and mortality of COVID-19.

Methods

In this cross-sectional study, 311 cases with COVID-19 approved by the CORONALAB database in the Center for Disease Control and Prevention (CDC) in southern Iran were selected using systematic random sampling from 15 May to 13 June 2020. The data were collected through interviews and phone calls using a researcher-made questionnaire.

Results

The mean age of the participants was 45.82 ± 17.92 years, and the male to female ratio was 1.57:1. In addition, the Case Fatality Rate (CFR) was 4.50%, and the disease was severe in 47.5% of the cases. The most common clinical symptoms were cough (39.22%), fever (31.83%), and dyspnea (24.76%). The severity of COVID-19 was significantly associated with age and history of Cardiovascular Disease (CVD). Besides, the mortality of COVID-19 was significantly related to age, gender, hypertension, CVD, and Chronic Kidney Disease (CKD). The mean interval between the onset of the first symptom and referral to a health center was 3.02 ± 2.82 days. Additionally, the mean interval between the referral to health centers and testing was 0.88 ± 2.20 days.

Conclusion

Older patients, males, and those who had CVD, CKD, and hypertension required accurate healthcare and early intervention to prevent the exacerbation of COVID-19. Furthermore, the interval between the onset of the first symptom and testing was relatively long. Overall, early diagnosis, isolation, and treatment of patients were found to be essential to control COVID-19.

Trends in all-cause mortality of hospitalized patients due to SARS-CoV-2 infection from a monocentric cohort in Milan (Lombardy, Italy)

Background

Robust data on case fatality rate (CFR) among inpatients with COVID-19 are still lacking, and the role of patient characteristics in in-hospital deaths remains under-investigated. This study quantified the overall CFR and described its trend in a cohort of hospitalized patients with SARS-CoV-2 in Italy. Admission to ICU, death, or discharge were the secondary outcomes.

Methods

This retrospective study is based on administrative health data and electronic case records of inpatients consecutively admitted to Niguarda Hospital between 21 February and 8 November 2020.

Results

An overall CFR of 18% was observed. CFR was significantly reduced during the second wave of contagion (1 June to 30 September, 16%) compared with the first wave (21 February to 31 May, 21% p = 0.015). Such reduction was mainly observed among male inpatients between 40 and 80 years with limited comorbidities. Admission to ICU was associated with a high risk of mortality in both waves. The incidence of severe disease and the need for ICU admission were lower in the second wave.

Conclusion

CFR in SARS-CoV-2 inpatients was demonstrated to decrease over time. This reduction may partly reflect the changes in hospital strategy and clinical practice. The reasons for this improvement should be further investigated to plan an exit strategy in case of future outbreaks.

Key messages

What is already known on this topic

Before the advent of anti-COVID-19 vaccines, a multi-wave pattern of contagion was observed, and this trend conditioned the inpatient case fatality rate (CFR), which varied over time accordingly to the waves of contagion.

Only preliminary results on the in-hospital mortality trend are available, along with a partial analysis of its determinants. Consequently, robust data on CFR among inpatients with SARS-CoV-2 infection are still lacking, and the role of patient characteristics in in-hospital deaths remains under-investigated.

What this study adds

This study shows that the in-hospital mortality in patients with SARS-CoV-2 infection decreases over time.

Such reduction was mainly observed among male inpatients between 40 and 80 years with limited comorbidities. Admission to ICU was invariably associated with a high risk of mortality during the whole study period (21 February to 8 November 2020), but the incidence of severe disease and the need for ICU admission were lower in the second wave of contagions (1 October to 8 November 2020). This reduction may partly reflect the impact of changes in hospital strategy and clinical practice. The reasons for this improvement should be further investigated to inform the response to future outbreaks and to plan exit strategy by prioritizing high-risk populations.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10389-021-01675-y.

Mortality comparisons of COVID-19 with all-cause and non-communicable diseases in Cyprus, Iceland and Malta: lessons learned and forward planning

OBJECTIVES

The COVID-19 pandemic has spread throughout the world, including Cyprus, Iceland and Malta. Considering the small population sizes of these three island countries, it was anticipated that COVID-19 would be adequately contained and mortality would be low. This study aims to compare and contrast COVID-19 mortality with mortality from all causes and common non-communicable diseases (NCDs) over 8 months between these three islands.

METHODS

Data were obtained from the Ministry of Health websites and COVID dashboards from Cyprus, Iceland and Malta. The case-to-fatality ratio (CFR) and years of life lost (YLLs) were calculated. Comparisons were made between the reported cases, deaths, CFR, YLLs, swabbing rates, restrictions and mitigation measures.

RESULTS

Low COVID-19 case numbers and mortality rates were observed during the first wave and transition period in Cyprus, Iceland and Malta. The second wave saw a drastic increase in the number of confirmed cases and mortality rates, especially for Malta, with high CFR and YLLs. Similar restrictions and measures were evident across the three island countries. Results show that COVID-19 mortality was generally lower than mortality from NCDs.

CONCLUSIONS

The study highlights that small geographical and population size, along with similar restrictive measures, did not appear to have an advantage against the spread and mortality rate of COVID-19, especially during the second wave. Population density, an ageing population and social behaviours may play a role in the burden of COVID-19. It is recommended that a country-specific syndemic approach is used to deal with the local COVID-19 spread based on the population's characteristics, behaviours and the presence of other pre-existing epidemics.

Infection fatality ratio and case fatality ratio of COVID-19

The infection fatality ratio (IFR) is the risk of death per infection and is one of the most important epidemiological parameters. Enormous efforts have been undertaken to estimate the IFR for COVID-19. This study examined the pros and cons of several approaches. It is found that the frequently used approaches using serological survey results as the denominator and the number of confirmed deaths as the numerator underestimated the true IFR. The most typical examples are South Africa and Peru (before official correction), where the confirmed deaths are one-third of the excess deaths. We argue that the RT-PCR-based case fatality ratio (CFR) is a reliable indicator of the lethality of COVID-19 in locations where testing is extensive. An accurate IFR is crucial for policymaking and public-risk perception.

The clinical course of 239 cases of Japanese spotted fever in Ise Red Cross Hospital, 2006-2019

INTRODUCTION

Although the mortality rates associated with Japanese spotted fever (JSF) are unknown, advances in testing technology have led to an increase in JSF-induced mortality reported in clinical practice. Up-to-date clinical information is essential for accurate diagnosis and prompt treatment of JSF.

METHODS

This retrospective descriptive study included patients with JSF who were treated at the Ise Red Cross Hospital between 2006 and 2019. Diagnostic criteria included positive results of molecular-based tests during the acute phase and/or increased serum-specific antibody titers. This study was performed based on the clinical findings, clinical course, treatment, and prognosis in confirmed cases of JSF.

RESULTS

We investigated 239 patients with a confirmed diagnosis of JSF (48.1% men, mean age 69.2 years). Notably, 237 patients received tetracycline antibiotics, and eight patients died (one patient was misdiagnosed and died without adequate treatment). Four of the remaining patients had a multi-organ failure at the time of admission. However, among the 155 consecutive patients who received effective antibiotic therapy after 2012, we observed two deaths; one patient died of hemorrhage secondary to non-steroidal anti-inflammatory drug-induced duodenal ulcer.

CONCLUSIONS

Our study showed a case fatality rate of 3.3%, which indicates that JSF is a severe illness. Although a few cases of the fulminant disease are reported, early initiation of therapy was shown to improve JSF-induced mortality by approximately 1%. Prompt initiation of antibiotic therapy (even in the absence of genetic test results) is warranted in cases of suspected JSF.

[Epidemiological characteristics of COVID-19 cases in the Almería health district.]

OBJECTIVE

It is necessary to know epidemiological data of the current COVID-19 pandemic by health areas for its best control. The aim is to describe the epidemiological characteristics of the COVID-19 cases in the Almería Health District until June 21^st 2020 and the preventive and control measures carried out.

METHODS

Descriptive study of variables: sex, age, if they were health, social health personnel or any other personnel considered essential, history of previous trips, if they were institutionalized, date of declaration, clinical situation and variables related to severity, history of risk factors or underlying health conditions. Information sources: disease declaration files, and epidemiological surveys. Frequencies and percentages, cumulative incidence, and case fatality rates were calculated.

RESULTS

382 confirmed cases were reported, cumulative incidence of 126.65 for all the studied period of time. The average age was 52 years. 54.7% were women, 37.8% corresponded to workers in health and social health centers. The percentage of confirmed cases in families was 42,7%, with a 19.3% of secondary cases, 48.8% was related to previous trips. 83.8% of non-hospitalized women presented asthenia, and 85% of men, fever and general discomfort. Men presented a higher percentage of hospitalization (37.1%), ICU admissions (6.9%) and case fatality rate (6.4%). 27.1% of the cases were institutionalized people. The case fatality rate in nursing homes was 16.4%.

CONCLUSIONS

There has been a low incidence of COVID-19, with high intra-family transmission, greater severity in men, and low case fatality rate, the most affected groups being women who work in health and social-health centers, institutionalized people and people related to a previous trip. The prevention and control measures carried out, together with the confinement, would have helped prevent further spread of the virus.

COVID-19 lockdown - Blessing or disaster?

Despite the dubious results of the nationwide lockdown in India state after state continue to clamp lockdowns indiscriminately and claim that it is a panacea for all their ills. Unverified claims abound and myths are perpetuated without any basis. It is time to take a close look at the hard data and come to logical conclusions regarding the utility of prolonged open-ended lockdowns. Unfortunately, the evidence does not support the use of prolonged lockdowns as a useful strategy to combat the COVID-19 pandemic.

Epidemiological and clinical characteristics of severe fever with thrombocytopenia syndrome in southern Anhui Province, 2011-2020

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging hemorrhagic fever, and the causative pathogen, the SFTS virus (SFTSV), was first discovered in China in 2010. In this study, a retrospective analysis of 86 patients that diagnosed with SFTS from two five-year periods (2011-2015 and 2016-2020) that was performed to explore the changes in epidemiology, clinical characteristics, laboratory parameters and prognosis between those two periods. The results showed that there were significant differences in age, the proportion of farmers, geographical distribution, the incidence of multiple organ dysfunction, the decrease in thrombocyte count, and the elevations of serum AST and lipase levels between the two groups (p<0.05). Additionally, the case-fatality rate in the 2016-2020 group (16.7%) was higher than that in the 2011-2015 group (6.25%), although the difference was not significant. Our study shows that SFTS is broadly distributed across Anhui Province. The mortality rate is high. May to July was the peak of the epidemic, and farmers constituted a high-risk group. In recent years, thrombocytopenia has become more serious, and multiple organ dysfunction is more common. Clinicians need to further strengthen their knowledge of the changing epidemiological and clinical characteristics of this disease.

Association of COVID-19 case fatality rate with disease burden: an ecological analysis in Italy during the first wave

Objectives: In Italy, the case fatality rate (CFR) of coronavirus disease 2019 (COVID-19) during the first wave of the pandemic showed significant geographic heterogeneity. The aim of this study was to explore the possible association between the CFR and measures of disease burden in the Italian regions using an ecological approach.

Methods: Cumulated regional data for the period February 24 to May 11, 2020 were analysed to assess the association of the CFR with the cumulative incidence of COVID-19 and the ratio between the maximum number of COVID-19 patients in intensive care units (ICU) and ICU beds available before the pandemic (ICU load), adjusting for median age of the patients at disease onset, number of nasopharyngeal swabs performed per confirmed case, and prevalence of chronic diseases .

Results: During the study period, the COVID-19 CFR in the Italian regions ranged between 5.0% and 18.4%. On multivariable regression analysis, the CFR was found to be significantly associated with the cumulative incidence (relative rate (RR) 1.02 per 100 cases/1 million increase), median patient age (RR 1.07 per 1 year increase), and ICU load (RR 1.72, 2.18, and 2.57, for >40–70% vs ≤40%, 70–140% vs ≤40%, and ≥140 vs ≤40%, respectively).

Conclusions: A high burden of COVID-19 may contribute to increased disease fatality, possibly as a result of the increasing demand for care of critically ill patients beyond health system capability.

[A mathematical model to estimate the number of unreported SARS-CoV-2 infections in the early phase of the pandemic using Germany and Italy as examples]

Hintergrund

Gerade in der Frühphase einer Pandemie ist es schwierig, verlässliche Zahlen über deren Ausbreitung zu erhalten. Die derzeitige COVID-19-Pandemie und das damit verbundene umfassende, aber nicht vollständige Datenmonitoring bieten die Möglichkeit, die Dunkelziffer der nicht erfassten Fälle zu schätzen.

Ziel

Vorstellung eines einfachen mathematischen Modells, welches eine frühzeitige Abschätzung der Zahl nichtregistrierter Fälle (Dunkelziffer) ermöglicht.

Material und Methoden

Es werden die Prävalenzen der gemeldeten Infektionen in verschiedenen Altersgruppen mit Kennzahlen der altersabhängigen Kontaktzahlen kombiniert. Daraus wird für jede Altersgruppe eine korrigierte Prävalenz abgeleitet, mit der dann die Dunkelziffer geschätzt werden kann.

Ergebnisse

Unser Modell berechnet für Mitte April 2020 in Deutschland insgesamt 2,8-mal so viele Infektionen wie die Zahl der registrierten Infektionen (Fälle). Für Italien ergibt sich Mitte April 2020 ein Faktor von 8,3. Die daraus abgeleiteten Fallsterblichkeiten betragen 0,98 % für Deutschland und 1,51 % für Italien, welche deutlich näher zusammenliegen als die rein aus den zu dem Zeitpunkt vorhandenen Meldezahlen abgeleiteten Fallsterblichkeiten von 2,7 % und 12,6 %.

Diskussion

Die aus dem Modell abgeleitete Dunkelziffer kann die unterschiedlichen Beobachtungen in den Fallsterblichkeiten und der Zustände in der Frühphase der COVID-19-Pandemie in Deutschland und Italien zu einem großen Teil erklären. Das Modell ist einfach, schnell und robust implementierbar und kann gut darauf reagieren, wenn die Meldezahlen hinsichtlich der Altersstruktur nicht repräsentativ für die Bevölkerung sind. Wir empfehlen, dieses Modell für eine effiziente und frühzeitige Schätzung nichtgemeldeter Fallzahlen bei zukünftigen Epidemien und Pandemien in Betracht zu ziehen.

National surveillance of antimicrobial susceptibilities to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics and serotype distribution of invasive Streptococcus pneumoniae isolates in adults: results from the Surveillance of Multicenter Antimicrobial Resistance in Taiwan (SMART) programme in 2017-2020

Objectives

The aim of this study was to investigate the trends in serotypes and in vitro antimicrobial susceptibility of Streptococcus pneumoniae causing adult invasive pneumococcal disease (IPD) to dalbavancin, telavancin, tedizolid, eravacycline, omadacycline and other comparator antibiotics from 2017–2020 following implementation of the 13-valent pneumococcal conjugate vaccine (PCV-13) and during the COVID-19 (coronavirus disease 2019) pandemic.

Methods

During the study period, 237 S. pneumoniae isolates were collected from non-duplicate patients, covering 15.0% of IPD cases in Taiwan. Antimicrobial susceptibility testing was performed using a Sensititre® system. A latex agglutination method (ImmuLex™ Pneumotest Kit) was used to determine serotypes.

Results

Susceptibility rates were high for vancomycin (100%), teicoplanin (100%) and linezolid (100%), followed by ceftaroline (non-meningitis) (98.3%), moxifloxacin (94.9%) and quinupristin/dalfopristin (89.9%). MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline and omadacycline were generally low. Non-vaccine serotype 23A was the leading cause of IPD across the adult age range. Isolates of serotype 15B were slightly fewer than those of PCV-13 serotypes in patients aged ≥65 years. The overall case fatality rate was 15.2% (36/237) but was especially high for non-PCV-13 serotype 15B (21.4%; 3/14). Vaccine coverage was 44.7% for PCV-13 and 49.4% for the 23-valent pneumococcal polysaccharide vaccine (PPSV-23), but was 57% for both PCV-13 and PPSV-23.

Conclusion

The incidence of IPD was stationary after PCV-13 introduction and only dramatically decreased in the COVID-19 pandemic in 2020. The MIC₅₀ and MIC₉₀ values of dalbavancin, telavancin, tedizolid, eravacycline, omadacycline were generally low for S. pneumoniae causing adult IPD.

No association between the SARS-CoV-2 variants and mortality rates in the Eastern Mediterranean Region

As the novel coronavirus SARS-CoV-2 continues to spread in all countries, there is a growing interest in monitoring and understanding the impact of emerging strains on virus transmission and disease severity. Here, we analyzed SARS-CoV-2 genomic sequences reported in the Eastern Mediterranean Region (EMR) countries, as of 1 January 2021. The majority (~75%) of these sequences originated from three out of 22 EMR countries, and 65.8% of all sequences belonged to GISAID clades GR, GH, G and GV. A delay ranging between 30 and 150 days from sample collection to sequence submission was observed across all countries, limiting the utility of such data in informing public health policies. We identified ten common non-synonymous mutations represented among SARS-CoV-2 in the EMR and several country-specific ones. Two substitutions, spike_D614G and NSP12_P323L, were predominantly concurrent in most countries. While the single incidence of NSP12_P323L was positively correlated with higher case fatality rates in EMR, no such association was established for the double (spike_D614G and NSP12_P323L) concurrent variant across the region. Our study identified critical data gaps in EMR highlighting the importance of enhancing surveillance and sequencing capacities in the region.

Factors associated with length of stay and treatment outcome of Ebola patients treated at an Ebola treatment center in Sierra Leone during the peak period of the West African Ebola outbreak 2013-2016

Background

The World Health Organization (WHO) declared the West Africa Ebola epidemic as a Public Health Emergency of International Concern in August 2014. During the outbreak period, there were calls for the affected countries to construct Ebola treatment centres and reliable diagnostic laboratories closer to areas of transmission in order to improve the quality care of Ebola Virus Disease (EVD) patients. Delay in seeking treatment has been reported to have led to poor treatment outcome of EVD patients. Sierra Leone recorded more than 8000 probable and confirmed cases and more than 4000 EVD -related deaths nation-wide.

Methods

In this retrospective study, we investigated the effects of treatment delay, length of symptomatic period, EVD patients’ sex, age, occupation, region of residence, and clinical characteristics on the treatment outcome of 205 laboratory-confirmed EVD patients who were admitted at the Kenema Government Hospital Ebola Treatment Center (KGHETC) from 13/09/2014–26/11/2014; i.e. during the peak of 2013–2016 EVD outbreak in Sierra Leone. Specifically also, we determined the factors that were associated with the length of stay for EVD treatment for patients who were discharged alive.

Results

Majority (66.3%, n = 205/309) of the 309 suspected EVD patients with medical records at the KGHETC triage during the period under review were tested positive for EVD using reverse-transcriptase-polymerase chain reaction (RT-PCR) and had a definitive treatment outcome. Few (33.7%, n = 104/309) suspected EVD patients were not included in our analysis and were classified thus: 29.1% (n = 90/309) suspect EVD cases with negative RT-PCR results, 4.5% (n = 14/309) suspect cases with non-available RT-PCR result.

Of the 205 patients, 99 (48.3%) had a fatal outcome. For EVD patients that survived, we recorded a significant association (− 0.06, 95% Confidence Interval (CI) = − 0.14 – - 0.02, p = 0.004) between the Length of Stay (LOS) and for each kilometer travelled to seek treatment at the KGHETC. However, the association between EVD patients that were low skilled workers (− 5.91, 95% CI = − 24.60 – 12.79, p = 0.73), EVD patients who were children and pupils in junior school (− 0.86, 95% CI = − 12.86 – 11.14, p = 0.73), health seeking delay for EVD patients who resided in Kenema District where the KGHETC was located (− 0.49, 95% CI = − 0.12 – 1.09, p = 0.24), sex (− 1.77, 95% CI = − 8.75 – 5.21, p = 0.50), age (0.21, 95% CI = − 0.36 – 0.77, p = 0.57), referral status (1.21, 95% CI = − 17.67 – 20.09, p = 0.89) and the LOS in surviving patients were not statistically significant.

Conclusion

The high LOS for either treatment outcome for EVD patients that resided in the district in which the EVD treatment facility was located compared to those patients from other districts implies that health authorities should consider intensive health education with high priority given to seeking early EVD treatment, and the construction of strategic ETCs as important components in their response strategy.

Estimating the wave 1 and wave 2 infection fatality rates from SARS-CoV-2 in India

OBJECTIVE

There has been much discussion and debate around the underreporting of COVID-19 infections and deaths in India. In this short report we first estimate the underreporting factor for infections from publicly available data released by the Indian Council of Medical Research on reported number of cases and national seroprevalence surveys. We then use a compartmental epidemiologic model to estimate the undetected number of infections and deaths, yielding estimates of the corresponding underreporting factors. We compare the serosurvey based ad hoc estimate of the infection fatality rate (IFR) with the model-based estimate. Since the first and second waves in India are intrinsically different in nature, we carry out this exercise in two periods: the first wave (April 1, 2020-January 31, 2021) and part of the second wave (February 1, 2021-May 15, 2021). The latest national seroprevalence estimate is from January 2021, and thus only relevant to our wave 1 calculations.

RESULTS

Both wave 1 and wave 2 estimates qualitatively show that there is a large degree of "covert infections" in India, with model-based estimated underreporting factor for infections as 11.11 (95% credible interval (CrI) 10.71-11.47) and for deaths as 3.56 (95% CrI 3.48-3.64) for wave 1. For wave 2, underreporting factor for infections escalate to 26.77 (95% CrI 24.26-28.81) and to 5.77 (95% CrI 5.34-6.15) for deaths. If we rely on only reported deaths, the IFR estimate is 0.13% for wave 1 and 0.03% for part of wave 2. Taking underreporting of deaths into account, the IFR estimate is 0.46% for wave 1 and 0.18% for wave 2 (till May 15). Combining waves 1 and 2, as of May 15, while India reported a total of nearly 25 million cases and 270 thousand deaths, the estimated number of infections and deaths stand at 491 million (36% of the population) and 1.21 million respectively, yielding an estimated (combined) infection fatality rate of 0.25%. There is considerable variation in these estimates across Indian states. Up to date seroprevalence studies and mortality data are needed to validate these model-based estimates.

The emergence of novel SARS-CoV-2 variant P.1 in Amazonas (Brazil) was temporally associated with a change in the age and sex profile of COVID-19 mortality: A population based ecological study

BACKGROUND

Since the end of 2020, there has been a great deal of international concern about the variants of SARS-COV-2 B.1.1.7, identified in the United Kingdom; B.1.351 discovered in South Africa and P.1, originating from the Brazilian state of Amazonas. The three variants were associated with an increase in transmissibility and worsening of the epidemiological situation in the places where they expanded. The lineage B.1.1.7 was associated with the increase in case fatality rate in the United Kingdom. There are still no studies on the case fatality rate of the other two variants. The aim of this study was to analyze the mortality profile before and after the emergence of the P.1 strain in the Amazonas state.

METHODS

We analyzed data from the Influenza Epidemiological Surveillance Information System, SIVEP-Gripe (Sistema de Informação de Vigilância Epidemiológica da Gripe), comparing two distinct epidemiological periods: during the peak of the first wave, between April and May 2020, and in January 2021 (the second wave), the month in which the new variant came to predominate. We calculated mortality rates, overall case fatality rate and case fatality rate among hospitalized patients; all rates were calculated by age and gender and 95% confidence intervals (95% CI) were determined.

FINDINGS

We observed that in the second wave there were a higher incidence and an increase in the proportion of cases of COVID-19 in the younger age groups. There was also an increase in the proportion of women among Severe Acute Respiratory Infection (SARI) cases from 40% (2,709) in the first wave to 47% (2,898) in the second wave and in the proportion of deaths due to COVID-19 between the two periods varying from 34% (1,051) to 47% (1,724), respectively. In addition, the proportion of deaths among people between 20 and 59 years old has increased in both sexes. The case fatality rate among those hospitalized in the population between 20 and 39 years old during the second wave was 2.7 times the rate observed in the first wave (female rate ratio = 2.71; 95% CI: 1.9-3.9], p <0.0001; male rate ratio = 2.70, 95%CI:2.0-3.7), and in the general population the rate ratios were 1.15 (95% CI: 1.1-1.2) in females and 0.78 (95% CI: 0.7-0.8) in males].

INTERPRETATION

Based on this prompt analysis of the epidemiological scenario in the Amazonas state, the observed changes in the pattern of mortality due to COVID-19 between age groups and gender simultaneously with the emergence of the P.1 strain suggest changes in the pathogenicity and virulence profile of this new variant. Further studies are needed to better understanding of SARS-CoV-2 variants profile and their impact for the health population.

FUNDING

There was no funding for this study.

COVID-19 fatalities by zip codes and socioeconomic indicators across various U.S. regions

Background

There is a paucity of literature addressing COVID-19 case-fatality ratios (CFR) by zip code (ZC). We aim to analyze trends in COVID-19 CFR, population density, and socioeconomic status (SES) indicators (unemployment, median household income) to identify ZCs heavily burdened by COVID-19.

Methods

Cross-sectional study to investigate the US prevalence of COVD-19 fatalities by ZC and SES. CFRs were calculated from state/county Departments of Health. Inclusion criteria were counties that reported cases/deaths by ZC and a CFR≥2%. This study was reported in line with the STROCSS criteria.

Results

609/1,853 ZCs, spanning 327 counties in 7 states had CFRs ≥2%. A significant positive correlation was found between the CFR and median household income (Pearson correlation:0.107; 95% CI [289.1,1937.9]; p < 0.001). No significant correlations exist between the CFR, and population/mi (Sen-Crowe et al., 2020) [2] or unemployment rate. Significant associations exist between the CFR and young males and elderly females without public insurance. CFR was inversely associated with persons aged <44 and individuals aged ≥65. The percentage of nursing homes (NHs) within cities residing within high CFR ZCs range from 8.7% to 67.6%.

Conclusion

Significant positive association was found between the CFR and median household income. Population/mi (Sen-Crowe et al., 2020) [2] and unemployment rates, did not correlate to CFR. NHs were heavily distributed in high CFR zip codes. We recommend the targeted vaccination of zip codes with a large proportion of long-term care facilities. Finally, we recommend for improved screening and safety guidelines for vulnerable populations (e.g nursing home residents) and established protocols for when there is evidence of substantial infectious spread.

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First national sampling of COVID-19 Case Fatality Ratio (CFR) at the zip code level.

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Population density and unemployment rate did not correlate to COVID-19 CFR.

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Significant positive correlation was found between CFR and median household income.

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Nursing homes were concentrated in zip codes with high COVID-19 CFR.

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States should make COVID-19 data available at the zip code level.

Using serological studies to assess COVID-19 infection fatality rate in developing countries: A case study from one Colombian department

This study describe the infection fatality rate (IFR) by COVID-19 by age groups in one department of Colombia. It used results from a serological survey to stablish a closer estimation of the true proportion of infected people. It found an overall IFR of 0.24% quite lower than the overall CFR (5.6%). We conclude that CFR severely overestimate the lethality of COVID-19 in developing areas.

Geographic and demographic heterogeneity of SARS-CoV-2 diagnostic testing in Illinois, USA, March to December 2020

BACKGROUND

Availability of SARS-CoV-2 testing in the United States (U.S.) has fluctuated through the course of the COVID-19 pandemic, including in the U.S. state of Illinois. Despite substantial ramp-up in test volume, access to SARS-CoV-2 testing remains limited, heterogeneous, and insufficient to control spread.

METHODS

We compared SARS-CoV-2 testing rates across geographic regions, over time, and by demographic characteristics (i.e., age and racial/ethnic groups) in Illinois during March through December 2020. We compared age-matched case fatality ratios and infection fatality ratios through time to estimate the fraction of SARS-CoV-2 infections that have been detected through diagnostic testing.

RESULTS

By the end of 2020, initial geographic differences in testing rates had closed substantially. Case fatality ratios were higher in non-Hispanic Black and Hispanic/Latino populations in Illinois relative to non-Hispanic White populations, suggesting that tests were insufficient to accurately capture the true burden of COVID-19 disease in the minority populations during the initial epidemic wave. While testing disparities decreased during 2020, Hispanic/Latino populations consistently remained the least tested at 1.87 tests per 1000 population per day compared with 2.58 and 2.87 for non-Hispanic Black and non-Hispanic White populations, respectively, at the end of 2020. Despite a large expansion in testing since the beginning of the first wave of the epidemic, we estimated that over half (50-80%) of all SARS-CoV-2 infections were not detected by diagnostic testing and continued to evade surveillance.

CONCLUSIONS

Systematic methods for identifying relatively under-tested geographic regions and demographic groups may enable policymakers to regularly monitor and evaluate the shifting landscape of diagnostic testing, allowing officials to prioritize allocation of testing resources to reduce disparities in COVID-19 burden and eventually reduce SARS-CoV-2 transmission.