Coronavirus Disease Case Definitions, Diagnostic Testing Criteria, and Surveillance in 25 Countries with Highest Reported Case Counts

Underreporting of Cases in the COVID-19 Outbreak of Borriana (Spain) during Mass Gathering Events in March 2020: A Cross-Sectional Study

Determining the number of cases of an epidemic is the first function of epidemiological surveillance. An important underreporting of cases was observed in many locations during the first wave of the COVID-19 pandemic. To estimate this underreporting in the COVID-19 outbreak of Borriana (Valencia Community, Spain) in March 2020, a cross-sectional study was performed in June 2020 querying the public health register. Logistic regression models were used. Of a total of 468 symptomatic COVID-19 cases diagnosed in the outbreak through anti-SARS-CoV-2 serology, 36 cases were reported (7.7%), resulting in an underreporting proportion of 92.3% (95% confidence interval [CI], 89.5-94.6%), with 13 unreported cases for every reported case. Only positive SARS-CoV-2 polymerase chain reaction cases were predominantly reported due to a limited testing capacity and following a national protocol. Significant factors associated with underreporting included no medical assistance for COVID-19 disease, with an adjusted odds ratio [aOR] of 10.83 (95% CI 2.49-47.11); no chronic illness, aOR = 2.81 (95% CI 1.28-6.17); middle and lower social classes, aOR = 3.12 (95% CI 1.42-6.85); younger age, aOR = 0.97 (95% CI 0.94-0.99); and a shorter duration of illness, aOR = 0.98 (95% CI 0.97-0.99). To improve the surveillance of future epidemics, new approaches are recommended.

Safety and efficacy of COVID-19 vaccination in the Chinese population with pulmonary lymphangioleiomyomatosis: a single-center retrospective study

BACKGROUND

The safety and efficacy of vaccination against coronavirus disease 2019 (COVID-19) in patients with lymphangioleiomyomatosis (LAM) is still unclear. This study investigates COVID-19 vaccine hesitancy, vaccine safety and efficacy, and COVID-19 symptoms in LAM patients.

RESULTS

In total, 181 LAM patients and 143 healthy individuals responded to the questionnaire. The vaccination rate of LAM patients was 77.34%, and 15.7% of vaccinated LAM patients experienced adverse events. Vaccination decreased the risk of LAM patients developing anorexia [OR: 0.17, 95% CI: (0.07, 0.43)], myalgia [OR: 0.34, 95% CI: (0.13, 0.84)], and ageusia [OR: 0.34, 95% CI: (0.14, 0.84)]. In LAM patients, a use of mTOR inhibitors reduced the risk of developing symptoms during COVID-19, including fatigue [OR: 0.18, 95% CI: (0.03, 0.95)], anorexia [OR: 0.30, 95% CI: (0.09, 0.96)], and ageusia [OR: 0.20, 95% CI: (0.06, 0.67)].

CONCLUSIONS

Vaccination rates in the LAM population were lower than those in the general population, as 22.7% (41/181) of LAM patients had hesitations regarding the COVID-19 vaccine. However, the safety of COVID-19 vaccination in the LAM cohort was comparable to the healthy population, and COVID-19 vaccination decreased the incidence of COVID-19 symptoms in LAM patients. In addition, mTOR inhibitors seem not to determine a greater risk of complications in patients with LAM during COVID-19.

COVID-19 epidemiology and performance of the WHO clinical algorithm to diagnose COVID-19 in people with HIV from Ukraine

BACKGROUND

The two main objectives were to evaluate the COVID-19 point prevalence and the test performance of the WHO case definition to diagnose COVID-19 clinically in people with HIV in West Ukraine.

METHODS

Multicenter cross-sectional study in Lviv, Ukraine, from October 2020-November 2021. COVID-19 unvaccinated people with HIV were included regardless of COVID-19 symptoms at routine clinical visits and had standardized medical, quality of life (EQ(5D)) and SARS-CoV-2 serology assessments. Reported symptoms indicating potential COVID-19 events at inclusion or between March 2020 and inclusion were classified by the WHO case definition as suspected, probable or confirmed. A clinical COVID-19 case was defined as being SARS-CoV-2 seropositive with at least a suspected COVID-19 according to the WHO case definition. The primary endpoints were the clinical COVID-19 prevalence and the test characteristics of the WHO case definition with SARS-CoV-2 serology as reference. (Clinicaltrials.gov:NCT04711954).

RESULTS

The 971 included people with HIV were median 40 years, 38.8% women, 44.8% had prior AIDS, and 55.6% had comorbidities. SARS-CoV-2 seroprevalence was 40.1% (95%CI:37.0-43.1) and 20.5% (95%CI:18.0-23.1) had clinical COVID-19 median 4 months (IQR:2-7) before inclusion. Clinical COVID-19 occurred less frequently in people with HIV with tuberculosis history, injecting drug use, CD4+ T-cells <200/mL and unemployment. The quality of life was not impacted after COVID-19. An at least probable COVID-19 classification by the WHO case definition had 44.1% sensitivity (95%CI:38.7-49.7), 85.2% specificity (95%CI:81.5-88.4), 66.6% positive predictive value (95%CI:59.8-73.0) and 69.5% negative predictive value (95%CI:65.5-73.3) to diagnose COVID-19.

CONCLUSIONS

COVID-19 unvaccinated people with HIV from Ukraine had a significant COVID-19 rate and using the WHO case definition had insufficient diagnostic accuracy to diagnose these cases. The lower burden in vulnerable people with HIV was unexpected but might reflect a shielding effect.

High pre-Delta and early-Omicron SARS-CoV-2 seroprevalence detected in dried blood samples from Kinshasa (D.R. Congo)

Studies on the impact of the COVID-19 pandemic in sub-Saharan Africa have yielded varying results, although authors universally agree the real burden surpasses reported cases. The primary objective of this study was to determine SARS-CoV-2 seroprevalence among patients attending Monkole Hospital in Kinshasa (D.R. Congo). The secondary objective was to evaluate the analytic performance of two chemiluminescence platforms: Elecsys® (Roche) and VirClia® (Vircell) on dried blood spot samples (DBS). The study population (N = 373) was recruited in two stages: a mid-2021 blood donor cohort (15.5% women) and a mid-2022 women cohort. Crude global seroprevalence was 61% (53.9%-67.8%) pre-Delta in 2021 and 90.2% (84.7%-94.2%) post-Omicron in 2022. Anti-spike (S) antibody levels significantly increased from 53.1 (31.8-131.3) U/mL in 2021 to 436.5 (219.3-950.5) U/mL in 2022 and were significantly higher above 45 years old in the 2022 population. Both platforms showed good analytic performance on DBS samples: sensitivity was 96.8% for IgG (antiN/S) (93.9%-98.5%) and 96.0% (93.0%-98.0%) for anti-S quantification. These results provide additional support for the notion that exposure to SARS-CoV-2 is more widespread than indicated by case-based surveillance and will be able to guide the pandemic response and strategy moving forward. Likewise, this study contributes evidence to the reliability of DBS as a tool for serological testing and diagnosis in resource-limited settings.

[Response to the COVID-19 Health Crisis from a Gender Perspective: Lessons Learned]

OBJECTIVE

To delve deeper from a gender perspective into the lessons learned during the COVID-19 pandemic to address future health crises.

METHOD

Study with key informants with experience in public health and gender from the Ministerio de Sanidad, ministries of the autonomous communities, Institut Català de la Salut, Hospital de La Princesa, Escuela Andaluza de Salud Pública and Universidad País Vasco.

SOURCE OF INFORMATION

individual open-ended questionnaire on health and health inequalities/gender inequalities related to COVID-19. After presenting the findings, the key informants group discussed them in a meeting until reaching a consensus on the lessons learned.

RESULTS

The lack of clinical statistics by sex could compromise epidemiological surveillance, losing the opportunity to characterize the disease. The performance of essential services fell more on women, exhausting them with double and triple shifts; with the differences according to sex in the clinical presentation of COVID-19, and the criteria for hospitalization/admission to the intensive care unit, their access to health care decreased. Increased: gender violence and mental health problems; delaying recognition of the second effects of vaccines in women; partially due to information biases in clinical trials. The gender perspective was lacking in academic, healthcare, and health management areas.

CONCLUSIONS

Women's gender dimensions determined their higher frequency of COVID-19 and played a fundamental role in its control. Broadly considering the lessons learned will strengthen prevention systems and be able to provide effective responses to future health crises.

Evolving swabbing practices for COVID-19 in a New Zealand emergency department during the early stages of an emerging pandemic

OBJECTIVE

To review if tests for suspected COVID-19 were performed according to the Ministry of Health (MoH) case definitions, identify patterns associated with testing outside of the case definition, and discuss the potential impacts on hospital services.

METHODS

This was a retrospective audit of patients presenting to the Wellington Hospital ED between 24 March 2020 and 27 April 2020 who were swabbed for COVID-19 in ED. Swabs were audited against the March 15th and April 8th MoH COVID-19 case definitions.

RESULTS

Five hundred and thirty-six COVID-19 swabs for 518 patients were taken during the study period. There was poor alignment of testing with the March 15th case definition, with only 11.6% of the 164 swabs taken during this period meeting the case definition. Of the 145 swabs that did not meet the case definition, the majority (n = 119, 82.1%) met symptom criteria only. Alignment of testing with the wider April 8th case definition was much higher with 88.2% meeting criteria. Factors associated with being swabbed despite not meeting the case definitions included fever >38°, a diagnosis of cancer, subsequent hospital admission, and for the March case definition only 'contact with a traveller'.

CONCLUSION

There were associations found between testing outside of criteria and specific variables potentially perceived as high-risk. Poor alignment of testing with case definitions can impact hospital services through the (mis)use of limited laboratory testing capacity and implications for resource management. Improved communication and feedback between clinicians and policymakers may improve case definition implementation in a clinical setting.

Early response to COVID-19 in Brazil: The impact of a targeted approach to suspected cases and on epidemiological surveillance efforts

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entered Brazil before travel restrictions and border closures were imposed. This study reports the characteristics of suspected and confirmed coronavirus disease 2019 (COVID-19) cases among symptomatic international travelers in Brazil and their contacts.

Methods

The REDCap platform developed by the Brazilian Ministry of Health was analyzed to identify and investigate suspected cases of COVID-19 recorded during the period January 1 to March 20, 2020. The impact of Brazil's targeted approach to suspected cases from specific countries on epidemiological surveillance efforts during the early stages of the COVID-19 pandemic were analyzed.

Results

Based on molecular RT-PCR tests, there were 217 (4.2%) confirmed, 1030 (20.1%) unconfirmed, 722 (14.1%) suspected, and 3157 (61.6%) non-investigated cases among travelers returning from countries included on the alert list for surveillance, as defined by the Ministry of Health. Among the 3372 travelers who went to countries not included on the alert list, there were 66 (2.0%) confirmed, 845 (25.3%) unconfirmed, 521 (15.6%) suspected, and 1914 (57.2%) non-investigated cases. A comparison of the characteristics of confirmed cases returning from alert and non-alert countries did not reveal a statistically significant difference in symptoms. Almost half of the hospitalized travelers with known travel dates and hospitalization status (53.6%) were inbound from countries not included on the alert list, and RT-PCR tests were reported for only 30.5%.

Conclusions

Policies adopted at entry points to contain the introduction of SARS-CoV-2 in Brazil were not ideal. An analysis of the early response shows that surveillance of travelers, including testing strategies, data standards, and reporting systems, was insufficient.

Smart healthcare: A prospective future medical approach for COVID-19

COVID-19 has greatly affected human life for over 3 years. In this review, we focus on smart healthcare solutions that address major requirements for coping with the COVID-19 pandemic, including (1) the continuous monitoring of severe acute respiratory syndrome coronavirus 2, (2) patient stratification with distinct short-term outcomes (eg, mild or severe diseases) and long-term outcomes (eg, long COVID), and (3) adherence to medication and treatments for patients with COVID-19. Smart healthcare often utilizes medical artificial intelligence (AI) and cloud computing and integrates cutting-edge biological and optoelectronic techniques. These are valuable technologies for addressing the unmet needs in the management of COVID. By leveraging deep learning/machine learning capabilities and big data, medical AI can perform precise prognosis predictions and provide reliable suggestions for physicians' decision-making. Through the assistance of the Internet of Medical Things, which encompasses wearable devices, smartphone apps, internet-based drug delivery systems, and telemedicine technologies, the status of mild cases can be continuously monitored and medications provided at home without the need for hospital care. In cases that develop into severe cases, emergency feedback can be provided through the hospital for rapid treatment. Smart healthcare can possibly prevent the development of severe COVID-19 cases and therefore lower the burden on intensive care units.

Understanding COVID-19 reporting behaviour to support political decision-making: a retrospective cross-sectional study of COVID-19 data reported to WHO

OBJECTIVE

Daily COVID-19 data reported by WHO may provide the basis for political ad hoc decisions including travel restrictions. Data reported by countries, however, are heterogeneous and metrics to evaluate its quality are scarce. In this work, we analysed COVID-19 case counts provided by WHO and developed tools to evaluate country-specific reporting behaviours.

METHODS

In this retrospective cross-sectional study, COVID-19 data reported daily to WHO from 3 January 2020 until 14 June 2021 were analysed. We proposed the concepts of binary reporting rate and relative reporting behaviour and performed descriptive analyses for all countries with these metrics. We developed a score to evaluate the consistency of incidence and binary reporting rates. Further, we performed spectral clustering of the binary reporting rate and relative reporting behaviour to identify salient patterns in these metrics.

RESULTS

Our final analysis included 222 countries and regions. Reporting scores varied between -0.17, indicating discrepancies between incidence and binary reporting rate, and 1.0 suggesting high consistency of these two metrics. Median reporting score for all countries was 0.71 (IQR 0.55-0.87). Descriptive analyses of the binary reporting rate and relative reporting behaviour showed constant reporting with a slight 'weekend effect' for most countries, while spectral clustering demonstrated that some countries had even more complex reporting patterns.

CONCLUSION

The majority of countries reported COVID-19 cases when they did have cases to report. The identification of a slight 'weekend effect' suggests that COVID-19 case counts reported in the middle of the week may represent the best data basis for political ad hoc decisions. A few countries, however, showed unusual or highly irregular reporting that might require more careful interpretation. Our score system and cluster analyses might be applied by epidemiologists advising policy makers to consider country-specific reporting behaviours in political ad hoc decisions.

Variations in national surveillance reporting for Mpox virus: A comparative analysis in 32 countries

Objectives

Case Reporting and Surveillance (CRS) are crucial to combat the global spread of the Monkeypox virus (Mpox). To support CRS, the World Health Organization (WHO) has released standardized case definitions for suspected, probable, confirmed, and discarded cases. However, these definitions are often subject to localized adaptations by countries leading to heterogeneity in the collected data. Herein, we compared the differences in Mpox case definitions in 32 countries that collectively reported 96% of the global Mpox caseload.

Methods

We extracted information regarding Mpox case definitions issued by the competent authorities in 32 included countries for suspected, probable, confirmed, and discarded cases. All data were gathered from online public sources.

Results

For confirmed cases, 18 countries (56%) followed WHO guidelines and tested for Mpox using species specific PCR and/or sequencing. For probable and suspected cases, seven and eight countries, respectively were found to have not released definitions in their national documentations. Furthermore, none of the countries completely matched WHO's criteria for probable and suspected cases. Overlapping amalgamations of the criteria were frequently noticed. Regarding discarded cases, only 13 countries (41%) reported definitions, with only two countries (6%) having definition consistent with WHO guidelines. For case reporting, 12 countries (38%) were found to report both probable and confirmed cases, in line with WHO requirements.

Conclusion

The heterogeneity in case definitions and reporting highlights the pressing need for homogenization in implementation of these guidelines. Homogenization would drastically improve data quality and aid data-scientists, epidemiologists, and clinicians to better understand and model the true disease burden in the society, followed by formulation and implementation of targeted interventions to curb the virus spread.

Challenges and Opportunities for Global Genomic Surveillance Strategies in the COVID-19 Era

Global SARS-CoV-2 genomic surveillance efforts have provided critical data on the ongoing evolution of the virus to inform best practices in clinical care and public health throughout the pandemic. Impactful genomic surveillance strategies generally follow a multi-disciplinary pipeline involving clinical sample collection, viral genotyping, metadata linkage, data reporting, and public health responses. Unfortunately, current limitations in each of these steps have compromised the overall effectiveness of these strategies. Biases from convenience-based sampling methods can obfuscate the true distribution of circulating variants. The lack of standardization in genotyping strategies and bioinformatic expertise can create bottlenecks in data processing and complicate interpretation. Limitations and inconsistencies in clinical and demographic data collection and sharing can slow the compilation and limit the utility of comprehensive datasets. This likewise can complicate data reporting, restricting the availability of timely data. Finally, gaps and delays in the implementation of genomic surveillance data in the public health sphere can prevent officials from formulating effective mitigation strategies to prevent outbreaks. In this review, we outline current SARS-CoV-2 global genomic surveillance methods and assess roadblocks at each step of the pipeline to identify potential solutions. Evaluating the current obstacles that impede effective surveillance can improve both global coordination efforts and pandemic preparedness for future outbreaks.

Global SARS-CoV-2 seroprevalence from January 2020 to April 2022: A systematic review and meta-analysis of standardized population-based studies

BACKGROUND

Our understanding of the global scale of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection remains incomplete: Routine surveillance data underestimate infection and cannot infer on population immunity; there is a predominance of asymptomatic infections, and uneven access to diagnostics. We meta-analyzed SARS-CoV-2 seroprevalence studies, standardized to those described in the World Health Organization's Unity protocol (WHO Unity) for general population seroepidemiological studies, to estimate the extent of population infection and seropositivity to the virus 2 years into the pandemic.

METHODS AND FINDINGS

We conducted a systematic review and meta-analysis, searching MEDLINE, Embase, Web of Science, preprints, and grey literature for SARS-CoV-2 seroprevalence published between January 1, 2020 and May 20, 2022. The review protocol is registered with PROSPERO (CRD42020183634). We included general population cross-sectional and cohort studies meeting an assay quality threshold (90% sensitivity, 97% specificity; exceptions for humanitarian settings). We excluded studies with an unclear or closed population sample frame. Eligible studies-those aligned with the WHO Unity protocol-were extracted and critically appraised in duplicate, with risk of bias evaluated using a modified Joanna Briggs Institute checklist. We meta-analyzed seroprevalence by country and month, pooling to estimate regional and global seroprevalence over time; compared seroprevalence from infection to confirmed cases to estimate underascertainment; meta-analyzed differences in seroprevalence between demographic subgroups such as age and sex; and identified national factors associated with seroprevalence using meta-regression. We identified 513 full texts reporting 965 distinct seroprevalence studies (41% low- and middle-income countries [LMICs]) sampling 5,346,069 participants between January 2020 and April 2022, including 459 low/moderate risk of bias studies with national/subnational scope in further analysis. By September 2021, global SARS-CoV-2 seroprevalence from infection or vaccination was 59.2%, 95% CI [56.1% to 62.2%]. Overall seroprevalence rose steeply in 2021 due to infection in some regions (e.g., 26.6% [24.6 to 28.8] to 86.7% [84.6% to 88.5%] in Africa in December 2021) and vaccination and infection in others (e.g., 9.6% [8.3% to 11.0%] in June 2020 to 95.9% [92.6% to 97.8%] in December 2021, in European high-income countries [HICs]). After the emergence of Omicron in March 2022, infection-induced seroprevalence rose to 47.9% [41.0% to 54.9%] in Europe HIC and 33.7% [31.6% to 36.0%] in Americas HIC. In 2021 Quarter Three (July to September), median seroprevalence to cumulative incidence ratios ranged from around 2:1 in the Americas and Europe HICs to over 100:1 in Africa (LMICs). Children 0 to 9 years and adults 60+ were at lower risk of seropositivity than adults 20 to 29 (p < 0.001 and p = 0.005, respectively). In a multivariable model using prevaccination data, stringent public health and social measures were associated with lower seroprevalence (p = 0.02). The main limitations of our methodology include that some estimates were driven by certain countries or populations being overrepresented.

CONCLUSIONS

In this study, we observed that global seroprevalence has risen considerably over time and with regional variation; however, over one-third of the global population are seronegative to the SARS-CoV-2 virus. Our estimates of infections based on seroprevalence far exceed reported Coronavirus Disease 2019 (COVID-19) cases. Quality and standardized seroprevalence studies are essential to inform COVID-19 response, particularly in resource-limited regions.

Symptom-based case definitions for COVID-19: Time and geographical variations for detection at hospital admission among 260,000 patients

Introduction

Case definitions are used to guide clinical practice, surveillance and research protocols. However, how they identify COVID-19-hospitalised patients is not fully understood. We analysed the proportion of hospitalised patients with laboratory-confirmed COVID-19, in the ISARIC prospective cohort study database, meeting widely used case definitions.

Methods

Patients were assessed using the Centers for Disease Control (CDC), European Centre for Disease Prevention and Control (ECDC), World Health Organization (WHO) and UK Health Security Agency (UKHSA) case definitions by age, region and time. Case fatality ratios (CFRs) and symptoms of those who did and who did not meet the case definitions were evaluated. Patients with incomplete data and non-laboratory-confirmed test result were excluded.

Results

A total of 263,218 of the patients (42%) in the ISARIC database were included. Most patients (90.4%) were from Europe and Central Asia. The proportions of patients meeting the case definitions were 56.8% (WHO), 74.4% (UKHSA), 81.6% (ECDC) and 82.3% (CDC). For each case definition, patients at the extremes of age distribution met the criteria less frequently than those aged 30 to 70 years; geographical and time variations were also observed. Estimated CFRs were similar for the patients who met the case definitions. However, when more patients did not meet the case definition, the CFR increased.

Conclusions

The performance of case definitions might be different in different regions and may change over time. Similarly concerning is the fact that older patients often did not meet case definitions, risking delayed medical care. While epidemiologists must balance their analytics with field applicability, ongoing revision of case definitions is necessary to improve patient care through early diagnosis and limit potential nosocomial spread.

Infant regulation during the pandemic: Associations with maternal response to the COVID-19 pandemic, well-being, and socio-emotional investment

In the transition to parenthood, the COVID-19 pandemic poses an additional strain on parental well-being. Confirmed infections or having to quarantine, as well as public health measures negatively affect parents and infants. Contrary to previous studies mainly focusing on the well-being of school-aged children and their parents during lockdown periods, the present study investigated how mothers of infants respond to the COVID-19 pandemic and whether this is related to maternal well-being, maternal socio-emotional investment, and infant regulation. Between April and June 2021, 206 mothers of infants (M_age  = 7.14 months, SD_age  = 3.75 months) reported on COVID-19 infections, their response to the COVID-19 pandemic, their well-being, socio-emotional investment, and their infant's regulation. Exploratory factor analyses yielded five dimensions of maternal response to the COVID-19 pandemic: social distancing, worrying about the child, birth anxiety, distancing from the child, and information on COVID-19-related parenting behavior and support. These dimensions were related to mother-reported infant regulatory problems. Path analyses revealed paths via reduced maternal well-being and maternal socio-emotional investment. Maternal perceptions of infant regulatory problems are related to how the mothers respond to the COVID-19 pandemic. Better information about COVID-19-related parenting behavior and support might buffer against these effects.

Public health impact of covid-19 vaccines in the US: observational study

OBJECTIVE

To evaluate the impact of vaccine scale-up on population level covid-19 mortality and incidence in the United States.

DESIGN

Observational study.

SETTING

US county level case surveillance and vaccine administration data reported from 14 December 2020 to 18 December 2021.

PARTICIPANTS

Residents of 2558 counties from 48 US states.

MAIN OUTCOME MEASURES

The primary outcome was county covid-19 mortality rates (deaths/100 000 population/county week). The secondary outcome was incidence of covid-19 (cases/100 000 population/county week). Incidence rate ratios were used to compare rates across vaccination coverage levels. The impact of a 10% improvement in county vaccination coverage (defined as at least one dose of a covid-19 vaccine among adults ≥18 years of age) was estimated During the eras of alpha and delta variant predominance, the impact of very low (0-9%), low (10-39%), medium (40-69%), and high (≥70%) vaccination coverage levels was compared.

RESULTS

In total, 30 643 878 cases of covid-19 and 439 682 deaths associated with covid-19 occurred over 132 791 county weeks. A 10% improvement in vaccination coverage was associated with an 8% (95% confidence interval 8% to 9%) reduction in mortality rates and a 7% (6% to 8%) reduction in incidence. Higher vaccination coverage levels were associated with reduced mortality and incidence rates during the eras of alpha and delta variant predominance.

CONCLUSIONS

Higher vaccination coverage was associated with lower rates of population level covid-19 mortality and incidence in the US.