A forensic analysis of SARS-CoV-2 cases and COVID-19 mortality misreporting in the Brazilian population

Discrepancies Between Preliminary and Final COVID-19 Mortality Data - the Case of Serbia

Since the start of the COVID-19 pandemic, countries have scrambled to set up data collection and dissemination pipelines. These data end up in various online datasets. While it has been evident from the beginning that these preliminary data produced by some countries are not very reliable, the mortality data from Serbia seemed particularly problematic. These data are included in all major COVID-19 databases and utilized for research purposes worldwide. Discrepancies were identified between the preliminary mortality data reported through the emergency necessitated system and the final mortality data generated by the regular vital statistics pipeline. The number of deaths due to COVID-19 in Serbia, as reported preliminarily, does not align with the final death toll, which is more than three times higher. To evaluate the impact of the problematic data on research, we identified databases that include these data and reviewed the articles that utilized them. Our literature review identified at least 86 studies that were impacted by these problematic data. We strongly advise researchers to disregard the preliminary COVID-19 mortality data from Serbia. If all-cause mortality data is available, any preliminary data should be validated using excess mortality.

The impact of an enhanced health surveillance system for COVID-19 management in Serrana, Brazil

Objective

To describe the successful implementation of an enhanced public health surveillance system based on early detection, tracing contacts, and patient follow-up and support.

Study design

A prospective observational cohort study conducted in Serrana, São Paulo State, Brazil.

Methods

The implementation was based on four axes: increasing the access to SARS-CoV-2 testing; correct swab collection; testing patients with mild symptoms; and patient follow-up. Positivity rate, patient demographic and clinical characteristics, dynamics of disease severity, SARS-CoV-2 genome evolution, and the impact on COVID-19 research were assessed from August 23, 2020 to February 6, 2021 (between epidemiological week 35/2020 and 5/2021, a total of 24 weeks).

Results

The number of sites collecting rt-PCR for SARS-CoV-2 was increased from one to seven points and staff was trained in the correct use of personal protective equipment and in the swab collection technique. During the study period, 6728 samples were collected from 6155 participants vs. 2770 collections in a similar period before. SARS-CoV-2 RNA was detected in 1758 (26.1%) swabs vs. 1117 (36.7%) before the implementation of the surveillance system (p < 0.001). Positivity rates varied widely between epidemiological weeks 35/2020 and 5/2021 (IQR, 12.8%-31.3%). Out of COVID-19 patients, 91.1% were adults at a median age of 35 years (IQR, 25-50 years), 42.6% were men and 57.4% were women, with a SARS-CoV-2 positivity rate of 28.6% and 24.4% (p < 0.001), respectively. The most common symptoms were headache (72.6%), myalgia (65.0%), and cough (61.7%). Comorbidities were found in 20.8% of patients, the most common being hypertension and diabetes. According to the World Health Organization clinical progression scale, 93.5% of patients had mild disease, 1.6% were hospitalized with moderate disease, 3.2% were hospitalized with severe disease, and 1.4% died. The enhanced surveillance system led to the development of COVID-19 related research.

Conclusions

The enhanced surveillance system in Serrana improved COVID-19 understanding and management. By integrating community and academic institutions, it was possible to monitor SARS-CoV-2 positive cases and variants, follow the epidemic trend, guide patients, and develop relevant research projects.

SARS-CoV-2 infections in 165 countries over time

BACKGROUND

Understanding the dynamics of the COVID-19 pandemic and evaluating the efficacy of control measures requires knowledge of the number of infections over time. This number, however, often differs from the number of confirmed cases because of a large fraction of asymptomatic infections and different testing strategies.

METHODS

This study uses death count statistics, age-dependent infection fatality risks, and stochastic modeling to estimate the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections among adults (aged 20 years or older) in 165 countries over time, from early 2020 until June 25, 2021. The accuracy of the approach is confirmed through comparison with previous nationwide seroprevalence surveys.

RESULTS

The estimates presented reveal that the fraction of infections that are detected vary widely over time and between countries, and hence confirmed cases alone often yield a false picture of the pandemic. As of June 25, 2021, the nationwide cumulative fraction of SARS-CoV-2 infections (cumulative infections relative to population size) was estimated as 98% (95% confidence interval [CI] 93-100%) for Peru, 83% (95% CI 61-94%) for Brazil, and 36% (95% CI 23-61%) for the United States.

CONCLUSIONS

The time-resolved estimates presented expand the possibilities to study the factors that influenced and still influence the pandemic's progression in 165 countries.