Should we ignore SARS-CoV-2 disease?

Current World Health Organization (WHO) reports claim a decline in COVID-19 testing and reporting of new infections. To discuss the consequences of ignoring severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, the endemic characteristics of the disease in 2023 with the ones estimated before using 2022 data sets are compared. The accumulated numbers of cases and deaths reported to the WHO by the 10 most infected countries and global figures were used to calculate the average daily numbers of cases DCC and deaths DDC per capita and case fatality rates (CFRs = DDC/DCC) for two periods in 2023. In some countries, the DDC values can be higher than the upper 2022 limit and exceed the seasonal influenza mortality. The increase in CFR in 2023 shows that SARS-CoV-2 infection is still dangerous. The numbers of COVID-19 cases and deaths per capita in 2022 and 2023 do not demonstrate downward trends with the increase in the percentages of fully vaccinated people and boosters. The reasons may be both rapid mutations of the coronavirus, which reduced the effectiveness of vaccines and led to a large number of re-infections, and inappropriate management.

Differences in Covid-19 mortality among persons 70 years and older in an integrated care setting in region Stockholm: a multi-level analysis between March 2020-February 2021.

BACKGROUND: In Norrtälje municipality, within Region Stockholm, there is a joint integrated care organisation providing health and social care, which may have facilitated a more coordinated response to the covid-19 pandemic compared to the otherwise decentralised Swedish system. This study compares the risk of covid-19 mortality among persons 70 years and older, in the municipalities of Stockholm, Södertälje, and Norrtälje, while considering area and individual risk factors. METHODS: A population-based study using linked register data to examine covid-19 mortality among those 70 + years (N = 127,575) within the municipalities of interest between the periods March-August 2020 and September 2020-February 2021. The effect of individual and area level variables on covid-19 mortality among inhabitants in 68 catchment areas were examined using multi-level logistic models. RESULTS: Individual factors associated with covid-19 mortality were sex, older age, primary education, country of birth and poorer health as indicated by the Charlson Co-morbidity Index. The area-level variables associated were high deprivation (OR: 1.56, CI: 1.18-2.08), population density (OR: 1.14, CI: 1.08-1.21), and usual care. Together, this explained 85.7% of the variation between catchment areas in period 1 and most variation was due to individual risk factors in period 2. Little of the residual variation was attributed to differences between catchment areas. CONCLUSION: Integrated care in Norrtälje may have facilitated a more coordinated response during period 1, compared to municipalities with usual care. In the future, integrated care should be considered as an approach to better protect and meet the care needs of older people during emergency situations.

COVID-19 admissions and mortality in patients with early inflammatory arthritis: results from a UK national cohort.

OBJECTIVE: To describe the risks and predictors of coronavirus disease 2019 (COVID-19) hospitalization and mortality among patients with early inflammatory arthritis (EIA), recruited to the National Early Inflammatory Arthritis Audit (NEIAA). METHODS: NEIAA is an observational cohort. We included adults with EIA from Feb 2020 to May 2021. Outcomes of interest were hospitalization and death due to COVID-19, using NHS Digital linkage. Cox proportional hazards were used to calculate hazard ratios for outcomes according to initial treatment strategy, with adjustment for confounders. RESULTS: From 14 127 patients with EIA, there were 143 hospitalizations and 47 deaths due to COVID-19, with incidence rates per 100 person-years of 0.93 (95% CI 0.79, 1.10) for hospitalization and 0.30 (95% CI 0.23, 0.40) for death. Increasing age, male gender, comorbidities and ex-smoking were associated with increased risk of worse COVID-19 outcomes. Higher baseline DAS28 was not associated with COVID-19 admissions [confounder adjusted hazard ratio (aHR) 1.10; 95% CI 0.97, 1.24] or mortality (aHR 1.11; 95% CI 0.90, 1.37). Seropositivity was not associated with either outcome. Higher symptom burden on patient-reported measures predicted worse COVID-19 outcomes. In unadjusted models, CS associated with COVID-19 death (HR 2.29; 95% CI 1.02, 5.13), and SSZ monotherapy associated with COVID-19 admission (HR 1.92; 95% CI 1.04, 3.56). In adjusted models, associations for CS and SSZ were not statistically significant. CONCLUSION: Patient characteristics have stronger associations with COVID-19 than the initial treatment strategy in patients with EIA. An important limitation is that we have not looked at treatment changes over time.

EuCARE-hospitalised study protocol: a cohort study of patients hospitalised with COVID-19 in the EuCARE project.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), can lead to hospitalisation, particularly in elderly, immunocompromised, and non-vaccinated or partially vaccinated individuals. Although vaccination provides protection, the duration of this protection wanes over time. Additional doses can restore immunity, but the influence of viral variants, specific sequences, and vaccine-induced immune responses on disease severity remains unclear. Moreover, the efficacy of therapeutic interventions during hospitalisation requires further investigation. The study aims to analyse the clinical course of COVID-19 in hospitalised patients, taking into account SARS-CoV-2 variants, viral sequences, and the impact of different vaccines. The primary outcome is all-cause in-hospital mortality, while secondary outcomes include admission to intensive care unit and length of stay, duration of hospitalisation, and the level of respiratory support required. METHODS: This ongoing multicentre study observes hospitalised adult patients with confirmed SARS-CoV-2 infection, utilising a combination of retrospective and prospective data collection. It aims to gather clinical and laboratory variables from around 35,000 patients, with potential for a larger sample size. Data analysis will involve biostatistical and machine-learning techniques. Selected patients will provide biological material. The study started on October 14, 2021 and is scheduled to end on October 13, 2026. DISCUSSION: The analysis of a large sample of retrospective and prospective data about the acute phase of SARS CoV-2 infection in hospitalised patients, viral variants and vaccination in several European and non-European countries will help us to better understand risk factors for disease severity and the interplay between SARS CoV-2 variants, immune responses and vaccine efficacy. The main strengths of this study are the large sample size, the long study duration covering different waves of COVID-19 and the collection of biological samples that allows future research. TRIAL REGISTRATION: The trial has been registered on ClinicalTrials.gov. The unique identifier assigned to this trial is NCT05463380.

Association between Racial Residential Segregation and COVID-19 Mortality.

This study investigates the impact of racial residential segregation on COVID-19 mortality during the first year of the US epidemic. Data comes from the Center for Disease Control and Prevention (CDC), and the Robert Wood Johnson Foundation's and the University of Wisconsin's joint county health rankings project. The observation includes a record of 8,670,781 individuals in 1488 counties. We regressed COVID-19 deaths, using hierarchical logistic regression models, on individual and county-level predictors. We found that as racial residential segregation increased, mortality rates increased. Controlling for segregation, Blacks and Asians had a greater risk of mortality, while Hispanics and other racial groups had a lower risk of mortality, compared to Whites. The impact of racial residential segregation on COVID-19 mortality did not vary by racial group.

Research Note: COVID-19 Is Not an Independent Cause of Death.

The COVID-19 pandemic has had overwhelming global impacts with deleterious social, economic, and health consequences. To assess the COVID-19 death toll, researchers have estimated declines in 2020 life expectancy at birth (e0). When data are available only for COVID-19 deaths, but not for deaths from other causes, the risks of dying from COVID-19 are typically assumed to be independent of those from other causes. In this research note, we explore the soundness of this assumption using data from the United States and Brazil, the countries with the largest number of reported COVID-19 deaths. We use three methods: one estimates the difference between 2019 and 2020 life tables and therefore does not require the assumption of independence, and the other two assume independence to simulate scenarios in which COVID-19 mortality is added to 2019 death rates or is eliminated from 2020 rates. Our results reveal that COVID-19 is not independent of other causes of death. The assumption of independence can lead to either an overestimate (Brazil) or an underestimate (United States) of the decline in e0, depending on how the number of other reported causes of death changed in 2020.

Long-Term Air Pollution Exposure and COVID-19 Mortality: A Patient-Level Analysis from New York City.

Rationale: Risk factors for coronavirus disease (COVID-19) mortality may include environmental exposures such as air pollution. Objectives: To determine whether, among adults hospitalized with PCR-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), long-term air pollution exposure is associated with the risk of mortality, ICU admission, or intubation. Methods: We performed a retrospective analysis of SARS-CoV-2 PCR-positive patients admitted to seven New York City hospitals from March 8, 2020, to August 30, 2020. The primary outcome was mortality; secondary outcomes were ICU admission and intubation. We estimated the annual average fine particulate matter (particulate matter ⩽2.5 µm in aerodynamic diameter [PM2.5]), nitrogen dioxide (NO2), and black carbon (BC) concentrations at patients' residential address. We employed double robust Poisson regression to analyze associations between the annual average PM2.5, NO2, and BC exposure level and COVID-19 outcomes, adjusting for age, sex, race or ethnicity, hospital, insurance, and the time from the onset of the pandemic. Results: Among the 6,542 patients, 41% were female and the median age was 65 (interquartile range, 53-77) years. Over 50% self-identified as a person of color (n = 1,687 [26%] Hispanic patients; n = 1,659 [25%] Black patients). Air pollution exposure levels were generally low. Overall, 31% (n = 2,044) of the cohort died, 19% (n = 1,237) were admitted to the ICU, and 16% (n = 1,051) were intubated. In multivariable models, a higher level of long-term exposure to PM2.5 was associated with an increased risk of mortality (risk ratio, 1.11 [95% confidence interval, 1.02-1.21] per 1-µg/m3 increase in PM2.5) and ICU admission (risk ratio, 1.13 [95% confidence interval, 1.00-1.28] per 1-µg/m3 increase in PM2.5). In multivariable models, neither NO2 nor BC exposure was associated with COVID-19 mortality, ICU admission, or intubation. Conclusions: Among patients hospitalized with COVID-19, a higher long-term PM2.5 exposure level was associated with an increased risk of mortality and ICU admission.

The COVID-19 pandemic and the timing of government response: A comparison of four Nordic countries March-June 2020.

OBJECTIVES: The aim is to compare Sweden, Denmark, Finland and Norway regarding government response to the COVID-19 pandemic in mid-March-June 2020 using the Oxford Government Response Tracker. STUDY DESIGN: Descriptive longitudinal ecological study. METHODS: Descriptive analysis of time series data. RESULTS: Sweden displayed a far lower response index in March. By late April indexes were similar. In May-June, response indexes were lower in Finland and Norway than in Sweden. The average response index in mid-March-June was similar in Sweden, Finland and Norway. CONCLUSIONS: The government response in the four countries indicates that timing of response was essential. Sweden's slow and weak initial government response in March-April was followed by less loosening of government response in May-June compared with, especially, Finland and Norway, which resulted in similar average government response in mid-March-June for the three countries. As a comparison, COVID-19 mortality per capita was 10 times higher in Sweden than in Finland and Norway, and five times higher than in Denmark during the same period.

Mortality in patients with interstitial lung diseases hospitalized by severe or critical COVID-19.

BACKGROUND: Since the first case of severe COVID-19, its effect on patients with previous interstitial lung disease (ILD) has been uncertain. We aimed to describe baseline clinical characteristics in ILD patients hospitalized by critical COVID and compare mortality during hospitalization. METHODS: We studied patients with ILD with COVID-19 and a control group matched by age, 1:2 ratio with COVID-19 without previous lung disease. On admission, laboratory tests and sociodemographic variables were evaluated. We evaluated patients critically ill and compared baseline characteristics and mortality in each group. Additionally, we performed a sub-analysis of ILD patients who died versus survivors. RESULTS: Forty-one patients and 82 controls were analyzed. In the group of ILD with COVID-19 there was a predominance of women (65 versus 33%: p < 0.001); lower leukocytes (9 ± 6 versus 11 ± 7, p = 0.01) and neutrophils (8 ± 5 versus 10 ± 6, p = 0.02). The most common ILD was secondary to autoimmune diseases. Patients with ILD and critical COVID-19 showed a significantly higher mortality compared with those without previous ILD (63 versus 33%, p = 0.007). Patients who died in this group had higher BMI (28 ± 6 versus 25 ± 4 kg/m2, p = 0.05), less extended hospital stay (20 ± 17 versus 36 ± 27 days, p = 0.01), and fewer days of evolution (9 ± 7 versus 16 ± 16, p = 0.05). CONCLUSIONS: We found higher mortality in patients with ILD with critical COVID-19. Higher BMI and comorbidities were present in the non-survivors.

Spatial associations of long-term exposure to diesel particulate matter with seasonal and annual mortality due to COVID-19 in the contiguous United States.

BACKGROUND: People with certain underlying respiratory and cardiovascular conditions might be at an increased risk for severe illness from COVID-19. Diesel Particulate Matter (DPM) exposure may affect the pulmonary and cardiovascular systems. The study aims to assess if DPM was spatially associated with COVID-19 mortality rates across three waves of the disease and throughout 2020. METHODS: We tested an ordinary least squares (OLS) model, then two global models, a spatial lag model (SLM) and a spatial error model (SEM) designed to explore spatial dependence, and a geographically weighted regression (GWR) model designed to explore local associations between COVID-19 mortality rates and DPM exposure, using data from the 2018 AirToxScreen database. RESULTS: The GWR model found that associations between COVID-19 mortality rate and DPM concentrations may increase up to 77 deaths per 100,000 people in some US counties for every interquartile range (0.21 µg/m3) increase in DPM concentration. Significant positive associations between mortality rate and DPM were observed in New York, New Jersey, eastern Pennsylvania, and western Connecticut for the wave from January to May, and in southern Florida and southern Texas for June to September. The period from October to December exhibited a negative association in most parts of the US, which seems to have influenced the year-long relationship due to the large number of deaths during that wave of the disease. CONCLUSIONS: Our models provided a picture in which long-term DPM exposure may have influenced COVID-19 mortality during the early stages of the disease. That influence appears to have waned over time as transmission patterns evolved.

Prognostic value of R wave peak time in COVID-19 pneumonia.

BACKGROUND: R wave peak time (RWPT) is also known as intrinsicoid deflection time or ventricular activation time. It shows the conduction time from the endocardium in the ventricle to the epicardium. It provides diagnostic and prognostic information for many cardiovascular diseases, such as RWPT prolongation, left ventricular hypertrophy, volume overload, conduction system abnormalities, and myocardial ischemia. Objectives The aim of this study is to investigate the relationship between COVID-19 mortality and RWPT in superficial ECG. METHODS: This study retrospectively examined 640 patients diagnosed with COVID-19 and treated in an intensive care unit at a single center between January 2021 and June 2022. All patients included in the study had clinical and radiological characteristics and signs of COVID-19 pneumonia. RESULTS: 640 patients included in the study were divided into 2 groups: surviving and deceased. There were 510 patients in the surviving group and 130 patients in the deceased group. The deceased group was found to be significantly older. The number of patients with COPD was higher in the deceased group. Troponin, lactate dehydrogenase (LDH), C-reactive protein (CRP), D-dimer and T-peak to T-end interval(Tpe) and RWPT were found to be significantly increased in the deceased group. In binary logistic regression analysis; age, COPD, LDH, CRP, troponin, D-dimer, Tpe interval, RWPT were determined as independent risk factors for mortality. CONCLUSIONS: Prolonged RWPT is useful in risk stratification for COVID-19 pneumonia mortality.

Effectiveness of bivalent COVID-19 boosters against COVID-19 mortality in people aged 65 years and older, Australia, November 2022 to May 2023.

We followed 4,081,257 Australian adults aged ≥ 65 years between November 2022 and May 2023 for COVID-19-specific mortality, when recombinant SARS-CoV-2 Omicron lineages (predominantly XB and XBB) as well as BA.2.75 were circulating. Compared with a COVID-19 booster targeting ancestral SARS-CoV-2 given > 180 days earlier, the relative vaccine effectiveness against COVID-19 death of a bivalent (ancestral/BA.1 or ancestral/BA.4-5) booster given 8 to 90 days earlier was 66.0% (95%CI: 57.6 to 72.2%) and that of a monovalent ancestral booster given 8 to 90 days earlier was 44.7% (95%CI: 23.9 to 59.7%).

Low education predicts large increase in COVID-19 mortality: the role of collective culture and individual literacy.

BACKGROUND: Although many studies have found a high correlation between socio-economic inequalities and risk of COVID-19 deaths, there is a reason to believe that much of this association is the product of differing levels of education. STUDY DESIGN: We use a multi-level negative binomial regression model for analyzing COVID-19 mortality. METHODS: We present multivariate models of fortnightly (n = 60) COVID-19 deaths in 3108 US counties for the period January 20, 2020, to May 10, 2022. We model the direct (unmediated) effect of education, controlling for economy, race, geography, lack of vaccination, political orientation (vote Republican), poor health, and lack of preventative health behavior. RESULTS: After controlling for correlated risk factors and indirect mechanisms that mediate education's impact on COVID-19 mortality, we find a strong direct (unmediated) correlation between low education and COVID-19 mortality (incidence rate ratio = 1.17; 95% confidence interval: 1.15, 1.20). We theorize that this correlation reflects education's relationship with (1) collective cultures, such as norms of mask wearing, and (2) individual literacy, such as ability to engage with scientific communication. CONCLUSIONS: Low education is strongly correlated with COVID-19 deaths, with an effect size of a university degree comparable to that of being aged >65 years. If this correlation is indeed causal, then it would imply that low education accounts for between 1 in 10 and 1 in 7 deaths in low-education counties. Education should be conceptualized as a potential high-risk factor for COVID-19 death and be taken into account when attempting to combat COVID-19 in disadvantaged communities. The effect of education cannot be reduced to its impact on vaccination or correlation with poor health or economic status, but it seems likely that low-education communities have collective cultures that expose individuals to greater risks and lack of individual literacy that limits engagement with public health messaging.

The Search of Association of HLA Class I and Class II Alleles with COVID-19 Mortality in the Russian Cohort.

HLA genes play a pivotal role in the immune response via presenting the pathogen peptides on the cell surface in a host organism. Here, we studied the association of HLA allele variants of class I (loci A, B, C) and class II (loci DRB1, DQB1, DPB1) genes with the outcome of COVID-19 infection. We performed high-resolution sequencing of class HLA I and class II genes based on the sample population of 157 patients who died from COVID-19 and 76 patients who survived despite severe symptoms. The results were further compared with HLA genotype frequencies in the control population represented by 475 people from the Russian population. Although the obtained data revealed no significant differences between the samples at a locus level, they allowed one to uncover a set of notable alleles potentially contributing to the COVID-19 outcome. Our results did not only confirm the previously discovered fatal role of age or association of DRB1*01:01:01G and DRB1*01:02:01G alleles with severe symptoms and survival, but also allowed us to single out the DQB1*05:03:01G allele and B*14:02:01G~C*08:02:01G haplotype, which were associated with survival. Our findings showed that not only separate allele, but also their haplotype, could serve as potential markers of COVID-19 outcome and be used during triage for hospital admission.

Does atmospheric dimethyldiselenide play a role in reducing COVID-19 mortality?

Environmental selenium (Se) distribution in the US is uneven, yet US residents appear to have a relatively narrow range of serum Se concentrations, according to the NHANES III survey data; this is probably due to the modern food-distribution system. In the US, Se concentration in alfalfa leaves has been used as a proxy for regional Se exposure (low, medium or high, corresponding to ≤ 0.05, 0.06-0.10 and ≥ 0.11 ppm respectively). Se in plants, soil, water, and bacteria can be transformed into volatile dimethyldiselenide, which can be inhaled and excreted via the lung. Hence, pulmonary Se exposure may be different in states with different atmospheric Se levels. We found a significantly higher death rate from COVID-19 in low-Se states than in medium-Se or high-Se states, though the case densities of these states were not significantly different. Because inhaled dimethyldiselenide is a potent inducer of nuclear-factor erythroid 2 p45-related factor 2 (Nrf2), exposure to higher atmospheric dimethyldiselenide may increase Nrf2-dependent antioxidant defences, reducing the activation of NFκB by SARS-CoV-2 in the lung, thereby decreasing cytokine activation and COVID-19 severity. Atmospheric dimethyldiselenide may thereby play a role in COVID-19 mortality, although the extent of its involvement is unclear.

COVID-19 vaccination and all-cause and non-COVID-19 mortality. A revaluation of a study carried out in an Italian Province.

The COVID-19 vaccination prevents COVID-19 specific mortality. Well planned population-based studies, however, are necessary to evaluate the overall effectiveness of vaccination programmes. A study carried out in the province of Pescara is used to illustrate the potential biases that may affect such studies. The Pescara study analysed total and non-COVID-19 mortality and the occurrence of Potentially Vaccine-Related Serious Adverse Events (PVR-SAEs) in vaccinated and unvaccinated people, from January 2021, when vaccines became available, to July 2022. The study reported a lower probability of both total and non-COVID-19 death in vaccinated people. However, the authors did not include in the denominator of the unvaccinated cohort the population experience of the vaccinated cohort before vaccination (immortal time bias). Correcting the denominator of the unvaccinated cohort, the crude death rate of vaccinated and unvaccinated persons becomes the same. For the same reason, the unvaccinated non-COVID-19 mortality was overestimated, as was the mortality of people receiving only one or two vaccine doses. Confounding by indication and the healthy vaccinee bias will also be discussed, as well as the bias deriving by not considering the evolution of risk over time.

Coronavirus Disease 2019 (COVID-19) Disease Severity: Pregnant vs Nonpregnant Women at 82 Facilities.

BACKGROUND: Pregnancy has been reported to be a risk factor for severe COVID-19. We evaluated the impact of pregnancy on severe COVID-19 and mortality in an electronic medical record (EMR) database that enabled exclusion of labor and delivery (L&D) encounters. METHODS: In this retrospective cohort study, EMRs from 82 healthcare facilities in the Cerner COVID-19 Datamart were analyzed. The study comprised 38 106 individuals aged 18-45 years old with COVID-19 who had emergency department, urgent care, or inpatient encounters from December 2019 to September 2020. Subgroups were balanced through propensity score weights for age, race, smoking status, and number of comorbidities. The primary outcome was COVID-19-related mortality; secondary outcomes were markers of severe COVID-19: intubations, mechanical ventilation, use of vasopressors, diagnosis of sepsis, and diagnosis of acute respiratory distress syndrome. RESULTS: In comparing pregnant and nonpregnant women, no statistical differences were found for markers of severe COVID-19, after adjusting for age, smoking, race, and comorbidities. The adjusted odds of an inpatient encounter were higher for pregnant vs nonpregnant women (adjusted odds ratio [aOR], 13.2; 95% confidence interval [CI], 11.6-15.3; P < .001), but notably lower after excluding L&D encounters (aOR, 2.3; 95% CI, 1.89-2.88; P < .001). In comparison to women without L&D encounters, hospitalization was significantly more likely for men. CONCLUSIONS: We did not find an increased risk of severe COVID-19 or mortality in pregnancy. Hospitalization does not necessarily indicate severe COVID-19 in pregnancy, as half of pregnant patients with COVID-19 were admitted for L&D encounters in this study.

Eliciting Beliefs about COVID-19 Prevalence and Mortality: Epidemiological Models Compared with The Street.

Subjective belief elicitation about uncertain events has a long lineage in the economics and statistics literatures. Recent developments in the experimental elicitation and statistical estimation of subjective belief distributions allow inferences about whether these beliefs are biased relative to expert opinion, and the confidence with which they are held. Beliefs about COVID-19 prevalence and mortality interact with risk management efforts, so it is important to understand relationships between these beliefs and publicly disseminated statistics, particularly those based on evolving epidemiological models. The pandemic provides a unique setting over which to bracket the range of possible COVID-19 prevalence and mortality outcomes given the proliferation of estimates from epidemiological models. We rely on the epidemiological model produced by the Institute for Health Metrics and Evaluation together with the set of epidemiological models summarised by FiveThirtyEight to bound prevalence and mortality outcomes for one-month, and December 1, 2020 time horizons. We develop a new method to partition these bounds into intervals, and ask subjects to place bets on these intervals, thereby revealing their beliefs. The intervals are constructed such that if beliefs are consistent with epidemiological models, subjects are best off betting the same amount on every interval. We use an incentivised experiment to elicit beliefs about COVID-19 prevalence and mortality from 598 students at Georgia State University, using six temporally-spaced waves between May and November 2020. We find that beliefs differ markedly from epidemiological models, which has implications for public health communication about the risks posed by the virus.

The link between Toxoplasma gondii infections and higher mortality in COVID-19 patients having schizophrenia.

A strong link between schizophrenia and a higher mortality rate from SARS-CoV-2 infections has been reported for schizophrenia patients, with a mortality odds ratio (OR) of 2.67 compared to normal patients, after adjustment of the OR for age, sex, race and extra risk factors. In addition, an extensive number of papers have reported a very strong link between schizophrenia and Toxoplasma gondii infections. A meta-analysis of 38 studies of links between schizophrenia and T. gondii antibody seroprevalence resulting from previous infections indicated that the likelihood of T. gondii infection in schizophrenia patients was 2.7 times higher than the general population. In other words, the meta-analysis indicated that schizophrenia patients had an odds ratio of 2.7 of T. gondii infection compared to the general population. This indicates that compared to the general population, schizophrenia patients have virtually the same odds ratio for having a T. gondii infection and for mortality from a COVID-19 infection. This suggests that T. gondii infections, directly or indirectly, have a relationship with higher mortality in COVID-19 patients having schizophrenia. This conclusion would also apply to the general population.

Ambient air pollution and COVID-19 risk: Evidence from 35 observational studies.

BACKGROUND AND AIMS: The coronavirus disease 2019 (COVID-19) pandemic is severely threatening and challenging public health worldwide. Epidemiological studies focused on the influence of outdoor air pollution (AP) on COVID-19 risk have produced inconsistent conclusions. We aimed to quantitatively explore this association using a meta-analysis. METHODS: We searched for studies related to outdoor AP and COVID-19 risk in the Embase, PubMed, and Web of Science databases. No language restriction was utilized. The search date entries were up to August 13, 2021. Pooled estimates and 95% confidence intervals (CIs) were obtained with random-/fixed-effects models. PROSPERO registration number: CRD42021244656. RESULTS: A total of 35 articles were eligible for the meta-analysis. For long-term exposure to AP, COVID-19 incidence was positively associated with 1 µg/m3 increase in nitrogen dioxide (NO2; effect size = 1.042, 95% CI 1.017-1.068), particulate matter with diameter <2.5 µm (PM2.5; effect size = 1.056, 95% CI 1.039-1.072), and sulfur dioxide (SO2; effect size = 1.071, 95% CI 1.002-1.145). The COVID-19 mortality was positively associated with 1 µg/m3 increase in nitrogen dioxide (NO2; effect size = 1.034, 95% CI 1.006-1.063), PM2.5 (effect size = 1.047, 95% CI 1.025-1.1071). For short-term exposure to air pollutants, COVID-19 incidence was positively associated with 1 unit increase in air quality index (effect size = 1.001, 95% CI 1.001-1.002), 1 µg/m3 increase NO2 (effect size = 1.014, 95% CI 1.011-1.016), particulate matter with diameter <10 µm (PM10; effect size = 1.005, 95% CI 1.003-1.008), PM2.5 (effect size = 1.003, 95% CI 1.002-1.004), and SO2 (effect size = 1.015, 95% CI 1.007-1.023). CONCLUSIONS: Outdoor air pollutants are detrimental factors to COVID-19 outcomes. Measurements beneficial to reducing pollutant levels might also reduce the burden of the pandemic.