Risk Of Infectious Diseases Research Articles

Introduction to the Special Issue on Understanding the Spread of COVID-19, Part 2

Infectious diseases are transmitted between human hosts when in close contact over space and time. Recently, an unprecedented amount of spatial and spatiotemporal data have been made available that can be used to improve our understanding of the spread of COVID-19 and other infectious diseases. This understanding will be paramount to prepare for future pandemics through spatial algorithms and systems to collect, capture, curate and analyze complex, multi-scale human movement data to solve problems such as infectious diseases prediction, contact tracing, and risk assessment. In exploring and deepening the conversation around this topic, the five articles included in the second volume of this special issue employ diverse theoretical perspectives, methodologies, and frameworks, including but not limited to close contact modeling, infectious diseases spread prediction, mobility analysis, effective testing and intervention strategies. Rather than focusing on a narrow set of problems, these articles provide a glimpse into the diverse possibilities of leveraging spatial and spatiotemporal data for pandemic preparedness.

Investigation of HBV, HCV, and HIV seropositivity in healthcare workers of reproductive age

Background: Hepatitis B virus (HBV), hepatitis C virus (HCV), and Human Immunodeficiency Virus (HIV) infections are health problems that threaten human health. This study, it was aimed to investigate HBV, HCV, and HIV seropositivity in female healthcare workers of childbearing age in our hospital.
 Materials and Methods: 1224 women working in our hospital, who were of childbearing age, were included in the study. The HBsAg, Anti-HBc total, Anti-HBs, Anti-HCV, and anti-HIV results of the patients were analyzed using the hospital database.
 Results: Seven (0.5%) of reproductive-age female healthcare workers were positive for HBsAg. While anti-HBs positivity was detected in 1128 (93.6%) of 1224 healthcare workers, anti-HBs and anti-HBc were positive in 80 (6.53%) patients. Both anti-HBs and anti-HBc were negative in 16 (1.3%) subjects (neither vaccinated nor exposed to HBV).
 Conclusions: Healthcare workers are at high risk for viral hepatitis and other infectious viral diseases. The fact that the frequency of HBV, HCV, and HIV among healthcare professionals of reproductive age is quite low in our region shows that the training for healthcare professionals has been quite successful in recent years, both in our country and in our region.
 Due to the high contagiousness of viral hepatitis B in our country, not only healthcare professionals of reproductive age but all healthcare personnel should be meticulously vaccinated. It is very important to implement standard infection control programs for HBV, HCV, and HIV and to increase compliance with national and international programs.

Morbidity through 3 Years of Age in Children of Women Using Methamphetamine during Pregnancy: A National Registry Study

Background: There is a lack of studies on methamphetamine (MA) exposure and morbidity in children beyond the perinatal period. Objectives: We compared morbidity in children (0–3 years) with prenatal MA exposure to opioid-exposed and to non-exposed children. Methods: We used data from a Czech nationwide, registry-based cohort study (2000–2014). Children, who reached 3 years of age, of mothers hospitalized with (i) MA use disorder during pregnancy (MA; n = 194), (ii) opioid use disorder during pregnancy (opioids; n = 166), and (iii) general population (GP; n = 1,294,349) with no recorded history of substance use disorder (SUD). Information on inpatient contacts, length of stay, and diagnoses (International Statistical Classification of Diseases and Related Health Problems 10th Revision [ICD-10]) were assessed. Crude and adjusted odds ratios (aOR), 95% confidence interval (CI) for the risk of hospitalization, and for getting diagnosis from the ICD-10 diagnosis chapters were calculated using binary logistic regression. A stratified analysis on hospitalizations with SUD of mothers was performed. Results: No significant differences were found in the measures of hospitalization between the MA and opioid groups. Children prenatally exposed to MA and opioids had higher numbers of hospitalizations and diagnoses and longer stays in hospital than children in the GP. Increased risks of certain infectious and parasitic diseases were found in both MA (aOR = 1.6; CI: 1.1–2.3) and opioid (aOR = 1.9; 1.3–2.8) groups as compared to the GP group. The most pronounced difference in stratified analysis on maternal hospitalizations related to SUD after birth was observed for injury, poisoning, and certain other consequences of external causes in the strata of the MA group who had hospitalized mothers (aOR 6.3, 1.6–24.6) compared to the strata without maternal hospitalizations (aOR 1.4, 0.9–2.3). Conclusion: This study suggests that children born to mothers using MA during pregnancy have similar morbidity during the first 3 years of life but higher than the GP. The excess of risk was primarily due to infections and injuries in the MA group.

Enhancing systematic review with machine learning modelling for global health research

Systematic reviews and meta-analyses have long been adopted in global health research for aggregating existing studies. Although these analyses can synthesise existing evidence, additional insights from published studies can be unlocked by curating published studies and performing further modelling analysis. Yuan-Yuan Zhang and colleagues1 show that systematically reviewing, geolocating, and modelling published studies on spotted fever group rickettsioses (SFGR) can model infectious disease risks at a global scale.

Masks, ventilation and exposure time: A web-based calculator of indoor COVID-19 infection risk

Two and half years into the COVID-19 pandemic, there is quite a lot of confusion over public health guidance necessary in order to reduce disease infection risks, from room air ventilation, the use of air cleaners, and type of mask and whether or not to wear a mask. This paper describes the development of a novel web-based calculator for use by the public to assess COVID-19 infection risks between a source and receiver in a typical room. The aim is to inform the disease infection risk in response to varying exposure times, mask-wearing, and viral variant in circulation. The calculator is based on the state-of-the-art research evidence, i.e., a room air ventilation model, mask infiltration efficiencies, room cleaner efficiencies, the quanta emission rates of various viral variants of COVID-19, and the modified Wells Riley equations. The results show that exposure times are critical in determining transmission risk. Masks are important and can reduce infection risk especially over shorter exposure times and for lower source emission quantum. N95 respirators are by far the most effective, especially for Omicron, and the results indicate that N95 respirators are necessary for the more infectious variants. Increasing fresh air ventilation rates from 2ac/h to 6ac/h can have a considerable impact in reducing transmission risk in a well-mixed space. Going from 6 ac/h to 12ac/h is less effective especially at lower exposure times. Venues can be classified in terms of risk, and appropriate high ventilation rates might be recommended for high-risk, speaking loudly and singing, such as classrooms and theatres. However, for low risk, quiet and speaking softly venues, such as offices and libraries, higher ventilation rates may not be required; instead, mechanical ventilation systems in combination with air cleaners can effectively remove small fraction size aerosol particles. The web-based calculator provides an easy-to-use and valuable tool for use in estimating infection risk.

Molecular docking, synthesis and antimicrobial evaluation of metal complexes with Schiff base

The appearance of resistant bacteria was found to reduce the efficiency of antimicrobial therapies with the current antibiotics, thereby increasing the need for more efficient drugs for the treatment of infections. A microbial infection affects tremendously to the human health and antimicrobials are one of the mainly successful forms of chemotherapy which saves the human population from the risk of infectious diseases. In this regard, the present study involves synthesis of transition metal complexes have often shown the immense antimicrobial activity. In this article, metal complexes were synthesized using different metals such as of Zn(II), Hg(II), Pt(II) and Pd(II), using Schiff’s base derived from amino and carbonyl ligand. All the synthesized compounds were characterized using IR, NMR, and mass spectral data and also by UV–visible spectra, molar electric conductance, magnetic susceptibility and thermal studies. Moreover, the antimicrobial activities of metal complexes were demonstrated using both gram negative and gram positive bacteria. The synthetic series of title compounds 6a-d, the compounds 6c and 6d with platinum and palladium metal were found to be active. The complex 6c has shown excellent antimicrobial activity and the result was also confirmed by molecular docking.

Smoking is associated with infection risk in healthy blood donors

ObjectivesThere is a gap in knowledge about the effects of smoking on overall infection risk in otherwise healthy populations, possibly leading to underestimation of the dangers of smoking. The present study aimed to examine the association of smoking with the risk of infections in a large cohort of healthy blood donors. MethodsThis cohort study used questionnaire and health register data from 127 831 Danish blood donors. Multivariable Cox proportional hazards analysis was applied to estimate the association of current smoking with the risk of all-cause infection defined as hospital-based treatment for infection or filled prescriptions of antimicrobials stratified for age and adjusted for relevant confounders. ResultsAmong 18 272 current smokers, 12 272 filled an antimicrobial prescription and 2035 received hospital-based treatment for infections. Among 101 974 non-smokers, 65 117 filled a prescription and 8501 received hospital-based treatment for infections. Smokers had a higher risk of all-cause infection than non-smokers (hazard ratio estimates were 1.27 in males and 1.33 in females for hospital-based treatment and 1.11 in males and up to 1.20 in females for filled prescriptions). Smoking was most strongly associated with an increased incidence of respiratory tract infection, abscesses, skin infection, and prescriptions for these ailments (hazard ratio up to 2.29). Furthermore, smokers' risk of filled prescriptions of broad-spectrum penicillin was increased (hazard ratio up to 1.96). ConclusionsCurrent smoking was strongly associated with the risk of hospital-based treatment of infection and filled prescriptions of antimicrobials in a large cohort of healthy individuals. These findings warrant an increased focus on infectious disease risk among smokers.

Evaluation of a Geographic Screening Protocol for Chronic Parasitic Infections Before Kidney Transplant: An Institutional Experience in Minnesota.

Pretransplant recommendations advise risk-based screening for strongyloidiasis, schistosomiasis, and Chagas disease. We evaluated the implementation of a chronic parasite screening protocol at a health system in a nonendemic region serving a large foreign-born population. Candidates listed for kidney transplant at Hennepin Healthcare (Minneapolis, MN) between 2010 and 2020 were included. Country of birth and serologic screening for strongyloidiasis, schistosomiasis, and Chagas disease were retrospectively obtained from electronic medical records. Parasite screening frequency and seropositivity was assessed before and after implementation of a geographic risk factor-based screening protocol in 2014. Cost-efficiency of presumptive treatment was modeled. Of 907 kidney transplant candidates, 312 (34%) were born in the United States and 232 (26%) outside the United States, with the remainder missing country of birth information. The 447 (49%) candidates evaluated after implementation of the screening protocol had fewer unidentified countries of birth (53%-27%, P < 0.001) and were more frequently screened for strongyloidiasis, schistosomiasis, and Chagas disease (14%-44%, 8%-22%, and 1-14%, respectively, all Ps < 0.001). The number of identified seropositive candidates increased after protocol implementation from two to 14 for strongyloidiasis and from one to 11 for schistosomiasis, with none seropositive for Chagas disease. The cost-efficiency model favored presumptive ivermectin when strongyloidiasis prevalence reaches 30% of those screened. Implementing a geographic risk screening protocol before kidney transplant increases attention to infectious disease risk associated with country of birth and identification of chronic parasitic infections. In populations with higher strongyloidiasis prevalence or lower ivermectin costs, presumptive treatment may be cost-efficient.

Developing a risk assessment method for infectious diseases focusing on COVID-19 based on the Delphi method and fuzzy analytical hierarchy process.

Given the coronavirus 2019 (COVID-19) risk, it is essential to develop a comprehensive risk assessment method to manage the risk of the infectious diseases. This study aimed to develop a risk assessment method for infectious diseases focusing on COVID-19. This study was based on the fuzzy Delphi method (FDM) and fuzzy analytical hierarchical process (FAHP) in three steps: (a) designing the preliminary risk assessment algorithm by reviewing the literature, (b) corroborating the designed structure based on the majority opinions of the expert panel and assigning scores to different factors according to the Delphi method, and (c) determining the weight of components and their factors based on the FAHP. The COVID-19 risk index (CVRI) was found to be affected by four components and 19 factors. The four components consisted of the probability of getting sick (5 factors), disease severity (4 factors), health beliefs level (3 factors), and exposure rate (6 factors). The identified components and their relevant factors had different weights and effects on the CVIR. The weights of probability, severity, health beliefs level, and exposure rate components were 0.27, 0.20, 0.14, and 0.38, respectively. The CVRI was found to range from 0.54 to 0.82, defined in three levels. Given the significant effects of identified components, factors, and parameters on the incidence of COVID-19 on the one hand and using the FDM and FAHP on the other, the proposed method can be considered as an appropriate method for managing the risk of COVID-19 and other infectious diseases.

High-density lipoprotein revisited: biological functions and clinical relevance.

Previous interest in high-density lipoproteins (HDLs) focused on their possible protective role in atherosclerotic cardiovascular disease (ASCVD). Evidence from genetic studies and randomized trials, however, questioned that the inverse association of HDL-cholesterol (HDL-C) is causal. This review aims to provide an update on the role of HDL in health and disease, also beyond ASCVD. Through evolution from invertebrates, HDLs are the principal lipoproteins, while apolipoprotein B-containing lipoproteins first developed in vertebrates. HDLs transport cholesterol and other lipids between different cells like a reusable ferry, but serve many other functions including communication with cells and the inactivation of biohazards like bacterial lipopolysaccharides. These functions are exerted by entire HDL particles or distinct proteins or lipids carried by HDL rather than by its cholesterol cargo measured as HDL-C. Neither does HDL-C measurement reflect the efficiency of reverse cholesterol transport. Recent studies indicate that functional measures of HDL, notably cholesterol efflux capacity, numbers of HDL particles, or distinct HDL proteins are better predictors of ASCVD events than HDL-C. Low HDL-C levels are related observationally, but also genetically, to increased risks of infectious diseases, death during sepsis, diabetes mellitus, and chronic kidney disease. Additional, but only observational, data indicate associations of low HDL-C with various autoimmune diseases, and cancers, as well as all-cause mortality. Conversely, extremely high HDL-C levels are associated with an increased risk of age-related macular degeneration (also genetically), infectious disease, and all-cause mortality. HDL encompasses dynamic multimolecular and multifunctional lipoproteins that likely emerged during evolution to serve several physiological roles and prevent or heal pathologies beyond ASCVD. For any clinical exploitation of HDL, the indirect marker HDL-C must be replaced by direct biomarkers reflecting the causal role of HDL in the respective disease.

Health risks of solid waste management practices in rural Ghana: A semi-quantitative approach toward a solid waste safety plan

Inadequate solid waste management (SWM) can lead to environmental contamination and human health risks. The health risks from poor SWM can vary based on specific practices and exposure pathways. Thus, it is necessary to adequately understand the local context. This information, however, is rarely available in low-resource settings, particularly in rural areas. A solid waste safety plan could be helpful in these settings for gathering necessary data to assess and minimize health risks. As a step in developing such a tool, a semi-quantitative health risk analysis of SWM practices in nine Ghanaian rural villages was undertaken. Data on SWM in each village were collected through qualitative field observations and semi-structured interviews with local stakeholders. SWM-related health risks were assessed using the collected data, similar case studies in the scientific literature and dialogue among an assembled team of experts. The analysis identified context-specific practices and exposure pathways that may present the most substantial health risks as well as targeted solutions for mitigation risks. A risk assessment matrix was developed to quantify SWM risks as low, medium, high, or very high based on the likelihood and severity of identified hazards. The highest SWM risks were identified from dumpsites and uncontrolled burying of solid waste. More specifically, a very high or high risk of infectious and vector-borne diseases from SWM in the villages was identified, both in the disposal of solid waste in dumpsites and uncontrolled burying of solid waste. Additionally, a very high or high risk of inhalation, ingestion or dermal contact with contaminants was found in the disposal of solid waste in dumpsites, open burning of waste and reuse of waste from dumpsites as compost. The results demonstrate the potential value of a solid waste safety plan and a parsimonious approach to collect key local data to inform its contents.

Is it just a cure? Re-evaluating the effects of prenatal exposure to the Great Chinese Famine on the risk of infectious diseases in adulthood

BackgroundVery limited studies focused on the early-life adversities on infectious diseases. Taking the Great Chinese famine as a natural experiment, this study re-evaluated the long-term effect of prenatal famine exposure on infectious diseases by using nationally representative data. MethodsUsing difference-in-difference (DID) models, we analyzed 215,216 adults who participated in the Second National Sample Survey on Disability in 2006 across 734 counties of China to detect the effects of prenatal exposure to the Great Chinese Famine on the risk of infectious diseases in adulthood. Infectious diseases were ascertained by using the combination of self-reports or family members’ reports and on-site medical diagnosis by experienced specialists, and the severity of famine was measured by the cohort size shrinkage index (CSSI) at the county level. ResultsAll DID estimates of the effects of famine on the probability of infectious diseases were insignificant, with a coefficient of 0.0007 (−0.0024, 0.0026) for all participants and coefficients of 0.0001 (−0.0041, 0.0043) and −0.0002 (−0.0036, 0.0033) for males and females, respectively. That is, the famine cohort dwelling in regions with a greater intensity of famine had similar levels of infectious disease risks than the cohorts with post-famine prenatal exposure experience in less affected famine regions. Furthermore, there were no significant famine and post-famine cohort differences in the DID estimates by examining the variations in subgroups with different types of infectious diseases (trachoma, poliomyelitis, tuberculosis, maternal infections and other infectious diseases). ConclusionNo significant impact of prenatal exposure to the Chinese famine was observed on the risk of infectious diseases in adulthood. Famine survivors may be “cured” by the famine and were resilient to adverse environments in their life course because selective mortality may weaken the association between adverse prenatal exposure and later health.

International travel in the pandemic era: Implications for health advice.

International travel is resuming, but theCOVID-19 pandemic has radically changed the context in terms of regulation, risks and models of travel. Providing travel health advice is an important role for general practice. Theaim of thisarticle is to cover the changed context and wide-ranging implications of the COVID‑19 pandemic for travel health advice. Travel in the COVID-19 era requires travellers to be well informed and prepared to comply with complex and evolving public health measures. There are changing patterns of infectious disease risk related to the impacts of the pandemic, increasing antimicrobial resistance and climate change. New models of travel include a shift towards greater environmental sustainability.

Occupational Risks to Pregnant Anesthesia Trainees and Physicians: Are We Ignoring Something Important?

The proportion of women taking up anesthesiology and critical care as their careers has increased considerably in the last decade. Currently, women constitute 35%-40% of the total anesthesia workforce in some countries. Most resident doctors and a significant proportion of practicing physicians in anesthesia are in the reproductive age group. They are or will become pregnant at some point in their training program or career. This review focuses on all work-related exposure risks for anesthesia professionals during pregnancy, like risks of infectious diseases, radiation, stress, violence against doctors, and even peer support that can have deleterious effects on the health of pregnant physicians and the health of their unborn fetus. An occupational work environment more compatible with pregnancy is the need of the hour.

BLOOD PRODUCT SAFETY

Background: Blood transfusion services are attempted to utilize human blood as a basic element for humanitarian purposes. Both blood and blood products are playing a crucial role in health services. Blood transfusion is a medical procedure that contains risks due to the possible risk of Blood-transfusion related infectious disease. Each blood product is requisite to be screened for blood-transfusion related infectious disease at least in 4 parameter such as Hepatitis B Surface Antigen (HBsAg), HIV 1/ HIV 2 Antibody, Hepatitis C antibody (anti-HCV) and Syphilis. Blood-transfusion related Infectious disease can be detected through antibody or antigen detection by various methods such as Chemiluminescence Immuno Assay (CLIA). Methods: This paper is a literature review, Results: CLIA has been developed in various field including clinical diagnosis of various disease due to its selective, sensitive, speedy and short time analysis time consuming. Conventional immunoassay methods requires longer incubation time, longer turnaround time and shorter detection range. Conclusion:CLIA can be used to reduce examination time while increasing its sensitivity and spesificity.

English

Vitamin D deficiency (VDD) is a public health problem which affects all human beings including dark-skinned subjects. In children, it can cause disabilities associated with skeletal abnormalities such as rickets or stunted growth. VDD is also associated with a significant risk of extra-skeletal, infectious, auto-immune, neoplastic, and cardiovascular diseases. The concentration of 25 (OH) D is currently considered as the best VDD indicator. Whereas VDD has been well studied in Western countries and North America, very few studies have been conducted in sub-Saharan Africa. The aim of this study was to assess the prevalence and risk factors of VDD in children aged between 0 to 59 months. This is a cross-sectional prospective study conducted from August 5, 2019, to November 30, 2020. A total of three hundred children were included in this study, two hundred of whom were malnourished and the rest with a normal P/T ratio. The variables studied were vitamin D, serum calcium, magnesium, phosphorus and iron. Ferritin, haemoglobin, protein, albumin and prealbumin were also studied. The prevalence of VDD in the general population was 30%. No significant statistical difference in vitamin D concentration values was noticed between malnourished and nourished children with p = 0.388. Children over 24 months of age are 2.34 times more likely to be VDD than others. Given the prevalence of VDD in the study population, it would be necessary to integrate screening and supplementation into current medical practice. &nbsp; Key words: Vitamin D deficiency, malnutrition, children under 5 years of age, risk factors.

Frequency and risk factors of bloodborne infectious diseases among informal solid waste handlers: A cross-sectional study.

Objective: To determine the frequency and risk factors of bloodborne infectious diseases among informal solid waste handlers. Study Design: Cross-sectional Analytical study. Setting: Marghzar Colony, Lahore, Pakistan. Period: October to November 2019. Material &amp; Methods: Convenience enrollment of 101 informal solid waste handlers out of total 150 invited subjects resulted in a response rate of 67.3%. A predesigned proforma was administered to collect demographic and clinical information. Whole blood specimen collected for subsequent screening of hepatitis B, hepatitis C &amp; human immunodeficiency virus by rapid immune-chromatographic technique. Crosstabs analysis performed to calculate the odds ratios for bloodborne infectious diseases and chi square test used to find the association between risk factors and bloodborne infectious diseases. Results: Mean age of study population was 31.9±12.8 years. Participation of females 65.3% was higher than males 34.7%. Overall 4.0% frequency of bloodborne infectious diseases included 2.0% hepatitis B and 2.0% hepatitis C. None of the respondents had HIV or co-infection of hepatitis B and C. Frequency of those who collected waste from clinical sites was 6.0%, who received sharps injuries (100.0%), and who never used personal protective equipment (100.0%). Gender male [OR=6.094; 95.0% CI, 0.609–60.927], smoking [OR=5.056; 95.0% CI, 0.454–56.245], and waste collection from clinical site [OR=6.133; 95.0% CI, 0.537–70.057] showed a higher risk of bloodborne infectious diseases. Conclusion: The proportions of hepatitis, sharps injuries and not using personal protective equipment were high among informal solid waste handlers. Waste collection from clinical sites showed higher risk of occupational transmission of hepatitis.

Formulation of a thermo-sensitive hydro-gel for ulcerative colitis treatment.

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that causes chronic intestinal inflammation in gastrointestinal (GI) tract, mainly in innermost lining of colonic mucosa. In any of the UC drug therapy regimens, maintaining remission is challenging and about 20-40% of patients don't respond to conventional UC medications, namely, amino salicylates, steroids and immunosuppressive drugs. These agents can weaken the patient's immune system thus enhancing the risk of infectious diseases. Therefore, in our exploration we probed to test marine-derived anti-inflammatory compounds as potential agents to treat UC. Fucoidan, a complex fucose-rich sulphated polysaccharide originated in edible brown algae with known anti-inflammatory properties was isolated from Turbinaria ornate. Collagen (Achillis tendon) is another agent that may provide a beneficial effect in wound healing and tissue regeneration. Collagen was also reported to possess anti-UC properties. Collagen has a limitation of being in solution form even at high concentrations. We therefore formulated fucoidan with collagen that underwent a sol-gel transition and yielded a gel like consistency in situ. This formulation showed sustained release of fucoidan for about 12 hours. The fucoidan, collagen and the fucoidan-collagen formulation were tested in the dextran sodium sulfate (DSS) induced colitis model in mice. In comparison to the vehicle treated group, fucoidan-collagen hydrogel formulation led to significant reduction in the clinical scores and rectal bleeding, which was higher than the reference standard, mesalamine and those seen with fucoidan and collagen given alone.

Assessment of indoor air quality and risk of COVID-19 infection in Spanish secondary school and university classrooms

Despite the risk of transmission of SARS-CoV-2, Spanish educational centers were reopened after six months of lockdown. Ventilation was mostly adopted as a preventive measure to reduce the transmission risk of the virus. However, it could also affect indoor air quality (IAQ). Therefore, here we evaluate the ventilation conditions, COVID-19 risk, and IAQ in secondary school and university classrooms in Toledo (central Spain) from November 2020 to June 2021. Ventilation was examined by monitoring outdoor and indoor CO2 levels. CO2, occupancy and hygrothermal parameters, allowed estimating the relative transmission risk of SARS-CoV-2 (Alpha and Omicron BA.1), Hr, under different scenarios, using the web app COVID Riskairborne. Additionally, the effect of ventilation on IAQ was evaluated by measuring indoor/outdoor (I/O) concentration ratios of O3, NO2, and suspended particulate matter (PM). University classrooms, particularly the mechanically ventilated one, presented better ventilation conditions than the secondary school classrooms, as well as better thermal comfort conditions. The estimated Hr for COVID-19 ranged from intermediate (with surgical masks) to high (no masks, teacher infected). IAQ was generally good in all classrooms, particularly at the university ones, with I/O below unity, implying an outdoor origin of gaseous pollutants, while the source of PM was heterogeneous. Consequently, controlled mechanical ventilation systems are essential in educational spaces, as well as wearing well-fitting FFP2–N95 masks indoors is also highly recommended to minimize the transmission risk of COVID-19 and other airborne infectious diseases.

Analyzing the GHSI puzzle of whether highly developed countries fared worse in COVID-19

Global Health Security Index (GHSI) categories are formulated to assess the capacity of world countries to deal with infectious disease risks. Thus, higher values of these indices were expected to translate to lower COVID-19 severity. However, it turned out to be the opposite, surprisingly suggesting that higher estimated country preparedness to epidemics may lead to higher disease mortality. To address this puzzle, we: (i) use a model-derived measure of COVID-19 severity; (ii) employ a range of statistical learning approaches, including non-parametric machine learning methods; (iii) consider the overall excess mortality, in addition to official COVID-19 fatality counts. Our results suggest that the puzzle is, to a large extent, an artifact of oversimplified data analysis and a consequence of misclassified COVID-19 deaths, combined with the higher median age of the population and earlier epidemics onset in countries with high GHSI scores.