Epidemiology of COVID-19 in Mexico: Symptomatic profiles and presymptomatic people

Clinical Characteristics of Hospitalized Patients With COVID-19 and Their Association With the Progression to Critical Illness and Death: A Single-Center Retrospective Study From Northwestern Mexico

OBJECTIVE

The objective of this study was to associate the epidemiological and clinical characteristics of patients hospitalized for COVID-19 with the progression to critical illness and death in northwestern Mexico.

METHODS

From March to October 2020, we collected the demographic and clinical characteristics of 464 hospitalized patients from northwestern Mexico.

RESULTS

Sixty-four percent (295/464) of the patients became critically ill. Age, occupation, steroid and antibiotic use at previous hospitalization, and underlying diseases (hypertension, obesity, and chronic kidney disease) were associated with critical illness or death (p: < 0.05). No symptoms were associated with critical illness. However, the parameters such as the heart rate, respiratory rate, oxygen saturation, and diastolic pressure and the laboratory parameters such as the glucose, creatinine, white line cells, hemoglobin, D-dimer, and C-reactive protein, among others, were associated with critical illness (p: < 0.05). Finally, advanced age, previous hospital treatment, and the presence of one or more underlying diseases were associated with critical illness and death (p: < 0.02).

CONCLUSIONS

Several epidemiological (e.g., age and occupation) and clinical factors (e.g., previous treatment, underlying diseases, and vital signs and laboratory parameters) were associated with critical illness and death in patients hospitalized with COVID-19. These data provide us with possible markers to avoid critical illness or death from COVID-19 in our region.

Acute respiratory distress syndrome in patients with COVID-19 vs. Non-COVID-19: clinical characteristics and outcomes in a tertiary care setting in Mexico City

BACKGROUND

Acute Respiratory Distress Syndrome (ARDS) due tocoronavirus disease (COVID-19) infection has a unique phenotype generating a growing need to determine the existing differences that can alter existing evidence-based management strategies for ARDS.

RESEARCH QUESTION

What differences does the clinical profile of patients with ARDS due to COVID 19 and Non-COVID 19 have?

STUDY DESIGN AND METHODS

We conducted a comparative, observational, retrospective study in the Intensive Care Unit (ICU)of a third-level hospital in Mexico City, from March 2020 through March 2022. Clinical, echocardiographic, and laboratory variables were compared between patients with ARDS due to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and those due to other etiologies.

RESULTS

We enrolled 140 patients with a diagnosis of ARDS. The study group of COVID-19 etiology were younger males, higher body mass index, progressed to organ dysfunction, required more frequently renal replacement therapy, and higher SOFA score. There was no difference in rates of right ventricular dysfunction.

INTERPRETATION

COVID-19 ARDS exhibit much greater severity that led to higher admission and mortality rates, whilst being younger and less comorbid.

Characteristics of COVID-19 and mortality-associated factors during the first year of the pandemic in southeast Mexico

Aim: The present study was designed to evaluate the clinical characteristics of COVID-19 and mortality-associated factors during the first year of the pandemic in patients from southeastern Mexico. Patient & methods: A total of 953 records from patients with COVID-19 were cross-sectionally studied in a primary care hospital in southeast Mexico between 2020 and 2021. Results: The prevalent symptoms were fever (78.6%), cough (80.5%) and headache (82.8%) and dyspnea reached 13.5%. The mortality rate was 7.63% and the clinical variables associated with it were age >60 years, hypertension, severe disease, radiographic pneumonia, days to diagnosis and having two Mayan surnames. Conclusion: Future health strategies should consider age, comorbidities, disease severity, clinical manifestations and possessing ethnicity of risk (i.e., Mayan genetic background).

Implication of myddosome complex genetic variants in outcome severity of COVID-19 patients

BACKGROUND/PURPOSE(S)

During a viral infection, the immune response is mediated by the toll-like receptors and myeloid differentiation Factor 88 (MyD88) that play an important role sensing infections such as SARS-CoV-2 which has claimed the lives of more than 6.8 million people around the world.

METHODS

We carried out a cross-sectional with a population of 618 SARS-CoV-2-positive unvaccinated subjects and further classified based on severity: 22% were mild, 34% were severe, 26% were critical, and 18% were deceased. Toll Like Receptor 7 (TLR7) single-nucleotide polymorphisms (rs3853839, rs179008, rs179009, and rs2302267) and MyD88 (rs7744) were genotyped using TaqMan OpenArray. The association of polymorphisms with disease outcomes was performed by logistic regression analysis adjusted by covariates.

RESULTS

A significant association of rs3853839 and rs7744 of the TLR7 and MyD88 genes, respectively, was found with COVID-19 severity. The G/G genotype of the rs3853839 TLR7 was associated with the critical outcome showing an Odd Ratio = 1.98 (95% IC = 1.04-3.77). The results highlighted an association of the G allele of MyD88 gene with severe, critical and deceased outcomes. Furthermore, in the dominant model (AG + GG vs. AA), we observed an Odd Ratio = 1.70 (95% CI = 1.02-2.86) with severe, Odd Ratio = 1.82 (95% CI = 1.04-3.21) with critical, and Odd Ratio = 2.44 (95% CI = 1.21-4.9) with deceased outcomes.

CONCLUSION

To our knowledge this work represents an innovative report that highlights the significant association of TLR7 and MyD88 gene polymorphisms with COVID-19 outcomes and the possible implication of the MyD88 variant with D-dimer and IFN-α concentrations.

[Occupational disease by COVID-19 in healthcare workers]

Background

1 out of 5 cases of COVID-19 in Mexico occurred in health workers, and the high risk of contagion in these workers caused absenteeism due to temporary leave from work (TLfW), as well as the need to establish qualification criteria for COVID-19 as an occupational disease (OD). There are no quantitative data about the labor population to whom this benefit has been provided, nor on the economic impact of not being qualified as OD.

Objective

To estimate the prevalence of qualification of OD by COVID-19 in health workers from a tertiary care hospital (TCH).

Material and methods

Descriptive, cross-sectional, and retrospective study carried out from March 2020 to April 2021, which included health workers from a TCH who had TLfW due to COVID-19 and were working 14 days before it was issued. Variables such as OD, days of TLfW, category, among others, were analyzed, as well as the economic income lost by remaining as a general disease (GD). It was used descriptive statistics.

Results

A total of 654 health workers had TLfW due to COVID-19, with a prevalence of OD of 18.5%; 17 days of TLfW were granted on average. Nurses were classified with the high number of OD, and the category with the highest prevalence was cleaning and hygiene assistant (36%). 5310 days of TLfW were subsidized as GD, equivalent to $510,385.60 (Mexican pesos) that were not granted as an economic benefit to the population that did not have an OD qualification due to COVID-19.

Conclusions

The prevalence of recognition of COVID-19 as OD was low; most of TLfWs were subsidized as GDs.

Host traits, ownership behaviour and risk factors of SARS-CoV-2 infection in domestic pets in Mexico

SARS-CoV-2 can infect pets under natural conditions, which raises questions about the risk factors related to the susceptibility of these animals to infection. The status of pet infection by SARS-CoV-2 in Mexico is not well-understood. We aimed to estimate the frequency of positive household cats and dogs to viral RNA and antibodies for SARS-CoV-2 during the second wave of human infections in Mexico, and to recognize the major risk factors related to host and pet ownership behaviour. We evaluated two study groups, cats and dogs from COVID-19-infected/-suspected households (n = 44) and those admitted for veterinary care for any reason at several veterinary hospitals in Puebla City, Mexico (n = 91). Using RT-PCR, we identified the presence of SARS-CoV-2 RNA in swabs of four dogs (18.18%) and zero cats in COVID-19-infected/-suspected households; within this group, 31.82% of dogs and 27.27% of cats were tested IgG ELISA-positive; and neutralizing antibodies were detected in one dog (4.55%) and two cats (9.09%). In the random group (pets evaluated at private clinics and veterinary teaching hospital), 25.00% of dogs and 43.59% of cats were ELISA-positive and only one cat showed neutralizing antibodies (2.56%). Older than 4-year-old, other pets at home, and daily cleaning of pet dish, were each associated with an increase in SARS-CoV-2 infection (p < 0.05). Allowing face lick, sharing bed/food with pets and owner tested positive or suspected COVID-19 were not significant risk factors, but more than 4 h the owner spent away from home during the lockdown for COVID-19 (OR = 0.37, p = 0.01), and outdoor pet food tray (OR = 0.32, p = 0.01) significantly decreased the risks of SARS-CoV-2 infection in pets, suggesting that time the owner spends with their pet is an important risk factor.

Oxidative Damage by 3-nitrotyrosine in Young Adults with Obesity: Its Implication in Chronic and Contagious Diseases

INTRODUCTION

Cellular damage by oxidation occurs in numerous chronic diseases, such as obesity, type II diabetes, cardiovascular disease, nonalcoholic fatty liver, etc. The oxidized compound 3-nitrotyrosine is a marker of oxidative stress and protein oxidation damage.

OBJECTIVE

The article aims to assess whether 3-nitrotyrosine levels are higher in young people with obesity than in the same population without obesity.

METHODS

Anthropometry and blood chemistry analyses were performed on 24 young Mexican participants (18-30 years old), categorized into two groups based on their waist circumference: Withobesity (≥ 80 cm women; ≥ 90 cm men) and without-obesity (<80 cm women; <90 cm men). Additionally, 3-nitrotyrosine blood values were quantified by ELISA.

RESULTS

Except for HDL-cholesterol, the mean values of lipids increased in women and men with obesity (p<0.05), and 3-nitrotyrosine concentration (nM/μg total protein) was higher by 60% in the group with-obesity compared to the group without-obesity, both for women (66.21 ± 23.85 vs. 40.69 ± 16.25, p<0.05) and men (51.72 ± 20.56 vs. 30.52 ± 5.21, p<0.05).

CONCLUSION

Oxidative damage measured by compound 3-nitrotyrosine was higher in the group with obesity than in the group without obesity, which, if not controlled, could lead to a chronic oxidative condition and thereby to a degree of cellular aging with adverse health effects.

Assessing Associations Between COVID-19 Symptomology and Adverse Outcomes After Piloting Crowdsourced Data Collection: Cross-sectional Survey Study

BACKGROUND

Crowdsourcing is a useful way to rapidly collect information on COVID-19 symptoms. However, there are potential biases and data quality issues given the population that chooses to participate in crowdsourcing activities and the common strategies used to screen participants based on their previous experience.

OBJECTIVE

The study aimed to (1) build a pipeline to enable data quality and population representation checks in a pilot setting prior to deploying a final survey to a crowdsourcing platform, (2) assess COVID-19 symptomology among survey respondents who report a previous positive COVID-19 result, and (3) assess associations of symptomology groups and underlying chronic conditions with adverse outcomes due to COVID-19.

METHODS

We developed a web-based survey and hosted it on the Amazon Mechanical Turk (MTurk) crowdsourcing platform. We conducted a pilot study from August 5, 2020, to August 14, 2020, to refine the filtering criteria according to our needs before finalizing the pipeline. The final survey was posted from late August to December 31, 2020. Hierarchical cluster analyses were performed to identify COVID-19 symptomology groups, and logistic regression analyses were performed for hospitalization and mechanical ventilation outcomes. Finally, we performed a validation of study outcomes by comparing our findings to those reported in previous systematic reviews.

RESULTS

The crowdsourcing pipeline facilitated piloting our survey study and revising the filtering criteria to target specific MTurk experience levels and to include a second attention check. We collected data from 1254 COVID-19-positive survey participants and identified the following 6 symptomology groups: abdominal and bladder pain (Group 1); flu-like symptoms (loss of smell/taste/appetite; Group 2); hoarseness and sputum production (Group 3); joint aches and stomach cramps (Group 4); eye or skin dryness and vomiting (Group 5); and no symptoms (Group 6). The risk factors for adverse COVID-19 outcomes differed for different symptomology groups. The only risk factor that remained significant across 4 symptomology groups was influenza vaccine in the previous year (Group 1: odds ratio [OR] 6.22, 95% CI 2.32-17.92; Group 2: OR 2.35, 95% CI 1.74-3.18; Group 3: OR 3.7, 95% CI 1.32-10.98; Group 4: OR 4.44, 95% CI 1.53-14.49). Our findings regarding the symptoms of abdominal pain, cough, fever, fatigue, shortness of breath, and vomiting as risk factors for COVID-19 adverse outcomes were concordant with the findings of other researchers. Some high-risk symptoms found in our study, including bladder pain, dry eyes or skin, and loss of appetite, were reported less frequently by other researchers and were not considered previously in relation to COVID-19 adverse outcomes.

CONCLUSIONS

We demonstrated that a crowdsourced approach was effective for collecting data to assess symptomology associated with COVID-19. Such a strategy may facilitate efficient assessments in a dynamic intersection between emerging infectious diseases, and societal and environmental changes.

Epidemiological Profile and Social Welfare Index as Factors Associated with COVID-19 Hospitalization and Severity in Mexico City: A Retrospective Analysis

Epidemiological data indicate that Mexico holds the 19th place in cumulative cases (5506.53 per 100,000 inhabitants) of COVID-19 and the 5th place in cumulative deaths (256.14 per 100,000 inhabitants) globally and holds the 4th and 3rd place in cumulative cases and deaths in the Americas region, respectively, with Mexico City being the most affected area. Several modifiable and non-modifiable risk factors have been linked to a poor clinical outcome in COVID-19 infection; however, whether socioeconomic and welfare factors are associated with clinical outcome has been scanty addressed. This study tried to investigate the association of Social Welfare Index (SWI) with hospitalization and severity due to COVID-19. A retrospective analysis was conducted at the Centro Médico Nacional "20 de Noviembre"-ISSSTE, based in Mexico City, Mexico. A total of 3963 patients with confirmed or suspected COVID-19, registered from March to July 2020, were included, retrieved information from the Virology Analysis and Reference Unit Database. Demographic, symptoms and clinical data were analyzed, as well as the SWI, a multidimensional parameter based on living and household conditions. An adjusted binary logistic regression model was performed in order to compare the outcomes of hospitalization, mechanical ventilation requirement (MVR) and mortality between SWI categories: Very high (VHi), high (Hi), medium (M) and low (L). The main findings show that lower SWI were independently associated with higher probability for hospital entry: VHi vs. Hi vs. M vs. L-SWI (0 vs. +0.24 [OR = 1.24, CI95% 1.01-1.53] vs. +0.90 [OR = 1.90, CI95% 1.56-2.32] vs. 0.73 [OR = 1.73, CI95% 1.36-2.19], respectively); Mechanical Ventilation Requirement: VHi vs. M vs. L-SWI (0 vs. +0.45 [OR = 1.45, CI95% 1.11-1.87] vs. +0.35 [OR = 1.35, CI95% 1.00-1.82]) and mortality: VHi vs. Hi vs. M (0 vs. +0.54 [OR = 1.54, CI95% 1.22-1.94] vs. +0.41 [OR = 1.41, CI95% 1.13-1.76]). We concluded that SWI was independently associated with the poor clinical outcomes in COVID-19, beyond demographic, epidemiological and clinical characteristics.

A(H3N2) antigenic variation of influenza is associated with low vaccine efficacy in the early 2018 influenza season in Mexico City

OBJECTIVES

We evaluated the VE and the mutations of the viruses present in the Mexican population at the beginning of 2018.

METHODS

We diagnosed influenza in outpatients with a high-performance Rapid Influenza Diagnostic Test (RIDT) qRT-PCR. Descriptive statistics were used to describe the study population, while the chi-square test was used to determine clinical variables. VE was analyzed through a negative test design. We sequenced the hemagglutinin (HA) gene, performed a phylogenetic analysis, and analyzed the nonsynonymous substitutions both in and outside antigenic sites.

RESULTS

Of the 240 patients analyzed, 42.5% received the trivalent vaccine, and 37.5% were positive for influenza. The VE for the general population for any influenza virus type or subtype was 37.0%, while the VE for the predominant influenza A(H3N2) subtype was the lowest (19.7%). The phylogenetic analysis of HA showed the co-circulation of clades and subclades 3C.2a1, 3C.2a1b, 3C.2a2, 3C.2a2re, 3C.2a3, and 3C.3a with identities approximately 97-98% similar to the vaccine composition.

CONCLUSION

Low VE was related to the co-circulation of multiple clades and subclades of influenza A(H3N2), with sufficient genetic and phenotypic distance to allow for the infection of vaccinated individuals.

Clinical presentation of COVID-19 at the time of testing and factors associated with pre-symptomatic cases in Cameroon

Objectives

To describe the clinical features at time of testing and explore factors associated with SARS-CoV-2 infection and pre-symptomatic cases in Cameroon.

Methods

Data was collected on people in Cameroon who participated in COVID-19 testing by real-time reverse transcriptase-polymerase chain reaction between 1 March and 5 October 2020. After descriptive analysis, multivariate logistic regression was used to identify factors associated with SARS-CoV-2 infection and pre-symptomatic cases.

Results

Of 85 206 test participants, 14 863 (17.4%) were infected with SARS-CoV-2. The median age for cases was 38.4 years (interquartile range 29.6-49.4); 6.1% were aged <19 years, and 6.3% were ≥65 years. Of these cases, 46.5% had at least one symptom/sign with a median time from illness onset to testing of 6 days (interquartile range 3-9). Cough (64.2%), headache (46.5%), fatigue/malaise (46.0%), shortness of breath (30.6%) and myalgia/arthralgia (25.6%) were the most commonly observed symptoms/signs. Pre-symptomatic SARS-CoV-2 infection was associated with age <50 years, being male and absence of comorbidities.

Conclusion

This study provides a comprehensive summary of the early clinical profile of SARS-CoV-2 infection during the first wave of COVID-19 in Cameroon, which was dominated by pre-symptomatic illness. These findings would be helpful for SARS-CoV-2 surveillance and control at a regional level.

Socio-demographical Profile of 7285 SARS-Cov-2 Positive Early Cases; Comparison with National Four Epidemic Waves

Background: Objectives were to investigate aspects of the COVID-19 epidemics via testing the individuals who were referred to Aramesh Medical Laboratory in Tehran and to integrate the molecular results with epidemiological data since the beginning of the epidemic. Methods: In this cross-sectional Study 77528 outpatients were referred to Aramesh Medical laboratory by physicians for the diagnosis of SARS-CoV-2 infection between March 2019 and May 2021. Viral acid nucleic extracted from nasal and throat specimens and subsequently amplified using Reverse Transcriptase Real-Time PCR. Laboratory data including Ct values compared with epidemic peaks of COVID-19 countrywide. Statistical Analysis was done by SPSS 21 Software. Results: 14312 (18.46%) tested positive.36.5% of the positive cases were in the 30 to 39 years old age group. The positive result rate was significantly different based on months, ranging from 6% to 28%, compatible with four recognized epidemic peaks encompassing the end of March through the first week of April (first epidemic peak), from June to July 2020 (second epidemic peak), October until mid of November 2020 (third epidemic wave) followed by the end of April to May 2021 (until the end period of study, in the middle of 4th peak). In 37.8% of cases, the Ct value was between 21 and 28. Two separate trends were seen for Ct ≤ 25 and Ct ≤ 20 for the first and fourth epidemic peaks, respectively. There was an association between the number of total monthly positive results and total deaths in the country, especially with the second to third peaks (in the course of summer 2020) and fourth epidemic peak. Conclusion: It might be useful to consider laboratory admission rates as an indicator for changes in the epidemic level in the country to continue the SARS-CoV-2 surveillance in accordance with public decision-makers.

Impact of layered non-pharmacological interventions on COVID-19 transmission dynamics in Yucatan, Mexico

Background

The pandemic propagation of SARS-CoV-2 led to the adoption of a myriad of non-pharmacological interventions (NPIs, e.g., social distancing, mobility restrictions, gathering restrictions) in the Americas. Using national epidemiological data, here we report the impact of the layered adoption of multiple NPIs aimed at curving SARS-CoV-2 transmission in Yucatan State, Mexico.

Methods

Data from suspected and laboratory confirmed COVID-19 cases during 2020 were analyzed by age groups and sex, clinical signs, and symptoms as well as outcome. The impact of NPIs was quantified using time-varying reproduction numbers (R t) estimated as a time-series and by sectors of the city.

Findings

A total of 69,602 suspected cases were reported, 39.3% were laboratory-confirmed. Men were hospitalized (60.2%), more severely ill (3% vs 1.9%) and more likely to die (62%) than women. Early in the outbreak, all sectors in Merida hadR t estimates above unity. Once all NPÍs were in place,R t values were dramatically reduced below one, and in the last interval transmission estimates ofR t remained below one in all sectors.

Interpretation

In the absence of a COVID-19 vaccination program, the combination and wide adherence of NPÍs led to a low and stable trend in SARS-CoV-2 transmission that did not overwhelm the health sector. Our study reflects that a controlled and planned ease of restrictions to balance health, social and economic recovery resulted in a single wave of transmission that prolonged at low and stable levels.

Funding

GVP received funding from Emory University via the MP3 Initiative.

Epidemiological and Clinical Characteristics of Hospitalized Pediatric Patients with SARS-CoV-2 Infection in Mexico City, Mexico

Background

Evidence from across the world suggests that the pediatric population shows different clinical manifestations and has a lower risk of severe presentation of SARS-CoV-2 infection compared to adults. However, Mexico has one of the highest mortality rates in the pediatric population due to SARS-CoV-2 infection. Therefore, our objective was to explore the epidemiological and clinical characteristics associated with a positive confirmatory test in the Mexican pediatric population admitted to a tertiary care hospital in Mexico City.

Methods

Clinical, imaging and laboratory data were retrospectively collected from 121 children hospitalized during the period from March 4th, 2020, to August 8th, 2021. The patients were identified as suspicious cases according to the guidelines of the General Directorate of Epidemiology of Mexico. Real-time polymerase chain reaction (RT-PCR) tests were used to confirm SARS-CoV-2 infection. Categorical variables were compared using the Chi-square test, and propensity score matching was performed to determine univariate and multivariate odds ratios of the population regarding a positive vs. negative SARS-CoV-2 result.

Results

Of the 121 children, 36 had laboratory-confirmed SARS-CoV-2 infection. The main risk for SARS-CoV-2-associated pediatric hospitalization was contact with a family member with SARS-CoV-2. It was also found that fever and fatigue were statistically significantly associated with a positive SARS-CoV-2 test in multivariate models. Clinical and laboratory data in this Mexican hospitalized pediatric cohort differ from other reports worldwide; the mortality rate (1.6%) of the population studied was higher than that seen in reports from other countries.

Conclusion

Our study found that fever and fatigue at hospital presentation as well as an antecedent exposure to a family member with SARS-CoV-2 infection were important risk factors for SARS-CoV-2 positivity in children at hospital admission.

Seroconversion dynamic and SARS-CoV-2 seropositivity in unvaccinated population during the first and second outbreaks in Mexico

Serosurveillance helps establish reopening guidelines and determine the immunity levels in different populations to reach herd immunity. Then, there is an urgent need to estimate seroprevalence population wide. In Mexico, information about COVID-19 cases and related deaths is scarce. Also, there is no official serosurveillance, limiting our knowledge of the impact of the SARS-CoV-2 pandemic. Here, we report the prevalence of anti-SARS-CoV-2 antibodies in 522,690 unvaccinated people from July 5th to December 31st, 2020. The overall seroprevalence was 32.8% and highest in adults aged 30–39 years (38.5%) than people under 20 years (33.0%) or older (28.9%). Moreover, in a cohort of 1655 individuals confirmed COVID-19 by PCR, we found that symptomatic people (HR = 2.56) increased seroconversion than presymptomatic. Also, we identified that the most discriminative symptoms for COVID-19 that could predict seroconversion were anosmia and ageusia (HR = 1.70), fever, myalgia/arthralgia, and cough (HR = 1.75). Finally, we found that obese people had lower seroconversion (HR = 0.53) than healthy people, but the opposite happens in diabetic people (HR = 1.39). These findings reveal that around one-third of Mexican outpatients had anti-SARS-CoV-2 antibodies before vaccination. Also, some symptoms improve empirically COVID-19 diagnosis and seroconversion. This information could help fine-tune vaccination schemes and the reopening and back-to-work algorithms.

Variation in global COVID-19 symptoms by geography and by chronic disease: A global survey using the COVID-19 Symptom Mapper

BACKGROUND

COVID-19 is typically characterised by a triad of symptoms: cough, fever and loss of taste and smell, however, this varies globally. This study examines variations in COVID-19 symptom profiles based on underlying chronic disease and geographical location.

METHODS

Using a global online symptom survey of 78,299 responders in 190 countries between 09/04/2020 and 22/09/2020, we conducted an exploratory study to examine symptom profiles associated with a positive COVID-19 test result by country and underlying chronic disease (single, co- or multi-morbidities) using statistical and machine learning methods.

FINDINGS

From the results of 7980 COVID-19 tested positive responders, we find that symptom patterns differ by country. For example, India reported a lower proportion of headache (22.8% vs 47.8%, p<1e-13) and itchy eyes (7.3% vs. 16.5%, p=2e-8) than other countries. As with geographic location, we find people differed in their reported symptoms if they suffered from specific chronic diseases. For example, COVID-19 positive responders with asthma (25.3% vs. 13.7%, p=7e-6) were more likely to report shortness of breath compared to those with no underlying chronic disease.

INTERPRETATION

We have identified variation in COVID-19 symptom profiles depending on geographic location and underlying chronic disease. Failure to reflect this symptom variation in public health messaging may contribute to asymptomatic COVID-19 spread and put patients with chronic diseases at a greater risk of infection. Future work should focus on symptom profile variation in the emerging variants of the SARS-CoV-2 virus. This is crucial to speed up clinical diagnosis, predict prognostic outcomes and target treatment.

FUNDING

We acknowledge funding to AAF by a UKRI Turing AI Fellowship and to CEC by a personal NIHR Career Development Fellowship (grant number NIHR-2016-090-015). JKQ has received grants from The Health Foundation, MRC, GSK, Bayer, BI, Asthma UK-British Lung Foundation, IQVIA, Chiesi AZ, and Insmed. This work is supported by BREATHE - The Health Data Research Hub for Respiratory Health [MC_PC_19004]. BREATHE is funded through the UK Research and Innovation Industrial Strategy Challenge Fund and delivered through Health Data Research UK. Imperial College London is grateful for the support from the Northwest London NIHR Applied Research Collaboration. The views expressed in this publication are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care.

The feasibility of masks and face shields designed by 3D printing makers; some considerations of their use against the COVID-19

The use of mask and face shield has been established as one of the main preventive measures for the control of COVID 19 spread. In Mexico, as well as in other regions of the world, 3D printing has been employed for the design and production of masks and face shields as personal protective equipment (PPE). These models have been fabricated mainly by the makers, industries, and university communities; therefore, it is necessary to analyze the feasibility of the 3D printed PPE to understand its advantages and limitations. In this work, some characteristics of masks and face shields fabricated by additive manufacturing were studied to explore their viability as protection against flow fluids similar to human sneeze. In the present paper, the PPE was designed, and 3D printed utilizing three types of polylactic acid (PLA) as base material. The morphology and the surface elemental analyses of sectioned samples were analyzed by scanning electron microscopy (SEM) and energy dispersion x-ray spectroscopy (EDS). Showing spacing between printed layers, porous areas, and dispersed copper particles. On the other hand, a computational fluid dynamics (CFD) simulation was carried out, the results demonstrated the importance of using PPE for protection of a possible exposure to a “contaminated” aerosol and human sneeze. Based on the abovementioned results, it is possible to consider the commercial PLA as suitable material for the manufacturing of PPE due to its capability to be disinfected employing isopropanol, ethanol, or commercial disinfectants.

COVID-19 Pandemic Effect on Energy Consumption in State Universities: Michoacan, Mexico Case Study

The COVID-19 pandemic has generated multiple impacts. In particular, in the educational sector, the virtual class modality generated changes in the patterns of energy consumption at the institutional level; the identification of this consumption will allow us to reflect on new energy saving and efficient use strategies. In this research, we present a case study of the effects of the COVID-19 pandemic on electricity consumption in 13 state universities in Michoacán, Mexico. Electric energy consumption has been evaluated before and during the presence of the COVID-19 between 2019 and 2020. The comparative analysis estimated the reduction in energy consumption and its economic and environmental impact. The results show a considerable decrease in electricity consumption, generating an average saving of 76.24 MWh/month, which translates into an annual emission reduction from 2019 to 2020 of approximately 497 TnCO2e, and in economic terms of $8,882.25 USD each month. In general, it was identified that consumption patterns in the use of machinery and computer equipment for administrative activities were drastically reduced. If education continues in virtual or hybrid modes, energy consumption schemes will continue to decline and institutions could move towards resilient, affordable, and sustainable models of energy production and consumption.

Control and Prevention of SARS-CoV-2 Outbreaks among Healthcare Workers from 129 Healthcare Facilities in Mexico

Few reports have shared the workflows to reduce SARS-CoV-2 infections among risk groups, including healthcare workers (HCWs). This study describes an occupational health program implemented to reduce the incidence of COVID-19 and establishes a back-to-work algorithm in HCWs of 129 Salud Digna outpatient care clinics in Mexico. This program was composed of training plans, screening SARS-CoV-2 infections, the containment of infections, follow-up COVID-19 cases, and continuing supervision in addition to the steady supply and training for the correct use of PPE. From 16 April 2020 to 15 April 2021, 7376 individuals were enrolled, of which 423 were excluded because they did not meet the inclusion criteria or refused the follow-up. In the cohort studied, we found a COVID-19 incidence of 35.4% (2610 individuals), lower hospitalization (0.11%), ICU (0.04%) and lethality rate (0.04%). Additionally, 85.9% of COVID-19 cases tested negative for SARS-CoV-2 after 14 days of the first positive test with an average isolation time of 26–33 days. Finally, 99% of people received personal protective equipment and adequate training to use it. Our results show that the program implemented reduced the hospitalization ICU admission and lethality in HCWs; we consider this workflow to help other workplaces offer safe conditions for HCWs and patients.

A Comprehensive Descriptive Epidemiological and Clinical Analysis of SARS-CoV-2 in West-Mexico during COVID-19 Pandemic 2020

This study aimed to summarize the epidemiological and clinical characteristics of COVID-19 from Western Mexico people during 2020. A retrospective analysis from an electronic database of people visiting a sentinel center for molecular SARS-CoV-2 confirmatory diagnosis by RT-PCR from April to December 2020 was carried out for epidemiological and clinical description of COVID-19. Out of 23,211 patients evaluated, 6918 (29.8%) were confirmed for SARS-CoV-2 infection (mean age 38.5 ± 13.99), mostly females (53.8%). Comorbidities, such as diabetes (34.7%), obesity (31.15%), and hypertension (31.8%), presented an increased odds OR = 1.27, CI = 1.14-1.41; OR = 1.08, CI = 1.01-1.16; and OR = 1.09, CI = 0.99-1.19, respectively, for viral-infection. Moreover, fever, headache, and dry cough were the most frequent symptoms. No infection difference among sex was found. Those patients >60 years old were prone to COVID-19 severity (OR = 3.59, CI = 2.10-6.14), evaluated by the number of manifested symptoms, increasing with age. In conclusion, a high SARS-CoV-2 prevalence was found in Western Mexico. Comorbidities were frequent in infected people; nevertheless, no association with disease outcomes was observed, in contrast with the highest disease severity risk found in older patients; however, continuous monitoring should be carried since comorbidities have been reported as aggravating factors. This study can help the health officials for the elaboration of planning efforts of the disease management and others in the future.

Therapeutic application of estrogen for COVID-19: Attenuation of SARS-CoV-2 spike protein and IL-6 stimulated, ACE2-dependent NOX2 activation, ROS production and MCP-1 upregulation in endothelial cells

The outbreak of COVID-19 has remained uncontained with urgent need for robust therapeutics. We have previously reported sex difference of COVID-19 for the first time indicating male predisposition. Males are more susceptible than females, and more often to develop into severe cases with higher mortality. This predisposition is potentially linked to higher prevalence of cigarette smoking. Nonetheless, we found for the first time that cigarette smoking extract (CSE) had no effect on angiotensin converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) expression in endothelial cells. The otherwise observed worse outcomes in smokers is likely linked to baseline respiratory diseases associated with chronic smoking. Instead, we hypothesized that estrogen mediated protection might underlie lower morbidity, severity and mortality of COVID-19 in females. Of note, endothelial inflammation and barrier dysfunction are major mediators of disease progression, and development of acute respiratory distress syndrome (ARDS) and multi-organ failure in patients with COVID-19. Therefore, we investigated potential protective effects of estrogen on endothelial cells against oxidative stress induced by interleukin-6 (IL-6) and SARS-CoV-2 spike protein (S protein). Indeed, 17β-estradiol completely reversed S protein-induced selective activation of NADPH oxidase isoform 2 (NOX2) and reactive oxygen species (ROS) production that are ACE2-dependent, as well as ACE2 upregulation and induction of pro-inflammatory gene monocyte chemoattractant protein-1 (MCP-1) in endothelial cells to effectively attenuate endothelial dysfunction. Effects of IL-6 on activating NOX2-dependent ROS production and upregulation of MCP-1 were also completely attenuated by 17β-estradiol. Of note, co-treatment with CSE had no additional effects on S protein stimulated endothelial oxidative stress, confirming that current smoking status is likely unrelated to more severe disease in chronic smokers. These data indicate that estrogen can serve as a novel therapy for patients with COVID-19 via inhibition of initial viral responses and attenuation of cytokine storm induced endothelial dysfunction, to substantially alleviate morbidity, severity and mortality of the disease, especially in men and post-menopause women. Short-term administration of estrogen can therefore be readily applied to the clinical management of COVID-19 as a robust therapeutic option.

Transmission dynamics and forecasts of the COVID-19 pandemic in Mexico, March-December 2020

Mexico has experienced one of the highest COVID-19 mortality rates in the world. A delayed implementation of social distancing interventions in late March 2020 and a phased reopening of the country in June 2020 has facilitated sustained disease transmission in the region. In this study we systematically generate and compare 30-day ahead forecasts using previously validated growth models based on mortality trends from the Institute for Health Metrics and Evaluation for Mexico and Mexico City in near real-time. Moreover, we estimate reproduction numbers for SARS-CoV-2 based on the methods that rely on genomic data as well as case incidence data. Subsequently, functional data analysis techniques are utilized to analyze the shapes of COVID-19 growth rate curves at the state level to characterize the spatiotemporal transmission patterns of SARS-CoV-2. The early estimates of the reproduction number for Mexico were estimated between Rt ~1.1-1.3 from the genomic and case incidence data. Moreover, the mean estimate of Rt has fluctuated around ~1.0 from late July till end of September 2020. The spatial analysis characterizes the state-level dynamics of COVID-19 into four groups with distinct epidemic trajectories based on epidemic growth rates. Our results show that the sequential mortality forecasts from the GLM and Richards model predict a downward trend in the number of deaths for all thirteen forecast periods for Mexico and Mexico City. However, the sub-epidemic and IHME models perform better predicting a more realistic stable trajectory of COVID-19 mortality trends for the last three forecast periods (09/21-10/21, 09/28-10/27, 09/28-10/27) for Mexico and Mexico City. Our findings indicate that phenomenological models are useful tools for short-term epidemic forecasting albeit forecasts need to be interpreted with caution given the dynamic implementation and lifting of social distancing measures.

The trade-off between mobility and vaccination for COVID-19 control: a metapopulation modelling approach

November 2020 received a string of encouraging results from leading vaccine developers raising hopes for the imminent availability of an effective and safe vaccine against the SARS-CoV-2. In the present work, we discuss the theoretical impact of introducing a vaccine across a range of scenarios. In particular, we investigate how vaccination coverage, efficacy and delivery time affect the control of the transmission dynamics in comparison to mobility restrictions. The analysis is based on a metapopulation epidemic model structured by risk. We perform a global sensitivity analysis using the Sobol method. Our analysis suggest that the reduction of mobility among patches plays a significant role in the mitigation of the disease close to the effect of immunization coverage of 30% achieved in four months. Moreover, for an immunization coverage between 20% and 50% achieved in the first half of 2021 with a vaccine efficacy between 70% and 95%, the percentage reduction in the total number of SARS-CoV-2 infections is between 30% and 50% by the end of 2021 in comparison with the no vaccination scenario.

Population-Based COVID-19 Screening in Mexico: Assessment of Symptoms and Their Weighting in Predicting SARS-CoV-2 Infection

Background and Objectives: Sentinel surveillance in the early stage of the COVID-19 pandemic in Mexico represented a significant cost reduction and was useful in estimating the population infected with SARS-CoV-2. However, it also implied that many patients were not screened and therefore had no accurate diagnosis. In this study, we carried out a population-based SARS-CoV-2 screening in Mexico to evaluate the COVID-19-related symptoms and their weighting in predicting SARS-CoV-2 infection. We also discuss this data in the context of the operational definition of suspected cases of COVID-19 established by the Mexican Health Authority’s consensus. Materials and Methods: One thousand two hundred seventy-nine subjects were included. They were screened for SARS-CoV-2 using RT-PCR. The weighting of COVID-19 symptoms in predicting SARS-CoV-2 infection was evaluated statistically. Results: Three hundred and twenty-five patients were positive for SARS-CoV-2 and 954 were negative. Fever, asthenia, dysgeusia, and oxygen saturation predicted SARS-CoV-2 infection (odds ratios ranged from 1.74 to 4.98; p < 0.05). The percentage of asymptomatic COVID-19 patients was 36% and only 38.15% met the Mexican operational definition. Cq-values for the gene N of SARS-CoV-2 were significantly higher in asymptomatic subjects than in the groups of COVID-19 patients with neurological, respiratory, and/or musculoskeletal manifestations (p < 0.05). Conclusions: Dysgeusia, fever, and asthenia increased the odds of a positive result for COVID-19 1.74–4.98-fold among the study population. Patients with neurological, respiratory, and/or musculoskeletal manifestations had higher viral loads at COVID-19 diagnosis than those observed in asymptomatic patients. A high percentage of the participants in the study (61.85%) did not meet the operational definition for a suspected case of COVID-19 established by the Mexican Health Authority’s consensus, representing a high percentage of the population that could have remained without a COVID-19 diagnosis, so becoming a potential source of virus spread.