SARS-CoV-2 in Rural Latin America. A Population-based Study in Coastal Ecuador

High-Altitude Environment and COVID-19: SARS-CoV-2 Seropositivity in the Highest City in the World

Champigneulle, Benoit, Ivan Hancco, Richard Renan, Stéphane Doutreleau, Emeric Stauffer, Aurélien Pichon, Julien V. Brugniaux, Hélène Péré, Pierre Bouzat, David Veyer, and Samuel Verges. High-altitude environment and COVID-19: SARS-CoV-2 seropositivity in the highest city in the world. High Alt Med Biol. 22: 000-000, 2021. Background: A reduced coronavirus disease 2019 (COVID-19) diffusion has been suggested in high-altitude areas but remained questionable. Aims of this study were to estimate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seropositivity as well as the risk factors associated in La Rinconada, the highest city in the world (5,100-5,300 m), a gold-mining town located in southeastern Peru where >50,000 dwellers live in precarious sanitary conditions. Materials and Methods: We performed a cross-sectional study during a 1-week period in October 2020, using point-of-care lateral flow serological assays allowing detection of antibodies directed against SARS-CoV-2 among voluntary dwellers in La Rinconada. Participants were also questioned about potential occupational and environmental risk factors of COVID-19 occurrence. Results: In a sample of 159 dwellers tested in La Rinconada, 48.4% [95% confidence interval, CI: 40.5-56.4] were seropositive for the SARS-CoV-2. Occurrence of at least one symptom compatible with the COVID-19 over the past 6 months remained the only significant factor associated with SARS-CoV-2 seropositivity (adjusted odds ratio: 3.27; [95% CI: 1.70-6.44]; p < 0.001). Conclusions: The high rate of SARS-CoV-2 seropositivity observed in this small sample of highlanders does not support a protective effect of high-altitude against the COVID-19 spread and demonstrates its large dissemination in vulnerable populations. Clinical Trial Registration number: NCT04604249.

COVID-19 IgG seropositivity and its determinants in occupational groups of varying infection risks in two Andean cities of Ecuador before mass vaccination

BACKGROUND

The COVID-19 pandemic has caused over 68.7 million infections and 1.35 million deaths in South America. There are limited data on SARS-CoV-2 seropositivity and its determinants from Andean countries prior to mass vaccinations against COVID-19.

OBJECTIVE

To estimate SARS-CoV-2 seropositivity and its determinants before vaccination in occupational groups of adults presumed to have different levels of exposure and associations with potential symptomatology.

METHODS

We measured seropositivity of anti-SARS-CoV-2 IgG antibodies in a cross-sectional study of vaccine-naïve adults aged 18 years and older, recruited within three occupational risk groups (defined as low [LR], moderate [MR], and high [HR]) between January and September 2021 in two Andean cities in Ecuador. Associations with risk factors were estimated using logistic regression.

RESULTS

In a sample of 882 adults, IgG seropositivity for the three different occupational risk groups was 39.9% (CI 95% 35.3-44.6), 74.6% (CI 95% 66.4-81.4), and 39.0% (CI 95% 34.0-44.4) for the HR, MR, and LR groups, respectively. History of an illness with loss of taste and/or smell was significantly associated with seropositivity in all occupational groups, with adjusted ORs of 14.31 (95%CI, 5.83-35.12; p<0.001), 14.34 (95%CI 3.01-68.42; p<0.001), and 8.79 (95%CI 2.69-28.72; p<0.001), for the HR, MR, and LR groups, respectively; while fever was significant for the LR group with an adjusted OR of 1.24 (95%CI, 1.11-4.57; p = 0.025) and myalgia for the HR group with an adjusted OR of 2.07 (95%CI, 1.13-3.81; p = 0.019).

CONCLUSION

Notable proportions of seropositivity were seen in all occupational groups between January and September 2021 prior to mass vaccination. Loss of taste and/or smell was strongly associated with presence of anti-SARS-CoV-2 IgG antibodies irrespective of presumed occupational exposure risk.

Human viral pathogens in the wastewater-source water-drinking water continuum: Evidence, health risks, and lessons for future outbreaks in low-income settings

Human viral pathogens, including SARS-CoV-2 continue to attract public and research attention due to their disruption of society, global health, and the economy. Several earlier reviews have investigated the occurrence and fate of SARS-CoV-2 in wastewater, and the potential to use such data in wastewater-based epidemiology. However, comprehensive reviews tracking SARS-CoV-2 and other viral pathogens in the wastewater-water-drinking water continuum and the associated risk assessment are still lacking. Therefore, to address this gap, the present paper makes the following contributions: (1) critically examines the early empirical results to highlight the occurrence and stability of SARS-CoV-2 in the wastewater-source water-drinking water continuum, (2) discusses the anthropogenic and hydro(geo)logical processes controlling the circulation of SARS-CoV-2 in the wastewater-source water-drinking water continuum, (3) discusses the risky behaviour, drivers and high-risk settings in the wastewater-source water-drinking water continuum, (4) uses the available empirical data on SARS-CoV-2 occurrence in the wastewater-source water-drinking water continuum to discuss human health risks from multiple exposure pathways, gendered aspects of SARS-CoV-2 transmission via shared on-site sanitation systems, and (5) develops and risk mitigation strategy based on the available empirical evidence and quantitative human risk assessment data. Finally, it presents a comprehensive research agenda on SARS-CoV-2/COVID-19 to guide the mitigation of future similar outbreaks in low-income settings.

The dynamics and determinants of specific systemic and mucosal antibody responses to SARS-CoV-2 in three adult cohorts in the Ecuadorian Andes: a study protocol

Introduction

There are limited longitudinal data on the systemic and mucosal antibody responses to SARS-CoV-2 from Latin America, a region severely affected by COVID-19, and where vaccine strategies have been implemented during the evolving pandemic.

Objective

To evaluate determinants of seroprevalence and changes in levels of anti-SARS-CoV-2 antibodies longitudinally in adults with different levels of exposure to SARS-CoV-2 (defined a priori as low, medium, and high based on presumed occupational risk), in two Andean cities in Ecuador.

Methods

Longitudinal cohort study of 1,000 adults aged 18 years and older with questionnaire data and sample collection done at 0, 3, 6, and 12 months during the period 2020-2023. Observations collected included WHO-ISARIC questionnaire and peripheral blood and saliva samples for measurement of IgG and IgA antibodies, respectively. Planned analyses are tailored to the longitudinal nature of the outcomes defined by participants' antibody levels and aim at estimating their average trends with time since infection in each of the occupational groups, adjusted for demographics and calendar-time levels of SARS-CoV-2 infection in the general population. The latter reflect the impact of the national control measures such as vaccinations and movement restrictions.

Importance

Understanding the duration and the dynamics of waning immunity to SARS-CoV-2, in the context of exposures to emerging virus variants and immunization, will inform the implementation of targeted public health strategies in the Latin American region.

Ethics and Dissemination

This study will observe the bioethical principles of the Declaration of Helsinki. Informed written consent will be obtained. Samples from participants will be stored for up to three years after which they will be destroyed. The study protocol was approved by the Ecuadorian Ministry of Public Health Ethics Committee for COVID-19 Research. Antibody results will be provided to participants and participating institutions and to the national health authorities.

Poor sleep quality increases mortality risk: A population-based longitudinal prospective study in community-dwelling middle-aged and older adults

OBJECTIVES

To assess the association between sleep quality and all-cause mortality in community-dwelling adults living in rural Ecuador.

METHODS

Individuals aged ≥40years enrolled in the prospective population-based Three Villages Study cohort were included. Sleep quality was assessed by means of the Pittsburgh Sleep Quality Index. Study participants were evaluated at baseline and at every annual door-to-door survey until they remained enrolled in the study. Mixed models Poisson regression for repeated Pittsburgh Sleep Quality Index determinations and multivariate Cox-proportional hazards models were fitted to estimate mortality risk according to sleep quality.

RESULTS

Analysis included 1494 individuals (mean age: 56.6 ± 12.5years; 56% women) followed for a median of 6.3 ± 3.3years. At baseline, 978 (65%) individuals had good sleep quality and 516 (35%) had poor sleep quality. The effects of Pittsburgh Sleep Quality Index scores changing over time on mortality was confounded by the impact of the SARS-CoV-2 pandemic on both. One hundred ninety-five individuals (13%) died during the follow-up, resulting in a crude mortality rate of 1.58 per 100 person years (95% C.I.: 1.27-1.88) for individuals with good sleep quality, and 3.18 (95% C.I.: 2.53-3.82) for those with poor sleep quality at baseline. A multivariate Cox-proportional hazards model showed that individuals with poor sleep quality at baseline were 1.38 times (95% C.I.: 1.02-1.85) more likely to die compared to those with good sleep quality; in this model, increased age, poor physical activity, and high fasting glucose remained significant.

CONCLUSIONS

Poor sleep quality is associated with increased mortality risk among middle-aged and older adults.

Seroprevalence Of SARS-COV-2 infection in asymptomatic indigenous from the largest Brazilian periurban area

This study assessed the seroprevalence of SARS-CoV-2 in 496 asymptomatic individuals from Mato Grosso do Sul, located in Dourados, the largest periurban indigenous area in Brazil, from January 25 to February 4, 2021. The volunteers participated before receiving their first dose of the CoronaVac inactivated vaccine. For screening, blood samples were collected and analyzed using SARS-CoV-2 rapid tests and the enzyme-linked immunosorbent assay (ELISA). We observed varying trends in total anti-SARS-CoV-2 antibodies across different variables. Seropositivity among the participants tested was 63.70% (316/496) using the rapid test and 52.82% (262/496) were positive using the ELISA method. The majority of participants identified with the Guarani-Kaiowá ethnic group, with 66.15% (217/328), and other ethnic groups with 58.84% (193/328). The median age of the subjects was 30.5 years, with 79.57% (261/328) being femaleThis research showed the elevated seroprevalence of SARS-CoV-2 antibodies in asymptomatic Brazilians. The findings indicate a high seropositivity rate among the asymptomatic indigenous population of Midwest Brazil. This underscores the overlooked status of these communities and underscores the need for targeted national initiatives that emphasize the protection of vulnerable ethnic groups in the fight against COVID-19.

SARS-CoV-2 seroprevalence on the north coast of Peru: A cross-sectional study after the first wave

BACKGROUND

Peru had the second-highest number of COVID-19 cases in Latin America. After the first wave, Peru registered more than 900,000 cases of COVID-19 and more than 36,000 confirmed deaths from the disease. Tumbes, a border area with poor sanitation and not enough water, had the fifth highest death rate. The cross-sectional analytic study aimed: a) to assess seroprevalence of COVID-19 after the first wave; b) to assess sociodemographic determinants and symptoms associated with a positive COVID-19 antibody lateral flow test.

METHODOLOGY/PRINCIPAL FINDINGS

We performed this study between November 11th and November 30th, 2020, in an informal settlement in Tumbes. Individuals older than two years were invited to participate in a systematic random sample from one in every four households. Finger-prick blood samples were collected, and a census and symptom survey were applied. Within the chosen house, one adult over 18 years of age was chosen for a PCR-RT molecular test. Overall seroprevalence was 25.59%, adjusted seroprevalence was 24.82% (95%CI 22.49-27.25). Women had higher adjusted seroprevalence (28.03% vs 21.11%; 95% CI 24.83-31.41, p = 0.002). Symptoms as fever (PR 1.89: 95% CI 1.44-2.48, p<0.001), general discomfort (PR 1.67; 95% CI 1.23-2.26, p = 0.001), cough (PR 2.0; 95% CI 1.60-2.50, p<0.001), nasal congestion (PR 1.46; 95% CI 1.03-2.09, p = 0.036), respiratory distress (PR 1.64; 95% CI 1.04-2.56, p = 0.031), headache (PR 1.54; 95% CI 1.09-2.17, p = 0.014), anosmia (PR 1.78; 95% CI 1.01-3.14, p = 0.046) and ageusia (PR 2.31; 95% CI 1.48-3.61, p<0.001) were associated with a positive covid-19 antibody lateral flow test.

CONCLUSIONS/SIGNIFICANCE

The COVID-19 transmission and distribution were highlighted by this cross-sectional study. The data will help the Ministry of Health improve its monitoring, surveillance, and monitoring of respiratory community sequelae in the future.

Limitations introduced by a low participation rate of SARS-CoV-2 seroprevalence data

BACKGROUND

There has been a large influx of COVID-19 seroprevalence studies, but comparability between the seroprevalence estimates has been an issue because of heterogeneities in testing platforms and study methodology. One potential source of heterogeneity is the response or participation rate.

METHODS

We conducted a review of participation rates (PR) in SARS-CoV-2 seroprevalence studies collected by SeroTracker and examined their effect on the validity of study conclusions. PR was calculated as the count of participants for whom the investigators had collected a valid sample, divided by the number of people invited to participate in the study. A multivariable beta generalized linear model with logit link was fitted to determine if the PR of international household and community-based seroprevalence studies was associated with the factors of interest, from 1 December 2019 to 10 March 2021.

RESULTS

We identified 90 papers based on screening and were able to calculate the PR for 35 out of 90 papers (39%), with a median PR of 70% and an interquartile range of 40.92; 61% of the studies did not report PR.

CONCLUSIONS

Many SARS-CoV-2 seroprevalence studies do not report PR. It is unclear what the median PR rate would be had a larger portion not had limitations in reporting. Low participation rates indicate limited representativeness of results. Non-probabilistic sampling frames were associated with higher participation rates but may be less representative. Standardized definitions of participation rate and data reporting necessary for the PR calculations are essential for understanding the representativeness of seroprevalence estimates in the population of interest.

An ounce of prevention is worth a pound of cure-the arts as a vehicle for knowledge translation and exchange (KTE) in public health during a pandemic: a realist-informed developmental evaluation research protocol

INTRODUCTION

The COVID-19 crisis has led to the adoption of strict and coercive preventive measures. The implementation of these measures has generated negative impacts for many communities. The situation is especially worrisome for Indigenous communities in Peru. Therefore, it is necessary to recognise the contribution of the experiential knowledge of Indigenous communities and to implement innovative approaches. The use of art can be a promising avenue for working in partnership with Indigenous communities.The goal of this research is to (1) develop an intervention promoting barrier measures and vaccination to limit the transmission of COVID-19 among Indigenous communities using an arts-based and community-based knowledge translation and exchange (ACKTE) model; and (2) understand the contextual elements and mechanisms associated with the process of developing a preventive intervention using the ACKTE model.

METHODOLOGY AND ANALYSIS

This research will take place in Indigenous communities in Peru and will be based on a developmental evaluation guided by the principles of realist evaluation. Members of two Indigenous communities, local authorities, health professionals and artists will participate in the intervention development process as well as in the developmental evaluation. For data collection, we will conduct modified talking circles and semistructured individual interviews with stakeholders as well as an analysis of documents and artistic works produced.

ETHICS AND DISSEMINATION OF RESULTS

This research received the approval of the Université du Québec à Rimouski's research ethics board. In addition to scientific articles, the results of this research will be disseminated through videos and during an artistic performance.

COVID-19 in Latin America and the Caribbean: Two years of the pandemic

Worldwide, nations have struggled during the coronavirus disease 2019 (COVID-19) pandemic. However, Latin America and the Caribbean faced an unmatched catastrophic toll. As of March 2022, the region has reported approximately 15% of cases and 28% of deaths worldwide. Considering the relatively late arrival of SARS-CoV-2, several factors in the region were determinants of the humanitarian crisis that ensued. Pandemic unpreparedness, fragile healthcare systems, forthright inequalities, and poor governmental support facilitated the spread of the virus throughout the region. Moreover, reliance on repurposed and ineffective drugs such as hydroxychloroquine and ivermectin-to treat or prevent COVID-19-was publicised through misinformation and created a false sense of security and poor adherence to social distancing measures. While there were hopes that herd immunity could be achieved after the region's disastrous first peak, the emergence of the Gamma, Lambda, and Mu variants made this unattainable. This review explores how Latin America and the Caribbean fared during the first 2 years of the pandemic, and how, despite all the challenges, the region became a global leader in COVID-19 vaccination, with 63% of its population fully vaccinated.

Sustained COVID-19 community transmission and potential super spreading events at neglected afro-ecuadorian communities assessed by massive RT-qPCR and serological testing of community dwelling population

Background

Neglected ethnic minorities from underserved rural populations in Latin America are highly vulnerable to coronavirus disease 2019 (COVID-19) due to poor health infrastructure and limited access to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnosis. Esmeraldas is a mainly rural province of the Coastal Region of Ecuador characterized by a high presence of Afro-Ecuadorian population living under poverty conditions.

Objective

We herein present a retrospective analysis of the surveillance SARS-CoV-2 testing in community-dwelling population from Esmeraldas carried out by our university laboratory in collaboration with regional health authorities during the first week of October 2020, in a region where no public SARS-CoV-2 detection laboratory was available at that time.

Results

A total number of 1,259 people were tested for SARS-CoV-2 by Reverse Transcription quantitative Polimerasa Chain Reaction (RT-qPCR), resulting in an overall infection rate of 7.7% (97/1259, 95% CI: [6.32–9.35%]) for SARS-CoV-2, up to 12.1% in some communities. Interestingly, community-dwelling super spreaders with viral loads over 10⁸ copies/ml represented 6.2% of the SARS-CoV-2-infected population. Furthermore, anti-SARS-CoV-2 IgG serological tests were applied to the same study group, yielding an overall seroprevalence of 11.68% (95% CI: [9.98–13.62%]) but as high as 24.47% at some communities.

Conclusion

These results support active COVID-19 community transmission in Esmeraldas province during the first semester of the COVID-19 pandemic as it has been shown for other rural communities in the Ecuadorian Coastal Region.

Seroprevalence of IgM and IgG anti-SARS-COV-2 and associated factors among agricultural workers in Colombia

Background

The population of South America has been severely affected by the COVID-19 pandemic. In this region, during the year 2020, high seroprevalence percentages were reported, which have been associated with the socioeconomic characteristics of the population, mainly in urban areas. However, a relative lack of information on the dynamics of the pandemic in rural areas of these countries, where the population is more vulnerable, is still present. This study determined antibody prevalence against SARS-CoV-2 in urban and rural food producing workers in Colombia.

Methods

A total of 1242 workers, urban and rural, linked to poultry, dairy, and meat production and supply chains, were analyzed through a sociodemographic survey and two serological tests against S and N proteins of SARS-CoV-2.

Results

78.7% were male. 50.9% of the participants were rural inhabitants, with an average age of 40.9 years old. 39.2% had IgM and IgG against SARS-CoV-2 S protein and 31.3% against N protein for the same virus; 83.6% had not been tested with an RT-PCR test for COVID-19 and 75.7% did not report symptoms related to the disease. The associated risk factors were low education, OR: 1.46, greater number of cohabitants, OR: 1.36, and contact with people infected with COVID-19, OR: 2.03.

Conclusions

The seroprevalences found suggest an important interconnectivity between rural and urban areas, where asymptomatic subjects and sociodemographic factors facilitate the virus' spread in the population.

SARS-CoV-2 infection in free roaming dogs from the Amazonian jungle

During the ongoing COVID-19 pandemic, there were several reports of SARS-CoV-2 transmission from human to animals, mostly to companion cats and dogs but also to free ranging wild species like minks and deers. Under this scenario, SARS-CoV-2 surveillance in domestic animals to assess the risk of transmission between species have been suggested by the OIE. Here we present a case report of SARS-CoV-2 infection in free roaming dogs, found at a rural indigenous community from the Ecuadorian Amazonia. Oral and nasal swabs samples were collected from three dogs found during a COVID-19 surveillance intervention in Amazonian indigenous communities where severe COVID-19 outbreaks were suspected. Total RNA was extracted from dog samples and detection of SARS-CoV-2 gene targets N, ORF1ab and S was performed. The three dogs tested positive for at least two SARS-CoV-2 viral targets. Moreover, there was a high SARS-CoV-2 infection rate of 87.2% within this community. Given that 17.1% of SARS-CoV-2 positive individuals had an ultra high load greater than 10⁸ copies/ml, transmission from humans to dogs likely occurred. To our knowledge, this study is the first report of SARS-CoV-2 positive free roaming dogs. Also, as those animals were found in the Amazonian forest, SARS-CoV-2 transmission to wild mammals is a potential concern. Given the high presence of free roaming dogs associated to rural and indigenous communities in South America, the potential role of these domestic animals on COVID-19 spread would deserve further surveillance studies involving SARS-CoV-2 detection by PCR and molecular epidemiology based on genome sequencing to confirm human to dog transmission.

SARS-CoV-2 prevalence at eight urban health clinics in Nicaragua: possible implications for the COVID-19 pandemic

Objective

To assess the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in selected health clinics in the three largest urban areas in Nicaragua, where data regarding coronavirus disease 2019 (COVID-19) testing, morbidity and mortality is severely limited.

Methods

In this cross-sectional study, participants were tested for SARS-CoV-2 RNA by loop-mediated isothermal amplification (LAMP), and were tested for antibodies using immunoassays. A questionnaire recorded subjects' COVID-19-associated symptoms and risk factors. Data were collected from 22 February to 19 March 2021, 1 year after the first confirmed cases of SARS-CoV-2 in Nicaragua. Study participants were enrolled while attending routine check-ups or seeking care unrelated to COVID-19. Study participation was random and voluntary. All patients were eligible to participate. Symptom history was not part of the eligibility criteria.

Results

The prevalence of current SARS-CoV-2 infection was high (14%, LAMP-positive/seronegative). Antibody testing showed higher overall seroprevalence (38%). Cough was the symptom most strongly associated with being LAMP-positive (odds ratio 3.57, 95% confidence interval 2.65-4.81). Loss of smell had the highest positive predictive value, and was significantly associated with being LAMP-positive.

Conclusion

The prevalence of current SARS-CoV-2 infection and seropositivity were fairly high. More than half of the sample population had evidence of current or past infection. Knowledge of this previously unknown elevated level of infection is crucial for healthcare providers and policy makers.

An Analysis COVID-19 in Mexico: a Prediction of Severity

BACKGROUND

Coronavirus disease 2019 (COVID-19) causes a mild illness in most cases; forecasting COVID-19-associated mortality and the demand for hospital beds and ventilators are crucial for rationing countries' resources.

OBJECTIVE

To evaluate factors associated with the severity of COVID-19 in Mexico and to develop and validate a score to predict severity in patients with COVID-19 infection in Mexico.

DESIGN

Retrospective cohort.

PARTICIPANTS

We included 1,435,316 patients with COVID-19 included before the first vaccine application in Mexico; 725,289 (50.5%) were men; patient's mean age (standard deviation (SD)) was 43.9 (16.9) years; 21.7% of patients were considered severe COVID-19 because they were hospitalized, died or both.

MAIN MEASURES

We assessed demographic variables, smoking status, pregnancy, and comorbidities. Backward selection of variables was used to derive and validate a model to predict the severity of COVID-19.

KEY RESULTS

We developed a logistic regression model with 14 main variables, splines, and interactions that may predict the probability of COVID-19 severity (area under the curve for the validation cohort = 82.4%).

CONCLUSIONS

We developed a new model able to predict the severity of COVID-19 in Mexican patients. This model could be helpful in epidemiology and medical decisions.

Incidence of Adult-Onset Epilepsy and the Contributory Role of Neurocysticercosis in a Five-Year, Population-Based, Prospective Study in Rural Ecuador

This prospective cohort study aimed to assess incidence and etiology of adult-onset epilepsy in previously seizure-free Atahualpa residents aged ≥ 20 years. Persons with adult-onset epilepsy occurring over 5 years were identified from annual door-to-door surveys and other overlapping sources. Those who emigrated or declined consent were excluded at the administrative censoring date of the last survey when these subjects were interviewed. Persons who died and those who developed incident epilepsy were censored at the time of these outcomes. Poisson regression models adjusted for demographics, education, alcohol intake, and the length of observation time, were used to estimate annual adult-onset epilepsy incidence rate ratio and cumulative incidence. Systematic neuroimaging screening was offered to participants to get insights on the etiology of epilepsy. Individuals enrolled in this cohort (N = 1,480) contributed to 6,811.6 years of follow-up. Seventeen developed incident adult-onset epilepsy, for an annual incident rate of 249.2 per 100,000 persons-year (95% CI: 130.7-367.7). Cumulative incidence was 1,245.9 per 100,000 persons (95% CI: 653.7-1,838.3) after a mean of 4.6 (SE: 0.06) years of follow-up. Six persons with incident epilepsy had neurocysticercosis (35%). Individuals with neurocysticercosis were six times more likely to develop adult-onset epilepsy than those without this disease (IRR: 6.01; 95% CI: 2.16-16.7), after adjusting for relevant covariates. The attributable fraction of incident adult-onset epilepsy due to neurocysticercosis was 30.9% (95% CI: 25.6-46.2%). This rural Ecuadorian population has a high incidence of adult-onset epilepsy, with neurocysticercosis being an important contributory cause.

Risk for Subsequent SARS-CoV-2 Infection and Severe COVID-19 Among Community-Dwellers With Pre-Existing Cervicocephalic Atherosclerosis: A Population-Based Study

BACKGROUND

COVID-19 patients may develop atherosclerosis-related complications. Whether a proportion of these patients already had asymptomatic cervicocephalic atherosclerosis before SARS-CoV-2 infection is not known. This study assessed whether pre-existing cervicocephalic atherosclerosis increased the susceptibility to SARS-CoV-2 infection or resulted in more severe or fatal COVID-19.

METHODS

Individuals enrolled in the Atahualpa Project cohort who received head CT (for assessing carotid siphon calcifications) and B-mode ultrasounds (for measurement of the carotid intima-media thickness) prior to the pandemic were eligible for this study. Among this cohort, those who also received serological tests for detection of SARS-CoV-2 antibodies and clinical evaluations for assessment of COVID-19 severity were enrolled. Multivariate logistic regression and exposure-effect models were fitted to assess the association between pre-existing atherosclerosis biomarkers, and SARS-CoV-2 seropositivity and COVID-19 severity.

RESULTS

Overall, 154 of 519 study participants (30%) had evidence of cervicocephalic atherosclerosis. A total of 325 (63%) individuals became SARS-CoV-2 positive, and 65 (23.5%) of seropositive individuals had severe or fatal COVID-19. The risk of SARS-CoV-2 seropositive status did not differ across individuals with and without atherosclerosis biomarkers (P = .360). Likewise, seropositive individuals with pre-existing atherosclerosis were not more prone to develop severe or fatal COVID-19 than those without evidence of atherosclerosis (P = .274). Average estimated exposure effects of pre-existing cervicocephalic atherosclerosis versus no atherosclerosis over SARS-CoV-2 seropositivity and COVID-19 severity were not significant.

CONCLUSIONS

Pre-existing cervicocephalic atherosclerosis does not increase the risk of acquiring SARS-CoV-2 infection nor the severity of COVID-19 among seropositive individuals.

High SARS-CoV-2 Seroprevalence in Rural Peru, 2021: a Cross-Sectional Population-Based Study

Latin America has been severely affected by the COVID-19 pandemic. The COVID-19 burden in rural settings in Latin America is unclear. We performed a cross-sectional, population-based, random-selection SARS-CoV-2 serologic study during March 2021 in the rural population of San Martin region, northern Peru. In total, 563 persons from 288 houses across 10 provinces were enrolled, reaching 0.2% of the total rural population of San Martin. Screening for SARS-CoV-2 IgG antibodies was done using a chemiluminescence immunoassay (CLIA), and reactive sera were confirmed using a SARS-CoV-2 surrogate virus neutralization test (sVNT). Validation of the testing algorithm using prepandemic sera from two regions of Peru showed false-positive results in the CLIA (23/84 sera; 27%) but not in the sVNT, highlighting the pitfalls of SARS-CoV-2 antibody testing in tropical regions and the high specificity of the two-step algorithm used in this study. An overall 59.0% seroprevalence (95% confidence interval [CI], 55 to 63%) corroborated intense SARS-CoV-2 spread in San Martin. Seroprevalence rates between the 10 provinces varied from 41.3 to 74.0% (95% CI, 30 to 84%). Higher seroprevalence was not associated with population size, population density, surface area, mean altitude, or poverty index in Spearman correlations. Seroprevalence and reported incidence diverged substantially between provinces, suggesting regional biases of COVID-19 surveillance data. Potentially, limited health care access due to environmental, economic, and cultural factors might lead to undetected infections in rural populations. Additionally, test avoidance to evade mandatory quarantine might affect rural regions more than urban regions. Serologic diagnostics should be pursued in resource-limited settings to inform country-level surveillance and vaccination strategies and to support control measures for COVID-19.

IMPORTANCE Latin America is a global hot spot of the COVID-19 pandemic. Serologic studies in Latin America have been mostly performed in urban settings. Rural populations comprise 20% of the total Latin American population. Nevertheless, information on COVID-19 spread in rural settings is scarce. Using a representative population-based seroprevalence study, we detected a high seroprevalence in rural populations in San Martin, northern Peru, in 2021, reaching 41 to 74%. However, seroprevalence and reported incidence diverged substantially between regions, potentially due to limited health care access or test avoidance due to mandatory quarantine. Our results suggest that rural populations are highly affected by SARS-CoV-2 even though they are sociodemographically distinct from urban populations and that highly specific serological diagnostics should be performed in resource-limited settings to support public health strategies of COVID-19 control.

Cognitive sequelae of long COVID may not be permanent: A prospective study

BACKGROUND AND PURPOSE

Cognitive decline is a recognized manifestation of long COVID, even among patients who experience mild disease. However, there is no evidence regarding the length of cognitive decline in these patients. This study aimed to assess whether COVID-19-related cognitive decline is a permanent deficit or if it improves over time.

METHODS

Cognitive performance was evaluated by means of the Montreal Cognitive Assessment (MoCA) in COVID-19 survivors and noninfected individuals. All study participants had four cognitive evaluations, two of them before the pandemic and the other two, 6 and 18 months after the initial SARS-CoV-2 outbreak infection in the village. Linear mixed effects models for longitudinal data were fitted to assess differences in cognitive performance across COVID-19 survivors and noninfected individuals.

RESULTS

The study included 78 participants, 50 with history of mild COVID-19 and 28 without. There was a significant-likely age-related-decline in MoCA scores between the two prepandemic tests (β = -1.53, 95% confidence interval [CI] = -2.14 to -0.92, p < 0.001), which did not differ across individuals who later developed COVID-19 when compared to noninfected individuals. Six months after infection, only COVID-19 survivors had a significant decline in MoCA scores (β = -1.37, 95% CI = -2.14 to -0.61, p < 0.001), which reversed after 1 additional year of follow-up (β = 0.66, 95% CI = -0.11 to 1.42, p = 0.092). No differences were noticed among noninfected individuals when both postpandemic MoCA scores were compared.

CONCLUSIONS

Study results suggest that long COVID-related cognitive decline may spontaneously improve over time.

Factors Associated With a Persistent Seronegative Status 1 Year After a SARS-CoV-2 Massive Infection Outbreak in Community Dwellers Living in Rural Ecuador: A Prospective Population-based Study

Background

The SARS-CoV-2 pandemic is affecting millions of people living in rural areas of Low- and Middle-Income Countries and is causing an already anticipated devastating effect on the health and economics of these populations. More information is needed to modify behaviors that may counterbalance the consequences of mass spread of the virus in these underserved communities. This study aimed to identify factors associated with a persistent SARS-CoV-2 seronegative status 1 year after a massive infection outbreak in middle-aged and older adults living in rural Ecuador.

Methods

Individuals enrolled in the Atahualpa Project Cohort as of March 2020 received 5 rounds of tests for determination of SARS-CoV-2 antibodies in blood. Individuals who remained seronegative up to April 2021 were considered “persistently seronegative.” An adjusted Poisson regression model was fitted to estimate the incidence risk ratio of factors directly or inversely associated with a persistent seronegative status.

Results

A total of 673 individuals received baseline tests. Thirty-one declined consent or died and 429 seroconverted, leaving 213 seronegative subjects. Average SARS-CoV-2 incidence rate was 9.87 events (95% C.I.: 8.91-10.83) per 100 person-months of observation. The use of flushing toilet systems (instead of open latrines) increased 1.5 times the possibility of remaining seronegative. Likewise, every additional bedroom in the house increased by 15% the possibility of remaining seronegative. In contrast, every additional person in the house and having high cholesterol levels significantly reduced the possibility of remaining seronegative.

Conclusions

The use of flushing toilet systems and the number of bedrooms in the house directly influenced the possibility of remaining seronegative among individuals living in this rural setting. Study results also demonstrated a sustained transmission of the virus even after a significant proportion of the population has been infected. Our findings reinforce the mass spread of SARS-CoV-2 in rural communities.

High Prevalence of SARS-CoV-2 in an Indigenous Community of the Colombian Amazon Region

Introduction. COVID-19 is a pathology caused by the SARS-CoV-2 virus. The World Health Organization (WHO) has reported more than 225 million cases and 4.5 million deaths worldwide. Objective: To describe the seropositivity, spatial distribution, and clinical and sociodemographic variables of SARS-CoV-2 in a community of the Colombian Amazon region. Methods. In December 2020, a cross-sectional observational study was carried out in a population located in the Colombian Amazon in the municipality of Mitú. Sociodemographic and clinical data were taken. Besides, 589 blood samples were taken, and an antibody detection was carried out with an ELISA and a recombinant protein N antigen of SARS-CoV-2. Results. A seropositivity of 57.6% was observed. The highest proportion of the infection is located in inter-municipal transport zones. The bivariate analysis did not show differences in the SARS-CoV-2 infection rate concerning the variables sex, age range, and the presence of comorbidities (p > 0.05). The bivariate and multivariate analysis showed that being symptomatic and presenting neurological manifestations of the upper respiratory tract are clinical variables associated with SARS-CoV-2 infection (p < 0.05). One of the causes of this virus’s high spread in this community could be that 53.3% of the people were asymptomatic. Conclusions. Our data showed a high burden and transmission of SARS-CoV-2 in the indigenous community. This could be linked to cultural behaviors and the high infection rate in asymptomatic patients.

Body Composition in Community-Dwelling Older Adults Before and After SARS-CoV-2 Infection: A Longitudinal Prospective Study in a Rural Village Struck by the Pandemic

Background:

Information on the body composition of inhabitants of remote communities during the SARS-CoV-2 pandemic is limited. Using a longitudinal population-based study design, we assessed the association between SARS-CoV-2 infection and changes in body composition.

Methods:

Community-dwelling older adults living in a rural Ecuadorian village received body composition determinations before and 1 year after the pandemic as well as serological tests for detection of SARS-CoV-2 antibodies. The independent association between SARS-CoV-2 infection and abnormalities in body composition at follow-up was assessed by fitting linear mixed models for longitudinal data.

Results:

Of 327 enrolled individuals, 277 (85%) received baseline and follow-up body composition determinations, and 175 (63%) of them became SARS-CoV-2 seropositive. Overall, diet and physical activity deteriorated during the follow-up. Multivariate random-effects generalized least squares regression models that included the impact of time and seropositivity on follow-up body composition, showed that neither variable contributed to a worsening in body composition. Multivariate logistic regression models disclosed that the serological status at follow-up cannot be predicted by differences in body composition and other baseline covariates.

Conclusions:

Study results suggest no increased susceptibility to SARS-CoV-2 infection among older adults with abnormal body composition and no significant changes as a result of worse physical activity and dietary habits or seropositivity during the length of the study. Together with a previous study in the same population that showed decrease in hand-grip strength after SARS-CoV-2, results confirm that dynapenia (and not sarcopenia) is associated with SARS-CoV-2 infection in older adults.

COVID-19 spread, detection, and dynamics in Bogota, Colombia

Latin America has been severely affected by the COVID-19 pandemic but estimations of rates of infections are very limited and lack the level of detail required to guide policy decisions. We implemented a COVID-19 sentinel surveillance study with 59,770 RT-PCR tests on mostly asymptomatic individuals and combine this data with administrative records on all detected cases to capture the spread and dynamics of the COVID-19 pandemic in Bogota from June 2020 to early March 2021. We describe various features of the pandemic that appear to be specific to a middle income countries. We find that, by March 2021, slightly more than half of the population in Bogota has been infected, despite only a small fraction of this population being detected. The initial buildup of immunity contributed to the containment of the pandemic in the first and second waves. We also show that the share of the population infected by March 2021 varies widely by occupation, socio-economic stratum, and location. This, in turn, has affected the dynamics of the spread with different groups being infected in the two waves.

COVID-19-Lessons Learned and Questions Remaining

In this article, the editors of Clinical Infectious Diseases review some of the most important lessons they have learned about the epidemiology, clinical features, diagnosis, treatment and prevention of SARS-CoV-2 infection and identify essential questions about COVID-19 that remain to be answered.

Hand grip strength before and after SARS-CoV-2 infection in community-dwelling older adults

Objective

To assess the association between SARS‐CoV‐2 infection and decreased hand grip strength (HGS).

Design

Longitudinal population‐based study.

Setting

Community‐dwelling older adults (aged ≥60 years) living in a rural Ecuadorian village struck by the SARS‐CoV‐2 pandemic.

Participants

Of 282 enrolled individuals, 254 (90%) finished the study.

Measurements

HGS was measured 3 months before (January 2020) and 9 months after the introduction of the virus into the population (January 2021). SARS‐CoV‐2 antibody testing was performed in two rounds: in May–June (early) and September–November (late), 2020. An independent association between SARS‐CoV‐2 infection and HGS decline was assessed by fitting linear mixed models for longitudinal data. Changes in HGS scores in SARS‐CoV‐2 seropositive subjects, according to the time elapsed since seroconversion, were compared with those who remained seronegative.

Results

Overall, 149 (59%) individuals became seropositive for SARS‐CoV‐2. The mean HGS (in kg) was 25.3 ± 8.3 at baseline and 23.7 ± 8.1 at follow‐up (p = 0.028), with 140 individuals having >5% HGS decline between both measurements. The follow‐up HGS measurement decreased by 1.72 kg in seropositive individuals, and by 0.57 kg in their seronegative counterparts (p < 0.001). SARS‐CoV‐2 seropositive individuals were 2.27 times more likely (95% CI: 1.33–3.87) to have a lower HGS measurement at the time of follow‐up than those who remained seronegative. When compared with seronegative subjects, seropositive patients with early seroconversion were 3.41 times (95% CI: 1.73–6.74) more likely to have >5% HGS decline at the time of the follow‐up than those with later, i.e., more recent, infections.

Conclusions

This study shows an independent deleterious impact of SARS‐CoV‐2 on HGS that is more marked among individuals with infections that occurred more than 8 months before follow‐up HGS. Results suggest the possibility of chronic damage to skeletal muscles by SARS‐CoV‐2.

Syndemics & syndemogenesis in COVID-19 and rheumatic and musculoskeletal diseases: old challenges, new era

People with rheumatic and musculoskeletal diseases (RMDs) are facing several challenges during the COVID-19 pandemic, such as poor access to regular health services and drug shortages, particularly in developing countries. COVID-19 represents a syndemic, synergistic condition that interacts with and exacerbates pre-existing diseases such as RMDs, other co-morbidities and social conditions. The emerging evidence on both biological and non-biological factors implicated in worse outcomes in people with RMDs affected by the COVID-19 pandemic, whether infected by the virus or not, calls for the need to use more novel and holistic frameworks for studying disease. In this context, the use of a syndemic framework becomes particularly relevant. We appeal for a focus on the identification of barriers and facilitators to optimal care of RMDs in the context of the COVID-19 pandemic, in order to tackle both the pandemic itself and the health inequities inherent to it.

Seroprevalence of SARS-CoV-2 Infection and Adherence to Preventive Measures in Cuenca, Ecuador, October 2020, a Cross-Sectional Study

A door-to-door survey was organised in Cuenca, Ecuador, to determine the prevalence of COVID-19 infection and adherence of the population to COVID-19 preventive measures. A total of 2457 persons participated in the study; 584 (23.7%) reported having experienced at least one flu-like symptom since the onset of the pandemic. The maximum SARS-CoV-2 seroprevalence in Cuenca was 13.2% (CI: 12-14.6%) (IgM or IgG positive). Considering PCR confirmed infections, the prevalence was 11% (CI: 10-12.4%). There was no significant difference in seroprevalence between rural and urban areas. Participants aged 35-49 years old, living with a COVID-19 positive person, at least six people in a household, physical contact with someone outside the household, a contact with a person outside the home with flu-like symptoms, using public transport, and not having enough resources for living, significantly increased the odds for SARS-CoV-2 seropositivity. Overall, there was good adherence to COVID-19 preventive measures. Having known someone who tested positive for COVID-19, having a primary or secondary level of education, and having enough resources for living, significantly increased the odds for higher adherence. In conclusion, despite good overall adherence of the population of Cuenca with COVID-19 preventive measures, our study suggests high ongoing COVID-19 transmission in Cuenca, particularly in certain parishes. Prevention should not only focus on behavioural change, but on intensified testing strategies in demographical risk groups.

Cognitive decline among individuals with history of mild symptomatic SARS-CoV-2 infection: A longitudinal prospective study nested to a population cohort

BACKGROUND AND PURPOSE

Neurological complications of SARS-CoV-2 infection are noticed among critically ill patients soon after disease onset. Information on delayed neurological sequelae of SARS-CoV-2 infection is nil. Following a longitudinal study design, the occurrence of cognitive decline among individuals with a history of mild symptomatic SARS-CoV-2 infection was assessed.

METHODS

Stroke- and seizure-free Atahualpa residents aged ≥40 years, who had pre-pandemic cognitive assessments as well as normal brain magnetic resonance imaging and electroencephalogram recordings, underwent repeated evaluations 6 months after a SARS-CoV-2 outbreak infection in Atahualpa. Patients requiring oxygen therapy, hospitalization, and those who had initial neurological manifestations were excluded. Cognitive decline was defined as a reduction in the Montreal Cognitive Assessment (MoCA) score between the post-pandemic and pre-pandemic assessments that was ≥4 points greater than the reduction observed between two pre-pandemic MoCAs. The relationship between SARS-CoV-2 infection and cognitive decline was assessed by fitting logistic mixed models for longitudinal data as well as exposure-effect models.

RESULTS

Of 93 included individuals (mean age 62.6 ± 11 years), 52 (56%) had a history of mild symptomatic SARS-CoV-2 infection. Post-pandemic MoCA decay was worse in seropositive individuals. Cognitive decline was recognized in 11/52 (21%) seropositive and 1/41 (2%) seronegative individuals. In multivariate analyses, the odds for developing cognitive decline were 18.1 times higher among SARS-CoV-2 seropositive individuals (95% confidence interval 1.75-188; p = 0.015). Exposure-effect models confirmed this association (β = 0.24; 95% confidence interval 0.07-0.41; p = 0.006).

CONCLUSIONS

This study provides evidence of cognitive decline among individuals with mild symptomatic SARS-CoV-2 infection. The pathogenesis of this complication remains unknown.

SARS-CoV-2 RNA in Swabbed Samples from Latrines and Flushing Toilets: A Case-Control Study in a Rural Latin American Setting

Information about factors potentially favoring the spread of SARS-CoV-2 in rural settings is limited. Following a case–control study design in a rural Ecuadorian village that was severely struck by the pandemic, SARS-CoV-2 RNA were detected by real-time PCR in swabs obtained from inner and upper walls in 24/48 randomly selected latrines from case-houses and in 12/48 flushing toilets from paired control-houses (P = 0.014; McNemar’s test). This association persisted in a conditional logistic regression model adjusted for relevant covariates (OR: 4.82; 95% CI: 1.38–16.8; P = 0.014). In addition, SARS-CoV-2–seropositive subjects were more often identified among those living in houses with a latrine (P = 0.002). Latrines have almost five times the odds of containing SARS-CoV-2 RNA than their paired flushing toilets. Latrines are reservoirs of SARS-CoV-2 RNA, and it cannot be ruled out that latrines could contribute to viral transmission in rural settings. Frequent disinfection of latrines should be recommended to reduce the likelihood of fecal contamination.

COVID-19 by numbers - infections, cases and deaths

During the COVID-19 pandemic, governments face difficult decisions when being confronted with public health threats and economic needs. Decision making is further complicated by the different perception of the pandemic by the public. Politicians as well as the public need objective facts for guidance and numbers play here a crucial role. The current contribution compiles numbers for infections, cases and deaths with SARS-CoV-2 to serve as an orientation help.

Safety in Endoscopy for Patients and Healthcare Workers During the COVID-19 Pandemic

The coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is still wreaking havoc in many parts of the world and poses a great burden to healthcare systems worldwide. Mitigation and suppression strategies have been implemented globally but the disease has proven to be difficult to contain. Initially many elective gastrointestinal endoscopies were cancelled to reduce the risk of infection and conserve personal protective equipment, but many endoscopy units are now faced with the dilemma of resuming endoscopy service during the pandemic as indefinitely postponing diagnostic procedures may lead to a delay in the diagnosis and treatment of malignancies. Further concerns are surfacing as COVID-19 is now known to affect the gastrointestinal tract and may potentially be spread via the fecal-oral route. Until more effective drugs and vaccines are available, it is unlikely that the pandemic will wind down in the near future. Maintaining a balance between protecting healthcare workers and patients from being infected on the one hand and providing timely and effective clinical care on the other will become increasingly important as the pandemic persists. In this narrative review, the risk of COVID-19 infection for healthcare workers and patients undergoing endoscopy, and recommendations on maintaining safe, high-quality endoscopy practice will be discussed.

Late incidence of SARS-CoV-2 infection in a highly-endemic remote rural village. A prospective population-based cohort study

Data on SARS-CoV-2 transmission in rural communities is scarce or non-existent. A previous cross-sectional study in middle-aged and older adults enrolled in the Atahualpa Project Cohort demonstrated that 45% of participants had SARS-CoV-2 antibodies, 77% of whom were symptomatic. Here, we assessed the incidence of SARS-CoV-2 infection in the above-mentioned rural population. One month after baseline testing, 362 of 370 initially seronegative individuals were re-tested to assess incidence of seroconversion and associated risk factors. Twenty-eight of them (7.7%) became seropositive. The overall incidence rate ratio was 7.4 per 100 person months of potential virus exposure (95% C.I.: 4.7-10.2). Six seroconverted individuals (21.4%) developed SARS-CoV-2-related symptomatology. The only covariate significantly associated with seroconversion was the use of an open latrine. Predictive margins showed that these individuals were 2.5 times more likely to be infected (95% C.I.: 1.03-6.1) than those using a flushing toilet. Therefore, along one month, approximately 8% of seronegative individuals became infected, even after almost half of the population was already seropositive. Nevertheless, a smaller proportion of incident cases were symptomatic (21% versus 77% of the earlier cases), and no deaths were recorded. Whether this decreased clinical expression resulted from a lower viral load in new infections cannot be determined. Increased seroconversion in individuals using latrines is consistent with a contributory role of fecal-oral transmission, although we cannot rule out the possibility that latrines are acting as a proxy for poverty or other unknown interacting variables.

Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence Among Adults in a Tropical City of the Caribbean Area, Colombia: Are We Much Closer to Herd Immunity Than Developed Countries?

A serological survey was carried out in Monteria (500 000 population), a mid-size city in Colombia. An overall prevalence of 55.3% (95% confidence interval, 52.5%–57.8%) was found among a sample of 1.368 people randomly selected from the population. Test positivity was related to economic characteristics with the highest prevalence found in the most impoverished areas, representing 83.8% of the city’s population. We found a prevalence that might be associated with some important level of population immunity.

Age-specific mortality and immunity patterns of SARS-CoV-2

Estimating the size of the coronavirus disease 2019 (COVID-19) pandemic and the infection severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is made challenging by inconsistencies in the available data. The number of deaths associated with COVID-19 is often used as a key indicator for the size of the epidemic, but the observed number of deaths represents only a minority of all infections^1,2. In addition, the heterogeneous burdens in nursing homes and the variable reporting of deaths of older individuals can hinder direct comparisons of mortality rates and the underlying levels of transmission across countries³. Here we use age-specific COVID-19-associated death data from 45 countries and the results of 22 seroprevalence studies to investigate the consistency of infection and fatality patterns across multiple countries. We find that the age distribution of deaths in younger age groups (less than 65 years of age) is very consistent across different settings and demonstrate how these data can provide robust estimates of the share of the population that has been infected. We estimate that the infection fatality ratio is lowest among 5-9-year-old children, with a log-linear increase by age among individuals older than 30 years. Population age structures and heterogeneous burdens in nursing homes explain some but not all of the heterogeneity between countries in infection fatality ratios. Among the 45 countries included in our analysis, we estimate that approximately 5% of these populations had been infected by 1 September 2020, and that much higher transmission rates have probably occurred in a number of Latin American countries. This simple modelling framework can help countries to assess the progression of the pandemic and can be applied in any scenario for which reliable age-specific death data are available.

Frailty and SARS-CoV-2 infection. A population-based study in a highly endemic village

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Data on the association between frailty and SARS-CoV-2 infection is inconsistent.

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There are no studies addressing if frail subjects are more prone to acquire SARS-CoV-2 infection.

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We assessed the relationship between previously diagnosed frailty and SARS-CoV-2 in older adults.

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Frailty does not predispose to SARS-CoV-2 infection in community-dwelling older adults.

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Lack of confinement to retirement homes probably accounts for our findings.

Household Clustering of SARS-CoV-2 in Community Settings: A Study from Rural Ecuador

The SARS-CoV-2 pandemic is now expanding into the developing world with devastating consequences. Departing from a population-based study in rural Ecuador where all adult individuals (aged 40 years or older) were tested for SARS-CoV-2 IgG and IgM antibodies, we expanded it to include a house-based case-control component assessing in-house clustering and other variables potentially associated with infection. We selected houses where exactly two study participants lived and were both seropositive (case-houses), and matched 1:1 to control-houses where both were seronegative. Younger household members had an antibody test performed. Infected household members were found in 33 (92%) case-houses and in only six (17%) control-houses. In 28/29 discordant house pairs, the case-house had seropositive household members and the control-house did not (odds ratio: 28; 95% CI: 4.6-1,144). Our data demonstrate strong in-house clustering of infection in community settings, stressing the importance of early case ascertainment and isolation for SARS-CoV-2 control.

SARS-CoV-2-related mortality in a rural Latin American population

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There is no evidence on mortality rates of SARS-CoV-2 in remote rural settings.

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We calculated SARS-CoV-2 mortality rate of adults living in Atahualpa (rural Ecuador).

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SARS-CoV-2 mortality rate was 15.7/1,000, which increased to 68.9/1,000 when only older adults were considered.

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Most deaths occurred over a two-month period, and markedly decreased subsequently.

A sudden increase in adult mortality associated with respiratory diseases was noticed in Atahualpa (a rural Ecuadorian village), coinciding with the introduction of SARS-CoV-2 in the region. From a total of 1,852 individuals aged ≥18 years, 40 deaths occurred between January and June, 2020. In addition, a seroprevalence survey showed that 45% of the adult population have SARS-CoV-2 antibodies. Verbal autopsies revealed SARS-CoV-2 as the most likely cause of death in 29 cases. The mean age of suspected or confirmed SARS-CoV-2 cases was 76.9 ± 12.1 years, while that of those dying from unrelated causes was 60.3 ± 20.4 years (p = 0.003). The overall mortality rate was 21.6 per 1,000 population (95% C.I.: 15.9 – 29.2), almost three-quarters of it due to SARS-CoV-2 (15.7 per 1,000; 95% C.I.: 11 – 22.4). This configures a 266% of excess mortality when compared to 5.9 per 1,000 (95% C.I.: 3.3 – 10.6) deaths from other causes. When SARS-CoV-2 mortality rate was calculated in individuals aged ≥60 years, it raised up to 68.9 per 1,000 (95% C.I.: 47.8 – 98.4). After peaking in April and May, mortality significantly decreased. It is possible that the high proportion of infected individuals and the resulting herd immunity contributed to the observed reduction in mortality.