Risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation: results from the contact tracing strategy of the CoVIDA epidemiological surveillance study in Bogotá, Colombia, in 2020-2021.

OBJECTIVES: To estimate the risk factors for SARS-CoV-2 transmission in close contacts of adults at high risk of infection due to occupation, participants of the CoVIDA study, in Bogotá D.C., Colombia. SETTING: The CoVIDA study was the largest COVID-19 intensified sentinel epidemiological surveillance study in Colombia thus far, performing over 60 000 RT-PCR tests for SARS-CoV-2 infection. The study implemented a contact tracing strategy (via telephone call) to support traditional surveillance actions performed by the local health authority. PARTICIPANTS: Close contacts of participants from the CoVIDA study. PRIMARY AND SECONDARY OUTCOME MEASURES: SARS-CoV-2 testing results were obtained (RT-PCR with CoVIDA or self-reported results). The secondary attack rate (SAR) was calculated using contacts and primary cases features. RESULTS: The CoVIDA study performed 1257 contact tracing procedures on primary cases. A total of 5551 close contacts were identified and 1050 secondary cases (21.1%) were found. The highest SAR was found in close contacts: (1) who were spouses (SAR=32.7%; 95% CI 29.1% to 36.4%), (2) of informally employed or unemployed primary cases (SAR=29.1%; 95% CI 25.5% to 32.8%), (3) of symptomatic primary cases (SAR of 25.9%; 95% CI 24.0% to 27.9%) and (4) living in households with more than three people (SAR=22.2%; 95% CI 20.7% to 23.8%). The spouses (OR 3.85; 95% CI 2.60 to 5.70), relatives (OR 1.89; 95% CI 1.33 to 2.70) and close contacts of a symptomatic primary case (OR 1.48; 95% CI 1.24 to 1.77) had an increased risk of being secondary cases compared with non-relatives and close contacts of an asymptomatic index case, respectively. CONCLUSIONS: Contact tracing strategies must focus on households with socioeconomic vulnerabilities to guarantee isolation and testing to stop the spread of the disease.

Effectiveness and adherence to closed face shields in the prevention of COVID-19 transmission: a non-inferiority randomized controlled trial in a middle-income setting (COVPROSHIELD).

BACKGROUND: The use of respiratory devices can mitigate the spread of diseases such as COVID-19 in community settings. We aimed to determine the effectiveness of closed face shields with surgical face masks to prevent SARS-CoV-2 transmission in working adults during the COVID-19 pandemic in Bogotá, Colombia. METHODS: An open-label non-inferiority randomized controlled trial that randomly assigned participants to one of two groups: the intervention group was instructed to wear closed face shields with surgical face masks, and the active control group was instructed to wear only surgical face masks. The primary outcome was a positive reverse transcription polymerase chain reaction test, IgG/IgM antibody test for SARS-CoV-2 detection, or both during and at the end of the follow-up period of 21 days. The non-inferiority limit was established at - 5%. RESULTS: A total of 316 participants were randomized, 160 participants were assigned to the intervention group and 156 to the active control group. In total, 141 (88.1%) participants in the intervention group and 142 (91.0%) in the active control group completed the follow-up. PRIMARY OUTCOME: a positive SARS-CoV-2 test result was identified in one (0.71%) participant in the intervention group and three (2.1%) in the active control group. In the intention-to-treat analysis, the absolute risk difference was - 1.40% (95% CI [- 4.14%, 1.33%]), and in the per-protocol analysis, the risk difference was - 1.40% (95% CI [- 4.20, 1.40]), indicating non-inferiority of the closed face shield plus face mask (did not cross the non-inferiority limit). CONCLUSIONS: The use of closed face shields and surgical face masks was non-inferior to the surgical face mask alone in the prevention of SARS-CoV-2 infection in highly exposed groups. Settings with highly active viral transmission and conditions such as poor ventilation, crowding, and high mobility due to occupation may benefit from the combined use of masks and closed face shields to mitigate SARS-CoV-2 transmission. TRIAL REGISTRATION: ClinicalTrials.gov NCT04647305 . Registered on November 30, 2020.

Prediction of SARS-CoV-2 infection with a Symptoms-Based model to aid public health decision making in Latin America and other low and middle income settings.

Symptoms-based models for predicting SARS-CoV-2 infection may improve clinical decision-making and be an alternative to resource allocation in under-resourced settings. In this study we aimed to test a model based on symptoms to predict a positive test result for SARS-CoV-2 infection during the COVID-19 pandemic using logistic regression and a machine-learning approach, in Bogotá, Colombia. Participants from the CoVIDA project were included. A logistic regression using the model was chosen based on biological plausibility and the Akaike Information criterion. Also, we performed an analysis using machine learning with random forest, support vector machine, and extreme gradient boosting. The study included 58,577 participants with a positivity rate of 5.7%. The logistic regression showed that anosmia (aOR = 7.76, 95% CI [6.19, 9.73]), fever (aOR = 4.29, 95% CI [3.07, 6.02]), headache (aOR = 3.29, 95% CI [1.78, 6.07]), dry cough (aOR = 2.96, 95% CI [2.44, 3.58]), and fatigue (aOR = 1.93, 95% CI [1.57, 2.93]) were independently associated with SARS-CoV-2 infection. Our final model had an area under the curve of 0.73. The symptoms-based model correctly identified over 85% of participants. This model can be used to prioritize resource allocation related to COVID-19 diagnosis, to decide on early isolation, and contact-tracing strategies in individuals with a high probability of infection before receiving a confirmatory test result. This strategy has public health and clinical decision-making significance in low- and middle-income settings like Latin America.

Residual liver stiffness in the postpartum period in women with preeclampsia and healthy women: A case-control study.

OBJECTIVE: We aimed to assess the presence of residual liver stiffness in preeclampsia 45 days after delivery. STUDY DESIGN: This was a longitudinal case-control study to assess the association between residual liver stiffness, measured 45 days postpartum, and hypertensive disorders of pregnancy. Cases were obstetric patients admitted with hypertension during pregnancy (preeclampsia with and without severe features, or HELLP syndrome) between June 2019 and September 2021. Controls were obstetric patients with similar ages, social status, gestational age (assessed by the first-trimester ultrasound), and geographical areas between the same period. A 2:1 case-control match was considered. MAIN OUTCOME MEASURES: We recorded blood pressure and laboratory tests during the hospital stay. We measured the residual liver stiffness in preeclampsia participants and controls 45 days after delivery. RESULTS: We recruited 99 hypertensive patients and 46 control patients. The residual liver stiffness was higher in hypertensive cases than controls (4.6 [3.9-5.3] kPa vs. 4.0 [3.2-5.2] kPa; p = 0.039). Linear regression results showed that systolic and diastolic blood pressures and alanine aminotransferase positively correlated with liver stiffness values (p < 0.01). CONCLUSIONS: Preeclampsia and disease severity were associated with residual liver stiffness. Prospective studies should further evaluate the clinical implications of these findings.

SARS-CoV-2 Drive/Walk-Thru screening centers in Colombia: The CoVIDA Project / Centros de tamizaje masivo para SARS COV-2 en Colombia: Proyecto CoVIDA

Abstract Objective: The CoVIDA project is a public-private collaboration led by Universidad de los Andes that contributed to the SARS-CoV-2 epidemiological surveillance in Bogotá and nearby municipalities. We aimed to describe the development and performance of the Drive/Walk-through free RT- PCR for SARS-CoV-2 testing strategy implemented by CoVIDA. Material and method: We performed a descriptive analysis of the characteristics and performance of the CoVIDA Drive/Walk-through testing centers. The model and the process indicators to assess the model's performance were based on international experiences and scientific literature. Two screening centers were imple mented in shopping centers in the north and south of Bogotá. We reported the number of tests taken, the number of positive tests, and the number of participants that used the model by the type of occupations. Results: In total, 36,689 nasopharyngeal RT-PCR tests for SARS-CoV-2 were performed with a 5.75% cumulative positivity. Process indicators showed an excellent performance and an important contribution in reducing barriers to access to testing. Conclusions: the CoVIDA Drive/Walk-through testing centers supported the epidemiological surveillance in asymptomatic or mild-symptomatic population in Bo gotá. Low and middle-income countries can use this model as a cost-effective and innovative solution strategy to intensify testing and help mitigate the pandemic.

Resumen Objetivo: El proyecto CoVIDA es una colaboración público-privada liderada por la Universidad de los Andes que contribuyó a la vigilancia epidemiológica del SARS-CoV-2 en Bogotá y municipios cercanos. Nuestro objetivo fue describir el desarrollo y rendimiento de la estrategia de tamizaje gratuito con RT-PCR mediante un modelo Drive/Walk through para SARS-CoV-2 implementado por CoVIDA. Materiales y métodos: Realizamos un análisis descriptivo de las características y desempeño de los centros de tamizaje Drive/Walk through de CoVIDA. El modelo y los indicadores de proceso para evaluar el desempeño del modelo se basaron en experiencias internacionales y la literatura científica. Se implementaron dos cen tros de tamizaje en centros comerciales del norte y sur de Bogotá. Se reportó la cantidad de pruebas tomadas, pruebas positivas y de participantes que utilizaron el modelo de acuerdo con el tipo de ocupaciones. Resultados : En total, se realizaron 36,689 pruebas RT-PCR nasofaríngeas para SARS-CoV-2 con una positividad acumulada del 5,75%. Los indicadores de proceso mostraron un excelente desempeño y una contribución importante en la reducción de las barreras de acceso a las pruebas. Conclusiones: los centros de tamizaje con modelo Drive/Walk through de CoVIDA apoyaron la vigilancia epidemiológica en población asintomática o con síntomas leves en Bogotá. Los países de ingresos bajos y medianos pueden utilizar este modelo como una estrategia innovadora y rentable para aumentar la realización de las pruebas y ayudar a mitigar la pandemia.

Factors Associated With SARS-CoV-2 Infection in Bogotá, Colombia: Results From a Large Epidemiological Surveillance Study.

BACKGROUND: Epidemiologic surveillance of COVID-19 is essential to collect and analyse data to improve public health decision making during the pandemic. There are few initiatives led by public-private alliances in Colombia and Latin America. The CoVIDA project contributed with RT-PCR tests for SARS-CoV-2 in mild or asymptomatic populations in Bogotá. The present study aimed to determine the factors associated with SARS-CoV-2 infection in working adults. METHODS: COVID-19 intensified sentinel epidemiological surveillance study, from April 18, 2020, to March 29, 2021. The study included people aged 18 years or older without a history of COVID-19. Two main occupational groups were included: healthcare and essential services workers with high mobility in the city. Social, demographic, and health-related factors were collected via phone survey. Afterwards, the molecular test was conducted to detect SARS-CoV-2 infection. FINDINGS: From the 58,638 participants included in the study, 3,310 (5·6%) had a positive result. A positive result was associated with the age group (18-29 years) compared with participants aged 60 or older, participants living with more than three cohabitants, living with a confirmed case, having no affiliation to the health system compared to those with social health security, reporting a very low socioeconomic status compared to those with higher socioeconomic status, and having essential occupations compared to healthcare workers. INTERPRETATION: The CoVIDA study showed the importance of intensified epidemiological surveillance to identify groups with increased risk of infection. These groups should be prioritised in the screening, contact tracing, and vaccination strategies to mitigate the pandemic. FUNDING: The CoVIDA study was funded through donors managed by the philanthropy department of Universidad de los Andes.

Metered-dose inhalers versus nebulization for the delivery of albuterol for acute exacerbations of wheezing or asthma in children: A systematic review with meta-analysis.

OBJECTIVES: The benefits of metered-dose inhalers with a spacer (MDI+S) have increasingly been recognized as an alternative method of albuterol administration for treating pediatric asthma exacerbations. The aim of this systematic review was to compare the response to albuterol delivered through nebulization (NEB) with albuterol delivered through MDI+S in pediatric patients with asthma exacerbations. METHODS: We conducted an electronic search in MEDLINE/PubMed, EMBASE, Ovid, and ClinicalTrials. To be included in the review, a study had to a randomized clinical trial comparing albuterol delivered via NEB versus MDI+S; and had to report the rate of hospital admission (primary outcome), or any of the following secondary outcomes: oxygen arterial saturation, heart rate (HR), respiratory rate (RR), the pulmonary index score (PIS), adverse effects, and need for additional treatment. RESULTS: Fifteen studies (n = 2057) met inclusion criteria. No significant differences were found between the two albuterol delivery methods in terms of hospital admission (relative risk, 0.89; 95% confidence interval [CI], 0.55-1.46; I2 = 32%; p = .65). There was a significant reduction in the PIS score (mean difference [MD], -0.63; 95% CI, -0.91 to -0.35; I2 = 0%; p < .00001), and a significantly smaller increase in HR (better; MD -6.47; 95% CI, -11.69 to -1.25; I2 = 0%; p = .02) when albuterol was delivered through MDI+S than when it was delivered through NEB. CONCLUSIONS: This review, an update of a previously-published meta-analysis, showed a significant reduction in the PIS and a significantly smaller increase in HR when albuterol was delivered through MDI+S than when it was delivered through NEB.