Neutralizing Antibody Responses Elicited by Inactivated Whole Virus and Genetic Vaccines against Dominant SARS-CoV-2 Variants during the Four Epidemic Peaks of COVID-19 in Colombia.

Several SARS-CoV-2 variants of concern (VOC) and interest (VOI) co-circulate in Colombia, and determining the neutralizing antibody (nAb) responses is useful to improve the efficacy of COVID-19 vaccination programs. Thus, nAb responses against SARS-CoV-2 isolates from the lineages B.1.111, P.1 (Gamma), B.1.621 (Mu), AY.25.1 (Delta), and BA.1 (Omicron), were evaluated in serum samples from immunologically naïve individuals between 9 and 13 weeks after receiving complete regimens of CoronaVac, BNT162b2, ChAdOx1, or Ad26.COV2.S, using microneutralization assays. An overall reduction of the nAb responses against Mu, Delta, and Omicron, relative to B.1.111 and Gamma was observed in sera from vaccinated individuals with BNT162b2, ChAdOx1, and Ad26.COV2.S. The seropositivity rate elicited by all the vaccines against B.1.111 and Gamma was 100%, while for Mu, Delta, and Omicron ranged between 32 to 87%, 65 to 96%, and 41 to 96%, respectively, depending on the vaccine tested. The significant reductions in the nAb responses against the last three dominant SARS-CoV-2 lineages in Colombia indicate that booster doses should be administered following complete vaccination schemes to increase the nAb titers against emerging SARS-CoV-2 lineages.

Comparison of Anti-SARS-CoV-2 IgG Antibody Responses Generated by the Administration of Ad26.COV2.S, AZD1222, BNT162b2, or CoronaVac: Longitudinal Prospective Cohort Study in the Colombian Population, 2021/2022.

To mitigate the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), vaccines have been rapidly developed and introduced in many countries. In Colombia, the population was vaccinated with four vaccines. Therefore, this research aimed to determine the ability of the vaccines introduced in the National Vaccination Plan to prevent SARS-CoV-2 infection and induce seroconversion and sought to investigate the longevity of antibodies in the blood. We conducted a prospective, nonprobabilistic, consecutive cross-sectional cohort study in a population with access to vaccination with CoronaVac, Ad26.COV2.S, AZD1222, and BNT162b2 from March 2021 to March 2022. The study included 1327 vaccinated people. A plurality of participants were vaccinated with BNT162b2 (36.1%; n = 480), followed by Ad26.COV2.S (26.9%; n = 358), CoronaVac (24%; n = 331), and AZD1222 (11.9%; n = 158). The crude seroprevalence on day zero varied between 18.1% and 57.8%. Participants who received BNT162b2 had a lower risk of SARS-CoV-2 infection than those who received the other vaccines. Participants who were immunized with BNT162b2 and AZD1222 had a higher probability of losing reactivity on day 210 after receiving the vaccine.

Seroprevalence of SARS-CoV-2 Antibodies in Children and Adolescents: Results From a Population-Based Survey in 10 Colombian Cities.

Background. Understanding COVID-19 dynamics in Colombia during the first pandemic year (2020) gives important insights surrounding population's exposure risk and specific susceptibilities. Seroprevalence studies can aid in having a broader understanding of the disease, offering a more inclusive view of the pandemic's impact across the population. Methods. A population-based cross-sectional study to assess antibodies against SARS-CoV-2 in 10 Colombian cities was developed between September and December 2020. Cities were grouped according development typology (Robust (RD), Intermediate (ID) and Incipient (InD)). Detection of total antibodies (IgM + IgG) against SARS-CoV-2 was employed. Univariate Odds Ratios (OR) were estimated for antibody results and selected variables. Results. About 3124 children aged between 5 and 17 years were included. Factors related to lower seropositive results were affiliation to the employer-based health insurance in RD and ID cities (OR: 0.579, 95% CI 0.477-0.703, OR: 0.648, 95%CI 0.480-0.874 respectively) and living in a household with adequate access to public services only for ID cities (OR: 0.679. 95% CI 0.491-0.939). Higher seropositivity rates in RD and ID cities were seen in children belonging to the low socioeconomic stratum (RD: OR: 1.758, 95% CI 1.427-2.165; ID: OR: 2.288, 95% CI 1.599-3.275) and living in an overcrowded household (RD: OR: 1.846, 95% CI 1.467-2.323; ID: OR: 2.379, 95% CI 1.769-3.199). Conclusions. Children and adolescents showed substantial impact from the COVID-19 pandemic. Disadvantageous living conditions were found to be significantly related to having a positive SARS-CoV-2 antibody test. These results highlight the need to prioritize vulnerable populations in the context of health emergencies.

Low Neutralizing Antibody Titers against the Mu Variant of SARS-CoV-2 in 31 BNT162b2 Vaccinated Individuals in Colombia.

Global surveillance programs for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are showing the emergence of variants with mutations in the spike protein. Genomic and laboratory surveillance are important to determine if these variants may be more infectious or less susceptible to antiviral treatments and vaccine-induced antibodies. Three of the most predominant SARS-CoV-2 variants in Colombia during the epidemiological peaks of 2021 were isolated: Mu, a variant of interest; Gamma, a variant of concern; B.1.111, which lacks genetic markers associated with greater virulence. Microneutralization assays were performed by incubating 120 mean tissue culture infectious doses (TCID50) of each SARS-CoV-2 isolate with five two-fold serial dilutions of sera from 31 BNT162b2-vaccinated volunteers. The mean neutralization titer (MN50) was calculated by the Reed-Muench method. At the end of August, Mu represented 49% of coronavirus disease 2019 (COVID-19) cases in Colombia, followed by 25% of Gamma. In contrast, B.1.111 became almost undetectable. The evaluation of neutralizing antibodies suggests that patients vaccinated with BNT162b2 generate neutralizing antibody titers against the Mu variant at significantly lower concentrations relative to B.1.111 and Gamma. This study shows the importance of continuing surveillance programs of emerging variants, as well as the need to evaluate the neutralizing antibody response induced by other vaccines.

Seroprevalence of the SARS-CoV-2 antibody in healthcare workers: a multicentre cross-sectional study in 10 Colombian cities.

BACKGROUND: Healthcare workers are at increased risk of infection due to occupational exposure to SARS-CoV-2-infected patients. The objective of this study was to determine the seroprevalence of SARS-CoV-2 in healthcare workers in Colombia. METHODS: This study is a cross-sectional study focused on estimating the seroprevalence of SARS-CoV-2 antibodies in healthcare workers from 65 hospitals in 10 cities in Colombia during the second semester of 2020. The seroprevalence was determined using an automated immunoassay (Abbott SARS-CoV-2 CLIA IgG). The study included a survey to establish the sociodemographic variables and the risk of infection. A multivariate model was used to evaluate the association between the results of seroprevalence and risk factors. RESULTS: The global seroprevalence of antibodies against SARS-CoV-2 was 35% (95% Bayesian CI 33% to 37%). All the personnel reported the use of protective equipment. General services personnel and nurses presented the highest ratios of seroprevalence among the healthcare workers. Low socioeconomic strata have shown a strong association with seropositivity. CONCLUSION: This study estimates the prevalence of SARS-CoV-2 infection among healthcare workers. Even though all the personnel reported the use of protective equipment, the seroprevalence in the general services personnel and nurses was high. Also, a significant difference by cities was observed.

Characteristics of the high ioduria concentrations in schoolchildren and adolescents in Colombia. / Características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia.

OBJETIVES: To determine the characteristics of high ioduria concentrations in schoolchildren and adolescents in Colombia. MATERIALS AND METHODS: Secondary analysis of the 2015 National Survey of the Nutritional Situation in Colombia in participants aged 5 to 17 years, which included the measurement of ioduria. The criteria to measure the nutritional status of iodine were based on the median urinary iodine concentration in µg / L defined by the World Health Organization (WHO), where values ​​<100 are considered deficient, between 100-199 adequate, 200-299 above the requirements and> 300 excessive. Odds ratio measurements were also performed through logistic regression analysis. RESULTS: The national median iodine for schoolchildren and adolescents was 406.8 µg / L and 410.8 µg / L respectively, higher in the urban area (410.5 µg / L), in the Atlantic region the highest level was found for schoolchildren (423.7 µg / L) and in the central for adolescents (427.7 µg / L). 4.4% of schoolchildren and 2.2% of adolescents presented deficiency and in more than 75% of the population, there was excessive intake of iodine. The factors associated with excessive iodine intake in schoolchildren were age, ethnicity, region and wealth index, and for adolescents gender and geographic area. CONCLUSIONS: The iodine concentrations in Colombian schoolchildren and adolescents are higher than adequate according to WHO, the deficiency is very low and a serious public health problem occurs due to excessive iodine intake in three-quarters of the population.

OBJETIVOS: Determinar las características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia. MATERIALES Y MÉTODOS: Análisis secundario de la Encuesta Nacional de la Situación Nutricional en Colombia del 2015 en participantes de 5 a 17 años que incluyó la medición de yoduria. Los criterios para medir el estado nutricional del yodo se basaron en la mediana de la concentración de yodo urinario en µg/L definido por la Organización Mundial de la Salud (OMS), donde valores <100 son considerados como deficientes, entre 100-199 adecuada, 200-299 arriba de los requerimientos y >300 excesiva. Se realizaron además mediciones de razón de probabilidades a través de un análisis de regresión logística. RESULTADOS: La mediana de yoduria nacional para escolares y adolescentes fue 406,8 µg/L y 410,8 µg/L respectivamente, mayor en el área urbana (410,5 µg/L); en la región Atlántica se encontró el mayor nivel para escolares (423,7 µg/L) y en la central para adolescentes (427,7 µg/L). El 4,4% de escolares y el 2,2% de adolescentes presentaron deficiencia y en más del 75% de la población, hubo ingesta excesiva de yodo. Los factores asociados a la ingesta excesiva de yodo en escolares fueron edad, etnia, región e índice de riqueza; y para adolescentes el sexo y área geográfica. CONCLUSIONES: Las concentraciones de yoduria en escolares y adolescentes colombianos es superior al adecuado según OMS, la deficiencia es muy baja y se presenta un grave problema de salud pública por ingesta excesiva de yodo en tres cuartas partes de la población.

Características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia / Characteristics of the high ioduria concentrations in schoolchildren and adolescents in Colombia

RESUMEN Objetivos: Determinar las características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia. Materiales y métodos: Análisis secundario de la Encuesta Nacional de la Situación Nutricional en Colombia del 2015 en participantes de 5 a 17 años que incluyó la medición de yoduria. Los criterios para medir el estado nutricional del yodo se basaron en la mediana de la concentración de yodo urinario en µg/L definido por la Organización Mundial de la Salud (OMS), donde valores <100 son considerados como deficientes, entre 100-199 adecuada, 200-299 arriba de los requerimientos y >300 excesiva. Se realizaron además mediciones de razón de probabilidades a través de un análisis de regresión logística. Resultados: La mediana de yoduria nacional para escolares y adolescentes fue 406,8 µg/L y 410,8 μg/L respectivamente, mayor en el área urbana (410,5 µg/L); en la región Atlántica se encontró el mayor nivel para escolares (423,7 µg/L) y en la central para adolescentes (427,7 µg/L). El 4,4% de escolares y el 2,2% de adolescentes presentaron deficiencia y en más del 75% de la población, hubo ingesta excesiva de yodo. Los factores asociados a la ingesta excesiva de yodo en escolares fueron edad, etnia, región e índice de riqueza; y para adolescentes el sexo y área geográfica. Conclusiones: Las concentraciones de yoduria en escolares y adolescentes colombianos es superior al adecuado según OMS, la deficiencia es muy baja y se presenta un grave problema de salud pública por ingesta excesiva de yodo en tres cuartas partes de la población.

ABSTRACT Objetives: To determine the characteristics of high ioduria concentrations in schoolchildren and adolescents in Colombia. Materials and methods: Secondary analysis of the 2015 National Survey of the Nutritional Situation in Colombia in participants aged 5 to 17 years, which included the measurement of ioduria. The criteria to measure the nutritional status of iodine were based on the median urinary iodine concentration in µg / L defined by the World Health Organization (WHO), where values ​​<100 are considered deficient, between 100-199 adequate, 200-299 above the requirements and> 300 excessive. Odds ratio measurements were also performed through logistic regression analysis. Results: The national median iodine for schoolchildren and adolescents was 406.8 µg / L and 410.8 µg / L respectively, higher in the urban area (410.5 µg / L), in the Atlantic region the highest level was found for schoolchildren (423.7 µg / L) and in the central for adolescents (427.7 µg / L). 4.4% of schoolchildren and 2.2% of adolescents presented deficiency and in more than 75% of the population, there was excessive intake of iodine. The factors associated with excessive iodine intake in schoolchildren were age, ethnicity, region and wealth index, and for adolescents gender and geographic area. Conclusions: The iodine concentrations in Colombian schoolchildren and adolescents are higher than adequate according to WHO, the deficiency is very low and a serious public health problem occurs due to excessive iodine intake in three-quarters of the population.

Características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia / Characteristics of the high ioduria concentrations in schoolchildren and adolescents in Colombia

RESUMEN Objetivos: Determinar las características de las concentraciones elevadas de yoduria en escolares y adolescentes de Colombia. Materiales y métodos: Análisis secundario de la Encuesta Nacional de la Situación Nutricional en Colombia del 2015 en participantes de 5 a 17 años que incluyó la medición de yoduria. Los criterios para medir el estado nutricional del yodo se basaron en la mediana de la concentración de yodo urinario en µg/L definido por la Organización Mundial de la Salud (OMS), donde valores <100 son considerados como deficientes, entre 100-199 adecuada, 200-299 arriba de los requerimientos y >300 excesiva. Se realizaron además mediciones de razón de probabilidades a través de un análisis de regresión logística. Resultados: La mediana de yoduria nacional para escolares y adolescentes fue 406,8 µg/L y 410,8 μg/L respectivamente, mayor en el área urbana (410,5 µg/L); en la región Atlántica se encontró el mayor nivel para escolares (423,7 µg/L) y en la central para adolescentes (427,7 µg/L). El 4,4% de escolares y el 2,2% de adolescentes presentaron deficiencia y en más del 75% de la población, hubo ingesta excesiva de yodo. Los factores asociados a la ingesta excesiva de yodo en escolares fueron edad, etnia, región e índice de riqueza; y para adolescentes el sexo y área geográfica. Conclusiones: Las concentraciones de yoduria en escolares y adolescentes colombianos es superior al adecuado según OMS, la deficiencia es muy baja y se presenta un grave problema de salud pública por ingesta excesiva de yodo en tres cuartas partes de la población.

ABSTRACT Objetives: To determine the characteristics of high ioduria concentrations in schoolchildren and adolescents in Colombia. Materials and methods: Secondary analysis of the 2015 National Survey of the Nutritional Situation in Colombia in participants aged 5 to 17 years, which included the measurement of ioduria. The criteria to measure the nutritional status of iodine were based on the median urinary iodine concentration in µg / L defined by the World Health Organization (WHO), where values ​​<100 are considered deficient, between 100-199 adequate, 200-299 above the requirements and> 300 excessive. Odds ratio measurements were also performed through logistic regression analysis. Results: The national median iodine for schoolchildren and adolescents was 406.8 µg / L and 410.8 µg / L respectively, higher in the urban area (410.5 µg / L), in the Atlantic region the highest level was found for schoolchildren (423.7 µg / L) and in the central for adolescents (427.7 µg / L). 4.4% of schoolchildren and 2.2% of adolescents presented deficiency and in more than 75% of the population, there was excessive intake of iodine. The factors associated with excessive iodine intake in schoolchildren were age, ethnicity, region and wealth index, and for adolescents gender and geographic area. Conclusions: The iodine concentrations in Colombian schoolchildren and adolescents are higher than adequate according to WHO, the deficiency is very low and a serious public health problem occurs due to excessive iodine intake in three-quarters of the population.

Evaluation of nine serological rapid tests for the detection of SARS-CoV-2

[ABSTRACT]. Objective. To evaluate the operative capacity of nine serological rapid tests to detect the IgM/IgG antibodies response in serum from patients with SARS-CoV-2 in different clinical stages. Methods. A cross-sectional study of serological rapid tests was designed to compare the performance of the evaluated immunochromatographic tests for the diagnosis of SARS-CoV-2. A total of 293 samples was used, including negatives, asymptomatic, and symptomatic serum samples. Results. The sensitivity of the evaluated tests was low and moderate in the groups of asymptomatic serum samples and the group of serums coming from patients with less than 11 days since the onset of the symptoms. The specificity for the anti-SARS-CoV-2 antibodies tests ranged between 86.5%-99% for IgM and 86.5%-99.5% for IgG. The sensitivity and the likelihood ratio were different according to the study groups. The usefulness of these tests is restricted to symptomatic patients and their sensitivity is greater than 85% after 11 days from the appearance of symptoms. Conclusions. Serological tests are not an adequate strategy for the identification of asymptomatic and pre-symptomatic patients. Serological rapid tests for the detection of specific anti-SARS-CoV-2 antibodies can be used as a diagnostic aid, but diagnosis must be confirmed by RT-PCR. Rapid tests should be reserved for patients with symptoms lasting more than 11 days.

[RESUMEN]. Objetivo. Evaluar la capacidad operativa de nueve pruebas serológicas rápidas para detectar la respuesta de anticuerpos IgM/IgG en el suero de pacientes con SARS-CoV-2 en diferentes etapas clínicas. Métodos. Se diseñó un estudio transversal de las pruebas serológicas rápidas para comparar su rendimiento respecto del diagnóstico del SARS-CoV-2. Se utilizaron en total 293 muestras, inclusive muestras de suero de pacientes negativos, asintomáticos y sintomáticos. Resultados. La sensibilidad de las pruebas evaluadas fue baja y moderada en las muestras de suero del grupo de pacientes asintomáticos y en el grupo de pacientes con menos de 11 días desde el inicio de los síntomas. La especificidad de las pruebas de anticuerpos anti-SARS-CoV-2 varió entre 86,5%-99% para la IgM y 86,5%-99,5% para la IgG. La sensibilidad y la razón de verosimilitud (likelihood ratio) fueron diferentes según los grupos de estudio. La utilidad de estas pruebas se limita a los pacientes sintomáticos y su sensibilidad es superior al 85% después de 11 días de la aparición de los síntomas. Conclusiones. Las pruebas serológicas no son una estrategia adecuada para la identificación de los pacientes asintomáticos y presintomáticos. Las pruebas serológicas rápidas para la detección de anticuerpos específicos anti-SARS-CoV-2 pueden ser utilizadas como ayuda diagnóstica, pero el diagnóstico debe ser confirmado por RT-PCR. Las pruebas rápidas deben reservarse para los pacientes con síntomas que duren más de 11 días.

Care practices associated with breastfeeding among pregnant and lactating women / Prácticas de cuidado en mujeres gestantes y lactantes asociadas a la lactancia materna

Descriptive cross-sectional study with 417 pregnant women and 388 lactating women, belonging to a Comprehensive Care Program in Bogotá. A modular survey was applied with sociodemographic and health variables analyzed by frequency distributions, central tendency, and dispersion, with bivariate and multivariate analyses used to calculate odds ratios (OR) with 95% confidence intervals. 17% were under 18 years of age. Only 66.8% of all of the women had immediate skin-to-skin contact with their child. The risk factors for skin-to-skin contact and early initiation of breastfeeding were type of delivery (cesarean) (OR: 23.15, 95% Cl: 12.99,41.25) and (OR: 2.6, 95% Cl: 1.43, 4.73) respectively; In addition, newborn hospitalization for more than 3 days was also a risk factor for the early initiation of breastfeeding (OR: 2.85, 95% Cl: 1.42, 5.72). Not having skin-to-skin contact between the mother and her newborn was a risk factor for the early initiation of breastfeeding (OR: 2.43; Cl: 1.34; 4.41).

Estudio descriptivo transversal con 417 gestantes y 388 mujeres lactantes, perteneciente a Programa de Atención Integral en Bogotá. Encuesta modular aplicada con variables sociodemográficas y salud analizadas por distribuciones de frecuencia, tendencia central, dispersión, análisis bivariados y multivariados para calcular odds-ratios (OR) con intervalos de confianza (95%). 17% menores de 18 años. Solamente el 66.8% de todas las participantes tuvieron contacto piel a piel con sus hijos. Los factores de riesgo para el contacto piel a piel y el inicio temprano de la lactancia materna fueron el tipo de parto (cesárea) (OR: 23.15, IC95%: 12.99, 41.25) y (OR: 2.6, IC95%: 1.43, 4.73) r espectivamente; además, para el inicio temprano de la lactancia materna también fue factor de riesgo la hospitalización del recién nacido por más de 3 días (OR: 2.85, IC95%: 1.42, 5.72). No tener contacto piel a piel entre la madre y su recién nacido fue un factor de riesgo para el inicio temprano de la lactancia materna (OR: 2.43, 1C: 1.34, 4.41).

Isolation of Bacillus cereus in school restaurants in Colombia

Introduction: Bacillus cereus is recognized as a pathogen that causes food poisoning. It is a facultative aerobic metabolism bacterium capable of forming spores, which allows it to survive pasteurization and heating even by the gamma irradiation used to reduce pathogens in food. Objective: To study the presence of Bacillus cereus and its diarrheal toxin in rice and ready-to-eat cereals, flours, and starches in school restaurants in Colombia. Materials and methods: We conducted a descriptive cross-sectional study of ready-to-eat foods distributed in school restaurants in the departments with the most and the least notification of foodborne diseases to the surveillance system. Results: A total of 479 samples were collected from eight departments, 74 municipalities, and 363 school restaurants, 63% of which were rice samples and 37%, starchy food samples; 9% of them tested positive for Bacillus cereus. In 91% of the samples that tested positive, the bacterium was isolated with the presence of the diarrheal toxin. Conclusions: In all the departments with B. cereus in the samples, the factors directly related to food-borne diseases were the handling of raw materials and the poor thermal treatment of food. Strengthening surveillance by stimulating research and reporting on outbreaks of foodborne diseases is important to improve the quality of information, to develop communication, prevention and intersectional coordination and manipulation measures, as well as to take the necessary actions to guarantee the safety of food and to eliminate the risk factors that may contribute to this problem.