Wastewater-based epidemiology for COVID-19 using dynamic artificial neural networks.

Global efforts in vaccination have led to a decrease in COVID-19 mortality but a high circulation of SARS-CoV-2 is still observed in several countries, resulting in some cases of severe lockdowns. In this sense, wastewater-based epidemiology remains a powerful tool for supporting regional health administrations in assessing risk levels and acting accordingly. In this work, a dynamic artificial neural network (DANN) has been developed for predicting the number of COVID-19 hospitalized patients in hospitals in Valladolid (Spain). This model takes as inputs a wastewater epidemiology indicator for COVID-19 (concentration of RNA from SARS-CoV-2 N1 gene reported from Valladolid Wastewater Treatment Plant), vaccination coverage, and past data of hospitalizations. The model considered both the instantaneous values of these variables and their historical evolution. Two study periods were selected (from May 2021 until September 2022 and from September 2022 to July 2023). During the first period, accurate predictions of hospitalizations (with an overall range between 6 and 171) were favored by the correlation of this indicator with N1 concentrations in wastewater (r = 0.43, p < 0.05), showing accurate forecasting for 1 day ahead and 5 days ahead. The second period's retraining strategy maintained the overall accuracy of the model despite lower hospitalizations. Furthermore, risk levels were assigned to each 1 day ahead prediction during the first and second periods, showing agreement with the level measured and reported by regional health authorities in 95 % and 93 % of cases, respectively. These results evidenced the potential of this novel DANN model for predicting COVID-19 hospitalizations based on SARS-CoV-2 wastewater concentrations at a regional scale. The model architecture herein developed can support regional health authorities in COVID-19 risk management based on wastewater-based epidemiology.

Quantification and Whole Genome Characterization of SARS-CoV-2 RNA in Wastewater and Air Samples.

Wastewater-based epidemiology has emerged as a promising and efficacious surveillance system for SARS-CoV-2 and other infectious diseases in many nations. The process typically involves wastewater concentration, nucleic acid extraction, amplification of selected genomic segments, and detection and quantification of the amplified genomic segment. This methodology can similarly be leveraged to detect and quantify infectious agents, such as SARS-CoV-2, in air samples. Initially, SARS-CoV-2 was presumed to spread primarily through close personal contact with droplets generated by an infected individual while speaking, sneezing, coughing, singing, or breathing. However, a growing number of studies have reported the presence of SARS-CoV-2 RNA in the air of healthcare facilities, establishing airborne transmission as a viable route for the virus. This study presents a composite of established protocols to facilitate environmental detection, quantification, and sequencing of viruses from both wastewater and air samples.

Environmental Dissemination of SARS-CoV-2 in a University Hospital during the COVID-19 5th Wave Delta Variant Peak in Castile-León, Spain.

The dominant SARS-CoV-2 Delta variant (B.1.617.2) became the main circulating variant among countries by mid 2021. Attention was raised to the increased risk of airborne transmission, leading to nosocomial outbreaks even among vaccinated individuals. Considering the increased number of COVID-19 hospital admissions fueled by the spread of the variant, with Spain showing the highest COVID-19 rates in mainland Europe by July 2021, the aim of this study was to assess SARS-CoV-2 environmental contamination in different areas of a University Hospital in the region of Castile-León, Spain, during the peak of the 5th wave of COVID-19 in the country (July 2021). Air samples were collected from sixteen different areas of the Hospital using a Coriolis® µ air sampler. Surface samples were collected in these same areas using sterile flocked plastic swabs. RNA extraction followed by a one-step RT-qPCR were performed for detection of SARS-CoV-2 RNA. Of the 21 air samples, only one was positive for SARS-CoV-2 RNA, from the emergency waiting room. Of the 40 surface samples, 2 were positive for SARS-CoV-2 RNA, both from the microbiology laboratory. These results may be relevant for risk assessment of nosocomial infection within healthcare facilities, thus helping prevent and minimize healthcare staff's exposure to SARS-CoV-2, reinforcing the importance of always wearing appropriate and well-fit masks at all times and proper PPE when in contact with infected patients.

MAGE-I proteins and cancer-pathways: A bidirectional relationship.

Data emerged from the last 20 years of basic research on tumor antigens positioned the type I MAGE (Melanoma Antigen GEnes - I or MAGE-I) family as cancer driver factors. MAGE-I gene expression is mainly restricted to normal reproductive tissues. However, abnormal re-expression in cancer unbalances the cell status towards enhanced oncogenic activity or reduced tumor suppression. Anomalous MAGE-I gene re-expression in cancer is attributed to altered epigenetic-mediated chromatin silencing. Still, emerging data indicate that MAGE-I can be regulated at protein level. Results from different laboratories suggest that after its anomalous re-expression, specific MAGE-I proteins can be regulated by well-known signaling pathways or key cellular processes that finally potentiate the cancer cell phenotype. Thus, MAGE-I proteins both regulate and are regulated by cancer-related pathways. Here, we present an updated review highlighting the recent findings on the regulation of MAGE-I by oncogenic pathways and the potential consequences in the tumor cell behavior.

Dinámicas comunitarias y gubernamentales sobre la malaria en Guaviare-Colombia / Community and governmental dynamics related to malaria in Guaviare-Colombia

OBJETIVO: El objetivo del estudio fue describir las dinámicas comunitarias y gubernamentales en torno a la malaria, su control y prevención en el Municipio de San José del Guaviare, en el departamento de Guaviare (Colombia). MÉTODOS: Se realizó un estudio de métodos mixtos utilizando una encuesta que constaba de 45 preguntas sobre conocimientos, actitudes y prácticas y entrevistas semiestructuradas con personal médico y trabajadores del gobierno. RESULTADOS: Aceptaron realizar la encuesta 103 personas, el 72% fueron mujeres, edad promedio de 40,8 años, tiene acueducto el 60% y alcantarillado 53,4%. El 59% reportó haber tenido malaria, 76% reconoció un mosquito como el vector de la enfermedad, 6% reconoce al Anopheles como el vector. El 16,5% de los encuestados asegura que la malaria no es un problema de salud para ellos y sus familias. El uso de toldillos (74%) es considerado una eficaz protección. CONCLUSIONES: Se evidencia un buen conocimiento de la malaria después de los acuerdos de paz, sin embargo, los determinantes relacionados con suministro de agua, alcantarillado, difícil atención en zona rural y las escasas acciones interdisciplinarias son posibles elementos de riesgo para esta población.

The objective of the study was to describe the community and government dynamics around malaria, especially its control and prevention, in the Municipality of San José del Guaviare, in the sector of Guaviare (Colombia). METHODS: We conducted a mixed methods study using a survey consisting of 45 questions on knowledge, attitudes, and practices, and semi-structured interviews with medical personnel and government workers. RESULTS: 103 people responded to the survey. 72% were women, and the average age was 40.8 years. 60% had an aqueduct and 53.4% had sewers. 59% reported having had malaria, 76% recognized a mosquito as the vector of the disease, and 6% recognized Anopheles as the vector. 16.5% of those surveyed said that malaria was not a health problem for them and their families. 74% considered the use of mosquito nets an effective protection. CONCLUSIONS: While there is a good knowledge of malaria, difficulties related to water supply, sewage, care in rural areas and lack of interdisciplinary solutions pose possible risk factors for this population.

Knowledges, attitudes and practice regarding malaria in a vulnerable municipality in Colombia / Predicción fisicomatemática de la dinámica semestral de la malaria en Antioquia, Colombia

Introduction: In Colombia, malaria affects people in vulnerable conditions. In urban areas, disease control measures have decreased the incidence of malaria in the past 5 years. However, there is some government abandonment in areas with armed conflict. Objective: To determine the knowledges, attitudes and practice regarding malaria in Piñalito, a town located in the municipality of Vista Hermosa in the Meta department (Colombia), in the period 2016-2017. Methods: We conducted a mixed-methods study using a survey consisting of 45 questions on knowledge, attitudes, and practices and semistructured interviews with medical personnel and government workers. Results: Of the respondents, 89.13% said that malaria is a health problem, 63.04% said the disease is transmitted by a mosquito bite, main symptoms were reported to be high fever (78.26%) and headache (60.87%). A total of 73.91% of respondents affirmed using mosquito nets to avoid the disease. The community affirmed that they do not receive good medical attention (65.22%) and did not identify the active participation of the local health secretary to prevent malaria. Conclusions: The inhabitants of Piñalito demonstrated adequate knowledge about the disease and positive attitudes toward preventing malaria. However, they had negative perceptions about the actions of the secretary of health and the government for control and prevention of the disease.

Introducción: En Colombia, la malaria afecta a personas en condiciones de vulnerabilidad. En áreas urbanas, las medidas de control de enfermedades han disminuido la incidencia de malaria en los últimos 5 años. Sin embargo, existe cierto abandono del gobierno en áreas con conflicto armado. Objetivo: Determinar los conocimientos, actitudes y prácticas sobre la malaria en la población del municipio de Piñalito (Meta, Colombia), en el periodo 2016-2017. Métodos: Realizamos un estudio de métodos mixtos utilizando una encuesta de 45 preguntas sobre conocimientos, actitudes y prácticas de la población y entrevistas semiestructuradas con personal médico y trabajadores del gobierno. Resultados: De los encuestados, el 89,13 % dijo que la malaria es un problema de salud, el 63,04 % considera que la enfermedad se transmite por la picadura de un mosquito. Los síntomas principales fueron fiebre alta (78,26 %) y dolor de cabeza (60,87 %). El 73,91 % de los encuestados afirmó utilizar mosquiteros para evitar la enfermedad. La comunidad manifestó que no recibe buena atención médica (65,22 %) y no identificó la participación activa de la secretaría de salud local para prevenir la malaria. Conclusiones: Los habitantes de Piñalito demostraron un adecuado conocimiento sobre la enfermedad y actitudes positivas hacia la prevención de la malaria. Sin embargo, tenían percepciones negativas sobre las acciones de la secretaría de salud y del gobierno para el control y prevención de la enfermedad.

Salmonella Typhi Vaccination Response as a Tool for the Stratification of Risk in Patients with Predominantly Antibody Deficiencies.

Predominantly antibody deficiencies are the most frequent type of primary immunodeficiency (PID). Diagnosis requires evaluation of the immune function by distinguishing the presence or absence of a response against polysaccharide antigens. Salmonella enterica serovar Typhi-based vaccines have proved to be a suitable tool. We studied a group of patients with suspicion of primary immunodeficiency and classified them by final diagnosis. We analyzed the vaccination response to S. Typhi and other immune biomarkers and clinical data. The aim of this study was to classify patients regarding the intensity of their immune response measured as the difference between specific immunoglobulin G levels before and after vaccination and antibody levels in the post-vaccination sample in order to improve clinical decisions regarding follow up and treatment of immunodeficiency patients. We established four groups of response: Non responders (NR), Low responders (LR), Intermediate responders (IR), and High responders (HR), where we found differences in IgG, IgG1, IgG2, IgG4, IgA, IgA1, IgA2, and IgM, and where the finally achieved diagnosis was also different and corresponding to the level of vaccination response.

Sociodemographic and clinical characteristics related to the final condition of patients intoxicated by paraquat in a hospital in southwestern Colombia / Características sociodemográficas y clínicas relacionadas con la condición final de pacientes intoxicados por paraquat en un hospital del suroccidente de Colombia.

Introduction: Paraquat is an agrochemical that constitutes the first cause of death by poisoning in different countries. Objective: To relate sociodemographic and clinical characteristics with the final condition of patients intoxicated by paraquat in a hospital in southwestern Colombia. Materials and methods: This was an observational, descriptive, analytical, crosssectional, and retrospective study. We reviewed the medical records of patients diagnosed with paraquat poisoning at a level III hospital in Pasto, Colombia, from 2013 to 2018. We collected the data regarding their final condition (alive or deceased) and their sociodemographic, clinical, and paraclinical information. We established group comparisons and designed a binary logistic regression model. Results: We reviewed 299 records and, after the exclusion, we analyzed 160 cases. The characteristics related to the final condition of the patients were length of stay (OR = 0.124; 95% CI: 0.03-0.6; p = 0.009), heart rate (OR = 35.65; 95% CI: 1.44-884.78; p = 0.029), and initial creatinine (OR = 1.73; 95% CI: 1.23-2.44; p = 0.002). Conclusion: The proportion of case fatality was higher in patients with short hospital stay times and elevated heart rates and admission creatinine levels. This report may be useful as a rationale for the creation of a severity scale for the early detection of patients with adverse outcomes and their timely treatment.

Introducción. El herbicida paraquat constituye la primera causa de decesos por intoxicaciones en distintos países. Objetivo. Relacionar las características sociodemográficas y clínicas con la condición final de pacientes intoxicados por paraquat atendidos en un hospital del suroccidente de Colombia. Materiales y métodos. En este estudio observacional, descriptivo, analítico, transversal y retrospectivo, se revisaron las historias clínicas de pacientes atendidos por intoxicación con paraquat en una institución de tercer nivel de complejidad en Pasto (Colombia) entre el 2013 y el 2018. Se recolectó la información sobre la condición final (vivo o fallecido) de cada paciente, así como los datos sociodemográficos, clínicos y de los exámenes paraclínicos. Se establecieron comparaciones por grupos y se diseñó un modelo de regresión logística binaria. Resultados. Se filtró la información de 299 registros y se analizaron finalmente 160 casos. Las características relacionadas con la condición final de los pacientes fueron el tiempo de estancia (OR=0,124; IC95% 0,03-0,6; p=0,009), la frecuencia cardiaca (OR=35,65; IC95% 1,44-884,78; p=0,029) y la creatinina inicial (OR=1,73; IC95% 1,23-2,44; p=0,002). Conclusiones. La proporción de la letalidad fue mayor entre los pacientes con estancia hospitalaria corta, taquicardia y elevación de la concentración sérica de creatinina al ingreso. Este reporte puede ser útil como fundamento de una escala de gravedad para detectar a los pacientes con resultados adversos en la fase temprana para que puedan recibir una intervención oportuna.

Características sociodemográficas y clínicas relacionadas con la condición final de pacientes intoxicados por paraquat en un hospital del suroccidente de Colombia / Sociodemographic and clinical characteristics related to the final condition of patients intoxicated by paraquat in a hospital in southwestern Colombia

Introducción. El herbicida paraquat constituye la primera causa de decesos por intoxicaciones en distintos países. Objetivo. Relacionar las características sociodemográficas y clínicas con la condición final de pacientes intoxicados por paraquat atendidos en un hospital del suroccidente de Colombia. Materiales y métodos. En este estudio observacional, descriptivo, analítico, transversal y retrospectivo, se revisaron las historias clínicas de pacientes atendidos por intoxicación con paraquat en una institución de tercer nivel de complejidad en Pasto (Colombia) entre el 2013 y el 2018. Se recolectó la información sobre la condición final (vivo o fallecido) de cada paciente, así como los datos sociodemográficos, clínicos y de los exámenes paraclínicos. Se establecieron comparaciones por grupos y se diseñó un modelo de regresión logística binaria. Resultados. Se filtró la información de 299 registros y se analizaron finalmente 160 casos. Las características relacionadas con la condición final de los pacientes fueron el tiempo de estancia (OR=0,124; IC95% 0,03-0,6; p=0,009), la frecuencia cardiaca (OR=35,65; IC95% 1,44-884,78; p=0,029) y la creatinina inicial (OR=1,73; IC95% 1,23-2,44; p=0,002). Conclusiones. La proporción de la letalidad fue mayor entre los pacientes con estancia hospitalaria corta, taquicardia y elevación de la concentración sérica de creatinina al ingreso. Este reporte puede ser útil como fundamento de una escala de gravedad para detectar a los pacientes con resultados adversos en la fase temprana para que puedan recibir una intervención oportuna.

Introduction: Paraquat is an agrochemical that constitutes the first cause of death by poisoning in different countries. Objective: To relate sociodemographic and clinical characteristics with the final condition of patients intoxicated by paraquat in a hospital in southwestern Colombia. Materials and methods: This was an observational, descriptive, analytical, crosssectional, and retrospective study. We reviewed the medical records of patients diagnosed with paraquat poisoning at a level III hospital in Pasto, Colombia, from 2013 to 2018. We collected the data regarding their final condition (alive or deceased) and their sociodemographic, clinical, and paraclinical information. We established group comparisons and designed a binary logistic regression model. Results: We reviewed 299 records and, after the exclusion, we analyzed 160 cases. The characteristics related to the final condition of the patients were length of stay (OR = 0.124; 95% CI: 0.03-0.6; p = 0.009), heart rate (OR = 35.65; 95% CI: 1.44-884.78; p = 0.029), and initial creatinine (OR = 1.73; 95% CI: 1.23-2.44; p = 0.002). Conclusion: The proportion of case fatality was higher in patients with short hospital stay times and elevated heart rates and admission creatinine levels. This report may be useful as a rationale for the creation of a severity scale for the early detection of patients with adverse outcomes and their timely treatment.

Centralized and decentralized wastewater-based epidemiology to infer COVID-19 transmission - A brief review.

Wastewater-based epidemiology has shown to be a promising and innovative approach to measure a wide variety of illicit drugs that are consumed in the communities. In the same way as for illicit drugs, wastewater-based epidemiology is a promising approach to understand the prevalence of viruses in a community-level. The ongoing coronavirus disease 2019 (COVID-19) pandemic created an unprecedented burden on public health and diagnostic laboratories all over the world because of the need for massive laboratory testing. Many studies have shown the applicability of a centralized wastewater-based epidemiology (WBE) approach, where samples are collected at WWTPs. A more recent concept is a decentralized approach for WBE where samples are collected at different points of the sewer system and at polluted water bodies. The second being particularly important in countries where there are insufficient connections from houses to municipal sewage pipelines and thus untreated wastewater is discharged directly in environmental waters. A decentralized approach can be used to focus the value of diagnostic tests in what we call targeted-WBE, by monitoring wastewater in parts of the population where an outbreak is likely to happen, such as student dorms, retirement homes and hospitals. A combination of centralized and decentralized WBE should be considered for an affordable, sustainable, and successful WBE implementation in high-, middle- and low-income countries.

Long Term Cell Immune Response to COVID-19 Vaccines Assessment Using a Delayed-Type Hypersensitivity (DTH) Cutaneous Test.

OBJECTIVE: As we progress with mass vaccination against SARS-CoV-2, there are key questions about the immunogenicity of COVID-19 vaccines that still are not answered. Conventional methods to measure cellular immune responses are complex and expensive in a pandemic situation. PATIENTS AND METHODS: Forty healthy healthcare workers accepted to participate during the vaccination schedule with a mRNA vaccine against SARS-CoV-2. Measurement of Delayed-Type Hypersensitivity (DTH) cutaneous response after intradermal test of protein S of SARS-CoV-2 at day 35 and day 200 was performed. At the same time, a specific anti-RBD IgG using a classic ELISA before vaccination, and on days 0, 35, and 200 was performed. RESULTS: All 40 individuals had a positive DTH skin response at day 35, whereas 39 participants had a positive skin test at day 200. Moreover, although all 40 individuals showed a positive humoral response of specific IgG against spike protein at day 35, with most of them having significantly lower levels at day 200. CONCLUSION: DTH could be proposed as an ideal and easy method to predict cellular immunity response to mRNA vaccines 200 days after starting an immunization schedule with mRNA vaccine for COVID-19.

Easy approach to detect cell immunity to COVID vaccines in common variable immunodeficiency patients.

BACKGROUND: Patients with primary antibody deficiencies, such as Common Variable Immunodeficiency (CVID), have some problems to assess immune response after coronavirus disease (COVID) vaccination. Cutaneous delayed-type hypersensitivity (DTH) has the potential to be used as a useful, simple, and cheaper tool to assess T-cell (T lymphocyte) function. METHODS: Seventeen patients with CVID, a rare disease, received two doses of the mRNA-based Pfizer-BioNTech COVID-19 vaccine. Humoral Immune Response (HIR) was determined by measuring specific immunoglobulin G (IgG) antibodies, and Cellular Immune Response (CIR) was evaluated using an ex vivo interferon-gamma release assay (IGRA) and in vivo by DTH skin test. RESULTS: Two weeks after the second dose of the vaccine, 12 out of 17 CVID patients have high optical density (OD) ratios of specific anti-spike protein (S) IgG whereas five patients were negative or low. Ex vivo CIR was considered positive in 14 out of 17 S1-stimulated patients. Unspecific stimulation was positive in all 17 patients showing no T-cell defect. A positive DTH skin test was observed in 16 CVID patients. The only patient with negative DTH also had negative ex vivo CIR. CONCLUSIONS: The use of DTH to evaluate CIR was validated with an optimal correlation with the ex vivo CIR. The CIR after vaccination in patients with antibody deficiencies seems to have high precision and more sensitivity to antibodies-based methods in CVID. CLINICAL IMPLICATIONS: There is a remarkable correlation between cutaneous DTH and ex vivo IGRA after COVID vaccination. A COVID-specific skin DTH test could be implemented in large populations. CAPSULE SUMMARY: Cutaneous delayed-type hypersensitivity has the potential to be used as a useful, simple, and cheaper tool to assess T-cell functioning.

Effect of digestate loading rates on microalgae-based treatment under low LED light intensity.

Low red-LED irradiances are an attractive alternative for enhancing microalgae photobioreactors treating digestate due to their potential contribution in decreasing area footprints with low energy consumptions. However, more information is required regarding the influence of digestate load on treatment performance and biomass valorisation when low-intensity red-LEDs are applied. Thus, this study assessed microalgae-based photobioreactors treating food waste digestate under different concentrations (5%, 25%, 50%, and 75%, v/v) at low red-LED irradiance (15 µmol·m-2·s-1). The removal efficiencies of soluble chemical oxygen demand (sCOD) at the end of the experiment ranged from 45% to 75% when treating influent loads between 5.3 and 79.1 g sCOD·m-3·d-1 (5% and 75%-digestate), respectively. Total ammonia nitrogen (TAN) was applied in loading rates between 3.2 and 48.5 g TAN·m-3·d-1 (5% and 75%, respectively) and removed with maximum efficiencies of 90%-100% in all trials. Nitrification-denitrification was proportionally more relevant when treating 5%-digestate, whereas volatilisation was the primary process in 25%, 50% and 75% concentrations. Microalgae presented adequate yields in all treatments, except in 75%-digestate, likely due to the blocking of light by the high solids concentrations. The assessment of the microalgae community and chlorophyll-a and carotenoids suggested that chlorophytes, mainly Dictyosphaerium pulchellum and Scenedesmus sp. grew autotrophically, whereas cyanobacteria Pseudanabaena sp. grew mixotrophically. Moreover, the sustainability of red LED lighting applications can be increased by anaerobic digestion or agricultural valorisation of the biomass, enabled by its high N and P contents. Low-intensity red-LEDs may have promissory applications in the treatment of high-strength wastewaters.

Easy approach to detect cell immunity to COVID vaccines in common variable immunodeficiency patients

Background Patients with primary antibody deficiencies, such as Common Variable Immunodeficiency (CVID), have some problems to assess immune response after coronavirus disease (COVID) vaccination. Cutaneous delayed-type hypersensitivity (DTH) has the potential to be used as a useful, simple, and cheaper tool to assess T-cell (T lymphocyte) function.Methods Seventeen patients with CVID, a rare disease, received two doses of the mRNA-based Pfizer-BioNTech COVID-19 vaccine. Humoral Immune Response (HIR) was determined by measuring specific immunoglobulin G (IgG) antibodies, and Cellular Immune Response (CIR) was evaluated using an ex vivo interferon-gamma release assay (IGRA) and in vivo by DTH skin test.Results Two weeks after the second dose of the vaccine, 12 out of 17 CVID patients have high optical density (OD) ratios of specific anti-spike protein (S) IgG whereas five patients were negative or low. Ex vivo CIR was considered positive in 14 out of 17 S1-stimulated patients. Unspecific stimulation was positive in all 17 patients showing no T-cell defect. A positive DTH skin test was observed in 16 CVID patients. The only patient with negative DTH also had negative ex vivo CIR.Conclusions The use of DTH to evaluate CIR was validated with an optimal correlation with the ex vivo CIR. The CIR after vaccination in patients with antibody deficiencies seems to have high precision and more sensitivity to antibodies-based methods in CVID.Clinical Implications There is a remarkable correlation between cutaneous DTH and ex vivo IGRA after COVID vaccination. A COVID-specific skin DTH test could be implemented in large populations.Capsule Summary Cutaneous delayed-type hypersensitivity has the potential to be used as a useful, simple, and cheaper tool to assess T-cell functioning (AU)

Optimizing a Protocol to Assess Immune Responses after SARS-CoV-2 Vaccination in Kidney-Transplanted Patients: In Vivo DTH Cutaneous Test as the Initial Screening Method.

Previously, the delayed-type hypersensitivity (DTH) cutaneous test with the spike protein of SARS-CoV-2 has been shown to be a simple in vivo method to measure T-cell functionality after natural infection and in vaccinated individuals. METHODS: Twenty-five kidney-transplanted recipients were immunized with two doses of the mRNA-based Pfizer-BioNTech COVID19 vaccine three weeks apart. Cell-immune response (CIR) was evaluated ten weeks later using an in vivo DTH skin test and in vitro with an interferon gamma release assay (IGRA). Humoral Immune Response (HIR) was determined by the measurement of specific IgG anti-S1 SARS-CoV-2. RESULTS: Ten weeks after the second dose of the vaccine, 23 out of 25 transplanted patients had a positive DTH skin test, while in vitro CIR was considered positive in 20 patients. Unspecific stimulation was positive in all 25 patients, showing no T-cell defect. Seven out of twenty-five patients had a negative specific anti-spike IgG. CIR was positive in all immune-competent control patients. CONCLUSIONS: DTH is a useful, simple, and cheaper tool that can be used to assess cellular immune response, with an excellent correlation with the in vitro CIR. CIR assessment after vaccination in these immunocompromised patients is an excellent complement to HIR-based methods. This skin test could be used if classical in vitro methods cannot be applied.

The Beauty of Simplicity: Delayed-Type Hypersensitivity Reaction to Measure Cellular Immune Responses in RNA-SARS-Cov-2 Vaccinated Individuals.

BACKGROUND: Monitoring cellular immune responses elicited in vaccinated individuals is highly complicated. METHODS: 28 individuals participated during the vaccination process with 12 BNT162b2 mRNA (Pfizer) vaccine. Specific anti-RBD IgG using a classic ELISA was performed in days 10 and 20 (after one dose of the vaccine) and on day 35 (after two vaccine doses) in serum samples of all participants. In parallel, DTH (delayed-type hypersensitivity) Skin Test using S protein was performed before (11/28) and after two doses (28/28) of the vaccine. RESULTS: 6/28 individuals were considered positive for the specific anti-RBD IgG positive at day 10, whereas all 28 individuals were positive at day 20. Moreover, 28/28 individuals increased the OD ratios at day 36 (2 doses). DTH cutaneous test was performed on 11/28 participants at day 20 (1 dose) showing 8/11 a positive reaction at 12 h. DTH of all participants was performed on day 36 (2 doses), showing 28/28 positive reactions at 12 h. CONCLUSION: This report describes the first publication of the results obtained using an in vivo method, the classical DTH response to the Spike protein to assess T-cell immune responses in vaccinated individuals. This affordable and simple test would help to answer basic immunogenicity questions on large-scale population vaccine studies.

A novel application of delayed-type hipersensitivity reaction to measure cellular immune response in SARS-CoV-2 exposed individuals.

OBJECTIVE: To understand the anti-virus adaptive immune response occurring during SARS-Cov-2 infection is necessary to have methods to investigate cellular and humoral components. The goal of this study has been to investigate the utility of a specific spike-DTH test using a coronavirus recombinant protein in COVID-19 patients. METHODS: DTH studies were performed by intradermal injection of a commercial recombinant spike protein from SARS-CoV-2 along with conventional serology studies. RESULTS: Fifty-one COVID-19 patients were studied showing 84,3% of concordance with spike-DTH and anti-RBD-IgG. Spike-DTH was superior to identify seven more COVID-19 individuals. A high specificity was found with no positive spike DTH reactions in the non-sick individuals. The skin test also showed more stable results over time while specific anti-RBD-IgG decreased gradually. Clinical severity groups also showed a progressive gradient of larger positive spike-DTH. CONCLUSION: Specific spike DTH test seems to be an easy method to study cell immune response.

Caracterización sociodemográfica y clínica de pacientes diagnosticados con dengue y chikungunya en Nariño, Colombia / Clinical and socio-demographic characterization of patients diagnosed with dengue and chikungunya in Nariño, Colombia

RESUMEN Introducción: Existen más de 390 millones de personas infectadas y 20 000 muertes anualmente a causa del dengue en el mundo. El chikungunya ocasionó una larga epidemia en las Américas con más de 2 millones y medio de casos hasta el 2017. Objetivo: Identificar las características sociodemográficas y clínicas de los casos de dengue y chikungunya informados para el periodo 2014-2017 en Nariño, Colombia. Métodos: Se realizó un estudio observacional, descriptivo, de corte transversal. Se revisaron retrospectivamente las bases de datos del Instituto Departamental de Salud de Nariño y del Hospital Universitario Departamental de Nariño. Resultados: Para el periodo de estudio hubo 2 514 hospitalizaciones por dengue y 460 por chikungunya. Se identificaron 22 casos de dengue grave, con una muerte para el año 2017. La revisión de expedientes de 1 735 pacientes con información completa reveló que las manifestaciones clínicas más frecuentes para dengue fueron: fiebre (100 por ciento), cefalea (84,6 por ciento) y mialgias (83,7 por ciento), seguidos de artralgias, rash y dolor abdominal. El sexo masculino predominó en los casos de diagnóstico de dengue (56,8 por ciento) y el femenino en el diagnóstico de chikungunya (52,0 por ciento. Tanto dengue como chikungunya fueron más frecuentes en la población mayor de 40 años con el 24,5 por ciento y 27,2 por ciento, respectivamente. Conclusiones: La sintomatología similar y los casos complicados resaltan la necesidad de contar con diagnósticos oportunos y diferenciales y capacitación al personal de salud, apoyados por entidades gubernamentales. Se requiere generar programas de intervención enfocados a edades productivas y en regiones con condiciones medioambientales propicias para el desarrollo de vectores transmisores de enfermedades(AU)

Introduction: More than 390 million dengue cases and 20 000 deaths due to this condition are reported worldwide every year. Chikungunya caused a large epidemic in the Americas with more than two and a half million cases until the year 2017. Objective: Identify the clinical and socio-demographic characteristics of the dengue and chikungunya cases reported for the period 2014-2017 in Nariño, Colombia. Methods: A cross-sectional observational descriptive study was conducted. A retrospective review was carried out of the databases at Nariño Departmental Health Institute and Nariño Departmental University Hospital. Results: During the study period there were 2 514 hospital admissions with dengue and 460 with chikungunya. A total 22 severe dengue cases and one death were identified for the year 2017. Review of the medical records of 1 735 patients with complete information revealed that the most common clinical manifestations of dengue were fever (100 percent), headache (84.6 percent) and myalgia (83.7 percent), followed by arthralgia, rash and abdominal pain. A predominance was found of the male sex in dengue cases (56.8 percent) and of the female sex in chikungunya cases (52.0 percent). Both conditions were more frequent in the population aged over 40 years, with 24.5 percent and 27.2 percent, respectively. Conclusions: The similar symptoms and the presence of complicated cases highlight the need for timely differential diagnosis and the training of the health personnel, with the support of government agencies. It is required to develop intervention programs aimed at working ages and regions with environmental conditions favorable for the spread of disease(AU)