Increased threat of urban arboviral diseases from Aedes aegypti mosquitoes in Colombia.

Objectives: Our study targets the potential of the local urban mosquito Aedes aegypti to experimentally transmit chikungunya virus (CHIKV), dengue virus (DENV), yellow fever virus (YFV), and Zika virus (ZIKV). Methods: We collected eggs and adults of Ae. aegypti in Medellín, Colombia (from February to March 2020) for mosquito experimental infections with DENV, CHIKV, YFV and ZIKV and viral detection using the BioMark Dynamic arrays system. Results: We show that Ae. aegypti from Medellín was more prone to become infected, to disseminate and transmit CHIKV and ZIKV than DENV and YFV. Conclusions: Thus, in Colombia, chikungunya is the most serious threat to public health based on our vector competence data.

Virome analyses of Amblyomma cajennense and Rhipicephalus microplus ticks collected in Colombia.

Tick-borne viruses (TBV) have gained public health relevance in recent years due to the recognition of human-associated fatal cases and the increase in tick-borne disease and transmission. However, many tick species have not been studied for their potential to transmit pathogenic viruses, especially those found in Latin America. To gain better understanding of the tick virome, we conducted targeted amplification using broadly-reactive consensus-degenerate pan-viral targeting viruses from the genera Flavivirus, Bandavirus, Uukuvirus, and Orthonairovirus genus. Additionally, we conducted unbiased metagenomic analyses to investigate the presence of viral RNA sequences in Amblyomma cajennense, A. patinoi and Rhipicephalus microplus ticks collected from a horse slaughter plant in Medellín, Colombia. While no viral products were detected by PCR, results of the metagenomic analyses revealed the presence of viral genomes belonging to the genera Phlebovirus, Bandavirus, and Uukuvirus, including Lihan Tick Virus (LTV), which was previously reported in Rhipicephalus microplus from Colombia. Overall, the results emphasized the enormous utility of the next-generation sequencing in identifying virus genetic diversity presents in ticks and other species of vectors and reservoirs.

Etiological characterization of acute undifferentiated febrile illness in Apartadó and Villeta municipalities, Colombia, during COVID-19 pandemic.

Background: Acute undifferentiated febrile illness (AUFI) is one of the leading causes of illness in tropical regions. Although malaria is the most important cause, other pathogens such as Dengue (DENV), Leptospira and recently, Coronavirus Disease 2019 (COVID-19) have gained importance. In Colombia, few studies aimed to identify the etiology of AUFI. Most of them performed in Apartadó and Villeta municipalities, identifying the active circulation of several pathogens. Thus, we conducted a cross-sectional study in these municipalities to characterize the etiologies of AUFI during COVID-19 pandemic. Methods: An active surveillance was conducted between September and December 2021 in local hospitals of Apartadó and Villeta municipalities. Febrile patients were enrolled after voluntarily agreeing to participate in the study. Ten different etiologies were evaluated through direct, serological, molecular and rapid diagnostic methods. Results: In Apartadó a confirmed etiology was found in 60% of subjects, DENV (25%) being the most frequent, followed by leptospirosis (16.7%), malaria (10%), COVID-19 (8.3%), spotted fever group (SFG) rickettsiosis (6.7%) and Chikungunya (1.7%). In Villeta, a specific etiology was confirmed in 55.4% of patients, of which SFG rickettsiosis (39.3%) was the most frequent, followed by leptospirosis (21.4%), DENV (3.6%) and malaria (1.8%). No cases due to Mayaro, Yellow Fever, Oropouche and Venezuelan Equine Encephalitis viruses were detected. Conclusion: We confirm the relevance of dengue fever, leptospirosis, SFG rickettsiosis, COVID-19 and malaria as causes of AUFI in the municipality of Apartadó, and highlight the great importance of SFG rickettsiosis as the main cause of AUFI in the municipality of Villeta.

Molecular mechanisms by which the HIV-1 latent reservoir is established and therapeutic strategies for its elimination.

The human immunodeficiency virus type 1 (HIV-1) reservoir, composed of cells harboring the latent, integrated virus, is not eliminated by antiretroviral therapy. It therefore represents a significant barrier to curing the infection. The biology of HIV-1 reservoirs, the mechanisms of their persistence, and effective strategies for their eradication are not entirely understood. Here, we review the molecular mechanisms by which HIV-1 reservoirs develop, the cells and compartments where the latent virus resides, and advancements in curative therapeutic strategies. We first introduce statistics and relevant data on HIV-1 infection, aspects of pathogenesis, the role of antiretroviral therapy, and the general features of the latent HIV reservoir. Then, the article is built on three main pillars: The molecular mechanisms related to latency, the different strategies for targeting the reservoir to obtain a cure, and the current progress in immunotherapy to counteract said reservoirs.

Outbreak report of SARS-CoV-2 infection by airborne transmission: Epidemiologic and molecular evidence. / Reporte de un brote de infección por SARS-CoV-2 por transmisión aérea: evidencia epidemiológica y molecular

INTRODUCTION: It has been shown that the transmission of SARS-CoV-2 occurs mainly by air, and the risk of infection is greater in closed spaces. OBJECTIVE: To describe the epidemiology, virology and molecular characterization of a COVID-19 outbreak at a closed vaccination point during the third wave of SARS-CoV-2 in Colombia. MATERIALS AND METHODS: Diagnostic tests, interviews, sampling, cell cultures and viral sequencing were carried out, the latter being molecular characterization and lineage identification. RESULTS: Seven workers were positive for SARS-CoV-2; among these, 3 samples were analyzed, plus an additional sample belonging to the mother of the presumed index case; all samples were identified with lineage B.1.625, with a maximum of 2 nucleotides difference between them. CONCLUSIONS: Variant B.1.625 was identified as the cause of the COVID-19 outbreak, and a co-worker was also identified as the index case. Unexpectedly, attending a vaccination day became a risk factor for acquiring the infection.

Introducción. Se ha demostrado que la transmisión de SARS-CoV-2 se produce principalmente por vía aérea y el riesgo de infección es mayor en espacios cerrados con alta concentración de personas; este último factor se presentó en algunos de los puestos de vacunación de la ciudad de Medellín. Objetivo. Describir la epidemiología, virología y caracterización molecular de un brote de COVID-19 en un punto de vacunación cerrado durante la tercera ola de SARS-CoV-2 en Colombia. Materiales y métodos. Se realizaron test diagnósticos, entrevistas, toma de muestras, aislamiento viral y secuenciación genómica. Con esta última, se hizo la caracterización molecular y se identificó el linaje. Resultados. Siete trabajadores fueron positivos para SARS-CoV-2, y de estos, tres muestras fueron secuenciadas, más una muestra adicional perteneciente a la madre del presunto caso índice. Todas las muestras fueron identificadas con el linaje B.1.625, con un máximo de dos nucleótidos de diferencia entre ellas. Conclusiones. Se identificó la variante B.1.625 como la causante del brote de COVID-19, y también un compañero de trabajo fue identificado como el caso índice. De forma imprevista, asistir a una jornada de vacunación se convirtió en un factor de riesgo para adquirir la infección.

Outbreak report of SARS-CoV-2 infection by airborne transmission: Epidemiologic and molecular evidence / Reporte de un brote de infección por SARS-CoV-2 por transmisión aérea: evidencia epidemiológica y molecular

Introduction: It has been shown that the transmission of SARS-CoV-2 occurs mainly by air, and the risk of infection is greater in closed spaces. Objective: To describe the epidemiology, virology and molecular characterization of a COVID-19 outbreak at a closed vaccination point during the third wave of SARS-CoV-2 in Colombia. Materials and methods: Diagnostic tests, interviews, sampling, cell cultures and viral sequencing were carried out, the latter being molecular characterization and lineage identification. Results: Seven workers were positive for SARS-CoV-2; among these, 3 samples were analyzed, plus an additional sample belonging to the mother of the presumed index case; all samples were identified with lineage B.1.625, with a maximum of 2 nucleotides difference between them. Conclusions: Variant B.1.625 was identified as the cause of the COVID-19 outbreak, and a co-worker was also identified as the index case. Unexpectedly, attending a vaccination day became a risk factor for acquiring the infection.

Introducción. Se ha demostrado que la transmisión de SARS-CoV-2 se produce principalmente por vía aérea y el riesgo de infección es mayor en espacios cerrados con alta concentración de personas; este último factor se presentó en algunos de los puestos de vacunación de la ciudad de Medellín. Objetivo. Describir la epidemiología, virología y caracterización molecular de un brote de COVID-19 en un punto de vacunación cerrado durante la tercera ola de SARS-CoV-2 en Colombia. Materiales y métodos. Se realizaron test diagnósticos, entrevistas, toma de muestras, aislamiento viral y secuenciación genómica. Con esta última, se hizo la caracterización molecular y se identificó el linaje. Resultados. Siete trabajadores fueron positivos para SARS-CoV-2, y de estos, tres muestras fueron secuenciadas, más una muestra adicional perteneciente a la madre del presunto caso índice. Todas las muestras fueron identificadas con el linaje B.1.625, con un máximo de dos nucleótidos de diferencia entre ellas. Conclusiones. Se identificó la variante B.1.625 como la causante del brote de COVID-19, y también un compañero de trabajo fue identificado como el caso índice. De forma imprevista, asistir a una jornada de vacunación se convirtió en un factor de riesgo para adquirir la infección.

Natural SARS-CoV- 2 infection in domestic cats and dogs of humans diagnosed with COVID-19 in Valle de Aburrá, Antioquia / Infección natural por SARS-CoV-2 en gatos y perros domésticos de personas con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. OBJETIVO: Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. RESULTADOS: De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. CONCLUSIONES: Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión  zoonótica o entre especie.

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARSCoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. Objetivo. Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. Resultados. De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. Conclusiones. Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión zoonótica o entre especie.

Infección natural por SARS-CoV-2 en gatos y perros domésticos de personas con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia / Natural SARS-CoV- 2 infection in domestic cats and dogs of humans diagnosed with COVID-19 in Valle de Aburrá, Antioquia

Introducción. El síndrome respiratorio agudo grave causado por el nuevo coronavirus SARS-CoV-2 es causa de la emergencia sanitaria por la pandemia de COVID-19. Si bien el humano es el principal huésped vulnerable, en estudios experimentales y reportes de infección natural, se han encontrado casos de zoonosis inversa de SARS-CoV-2 en animales. Objetivo. Evaluar la infección natural por SARS-CoV-2 en gatos y perros de propietarios con diagnóstico de COVID-19 en el Valle de Aburrá, Antioquia, Colombia. Materiales y métodos. La circulación del SARS-CoV-2 se evaluó por RT-qPCR y RT-PCR en muestras de frotis nasofaríngeos y orofaríngeos de gatos y perros cuyos propietarios se encontraban dentro del periodo de los 14 días de aislamiento. Los casos positivos se verificaron amplificando fragmentos de los genes RdRp, N y E; se secuenció el gen RdRp y se analizó filogenéticamente. Resultados. De 80 animales evaluados, seis gatos y tres perros fueron casos confirmados de infección natural por SARS-CoV-2. Los animales no presentaron signos clínicos y sus propietarios, que padecían la infección, reportaron únicamente signos leves de la enfermedad sin complicaciones clínicas. En el análisis de una de las secuencias, se encontró un polimorfismo de un solo nucleótido (SNP) con un cambio en la posición 647, con sustitución del aminoácido serina (S) por una isoleucina (I). Los casos se presentaron en los municipios de Caldas, Medellín y Envigado. Conclusiones. Se infiere que la infección natural en los gatos y perros se asocia al contacto directo con un paciente con COVID-19. No obstante, no es posible determinar la virulencia del virus en este huésped, ni su capacidad de transmisión zoonótica o entre especie.

Introduction: The severe acute respiratory syndrome caused by the new coronavirus SARS-CoV-2 is the cause of the health emergency due to the COVID-19 pandemic. Although humans are the main susceptible host, experimental studies and reported cases of natural infection have evidenced scenarios of SARS-CoV-2 reverse zoonosis in animals. Objective: To evaluate the natural infection of SARS-CoV-2 in cats and dogs with owners diagnosed with COVID-19 in the Valle de Aburrá subregion in Antioquia, Colombia. Materials and methods. The circulation of SARS-CoV-2 was evaluated by RT-qPCR and RT-PCR in samples of nasopharyngeal and oropharyngeal smears from cats and dogs whose owners presented latent COVID-19 infection. Positive cases were verified through amplification of N, E and RdRp gene fragments; with the latter being sequenced and the phylogenetically analyzed. Results. From 80 tested animals, 6 cats and 3 dogs resulted positive for natural SARS-CoV-2 infection. These animals did not show any clinical signs; and their infected owners only reported mild signs of COVID-19, without clinical complications. Regarding analysis of one of the sequences, a single nucleotide polymorphism (SNP) was found, with a substitution in position 647, resulting in the change of the amino acid serine (S) for isoleucine (I). The cases occurred in the municipalities of Caldas, Medellín and Envigado. Conclusions. It is inferred that natural infection in cats and dogs is associated with direct contact with a positive COVID-19 patient.

Identification of CD8+ T cell subsets that normalize in early-treated people living with HIV receiving antiretroviral therapy.

BACKGROUND: Although combined antiretroviral therapy (cART) has decreased the mortality associated with HIV infection, complete immune reconstitution is not achieved despite viral suppression. Alterations of CD8+ T cells and some of their subpopulations, such as interleukin (IL)-17-producing cells, are evidenced in treated individuals and are associated with systemic inflammation and adverse disease outcomes. We sought to evaluate if different CD8+ T cell subsets are differentially normalized during a clinical follow-up of people living with HIV (PLWH) receiving suppressive cART. METHODS: We explored the changes in the frequencies, activation/exhaustion phenotypes (HLA-DR, CD38, PD-1, and TIM-3), and function (total and HIV-specific cells expressing CD107a, perforin, granzyme B, interferon [IFN]-γ and IL-17) of CD8+ T cells from early-treated PLWH receiving cART in a 1-year follow-up, using a multidimensional flow cytometry approach. RESULTS: Despite continuous cART-induced viral suppression and recovery of CD4+ T cells, after a 1-year follow-up, the CD8+ T cell counts, CD4:CD8 ratio, PD-1 expression, and IL-17 production by CD8+ T cells exhibited incomplete normalization compared with seronegative controls. However, the proportion of CD8+ T cells with an exhausted phenotype (co-expressing PD-1 andTIM-3), and cells co-expressing cytotoxic molecules (Perforin and Granzyme B), reached normalization. CONCLUSIONS: Although suppressive cART achieves normalization of CD4+ T cell counts, only particular subsets of CD8+ T cells are more rapidly normalized in PLWH receiving cART, which could be routinely used as biomarkers for therapy efficiency in these patients.

The Usefulness of Antigen Testing in Predicting Contagiousness in COVID-19.

Increasing the diagnostic capacity for COVID-19 (SARS-CoV-2 infection) is required to improve case detection, reduce COVID-19 expansion, and boost the world economy. Rapid antigen detection tests are less expensive and easier to implement, but their diagnostic performance has been questioned compared to reverse transcription-PCR (RT-PCR). Here, we evaluate the performance of the Standard Q COVID-19 antigen test for diagnosing SARS-CoV-2 infection and predicting contagiousness compared to RT-PCR and viral culture, respectively. The antigen test was 100.0% specific but only 40.9% sensitive for diagnosing infection compared to RT-PCR. Interestingly, SARS-CoV-2 contagiousness is highly unlikely with a negative antigen test since it exhibited a negative predictive value of 99.9% compared to viral culture. Furthermore, a cycle threshold (CT) value of 18.1 in RT-PCR was shown to be the one that best predicts contagiousness (area under the curve [AUC], 97.6%). Thus, screening people with antigen testing is a good approach to prevent SARS-CoV-2 contagion and allow returning to daily activities. IMPORTANCE The importance of our results is the excellent agreement between the Standard Q COVID-19 antigen test and the viral culture, indicating that it is important as a marker of contagiousness. Due to its high positive predictive value in situations of a high prevalence of infection, positive results do not require confirmation with another test. Likewise, its high negative predictive value for contagiousness makes possible to use this test as a criterion to discharge patients in isolation and screen people moving into environments that could facilitate the transmission of the virus. Screening people with antigen testing is a good approach to prevent SARS-CoV-2 contagion and allow returning to daily activities.

Neutralizing antibody titers to Omicron six months after vaccination with BNT162b2 in Colombia.

The emergence of the Omicron variant has generated concerns about the efficacy of COVID-19 vaccines. We evaluated the serum neutralizing activity of antibodies against the Omicron (lineage BA.1.1) by plaque reduction neutralizing test, as well as its correlation with age and gender, in a Colombian cohort six months after being vaccinated with BNT162b2 (Pfizer/BioNTech). Compared to all other variants analyzed, a significantly lower neutralizing activity (p<0.001) was observed against Omicron. Interestingly, older individuals exhibited lower titers against Omicron than those younger than 40. No statistical differences in neutralizing activity were observed according to gender. Our results showed that two doses of BNT162b2 might not provide robust protection against the Omicron variant over time. It is necessary to consider including changes in the composition of the vaccines to protect against new emerging variants of SARS-CoV-2 and campaigns to implement additional booster vaccinations.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection. / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

INTRODUCTION: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. OBJECTIVE: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. MATERIALS AND METHODS: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. RESULTS: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. CONCLUSION: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

Abstract | Introduction: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARS- CoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. Objective: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. Materials and methods: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. Results: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. Conclusion: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Resumen | Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56 bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

Epidemiology of Rickettsial Infection in the Municipality of Uramita, Colombia.

This study aimed to analyze epidemiological indicators related to seroprevalent and seroincident cases of spotted fever group rickettsiae (SFGR) and to identify housing conditions related to tick infestation. A prospective study (2016-2018) was conducted to examine rickettsial seropositivity in humans, domestic animals, and wild mammals in the municipality of Uramita, Antioquia, Colombia, where a previous Rickettsia rickettsii outbreak was reported from 2014 to 2015. The seroprevalence and its associated factors were estimated at baseline, and the seroincidence and its risk factors for humans were estimated 20 months later. A cross-sectional analysis was performed to evaluate the housing conditions linked to tick infestation. The SFGR seroprevalence was 26.70% (95% confidence interval [CI], 20.79-31.37), and the factors associated with SFGR seropositivity were male sex (adjusted prevalence ratio [PRa], 1.67; 95% CI, 1.19-2.32), age (evaluated in 5-year increments) (PRa, 1.05; 95% CI, 1.01-1.09), and household proximity (PRascattered vs. very near=3.87; 95% CI, 1.12-8.66). The overall seroincidence was 7.40% (95% CI, 4.71-11.06), and the factors associated with SFGR seroincident cases were the presence of wild animals (adjusted relative risk [RRa], 2.46; 95% CI, 1.06-4.72) and the presence of trees in the peri-domiciliary area (RRa, 0.47; 95% CI, 0.23-0.94). The prevalence of house tick infestation was 27.81% (95% CI, 21.93-34.80), and the factors associated with infestation were dirt floors (PRa, 5.88; 95% CI, 2.28-10.31), fiber cement roofs (PRa, 1.76; 95% CI, 1.07-2.83), and the presence of canines in peri-domiciliary or intra-domiciliary areas (PRa, 5.05; 95% CI, 3.31-7.19). Seropositivity rates for canines and opossums were 35.62% (26/73) and 100% (6/6), respectively. Identification of these factors will help to implement efficient surveillance programs in Colombia.

Seroprevalence of Varicella in Pregnant Women and Newborns in a Region of Colombia.

We estimate the seroprevalence of IgG antibodies to varicella zoster virus (VZV) based on the first serological study in a cohort of pregnant women and newborns from the Aburrá Valley (Antioquia-Colombia) who attended delivery in eight randomly chosen hospitals. An indirect enzyme immunoassay was used to determine anti-VZV IgG antibodies. Generalized linear models were constructed to identify variables that modify seropositivity. In pregnant women, seropositivity was 85.8% (95% CI: 83.4-85.9), seronegativity was 12.6% (95% CI: 10.8-14.6), and concordance with umbilical cord titers was 90.0% (95% CI: 89-91). The seropositivity of pregnant women was lower in those who lived in rural areas (IRR: 0.4, 95% CI: 0.2-0.7), belonged to the high socioeconomic status (IRR: 0.4, 95% CI: 0.2-0.7), and had studied 11 years or more (IRR: 0.6, 95% CI: 0.4-0.8). Among newborns, seropositivity was lower in those who weighed less than 3000 g (IRR: 0.8, 95% CI: 0.6-1.0). The high seropositivity and seronegativity pattern indicates the urgent need to design preconception consultation and vaccination reinforcement for women of childbearing age according to their sociodemographic conditions, to prevent infection and complications in the mother and newborn.

Autosomal dominant early onset Alzheimer's disease in the Mexican state of Jalisco: High frequency of the mutation PSEN1 c.1292C>A and phenotypic profile of patients.

Mutations in three genes (APP, PSEN1, and PSEN2) are the main cause of the autosomal dominant early-onset Alzheimer's disease (AD-EOAD). In PSEN1, the A431E (c.1292C>A, rs63750083) mutation is suspected to have exerted a founder effect in the State of Jalisco, Mexico. In Guadalajara, Jalisco, Mexico, this mutation was found in 46 index cases evaluated for AD-EOAD. In our genealogical analysis, 301 affected relatives of the mutation carriers were identified, 195 of whom were already deceased at the time of interview. Moreover, 560 descendants had a 50% risk of carrying the mutation, and 348 were potentially at risk. A systematic phenotyping was performed in 39 patients. The mean onset age was 42.5 ± 3.9 years, and no significant difference in onset age was observed between the male and female patients. Furthermore, a substantial clinical heterogeneity and high frequencies of spastic paraparesis, language disorders, and neuropsychiatric symptoms were observed. To our knowledge, the investigated families represent the second biggest population carrying a PSEN1 mutation in Latin America, offering a unique opportunity to study the genetic basis of Alzheimer's disease. Addressing AD-EOAD warrants an integral approach involving a deep understanding of its clinical behavior, as well as counseling protocols and prevention studies.

Isolation and characterization of an early SARS-CoV-2 isolate from the 2020 epidemic in Medellín, Colombia / [Aislamiento y caracterización de una cepa temprana de SARS-CoV-2 durante la epidemia de 2020 en Medellín, Colombia].

Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARSCoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.

Introducción. El nuevo coronavirus causante de un brote de enfermedad respiratoria aguda en China en diciembre de 2019 se identificó como SARS-CoV-2. La enfermedad, denominada COVID-19, fue declarada pandemia por la Organización Mundial de la Salud (OMS). El primer caso de COVID-19 en Colombia se reportó el 6 de marzo de 2020; en este estudio se caracterizó un aislamiento temprano del virus SARS-CoV-2 de una muestra ecolectada en abril de 2020. Objetivos. Describir y caracterizar una cepa temprana a partir de un aislamiento de SARSCoV-2 durante la pandemia en Colombia. Materiales y métodos. Se obtuvo una muestra de un paciente con COVID-19 confirmada por qRT-PCR; la muestra fue inoculada en diferentes líneas celulares hasta la aparición del efecto citopático. Para confirmar la presencia de SARS-CoV-2 en el cultivo, se utilizó la qRT-PCR a partir de los sobrenadantes, la inmunofluorescencia indirecta (IFI) en células Vero-E6, así como microscopía electrónica y secuenciación de nueva generación (nextgeneration sequencing). Resultados. Se confirmó el aislamiento de SARS-CoV-2 en células Vero-E6 por la aparición del efecto citopático tres días después de la infección, así como mediante la qRT-PCR y la IFI positiva con suero de paciente convaleciente positivo para SARS-CoV-2. Además, en las imágenes de microscopía electrónica de trasmisión y de barrido de células infectadas se observaron estructuras compatibles con viriones de SARS-CoV-2. Por último, se obtuvo la secuencia completa del genoma, lo que permitió clasificar el aislamiento como linaje B.1.5. Conclusiones. La evidencia presentada en este artículo permite confirmar el primer aislamiento de SARS-CoV-2 en Colombia. Además, muestra que esta cepa se comporta en cultivo celular de manera similar a lo reportado en la literatura para otros aislamientos y que su composición genética está acorde con la variante predominante en el mundo. Finalmente, se resalta la importancia que tiene el aislamiento viral para la detección de anticuerpos, para la caracterización genotípica y fenotípica de la cepa y para probar compuestos con potencial antiviral.

Human Rickettsiosis Caused by Rickettsia parkeri Strain Atlantic Rainforest, Urabá, Colombia.

We describe the clinical, serologic, and molecular findings of a new human rickettsiosis in Colombia. Antibodies against Rickettsia spp. were detected. PCR showed amplification of genes for R. parkeri strain Atlantic Rainforest. This new rickettsiosis of minor virulence could explain some of the undifferentiated acute febrile diseases in Colombia.

Aislamiento y caracterización de una cepa temprana de SARS-CoV-2 durante la epidemia de 2020 en Medellín, Colombia / Isolation and characterization of an early SARS-CoV-2 isolate from the 2020 epidemic in Medellín, Colombia

Introducción. El nuevo coronavirus causante de un brote de enfermedad respiratoria aguda en China en diciembre de 2019 se identificó como SARS-CoV-2. La enfermedad, denominada COVID-19, fue declarada pandemia por la Organización Mundial de la Salud (OMS). El primer caso de COVID-19 en Colombia se reportó el 6 de marzo de 2020; en este estudio se caracterizó un aislamiento temprano del virus SARS-CoV-2 de una muestra recolectada en abril de 2020. Objetivos. Describir y caracterizar una cepa temprana a partir de un aislamiento de SARS-CoV-2 durante la pandemia en Colombia. Materiales y métodos. Se obtuvo una muestra de un paciente con COVID-19 confirmada por qRT-PCR; la muestra fue inoculada en diferentes líneas celulares hasta la aparición del efecto citopático. Para confirmar la presencia de SARS-CoV-2 en el cultivo, se utilizó la qRT-PCR a partir de los sobrenadantes, la inmunofluorescencia indirecta (IFI) en células Vero-E6, así como microscopía electrónica y secuenciación de nueva generación (next-generation sequencing). Resultados. Se confirmó el aislamiento de SARS-CoV-2 en células Vero-E6 por la aparición del efecto citopático tres días después de la infección, así como mediante la qRT-PCR y la IFI positiva con suero de paciente convaleciente positivo para SARS-CoV-2. Además, en las imágenes de microscopía electrónica de trasmisión y de barrido de células infectadas se observaron estructuras compatibles con viriones de SARS-CoV-2. Por último, se obtuvo la secuencia completa del genoma, lo que permitió clasificar el aislamiento como linaje B.1.5. Conclusiones. La evidencia presentada en este artículo permite confirmar el primer aislamiento de SARS-CoV-2 en Colombia. Además, muestra que esta cepa se comporta en cultivo celular de manera similar a lo reportado en la literatura para otros aislamientos y que su composición genética está acorde con la variante predominante en el mundo. Finalmente, se resalta la importancia que tiene el aislamiento viral para la detección de anticuerpos, para la caracterización genotípica y fenotípica de la cepa y para probar compuestos con potencial antiviral.

Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARS-CoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.

Feasibility and Acceptability of a Culturally- and Linguistically-Adapted Smoking Cessation Text Messaging Intervention for Latino Smokers.

Objective: Assess the feasibility and acceptability of a culturally- and linguistically-adapted smoking cessation text messaging intervention for Latino smokers. Methods: Using a community-based strategy, 50 Latino smokers were recruited to participate in a smoking cessation pilot study. Participants received a 12-week text messaging intervention and were offered Nicotine Replacement Therapy (NRT) at no cost. We assessed biochemically verified abstinence at 12 weeks, text messaging interactivity with the program, NRT utilization, self-efficacy, therapeutic alliance, and satisfaction. Results: Participants were 44.8 years old on average (SD 9.80), and they were primarily male (66%) and had no health insurance (78%). Most of the participants were born in Mexico (82%) and were light smokers (1-10 CPD) (68%). All participants requested the first order of NRT, and 66% requested a refill. Participants sent an average of 39.7 text messages during the 12-week intervention (SD 82.70). At 12 weeks, 30% of participants were biochemically verified abstinent (88% follow-up rate) and working alliance mean value was 79.2 (SD 9.04). Self-efficacy mean score increased from 33.98 (SD 10.36) at baseline to 40.05 (SD 17.65) at follow-up (p = 0.04). The majority of participants (90.9%, 40/44) reported being very or extremely satisfied with the program. Conclusion: A culturally- and linguistically-adapted smoking cessation text messaging intervention for Latinos offers a promising strategy to increase the use of NRT, generated high satisfaction and frequent interactivity, significantly increased self-efficacy, produced high therapeutic alliance, and resulted in noteworthy cessation rates at the end of treatment. Additional testing as a formal randomized clinical trial is warranted.