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.

Seroprevalence of anti-SARS-CoV-2 antibodies in Colombia, 2020: A population-based study.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause very high morbidity and mortality throughout Latin American countries. However, few population-based seroprevalence surveys have been conducted to quantify attack rates and characterize drivers of transmission. METHODS: We conducted a population-based cross-sectional study to assess the seroprevalence of antibodies against SARS-CoV-2 in ten cities in Colombia between September and December 2020. The study involved multi-stage cluster sampling at each city. Participants provided a serum sample and answered a demographic and risk factor questionnaire. Prior infection by SARS-CoV-2 was ascertained using the "SARS-CoV-2 Total (COV2T) Advia Centaur - Siemens" chemiluminescence assay. FINDINGS: A total of 17863 participants from 7320 households participated in the study. Seroprevalence varied substantially between cities, ranging from 26% (95%CI 23-29 %) in Medellín to 68% (95%CI 62-74 %) in Guapi. There were no differences in seroprevalence by sex, but seropositivity was higher in certain ethnic groups. There was substantial heterogeneity in seroprevalence within cities, driven to a large extent by a strong association between socioeconomic stratum and seropositivity. INTERPRETATION: Colombia has been one of the Latin American countries most affected by the COVID-19 pandemic. This study documented very high attack rates in several Colombian cities by the end of 2020 and identified key drivers of heterogeneities including ethnicity and socioeconomic stratum. Few studies of seroprevalence of SARS-CoV-2 have been conducted in Latin America, and therefore this study contributes to the fundamental understanding of the pandemic in the region. FUNDING: The study was sponsored by, Ministerio de Ciencia y Tecnología e Innovación -CT361/2020, Ministerio de Salud y Protección Social, Fundación Universitaria del Norte, Imperial College of London, Universidad Nacional de Colombia (Sede Medellín), Universidad de Córdoba, California University, Unidad Nacional de Gestión del Riesgo, Centro de Atención y Diagnóstico de Enfermedades Infecciosas -CDI-, Centro Internacional de Entrenamiento e Investigaciones Médicas -CIDEIM-, Departamento Administrativo Nacional de Estadística - DANE, Fondo Nacional de Turismo -FONTUR-, Secretarías de Salud Departamentales, Distritales y Municipales and Instituto Nacional de Salud.

Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia.

OBJECTIVE: To estimate the age-specific incidence of symptomatic dengue and chikungunya in Colombia. METHOD: A passive facility-based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture-recapture methods. RESULTS: Of 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients. CONCLUSIONS: These findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.

Why are people with dengue dying? A scoping review of determinants for dengue mortality.

BACKGROUND: Dengue is a viral disease whose clinical spectrum ranges from unapparent to severe forms and fatal outcomes. Although dengue death is 99% avoidable, every year around 20,000 deaths are estimated to occur in more than 100 countries. We consider that, along with biological factors, social determinants of health (SDHs) are related to dengue deaths as well. METHODS: A scoping review was conducted to explore what has been written about the role of SDHs in dengue mortality. The inclusion criteria were that documents (grey or peer-reviewed) had to include information about dengue fatal cases in humans and be published between 1997 and 2013 and written in English, Spanish, Portuguese or French. The search was conducted using a set of key words related to dengue mortality in several electronic databases: PubMed, LILACS, COCHRANE, Scielo, Science Direct, WHOLIS, OpenGrey, OpenSingle and Google Scholar. Information on SDHs was categorized under individual, social and environmental, and health systems dimensions. A summative content analysis using QDA Miner was conducted to assess the frequency of information on SDHs and its contextual meaning in the reviewed literature. The role of each SDH in dengue mortality was assessed using content analysis results. RESULTS: From a total of 971 documents retrieved, 78 met the criteria. Those documents were published in the Americas region (50.0%), Asia (38.4%), Europe (9.0%) and Africa (2.6%). The described SDHs related to dengue deaths included, in the individual dimension: age, ethnicity, education, type of infection and immunological status; and in the social dimension: poverty and care-seeking behavior. The health systems dimension included access, opportunity, and quality of care, as well as health staff knowledge. Ethnicity was considered a determinant that depends on cultural and socioeconomic conditions. CONCLUSIONS: Along with biological factors, there are several SDHs related to dengue mortality. However, only a few of these have been systematically analyzed, suggesting the need for more studies on this subject to inform the design and implementation of sustainable interventions to decrease dengue mortality. These findings nevertheless provide a better understanding of the non-biological factors involved in dengue mortality.

Epidemiological trends of dengue disease in Colombia (2000-2011): a systematic review.

A systematic literature review was conducted to describe the epidemiology of dengue disease in Colombia. Searches of published literature in epidemiological studies of dengue disease encompassing the terms "dengue", "epidemiology," and "Colombia" were conducted. Studies in English or Spanish published between 1 January 2000 and 23 February 2012 were included. The searches identified 225 relevant citations, 30 of which fulfilled the inclusion criteria defined in the review protocol. The epidemiology of dengue disease in Colombia was characterized by a stable "baseline" annual number of dengue fever cases, with major outbreaks in 2001-2003 and 2010. The geographical spread of dengue disease cases showed a steady increase, with most of the country affected by the 2010 outbreak. The majority of dengue disease recorded during the review period was among those <15 years of age. Gaps identified in epidemiological knowledge regarding dengue disease in Colombia may provide several avenues for future research, namely studies of asymptomatic dengue virus infection, primary versus secondary infections, and under-reporting of the disease. Improved understanding of the factors that determine disease expression and enable improvement in disease control and management is also important.

Developing a social autopsy tool for dengue mortality: a pilot study.

BACKGROUND: Dengue fever is a public health problem in the tropical and sub-tropical world. Dengue cases have grown dramatically in recent years as well as dengue mortality. Colombia has experienced periodic dengue outbreaks with numerous dengue related-deaths, where the Santander department has been particularly affected. Although social determinants of health (SDH) shape health outcomes, including mortality, it is not yet understood how these affect dengue mortality. The aim of this pilot study was to develop and pre-test a social autopsy (SA) tool for dengue mortality. METHODS AND FINDINGS: The tool was developed and pre-tested in three steps. First, dengue fatal cases and 'near misses' (those who recovered from dengue complications) definitions were elaborated. Second, a conceptual framework on determinants of dengue mortality was developed to guide the construction of the tool. Lastly, the tool was designed and pre-tested among three relatives of fatal cases and six near misses in 2013 in the metropolitan zone of Bucaramanga. The tool turned out to be practical in the context of dengue mortality in Colombia after some modifications. The tool aims to study the social, individual, and health systems determinants of dengue mortality. The tool is focused on studying the socioeconomic position and the intermediary SDH rather than the socioeconomic and political context. CONCLUSIONS: The SA tool is based on the scientific literature, a validated conceptual framework, researchers' and health professionals' expertise, and a pilot study. It is the first time that a SA tool has been created for the dengue mortality context. Our work furthers the study on SDH and how these are applied to neglected tropical diseases, like dengue. This tool could be integrated in surveillance systems to provide complementary information on the modifiable and avoidable death-related factors and therefore, be able to formulate interventions for dengue mortality reduction.

Biomarcadores pronósticos de gravedad del dengue / Biomarkers for the prognosis of severe dengue

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Introduction: There are very few strategies for the early detection of the patients who might develop the severe form of the illness. Objective: To evaluate the utility of serum levels of some immune response mediators as early biomarkers for the severe dengue prognosis during the early phase of the illness. Materials and methods: Using a case-control design nested in a multicenter cohort from the AEDES network (a Colombian multicenter study), we compared TNF a, ST2, TRAIL and IDO levels in samples which were obtained during the early phase of the illness. Results: ST2, TRAIL and TNF a levels were higher in severe dengue patients compared with uncomplicated patients (p<0.0001), as follows: OR=24.8, CI95%= 6.1- 98.0; OR=18.0, CI95%= 4.6-69.1; OR=NC, CI95%= NC, respectively. We did not find statistically significant differences between IDO levels in severe dengue and uncomplicated dengue (p=1.000, OR=1.0, CI95%= 0.2-6.1). Conclusions: In the early phase of the dengue infection (96 hours), ST2, TRAIL and TNF a quantifications could contribute to the prediction of complications of the illness.

[Biomarkers for the prognosis of severe dengue]. / Biomarcadores pronósticos de gravedad del dengue.

INTRODUCTION: There are very few strategies for the early detection of the patients who might develop the severe form of the illness. OBJECTIVE: To evaluate the utility of serum levels of some immune response mediators as early biomarkers for the severe dengue prognosis during the early phase of the illness. MATERIALS AND METHODS: Using a case-control design nested in a multicenter cohort from the AEDES network (a Colombian multicenter study), we compared TNF a, ST2, TRAIL and IDO levels in samples which were obtained during the early phase of the illness. RESULTS: ST2, TRAIL and TNF a levels were higher in severe dengue patients compared with uncomplicated patients (p<0.0001), as follows: OR=24.8, CI95%= 6.1- 98.0; OR=18.0, CI95%= 4.6-69.1; OR=NC, CI95%= NC, respectively. We did not find statistically significant differences between IDO levels in severe dengue and uncomplicated dengue (p=1.000, OR=1.0, CI95%= 0.2-6.1). CONCLUSIONS: In the early phase of the dengue infection (96 hours), ST2, TRAIL and TNF a quantifications could contribute to the prediction of complications of the illness.

Dengue: un reto para el estado, la comunidad científica y el conjunto de la sociedad colombiana: [Editorial] / Dengue: A Challenge for the State, the Scientific Community, and Colombian Society as a Whole: [Editorial]

El dengue es la enfermedad viral transmitida por mosquitos de mayor impacto en el mundo (1). Su vector, el mosquito Aedes aegypti, crece en aguas limpias estancadas y tiene un hábitat urbano y domiciliario; el número y la densidad de sus criaderos guarda estrecha relación con la incidencia de casos en una comunidad. A partir del 2009, cerca del 53% de la población mundial vive en ciudades con menos de 500.000 habitantes (2), en la mayoría de las cuales las deficiencias de los servicios públicos obligan a la recolección de agua para el consumo humano. Esta circunstancia, sumada al calentamiento global y la consiguiente adaptación del mosquito del dengue a mayores alturas, explica en gran medida la diseminación del vector y de la enfermedad a un mayor número de regiones tropicales y subtropicales del mundo. Hoy, 2,5 billones de personas viven en los cerca de 100 países que reportan dengue, convirtiéndolo en un problema de alcance antes insospechado.

Dengue is the most impactful mosquito-borne viral disease in the world (1). Its vector, the Aedes aegypti mosquito, grows in clean stagnant waters and has an urban and domiciliary habitat; the number and density of their breeding sites are closely related to the incidence of cases in a community. As of 2009, about 53% of the world's population lives in cities with fewer than 500,000 inhabitants (2), in most of which deficiencies in public services force the collection of water for human consumption. This circumstance, added to global warming and the consequent adaptation of the dengue mosquito to higher altitudes, largely explains the spread of the vector and the disease to a greater number of tropical and subtropical regions of the world. Today, 2.5 billion people live in the nearly 100 countries that report dengue, making it a problem of previously unsuspected scope.

Evolución clínica de pacientes hospitalizados por dengue en una institución de salud de Bucaramanga, Colombia / Clinical evolution of dengue in hospitalized patients

Introducción. El dengue hemorrágico abarca todas las áreas tropicales y subtropicales del planeta, y causa medio millón de hospitalizaciones al año en el mundo. Se ha descrito que esta enfermedad afecta a un grupo cada vez mayor de adolescentes y adultos jóvenes. Objetivo. Describir las características clínicas de la población, tanto adulta como pediátrica, hospitalizada por dengue durante un periodo endémico y determinar los factores de riesgo asociados a mal pronóstico. Materiales y métodos. Cohorte retrospectiva de pacientes hospitalizados por dengue en los años 2006 y 2007 en la Clínica Chicamocha. Resultados. Se evaluaron 328 pacientes, 165 mujeres y 163 hombres, con mediana de edad de 25 años. Se encontraron 116 casos de dengue hemorrágico, de los cuales, 113 eran de grado II. De los 212 pacientes con dengue clásico, 156 presentaron extravasación, sangrado o trombocitopenia. El 82,4 por ciento tuvieron serología positiva. Los pacientes con dengue hemorrágico eran más jóvenes (20,1 contra 25,7 años, p=0,0054). El número mínimo de plaquetas y el valor máximo del hematocrito se alcanzaron alrededor del sexto día de enfermedad. Los menores de 13 años presentaron con menor frecuencia los síntomas típicos de dengue, aunque con un mayor porcentaje de ascitis, derrame y sangrado; además, tuvieron mayor riesgo de desarrollar dificultad respiratoria (riesgo relativo (RR)=3,59, IC95 por ciento 1,3-9,9, p=0,014) e hipotensión (RR=10,77, IC95 porcentaje 5,56-20,86, p<0,001). Conclusiones. La edad continúa siendo el factor predominante en la gravedad intrahospitalaria del dengue. Independientemente de ésta, un grupo de signos, síntomas y hallazgos de laboratorio al ingreso permite predecir la aparición de complicaciones.

[Clinical evolution of dengue in hospitalized patients]. / Evolución clínica de pacientes hospitalizados por dengue en una institución de salud de Bucaramanga, Colombia.

INTRODUCTION: Dengue hemorrhagic fever has extended to every tropical and subtropical area of the world, resulting in a half million hospitalizations every year. This disease appears to affect increasing numbers of adolescents and young adults. OBJECTIVE: The clinical characteristics were described for adult and pediatric dengue inpatients to establish risk factors associated with bad prognosis. MATERIALS AND METHODS: A cohort of dengue inpatients of years 2006 and 2007 was evaluated retrospectively at "Clínica Chicamocha", a high level hospital in Bucaramanga, Colombia. RESULTS: Of 328 patients evaluated, 165 were female and 163 were male with a median age of 25 years. Dengue hemorrhagic fever was diagnosed in 116 patients, of which 113 were classified grade II. Of the 212 patients with dengue fever, 156 developed signs of plasma leakage, bleeding or thrombocytopenia. A positive serology was indicated in 82.4% of the patients. Inpatients with dengue hemorrhagic fever were younger (20.1 vs. 25.7 years, p<0.0054). Both lowest level of platelets and highest hematocrit were reached at the sixth day of illness. Children presented the typical symptoms of dengue less frequently, but demonstrated a greater proportion of ascites, pleural effusion and bleeding, and a higher risk of developing respiratory distress (RR=3.59, 95%CI 1.3-9.9, p<0.014) and hypotension (RR=10.77, 95%CI 5.56-20.86, p<0.001). CONCLUSIONS: Age was the most determinant factor of severity in dengue inpatients. In addition, a combination of particular symptoms and laboratory data at the day of admission may predict the development of complications.

Temporal distribution of dengue virus serotypes in Colombian endemic area and dengue incidence. Re-introduction of dengue-3 associated to mild febrile illness and primary infection.

We have investigated the temporal distribution of dengue (DEN) virus serotypes in the department (state) of Santander, Colombia, in relation to dengue incidence, infection pattern, and severity of disease. Viral isolation was attended on a total of 1452 acute serum samples collected each week from 1998 to 2004. The infection pattern was evaluated in 596 laboratory-positive dengue cases using an IgG ELISA, and PRNT test. The dengue incidence was documented by the local health authority. Predominance of DEN-1 in 1998 and DEN-3 re-introduction and predominance in 2001-2003 coincided with outbreaks. Predominance of DEN-2 in 2000-2001 coincided with more dengue hemorrhagic fever (DHF). DEN-4 was isolated in 2000-2001 and 2004 but was not predominant. There was an annual increase of primary dengue infections (from 13.7 to 81.4%) that correlated with frequency of DEN-3 (r = 0.83; P = 0.038). From the total number of primary dengue infections DEN-3 (81.3%) was the most frequent serotype. DHF was more frequent in DEN-2 infected patients than in DEN-3 infected patients: 27.5 vs 10.9% (P < 0.05). DEN-3 viruses belonged to subtype C (restriction site-specific-polymerase chain reaction) like viruses isolated in Sri-Lanka and other countries in the Americas. Our findings show the importance of continuous virological surveillance to identify the risk factors of dengue epidemics and severity.

Temporal distribution of dengue virus serotypes in Colombian endemic area and dengue incidence: re-introduction of dengue-3 associated to mild febrile illness and primary infection

We have investigated the temporal distribution of dengue (DEN) virus serotypes in the department (state) of Santander, Colombia, in relation to dengue incidence, infection pattern, and severity of disease. Viral isolation was attended on a total of 1452 acute serum samples collected each week from 1998 to 2004. The infection pattern was evaluated in 596 laboratory-positive dengue cases using an IgG ELISA, and PRNT test. The dengue incidence was documented by the local health authority. Predominance of DEN-1 in 1998 and DEN-3 re-introduction and predominance in 2001-2003 coincided with outbreaks. Predominance of DEN-2 in 2000-2001 coincided with more dengue hemorrhagic fever (DHF). DEN-4 was isolated in 2000-2001 and 2004 but was not predominant. There was an annual increase of primary dengue infections (from 13.7 to 81.4 percent) that correlated with frequency of DEN-3 (r = 0.83; P = 0.038). From the total number of primary dengue infections DEN-3 (81.3 percent) was the most frequent serotype. DHF was more frequent in DEN-2 infected patients than in DEN-3 infected patients: 27.5 vs 10.9 percent (P < 0.05). DEN-3 viruses belonged to subtype C (restriction site-specific-polymerase chain reaction) like viruses isolated in Sri-Lanka and other countries in the Americas. Our findings show the importance of continuous virological surveillance to identify the risk factors of dengue epidemics and severity.

[Clinical criteria to diagnose dengue in its early stages]. / Criterios clínicos para diagnosticar el dengue en los primeros días de enfermedad.

INTRODUCTION: Clinical differentiation of dengue from other diseases with similar symptoms is difficult. The case definition of the World Health Organization (WHO) has high sensitivity but its specificity is very low. OBJECTIVE: A diagnostic scale was formulated for early clinical diagnosis of dengue that provided greater accuracy than that of the WHO definition. MATERIALS AND METHODS: A cohort of 251 adults (> 12 years of age) with unspecific acute febrile syndrome was selected from clinics located in Bucaramanga, Colombia. They consisted of 125 cases of dengue (serologically and/or virologically confirmed) and 126 with other febrile diseases. Clinical manifestations encountered during the first four days of dengue disease were determined, along with the diverse diagnostic combinations that were presented. RESULTS: : The scale consisted of the following criteria: presence of rash, positive tourniquet test, absence of nasal discharge, arthralgias, absence of diarrhea (1 point for each finding), leukocyte count < 4,000/mm3 (3 points) and platelet count < 180.000/mm3 (2 points). In a receiver-operating-characteristic curve, the predictive area of 81.0% was significantly superior to the one produced with WHO criteria, (70.0%, p < 0.001). Febrile syndrome with at least a 3 point score obtained the following values: sensitivity = 95.2%; specificity = 27.8%; positive predictive value = 56.7%; negative predicative value = 85.4%. With a 6-point score, sensitivity = 70.4%; specificity = 78.6%; positive predictive value = 76.5%; negative predicative value = 72.8%. With at least 8 points: sensitivity = 42.4%; specificity = 96%; positive predictive value = 91.4%; negative predictive value = 62.7%. With 9 or 10 points, specificity and positive predictive value were of 100%. CONCLUSION: The described scale proved useful for early clinical diagnosis of dengue, but requires validation for its application in endemic areas.

Criterios clínicos para diagnosticar el dengue en los primeros días de enfermedad / Clinical criteria to diagnose dengue in its early stages

Introducción. La definición de caso de dengue de la Organización Mundial de la Salud (OMS) tiene alta sensibilidad, pero es muy inespecífica. Objetivo. Formular una escala diagnóstica de mayor exactitud que la definición de la OMS para la identificación clínica temprana del dengue en áreas endémicas. Materiales y métodos. En una cohorte de adultos (>12 años) con síndrome febril agudo sin causa aparente en Bucaramanga, Colombia, compuesta por 125 casos de dengue (confirmados serológica o virológicamente) y 126 de síndrome febril de otra etiología, se determinaron las manifestaciones clínicas tempranas (en los primeros cuatro días de la enfermedad) asociadas al dengue y con ellas se formularon y evaluaron diversas combinaciones diagnósticas. Resultados. La escala compuesta por exantema, prueba de torniquete positiva, ausencia de rinorrea, artralgias, ausencia de diarrea (1 punto por cada hallazgo), recuentos de leucocitos <4.000/mm3 (3 puntos) y plaquetas <180.000/mm3 (2 puntos) exhibió un área bajo la curva de características operador-receptor de 81,04 por ciento, superior a la observada con los criterios de la OMS de 69,96 por ciento (p=0,0003). Con 3 puntos se obtuvo una sensibilidad de 95,2 por ciento; una especificidad de 27,8 por ciento; un valor diagnóstico positivo de 56,7 por ciento; un valor diagnóstico negativo de 85,4 por ciento. Con 6 puntos se obtuvo una sensibilidad de 70,4 por ciento; una especificidad de 78,6 por ciento; un valor diagnóstico positivo de 76,5 por ciento; un valor diagnóstico negativo de 72,8 por ciento. Con 8 puntos se obtuvo una sensibilidad de 42,4 por ciento; una especificidad de 96 por ciento; un valor diagnóstico positivo de 91,4 por ciento; un valor diagnóstico negativo de 62,7 por ciento. Con 9 o 10 puntos, la especificidad y el valor diagnóstico positivo fueron de 100 por ciento. Conclusión. La escala descrita puede ser útil para el diagnóstico clínico temprano del dengue en áreas endémicas.

[Evaluation of the World Health Organization clinical definition of dengue]. / Evaluación de la definición clínica de dengue sugerida por la Organización Mundial de la Salud.

INTRODUCTION: The distinction between dengue and other acute febrile diseases is difficult when based solely on symptoms. OBJECTIVE: An attempt was made to evaluate usefulness of dengue diagnoses in an endemic area (Bucaramanga, Colombia), based on the definitions recommended by the World Health Organization. MATERIALS AND METHODS: In a cohort >12 years of age with indications of acute febrile illness, the sensitivity, the specificity and the predictive values were determined based on the WHO dengue definition. Two or more of the following symptoms were included: headache, retroorbital pain, myalgia, arthralgia, rash, hemorrhagic manifestations, or leucopenia. RESULTS: One hundred-one cases of dengue and 89 patients with acute febrile illness were enrolled in the study. The dengue cases were confirmed by serological or by virus presence. The WHO case definitions showed sensitivity, 99%; specificity, 1%; positive predictive value, 53%, and negative predictive value, 50%. CONCLUSION: This clinical definition demonstrated high sensitivity, but a low specificity. Therefore, the clinical definition was useful for screening, but it did not differentiate between dengue and other febrile diseases.

Evaluación de la definición clínica de dengue sugerida por la Organización Mundial de la Salud / Evaluation of the World Health Organization clinical definition of dengue

Introducción. Clínicamente es difícil diferenciar el dengue de otras entidades con sintomatología similar. Objetivo. Evaluar la utilidad diagnóstica de la definición de caso presunto de dengue sugerida por la Organización Mundial de la Salud, en un área endémica (Bucaramanga, Colombia). Materiales y métodos. En una cohorte con síndrome febril agudo sin causa aparente (mayores de 12 años), se determinó la sensibilidad, la especificidad y los valores pronósticos de dicha definición que incluye dos o más de estas manifestaciones: cefalea, dolor retroocular, mialgias, artralgias, exantema, manifestaciones hemorrágicas y leucopenia. Resultados. Se incluyeron 101 pacientes de dengue, confirmados serológica o virológicamente, y 89 con síndrome febril agudo de otra etiología. La definición de caso exhibió una sensibilidad de 99 por ciento; especificidad de 1 por ciento; valor pronóstico positivo de 53 por ciento , y valor pronóstico negativo de 50 por ciento. Conclusión. Esta definición clínica es sensible, pero poco específica; por tanto, puede ser útil para tamizaje, pero no ayuda a diferenciar el dengue de otras enfermedades febriles

Vigilancia del dengue basada en el laboratorio: diferencias en el número de casos y virus aislados según la recolección del suero y la prueba serológica / Dengue surveillance in laboratory: differences in the number of cases and isolated virus according to collect serum and test

Introducción: El control del dengue depende de los datos de la vigilancia basada en el laboratorio. El objetivo de este estudio fue establecer las diferencias en número de casos (IgM positiva) y serotipos del virus según la estrategia de vigilancia. Materiales y métodos: Se compararon los resultados de dos estrategias de vigilancia. Primera (SIVIGILA local): de 337 casos con sospecha clínica de dengue se colectó un único suero (agudo o convaleciente) que se almacenó a 4oC. Se utilizó el estuche UMELISA DENGUE (IPK, Cuba) para detectar anticuerpos IgM y se hicieron intentos de aislamiento del virus en células C6/36. Segunda: de 318 casos sospechosos se colectaron sueros pareados que se almacenaron a -70oC, se usó una prueba local de MAC-ELISA y se intentó el aislamiento del virus como en la primera. Algunos sueros procesados por el MAC-ELISA se analizaron también por el UMELISA y los estuches Dengue IgM-capture ELISA (PANBIO) e IgM*ELISA anti-dengue (IPK, Cuba). Resultados: Se encontraron más casos IgM+ con la primera que con la segunda estrategia tanto con sueros agudos como convalecientes. Esto es, 61.1 vs 22/100 (p<0.001) y 86.8 vs 49.3/100 (p<0.001), respectivamente. Los resultados del MAC-ELISA concordaron 85/100 (k=0.29) con los del UMELISA, pero 90.4/100 (k=0.84 ) y 100/100 (k=1) con los estuches de PAMBIO e IgM*ELISA, respectivamente. Se encontraron diferencias significativas en la frecuencia del dengue en casos de la segunda estrategia, cuando el resultado de la serología con suero agudo o con pareado se comparó: 70 (22/100) vs 155 (48.7/100) (p<0.001). El aislamiento viral fue más exitoso de los sueros almacenados a -70oC que a 4oC: 17.8/100 vs. 4.7/100 (p<0.001). Se identificaron los 4 serotipos del virus. Se discuten la especificidad del UMELISA DENGUE y las consecuencias en el control del dengue en relación a la estrategia de vigilancia. Conclusiones: Se requiere evaluar la especificidad del estuche UMELISA considerando la alta frecuencia del dengue en casos con sospecha. El análisis de sueros pareados en la vigilancia del dengue es necesario para obtener información confiable