Clinical Indicators of Fatal Dengue in Two Endemic Areas of Colombia: A Hospital-Based Case-Control Study.

According to the World Health Organization, 98% of fatal dengue cases can be prevented; however, endemic countries such as Colombia have recorded higher case fatality rates during recent epidemics. We aimed to identify the predictors of mortality that allow risk stratification and timely intervention in patients with dengue. We conducted a hospital-based, case-control (1:2) study in two endemic areas of Colombia (2009-2015). Fatal cases were defined as having either 1) positive serological test (IgM or NS1), 2) positive virological test (RT-PCR or viral isolation), or 3) autopsy findings compatible with death from dengue. Controls (matched by state and year) were hospitalized nonfatal patients and had a positive serological or virological dengue test. Exposure data were extracted from medical records by trained staff. We used conditional logistic regression (adjusting for age, gender, disease's duration, and health-care provider) in the context of multiple imputation to estimate exposure to case-control associations. We evaluated 110 cases and 217 controls (mean age: 35.0 versus 18.9; disease's duration pre-admission: 4.9 versus 5.0 days). In multivariable analysis, retro-ocular pain (odds ratios [OR] = 0.23), nausea (OR = 0.29), and diarrhea (OR = 0.19) were less prevalent among fatal than nonfatal cases, whereas increased age (OR = 2.46 per 10 years), respiratory distress (OR = 16.3), impaired consciousness (OR = 15.9), jaundice (OR = 32.2), and increased heart rate (OR = 2.01 per 10 beats per minute) increased the likelihood of death (AUC: 0.97, 95% confidence interval: 0.96, 0.99). These results provide evidence that features of severe dengue are associated with higher mortality, which strengthens the recommendations related to triaging patients in dengue-endemic areas.

NMR metabolomics of cerebrospinal fluid differentiates inflammatory diseases of the central nervous system.

BACKGROUND: Myriad infectious and noninfectious causes of encephalomyelitis (EM) have similar clinical manifestations, presenting serious challenges to diagnosis and treatment. Metabolomics of cerebrospinal fluid (CSF) was explored as a method of differentiating among neurological diseases causing EM using a single CSF sample. METHODOLOGY/PRINCIPAL FINDINGS: 1H NMR metabolomics was applied to CSF samples from 27 patients with a laboratory-confirmed disease, including Lyme disease or West Nile Virus meningoencephalitis, multiple sclerosis, rabies, or Histoplasma meningitis, and 25 controls. Cluster analyses distinguished samples by infection status and moderately by pathogen, with shared and differentiating metabolite patterns observed among diseases. CART analysis predicted infection status with 100% sensitivity and 93% specificity. CONCLUSIONS/SIGNIFICANCE: These preliminary results suggest the potential utility of CSF metabolomics as a rapid screening test to enhance diagnostic accuracies and improve patient outcomes.

Análisis filogenético del virus del chikungunya en Colombia: evidencia de selección purificadora en el gen E1 / Phylogenetic analysis of Chikungunya virus in Colombia: Evidence of purifying selection in the E1 gene

Introducción. El virus del chikungunya, perteneciente al género Alphavirus de la familia Togaviridae, es un virus ARN de 11,8 kb, de cadena sencilla y polaridad positiva, transmitido por Aedes spp . Se han identificado tres genotipos a nivel mundial: el de Asia, el del este-centro-sur de África ( East/Central/South African, ECSA) y el de África occidental ( West African, WA). La fiebre del chikungunya es una enfermedad febril aguda, acompañada principalmente de inflamación en las articulaciones y erupción cutánea. Después de su aparición en las Américas en el 2013, los primeros casos en Colombia ocurrieron en septiembre de 2014 y hasta junio del 2015 se habían notificado 399.932 casos. Objetivo. Identificar el genotipo o los genotipos responsables de la primera epidemia por el virus del chikungunya en Colombia y la variabilidad genética asociada a su dispersión en el territorio nacional. Materiales y métodos. Se seleccionaron muestras de suero de pacientes con síntomas indicativos de fiebre del chikungunya durante 2014 y 2015. Se hizo una transcripción inversa seguida de reacción en cadena de la polimerasa del gen E1, así como su secuenciación, análisis filogenético y análisis de evolución adaptativa. Resultados. Se demostró la presencia exclusiva del genotipo de Asia en Colombia. Se registró un promedio de 0,001 sustituciones de bases por sitio, una identidad de 99,7 a 99,9 % en los nucleótidos y de 99,9 % en los aminoácidos entre las secuencias colombianas y las secuencias de las Américas. Los análisis de evolución adaptativa indicaron una fuerte selección purificadora en el gen E1 . Conclusiones. Se determinó la circulación del genotipo de Asia del virus del chikungunya como la causa de la primera epidemia en Colombia. Es necesario continuar con la vigilancia de genotipos, con el fin de detectar posibles cambios en la epidemiología, la eficacia ( fitness ) viral y la patogenia del virus.

Introduction: Chikungunya virus (CHIKV) is a single-stranded positive sense RNA virus that belongs to the Alphavirus genus of the family Togaviridae. Its genome is 11.8 kb in length, and three genotypes have been identified worldwide: Asian, East/Central/South African (ECSA) and West African. Chikungunya fever is an acute febrile disease transmitted by Aedes spp . that usually presents with polyarthralgia and cutaneous eruption. Following introduction of the virus to the Americas in 2013, the first cases in Colombia occurred in September of 2014, and they reached a cumulative total of 399,932 cases by June of 2015. Objective: To identify the genotype or genotypes responsible for the current epidemic in Colombia and to describe the genetic variability of the virus in the country. Materials and methods: Serum samples from patients presenting with symptoms compatible with Chikungunya fever during 2014-2015 were selected for the study. RT-PCR products of the E1 gene from these samples were used for sequencing and subsequent phylogenetic and adaptive evolution analyses. Results: The study identified only the presence of the Asian genotype in Colombia. Comparing the Colombian sequences with other sequences from the Americas revealed an average of 0.001 base substitutions per site, with 99.7% and 99.9% nucleotide identity and 99.9% amino acid identity. The adaptive evolution analysis indicated that the E1 gene is under strong purifying selection. Conclusions: The first epidemic of Chikunguya fever in Colombia was caused by the circulation of the virus Asian genotype. Further genotypic surveillance of the virus in Colombia is required to detect possible changes in its epidemiology, fitness and pathogenicity.

Phylogenetic analysis of Chikungunya virus in Colombia: Evidence of purifying selection in the E1 gene.

INTRODUCTION: Chikungunya virus (CHIKV) is a single-stranded positive sense RNA virus that belongs to the Alphavirus genus of the family Togaviridae. Its genome is 11.8 kb in length, and three genotypes have been identified worldwide: Asian, East/Central/South African (ECSA) and West African. Chikungunya fever is an acute febrile disease transmitted by Aedes spp. that usually presents with polyarthralgia and cutaneous eruption. Following introduction of the virus to the Americas in 2013, the first cases in Colombia occurred in September of 2014, and they reached a cumulative total of 399,932 cases by June of 2015.  OBJECTIVE: To identify the genotype or genotypes responsible for the current epidemic in Colombia and to describe the genetic variability of the virus in the country.  MATERIALS AND METHODS: Serum samples from patients presenting with symptoms compatible with Chikungunya fever during 2014-2015 were selected for the study. RT-PCR products of the E1 gene from these samples were used for sequencing and subsequent phylogenetic and adaptive evolution analyses.  RESULTS: The study identified only the presence of the Asian genotype in Colombia. Comparing the Colombian sequences with other sequences from the Americas revealed an average of 0.001 base substitutions per site, with 99.7% and 99.9% nucleotide identity and 99.9% amino acid identity. The adaptive evolution analysis indicated that the E1 gene is under strong purifying selection.  CONCLUSIONS: The first epidemic of Chikunguya fever in Colombia was caused by the circulation of the virus Asian genotype. Further genotypic surveillance of the virus in Colombia is required to detect possible changes in its epidemiology, fitness and pathogenicity.

Virology, immunology and pathology of human rabies during treatment.

BACKGROUND: Rabies is an acute fatal encephalitis caused by all members of the Lyssavirus genus. The first human rabies survivor without benefit of prior vaccination was reported from Milwaukee in 2005. We report a second unvaccinated patient who showed early recovery from rabies and then died accidentally during convalescence, providing an unparalleled opportunity to examine the histopathology as well as immune and virological correlates of early recovery from human rabies. METHODS: Case report, rapid fluorescent focus inhibition test, enzyme-linked immunosorbent assay, indirect and direct fluorescent antibody assays, reverse-transcriptase polymerase chain reaction, phylogenetic reconstruction, isolation in tissue culture, pathology and immunohistochemistry. RESULTS: The 9 year old died 76 days after presenting with rabies of vampire bat phylogeny transmitted by cat bite. Antibody response in serum and cerebrospinal fluid was robust and associated with severe cerebral edema. No rabies virus was cultured at autopsy. Rabies virus antigen was atypical in size and distribution. Rabies virus genome was present in neocortex but absent in brainstem. CONCLUSIONS: Clinical recovery was associated with detection of neutralizing antibody and clearance of infectious rabies virus in the central nervous system by 76 days but not clearance of detectable viral subcomponents such as nucleoprotein antigen or RNA in brain.

The relevance of dengue virus genotypes surveillance at country level before vaccine approval.

Dengue is a major threat for public health in tropical and subtropical countries around the world. In the absence of a licensed vaccine and effective antiviral therapies, control measures have been based on education activities and vector elimination. Current efforts for developing a vaccine are both promising and troubling. At the advent of the introduction of a tetravalent dengue vaccine, molecular surveillance of the circulating genotypes in different geographical regions has gained considerable importance. A growing body of in vitro, preclinical, and clinical phase studies suggest that vaccine conferred protection in a geographical area could depends on the coincidence of the dengue virus genotypes included in the vaccine and those circulating. In this review we present the state-of-the-art in this field, highlighting the need of deeper knowledge on neutralizing immune response for making decisions about future vaccine approval and the potential need for different vaccine composition for regional administration.

Transmisión del virus de la rabia entre murciélagos urbanos del departamento del Valle del Cauca, Colombia, 1999-2008 / Rabies virus transmission among urban bats in the department of Valle del Cauca, Colombia, 1999-2008

Introducción. La intromisión humana en ecosistemas silvestres ha provocado cambios de comportamiento en los murciélagos, con la consecuente invasión a viviendas, convirtiéndolos en un factor de riesgo para la transmisión de la rabia a humanos y mascotas. Objetivos. Determinar en el departamento del Valle del Cauca, las asociaciones entre hábitos de comportamiento y transmisión de rabia entre murciélagos y su significado epidemiológico con énfasis en riesgo para la población humana. Materiales y métodos. Durante el periodo de diciembre 1999 a junio 2008, fueron capturados 1.321 murciélagos por el programa de vigilancia de rabia en el departamento del Valle del Cauca. El diagnóstico de rabia se hizo por inmunofluorescencia directa e inoculación en ratones, utilizando tejido encefálico de los murciélagos capturados. La tipificación viral se hizo por inmunofluorescencia indirecta usando anticuerpos monoclonales. Resultados. Se detectaron dos ejemplares de Eptesicus brasiliensis positivos para rabia en los años 2000 y 2002, y dos casos más en especímenes de E. brasiliensis y Molossus molossus, en el 2008. No se detectó el virus de la rabia en E. brasiliensis ni en M. molossus, ni en ninguna otra especie durante los años 1999, 2001, 2003, 2004, 2006 y 2007. Se encontraron distintas especies de murciélagos, como E. brasiliensis, M. molossus, Myotis nigricans, Glossophaga soricina, Noctiliio albiventris y Carollia perspicillata, compartiendo refugios en casas. Se detectaron virus rábicos de las variantes antigénicas 3 y 4, en murciélagos M. molossus y E. brasiliensis. Conclusiones. La presencia en el Departamento del Valle del Cauca de las variantes antigénicas 3 y 4 del virus rábico en murciélagos no hematófagos de hábitos caseros, probablemente, ha sido facilitada por la deforestación de los hábitats naturales de estas especies; además, el estilo de arquitectura urbana provee un hábitat artificial que posibilita el contacto físico entre las especies y la transmisión de rabia entre ellas. Ante las dificultades para controlar la rabia en murciélagos y la falta de herramientas adecuadas, la vigilancia continua de la enfermedad en los murciélagos, basada en el diagnóstico y la tipificación de los virus rábicos por laboratorio, en de los asentamientos humanos y alrededor de ellos, la vacunación preventiva en animales domésticos y de producción, así como la educación de la comunidad (para la concientización del riesgo y la recolección pasiva de muestras para su análisis), se convierten en las mejores herramientas para prevenir la transmisión a humanos.

Introduction: Human activities in the wild have recently increased the changes in bat behavior and invasion of houses, turning these animals into a health threat for humans and pets. Objectives: To determine the associations between behavioral habits and rabies transmission among bats in the department of Valle del Cauca and to assess the risk the existence of rabies in house dwelling bats presents for human health. Material and methods: In the period from December 1999 to June 2008, 1,321 hematophagous and non-hematophagous bats were captured for rabies epidemiological surveillance in the department of Valle del Cauca, Colombia. Rabies was diagnosed by direct immunofluorescence test on the brain tissue of collected animals. Viral typification was achieved by indirect immunofluorecense using rabies specific monoclonal antibodies. Results: Four bats were positive for rabies: two Eptesicus brasiliensis in 2000 and 2002, and an Eptesicus brasiliensis and a Molossus molossus in 2008. During the years 1999, 2001, 2003, 2004, 2006 and 2007 no rabies virus was found in E. brasiliensis and M. molossus or in any other bat species. Various species including E. brasiliensis, M. molossus, Myotis nigricans, Glossophaga soricina, Noctiliio albiventris and Carollia perspicillata were found sharing shelters in houses. Rabies virus antigenic variants 3 and 4 were found in M. molossus and E. brasiliensis bats only. Conclusions: The presence and potential spread of rabies antigenic variants 3 and 4 to cities have very likely been facilitated by the perturbation of the natural habitats of non-hematophagous bats in the department of Valle del Cauca; the urban architecture style also provides an artificial habitat which allows for physical contact and rabies transmission among the species. Seeing the difficulty for controlling rabies in bats and the lack of adequate tools, intensive laboratory based rabies surveillance in and around human settlements, preventive vaccination for house and production animals, and education for the community (in relation to increasing the awareness concerning the risk, and passive recollection of samples for analysis) represent major preventive strategies against bat rabies transmission to humans and pets.

Evaluación de la seroconversión como respuesta a la vacunación antirrábica en perros en el departamento del Valle del Cauca, Colombia, 2009 / Evaluation of the seroconversion as a response to rabies vaccination in dogs, Valle del Cauca, Colombia, 2009

Introducción. El departamento del Valle del Cauca ha estado libre de rabia canina por más de 20 años, aunque persisten focos de rabia silvestre que amenazan a humanos y sus mascotas; por ello, como medida preventiva. se realizan anualmente campañas de vacunación antirrábica canina. Objetivos. Medir el impacto de la vacunación en términos de seroconversión de anticuerpos neutralizadores y de porcentaje de perros con respuesta inmunitaria humoral adecuada, relacionando variables propias de estos animales y de las condiciones de vacunación. Discutir el significado epidemiológico de los resultados y sus implicaciones en salud pública. Materiales y métodos. Se obtuvo suero e información de 569 perros vacunados en los 42 municipios de Valle del Cauca. La inmunidad humoral se investigó por ELISA cuantitativa. La información se analizó con el programa Epi-Info 6.0. Resultados. El 9,1 % de los perros de la muestra fueron seronegativos y el 25,1 % no evidenciaron respuesta inmunitaria humoral adecuada a la vacunación. La concentración de anticuerpos disminuyó gradualmente desde la aplicación de la vacuna, y estuvo asociada a edad y calidad de las vacunas, aunque no estuvo asociada a sexo ni a raza. Conclusiones. Con el fin de aumentar los porcentajes de perros seropositivos y con respuesta inmunitaria humoral adecuada, se hacen las siguientes recomendaciones: 1) utilizar vacunas antirrábicas viables;2) aplicar dos dosis de vacuna durante los primeros seis meses de vida de los cachorros; 3) aplicar refuerzos de vacuna, por lo menos, una vez al año; 4) que las autoridades vigilen las actividades y los procesos programáticos relacionados con la vacunación antirrábica por particulares.

Introduction. The province of Valle del Cauca has been free of dog rabies for more than 20 years. However, sylvatic rabies foci remain which are threats to the health of the populace and its pets. Rabies vaccination campaigns are carried out annually in all 42 counties of the province. Objectives. The impact of dog vaccination was evaluated on the basis of humoral immunoresponse, population parameters and correlation with variables inherent to the vaccination process and logistics. Materials and methods. Sera and associated data were obtained from each of the 42 counties for a total sample of 569 rabies-vaccinated dogs. Rabies neutralizing antibodies were measured by quantitative ELISA. The data were analyzed with the statistical programs in Epi-Info 6.0. Results. Nearly 10% of dogs were seronegative (9.1%) and an additional 25.1% did not elicit an adequate humoral immune response to vaccination. Concentration of rabies neutralizing antibodies diminished gradually with the time after vaccination and was correlated with dog age and vaccine quality. No associations were noted between dog gender or breed. Conclusions. These data permit the following recommendations: (1) only viable, non expired rabies vaccines must be used to immunize animals, (2) two doses of rabies vaccine must be applied during the first six months of dog life, (3) booster immunizations must be administered every year, (4) practices and processes related to rabies vaccination in private institutions must inspected regularly by health authorities.

[Evaluation of the seroconversion as a response to rabies vaccination in dogs, Valle del Cauca, Colombia, 2009]. / Evaluación de la seroconversión como respuesta a la vacunación antirrábica en perros en el departamento del Valle del Cauca, Colombia, 2009.

INTRODUCTION: The province of Valle del Cauca has been free of dog rabies for more than 20 years. However, sylvatic rabies foci remain which are threats to the health of the populace and its pets. Rabies vaccination campaigns are carried out annually in all 42 counties of the province. OBJECTIVES: The impact of dog vaccination was evaluated on the basis of humoral immunoresponse, population parameters and correlation with variables inherent to the vaccination process and logistics. MATERIALS AND METHODS: Sera and associated data were obtained from each of the 42 counties for a total sample of 569 rabies-vaccinated dogs. Rabies neutralizing antibodies were measured by quantitative ELISA. The data were analyzed with the statistical programs in Epi-Info 6.0. RESULTS: Nearly 10% of dogs were seronegative (9.1%) and an additional 25.1% did not elicit an adequate humoral immune response to vaccination. Concentration of rabies neutralizing antibodies diminished gradually with the time after vaccination and was correlated with dog age and vaccine quality. No associations were noted between dog gender or breed. CONCLUSIONS: These data permit the following recommendations: (1) only viable, non expired rabies vaccines must be used to immunize animals, (2) two doses of rabies vaccine must be applied during the first six months of dog life, (3) booster immunizations must be administered every year, (4) practices and processes related to rabies vaccination in private institutions must inspected regularly by health authorities.

Brote de rabia humana transmitida por gato en el municipio de Santander de Quilichao, Colombia, 2008 / An outbreak of human rabies transmitted by a cat in the town of Santander de Quilichao, Colombia, 2008

Objetivos En marzo de 2008 ocurrió en el municipio de Santander de Quilichao- Cauca, Colombia, un brote de rabia de origen silvestre con 2 víctimas humanas. El presente artículo apunta a describir las técnicas diagnósticas de laboratorio, las acciones de investigación de campo y control de foco empleadas, y su significado epidemiológico e implicaciones en salud pública. Métodos La rabia se diagnosticó por inmunofluorescencia directa, prueba biológica en ratón, histopatología e inmunohistoquímica, y se tipificó utilizando anticuerpos monoclonales. La investigación de campo se enfocó en la búsqueda de contactos humanos y animales, identificación de casos sospechosos y búsqueda institucional de accidentes rábicos. El control de foco consistió en aplicación de tratamiento post exposición a la población expuesta, vacunación canina y felina, recolección y eliminación de animales callejeros y educación a la comunidad. Resultados Dos casos de rabia en humanos fueron diagnosticados y uno en gato por nexo epidemiológico. La variante antigénica 3 fue aislada de los casos humanos. Se vacunaron en total 11 369 caninos, 3 325 felinos y 217 humanos. Conclusiones Se confirma la amenaza para los humanos que representa la rabia en el ecosistema silvestre. El brote tuvo origen en vampiro y el transmisor a los humanos fue un gato confirmando a esta especie doméstica como vínculo entre la rabia de origen silvestre y el ecosistema urbano, por ende su importancia en el enfoque de las acciones de prevención y control de la rabia. Se resalta la necesidad de implementar y mantener acciones para el control de la rabia silvestre que permitan minimizar su impacto en humanos.

Objectives A sylvatic rabies outbreak during March 2008 caused two human deaths in the town of Santander de Quilichao in Cauca, Colombia. This article describes the diagnostic laboratory techniques used, the field investigation and focus control used, as well as this outbreak's epidemiological significance and implications for public health. Methods Rabies was diagnosed by direct immunofluorescence, biological tests involving inoculating mice, histopathology and immunohistochemistry and then typed by using monoclonal antibodies. Field investigation focused on searching for human and animal contacts, identifying suspicious cases and conducting an institutional search for rabid accidents. Focus control consisted of post-exposure treatment of the exposed population, vaccinating dogs and cats, collecting and eliminating stray animals and educating the community. Results Two human rabies cases were confirmed in the laboratory and another was inferred in a cat by epidemiological nexus. Antigenic variant 3 was isolated from the human cases. 11,369 dogs, 3,325 cats and 217 humans were vaccinated. Conclusions This study confirmed that rabies in the wild represents a threat for humans. The outbreak described here originated in vampire bats and was transmitted to humans by a cat, pointing out the nexus between wild rabies and the urban ecosystem which cats represent, thereby becoming a target for rabies' control and prevention activities. This study underlines the urgency of implementing and maintaining rabies control and prevention activities in the wild to minimise its impact on humans.

Brote de rabia urbana transmitida por perros en el distrito de Santa Marta, Colombia, 2006-2008 / Outbreak of urban rabies transmitted by dogs in Santa Marta, northern Colombia

Introducción. En el distrito de Santa Marta ocurrió un brote de rabia urbana entre abril de 2006 y enero de 2008, con cuatro casos fatales en humanos y 28 en perros. Objetivos. Describir el brote, las técnicas de diagnóstico de laboratorio y las acciones de control de foco empleadas. Medir el impacto de la vacunación antirrábica canina en términos de seroconversión de anticuerpos neutralizantes. Discutir el significado epidemiológico y las implicaciones en salud pública. Materiales y métodos. Los casos se diagnosticaron por inmunofluorescencia directa, prueba biológica en ratón e inmunohistoquímica. La tipificación viral se hizo por inmunofluorescencia indirecta. Las acciones de control consistieron en un censo canino, vacunación y tratamientos antirrábicos a la población expuesta, vacunación canina y felina, y educación comunitaria. La seroconversión fue investigada por medio de la prueba ELISA de captura. Resultados. La variante antigénica 1 se caracterizó en todos los casos. Se observó seropositividad en 77% de los perros vacunados y protección serológica contra la rabia, en 47%. No se observaron diferencias de la respuesta humoral entre sexos de los perros, pero sí existieron diferencias de los porcentajes de perros protegidos entre las comunas del distrito. Conclusiones. Este brote de rabia ha sido el de mayor magnitud en una ciudad colombiana, según los datos oficiales. Fue causado por perros, lo cual reitera la amenaza que aún representa la rabia urbana para la salud pública, a pesar de la existencia de vacunas eficientes. El control del brote se logró 20 meses después del primer caso en perros y 14 meses después de haberse iniciado la primera vacunación masiva en animales. Es necesario implementar y mantener acciones para el control de la rabia urbana y evitar su impacto en los humanos.

Introduction. An urban rabies outbreak occurred in the District of Santa Marta between April 2006 and January 2008, which resulted in the deaths of 4 humans and 28 dogs. Objectives. Three objectives were entertained—first, the diagnostic laboratory techniques were described as well as the rabies control actions taken; second, the impact of anti-rabies dog vaccination was assessed in terms of neutralizing antibody seroconversion; and third, the epidemiological significance and public health implications of the outbreak were examined. Materials and methods. Rabies diagnosis was achieved by direct immunofluorescence, inoculation of mice and immunohistochemistry. Typing of the virus was achieved by indirect immunofluorescence. Control activities included a dog population census, vaccination and treatments for persons exposed to rabies, mass vaccination of dogs and cats, and initiation of a community education program. Seroconversion was investigated by capture ELISA. Results. Antigenic variant 1 was detected in all cases. Of vaccinated dogs, 77% were seropositive, and 47% were seroprotected against rabies. No differences were found in the humoral response between dog gender; however significant differences in dog seroprotection were discovered between localized comunities in Santa Marta. Conclusions. The 2006-2008 urban rabies outbreak was the largest reported in a city in Colombia. It was caused by rabid dogs, and demonstrated that these animals are still a threat for human health despite the existence of efficient rabies vaccines. The control of the outbreak was achieved 20 months after the first rabies case in dogs, and 14 months after the initiation of the first mass vaccination of animals. The necessity of implementation and maintenance of rabies control strategies is underlined for minimizing human risk.

[Outbreak of urban rabies transmitted by dogs in Santa Marta, northern Colombia]. / Brote de rabia urbana transmitida por perros en el distrito de Santa Marta, Colombia, 2006-2008.

INTRODUCTION: An urban rabies outbreak occurred in the District of Santa Marta between April 2006 and January 2008, which resulted in the deaths of 4 humans and 28 dogs. OBJECTIVES: Three objectives were entertained-first, the diagnostic laboratory techniques were described as well as the rabies control actions taken; second, the impact of anti-rabies dog vaccination was assessed in terms of neutralizing antibody seroconversion; and third, the epidemiological significance and public health implications of the outbreak were examined. MATERIALS AND METHODS: Rabies diagnosis was achieved by direct immunofluorescence, inoculation of mice and immunohistochemistry. Typing of the virus was achieved by indirect immunofluorescence. Control activities included a dog population census, vaccination and treatments for persons exposed to rabies, mass vaccination of dogs and cats, and initiation of a community education program. Seroconversion was investigated by capture ELISA. RESULTS: Antigenic variant 1 was detected in all cases. Of vaccinated dogs, 77% were seropositive, and 47% were seroprotected against rabies. No differences were found in the humoral response between dog gender; however significant differences in dog seroprotection were discovered between localized comunities in Santa Marta. CONCLUSIONS: The 2006-2008 urban rabies outbreak was the largest reported in a city in Colombia. It was caused by rabid dogs, and demonstrated that these animals are still a threat for human health despite the existence of efficient rabies vaccines. The control of the outbreak was achieved 20 months after the first rabies case in dogs, and 14 months after the initiation of the first mass vaccination of animals. The necessity of implementation and maintenance of rabies control strategies is underlined for minimizing human risk.

[An outbreak of human rabies transmitted by a cat in the town of Santander de Quilichao, Colombia, 2008]. / Brote de rabia humana transmitida por gato en el municipio de Santander de Quilichao, Colombia, 2008.

OBJECTIVES: A sylvatic rabies outbreak during March 2008 caused two human deaths in the town of Santander de Quilichao in Cauca, Colombia. This article describes the diagnostic laboratory techniques used, the field investigation and focus control used, as well as this outbreak's epidemiological significance and implications for public health. METHODS: Rabies was diagnosed by direct immunofluorescence, biological tests involving inoculating mice, histopathology and immunohistochemistry and then typed by using monoclonal antibodies. Field investigation focused on searching for human and animal contacts, identifying suspicious cases and conducting an institutional search for rabid accidents. Focus control consisted of post-exposure treatment of the exposed population, vaccinating dogs and cats, collecting and eliminating stray animals and educating the community. RESULTS: Two human rabies cases were confirmed in the laboratory and another was inferred in a cat by epidemiological nexus. Antigenic variant 3 was isolated from the human cases. 11,369 dogs, 3,325 cats and 217 humans were vaccinated. CONCLUSIONS: This study confirmed that rabies in the wild represents a threat for humans. The outbreak described here originated in vampire bats and was transmitted to humans by a cat, pointing out the nexus between wild rabies and the urban ecosystem which cats represent, thereby becoming a target for rabies' control and prevention activities. This study underlines the urgency of implementing and maintaining rabies control and prevention activities in the wild to minimise its impact on humans.

Molecular epidemiology of rabies in Colombia 1994-2005 based on partial nucleoprotein gene sequences.

One hundred and twenty-four rabies viruses (RABV) were isolated from humans and eight species of mammals in Colombia during 1994-2005. To determine the genetic and reservoir-associated diversity cDNA fragments encoding 88 amino acids at the carboxyl terminus of the nucleoprotein were sequenced and used in phylogenetic analyses. Eight genetic lineages (GL) were characterized. GL1, GL2 and GL3 consisted of dog-associated antigenic variant (AV) 1 RABV, isolated in the centre-east, north and southwest of Colombia, respectively. GL1 is apparently extinct in Colombia. The GL4 were AV3, AV8 and non-determined (ND) AV viruses associated with hematophagous bats. The GL5 and GL6 consisted of AV4 viruses. GL6 isolate was found associated with Tadarida brasiliensis bats. GL5 segregated independently. The GL7 and GL8 segregated independently within clades associated with colonial insectivorous and solitary bats, respectively. Both of these were represented by NDAV viruses. Viruses isolated from humans grouped within GL2, GL3 and GL4, which in turn corresponded to AV1, 3, 8 and ND. Dogs and D. rotundus are the two major rabies reservoirs and vectors in Colombia. Insectivorous bats may also be important rabies reservoirs but spillovers to other species are rare. Our data were consistent with previous studies in which partial Psi, G and L gene sequences were analyzed. Our results confirmed the existence of RABV of unclassified AV in Colombia.

[Outbreaks of human rabies transmitted by vampire bats in Alto Baudó and Bajo Baudó municipalities, department of chocó, Colombia, 2004-2005]. / Brotes de rabia humana transmitida por vampiros en los municipios de Bajo y Alto Baudó, departamento del Chocó, Colombia 2004-2005.

INTRODUCTION: During months May to July 2004, a rabies outbreak in the Embera community of Birrinchao, in the Purricha river basin department of Choc6 was reported with 14 human deaths. Another rabies outbreak was reported in January 2005 in the black communities of Pató and Nauca in the neighboring municipality of Alto Baudó with 3 human deaths. OBJECTIVES: To describe the largest outbreaks of human rabies transmitted by vampire bats reported in Colombia to date. To describe the diagnostic laboratory techniques used, and the activities undertaken for the control of rabies in the area. To discuss the epidemiologic significance and public health implications of these rabies outbreaks. MATERIALS AND METHODS: Rabies diagnosis was achieved by direct immunofluorescence, inoculation of mice and immunohistochemistry. Typing of the virus was achieved by indirect immunofluorescence using monoclonal antibodies. Rabies control activities were undertaken in Bajo Baudó consisting in a population census, human vaccination and application of antirabies sera, vaccination of dogs and cats, and application of anticoagulant to bats. RESULTS: Four human cases were confirmed as positive for rabies in both rabies outbreaks. Another 13 rabies cases in humans were inferred by strong epidemiological links. Rabies antigenic variant 3 was identified in the samples studied. Rabies control activities were conducted for a human rabies outbreak caused by vampire bats. CONCLUSIONS: The human rabies outbreak in Bajo Baudó has been the largest reported in Colombia. It was caused by vampire bats, showing that these animals are a threat for human health. The implementation of control strategies for this kind of epizootic outbreaks is needed in South America. It remains unknown whether there is a link between this outbreak and one reported 6 months later in the neighboring municipality of Alto Baudó.

Comparación de la incidencia de complicaciones entre residentes y especialistas en la cateterización venosa central en un hospital universitario / Comparison of the incidence of complications between residents and specialists in the central venous cateterización in a university hospital

La cateterización venosa central es esencial para el manejo clínico de muchos pacientes (1). Este procedimiento que se realiza a diario en las Unidades de Cuidado Crítico, salas de Cirugía y Emergencias, conlleva riesgos inherentes que pueden generar complicaciones serias. Durante su entrenamiento, los residentes deben desarrollar las habilidades y destrezas necesarias para efectuar este procedimiento, siguiendo estrictamente los protocolos establecidos con el objeto de minimizar los posibles riesgos y sus complicaciones. Objetivo: Evaluar la calidad del proceso educacional en la cateterización venosa central, en términos de seguridad para el paciente en el Hospital Universitario Fundación Santa Fe de Bogotá. Métodos: Estudio de cohorte analítica. Se incluyeron todos los pacientes sometidos a una cateterización venosa central, en el período de octubre de 1991 a octubre de 2004 en un Hospital Universitario de Bogotá. Se comparó la incidencia de complicaciones mecánicas mayores: neumotórax, quilotórax y hemotórax, tanto en el grupo de especialistas como en el de residentes; además, se realizó un análisis estratificado de acuerdo a la ruta de inserción. Adicionalmente, se analizò la incidencia de bacteriemia relacionada con el catéter con la misma estratificación. Resultados: Durante el período de estudio se insertaron 6532 catéteres, de los cuales 2860 (43.78 por ciento) fueron colocados por especialistas y 3672 (56.22 por ciento) por residentes. Se registraron 60 complicaciones mecánicas mayores, de las cuales 38 se presentaron en el grupo de residentes y 22 en el grupo de especialistas. Riesgo relativo: 0,73; IC95 (0,40; 1,35). No se encontraron diferencias estadísticamente significativas cuando se hizo el análisis estratificado por las diferentes vías de inserción. En cuanto a la bacteriemia relacionada con catéter, se hallaron diferencias estadísticamente significativas entre los dos grupos. En el grupo de especialistas se presentaron 14 bacteriemias y en e...

A phylogenetic reconstruction of the epidemiological history of canine rabies virus variants in Colombia.

Historically, canine rabies in Colombia has been caused by two geographically distinct canine variants of rabies virus (RV) which between 1992 and 2002 accounted for approximately 95% of Colombian rabies cases. Genetic variant 1 (GV1) has been isolated up until 1997 in the Central Region and the Department of Arauca, and is now considered extinct through a successful vaccination program. Genetic variant 2 (GV2) has been isolated from the northern Caribbean Region and continues to circulate at present. Here we have analyzed two sets of sequence data based upon either a 147 nucleotide region of the glycoprotein (G) gene or a 258 nucleotide region that combines a fragment of the non-coding intergenic region and a fragment of the polymerase gene. Using both maximum likelihood (ML) and Markov chain Monte Carlo (MCMC) methods we have estimated the time of the most recent common ancestor (MRCA) of the two variants to be between 1983 and 1988. Reconstructions of the population history suggest that GV2 has been circulating in Colombia since the 1960s and that GV1 evolved as a separate lineage from GV2. Estimations of the effective population size at present show the GV2 outbreak to be approximately 20 times greater than that of GV1. Demographic reconstructions were unable to detect a decrease in population size concurrent with the elimination of GV1. We find a raised rate of nucleotide substitution for GV1 gene sequences when compared to that of GV2, although all estimates have wide confidence limits. We demonstrate that phylogenetic reconstructions and sequence analysis can be used to support incidence data from the field in the assessment of RV epidemiology.

[Molecular epidemiology of rabies epizootics in Colombia, 1994-2002: evidence of human and canine rabies associated with chiroptera]. / Epidemiología molecular de epizootias de rabia en Colombia, 1994-2002: evidencia de rabia humana y canina asociada a quirópteros.

Three urban rabies outbreaks have been reported in Colombia during the last two decades, one of which is ongoing in the Caribbean region (northern Colombia). The earlier outbreaks occurred almost simultaneously in Arauca (eastern Colombia) and in the Central region, ending in 1997. Phylogenetic relationships among rabies viruses isolated from the three areas were based on a comparison of cDNA fragments coding for the endodomain of protein G and a fragment of L protein obtained by RT-PCR. The sequenced amplicons which included the G-L intergenic region contained 902 base pairs. Phylogenetic analysis showed three distinct groups of viruses. Colombian genetic variant I viruses were isolated only from Arauca and the Central region, but are now apparently extinct. Colombian genetic variant II viruses were isolated in the Caribbean region and are still being transmitted in that area. The third group of bat rabies variants were isolated from two insectivorous bats, three domestic dogs and a human. This associates bat rabies virus with rabies in Colombian dogs and humans, and indicates bats to be a rabies reservoir of public health significance.

Molecular epidemiology of rabies epizootics in Colombia: evidence for human and dog rabies associated with bats.

Three urban rabies outbreaks have been reported in Colombia during the last two decades, one of these is occurring in the Caribbean Region (northern Colombia), while the other two occurred almost simultaneously in Arauca (eastern Colombia) and in the Central Region and ended in 1997. In order to derive phylogenetic relationships between rabies viruses isolated in these three areas, 902 nt cDNA fragments encoding the cytoplasmic domain of protein G and a fragment of protein L were obtained by RT-PCR. These amplicons contained the G-L intergenic region and were sequenced to draw phylogenetic trees. Phylogenetic analysis showed three distinct groups of viruses in the study sample. Colombian genetic variant I viruses were isolated in both Arauca and the Central Region. These viruses are apparently extinct in Colombia. Colombian genetic variant II viruses were isolated in the Caribbean Region and are still being transmitted in that area. The third group of viruses consists of viruses isolated from two insectivorous bats, three domestic dogs and a human. According to sequence analysis, the data here indicate that the isolates in this third group are bat rabies virus variants. This finding is the first that associates bats to rabies in Colombian dogs and humans, showing an unsuspected vector threatening animal and public health.

Epidemiología molecular de epizootias de rabia en Colombia, 1994-2002: evidencia de rabia humana y canina asociada a quirópteros / Molecular epidemiology of rabies epizooties in Colombia, 1994 - 2002. Evidence of human and canine rabies associated with bats

Tres brotes de rabia canina han sido informados en Colombia durante las pasadas dos décadas, uno de los cuales aún ocurre en la Región Caribe. Los otros dos ocurrieron en el departamento de Arauca y en la Región Central (departamentos de Boyacá y Cundinamarca) hasta 1997. Con la finalidad de investigar las relaciones filogenéticas existentes entre los virus r bicos aislados en las regiones mencionadas, se empleó la técnica de RT-PCR para obtener fragmentos de ADN de 902 nucleótidos complementarios a una región del ARN rábico codificante para el endodominio de la proteína G, para una parte de la proteína L, fragmentos que, además, contienen la región intergénica no codificante G-L. Los amplificados fueron secuenciados y agrupados en árboles filogenéticos. Los resultados mostraron la existencia de tres grupos de virus. Los virus r bicos pertenecientes a la variante genética colombiana I fueron aislados exclusivamente en el departamento de Arauca y la Región Central colombiana hasta 1997 y, aparentemente, se encuentran extintos. Los virus rábicos pertenecientes a la variante genética colombiana II fueron aislados exclusivamente en la Región Caribe, en donde actualmente su transmisión continúa. Un tercer grupo se compone de variantes rábicas originarias de quirópteros, que fueron aisladas de dos murciélagos insectívoros, tres perros y un humano. Con este trabajo se estableció una asociación entre los quirópteros y la rabia en perros y humanos en Colombia, lo cual los muestra como reservorios de importancia en salud pública.