Human parainfluenza virus in patients with influenza-like illness from Central and South America during 2006-2010.

BACKGROUND: Human parainfluenza viruses (HPIVs) are common viral causes of community-acquired pneumonia, particularly in children. The four types of HPIV have world-wide distribution; however, limited information exists about the epidemiological profile of HPIV in Latin-America. OBJECTIVE: Provide epidemiologic and phylogenetic information about HPIVs that circulated in Latin America between 2006 and 2010 to better characterize the extent and variability of this respiratory virus in the region. METHODS: Oropharyngeal swabs, demographic data and clinical characteristics were obtained from individuals with influenza-like illness in 10 Latin-American countries between 2006-2010. Specimens were analyzed with culture and molecular methods. RESULTS: A total of 30 561 individuals were enrolled; 991 (3·2%) were HPIV positive. Most infected participants were male (53·7%) and under 5 years of age (68·7%). The HPIV type most frequently isolated was HPIV-3 (403, 40·7%). In 66/2007 (3·3%) hospitalized individuals, HPIV was identified. The most frequent symptoms at enrollment were cough and rhinorrhea. We identified certain patterns for HPIV-1, -2 and -3 in specific cities. Phylogenetic analysis revealed a homogeneous distribution in the region. CONCLUSIONS: In the current scenario, no vaccine or treatment is available for this pathogen. Our results contribute to the scarce epidemiologic and phylogenetic information of HPIV in the region that could support the development of specific management.

Human rhinoviruses and enteroviruses in influenza-like illness in Latin America.

BACKGROUND: Human rhinoviruses (HRVs) belong to the Picornaviridae family with high similarity to human enteroviruses (HEVs). Limited data is available from Latin America regarding the clinical presentation and strains of these viruses in respiratory disease. METHODS: We collected nasopharyngeal swabs at clinics located in eight Latin American countries from 3,375 subjects aged 25 years or younger who presented with influenza-like illness. RESULTS: Our subjects had a median age of 3 years and a 1.2:1.0 male:female ratio. HRV was identified in 16% and HEV was identified in 3%. HRVs accounted for a higher frequency of isolates in those of younger age, in particular children < 1 years old. HRV-C accounted for 38% of all HRVs detected. Phylogenetic analysis revealed a high proportion of recombinant strains between HRV-A/HRV-C and between HEV-A/HEV-B. In addition, both EV-D68 and EV-A71 were identified. CONCLUSIONS: In Latin America as in other regions, HRVs and HEVs account for a substantial proportion of respiratory viruses identified in young people with ILI, a finding that provides additional support for the development of pharmaceuticals and vaccines targeting these pathogens.

Human metapneumovirus strains circulating in Latin America.

The human metapneumovirus (HMPV) is responsible for acute respiratory tract infections in young children, elderly patients, and immunocompromised hosts. In this study, we genetically analyzed the circulating HMPV in Central and South America from July 2008 to June 2009 and characterized the strains present in this region. Samples were collected during an international collaborative influenza like illness surveillance study and then sequenced with specific primers for the HMPV G gene. Our results show that two distinct clusters of HMPV circulated in Central and South America, subtypes A2 and B2 being the predominant strains.

Circulating strains of human respiratory syncytial virus in central and south America.

Human respiratory syncytial virus (HRSV) is a major cause of viral lower respiratory tract infections among infants and young children. HRSV strains vary genetically and antigenically and have been classified into two broad subgroups, A and B (HRSV-A and HRSV-B, respectively). To date, little is known about the circulating strains of HRSV in Latin America. We have evaluated the genetic diversity of 96 HRSV strains by sequencing a variable region of the G protein gene of isolates collected from 2007 to 2009 in Central and South America. Our results show the presence of the two antigenic subgroups of HRSV during this period with the majority belonging to the genotype HRSV-A2.

Molecular characterization of adenovirus circulating in Central and South America during the 2006-2008 period.

BACKGROUND: Human Adenoviruses are recognized pathogens, causing a broad spectrum of diseases. Serotype identification is critical for epidemiological surveillance, detection of new strains and understanding of HAdvs pathogenesis. Little data is available about HAdvs subtypes in Latin America. METHODS: In this study, we have molecularly characterized 213 adenoviruses collected from ILI presenting patients, during 2006-08, in Central and South America. RESULTS: Our results indicate that 161(76%) adenoviruses belong to subgroup C, 45 (21%) to subgroup B and 7 (3%) to subtype E4.

Abnormal humoral immune response to influenza vaccination in pediatric type-1 human immunodeficiency virus infected patients receiving highly active antiretroviral therapy.

Given that highly active antiretroviral therapy (HAART) has been demonstrated useful to restore immune competence in type-1 human immunodeficiency virus (HIV-1)-infected subjects, we evaluated the specific antibody response to influenza vaccine in a cohort of HIV-1-infected children on HAART so as to analyze the quality of this immune response in patients under antiretroviral therapy. Sixteen HIV-1-infected children and 10 HIV-1 seronegative controls were immunized with a commercially available trivalent inactivated influenza vaccine containing the strains A/H1N1, A/H3N2, and B. Serum hemagglutinin inhibition (HI) antibody titers were determined for the three viral strains at the time of vaccination and 1 month later. Immunization induced a significantly increased humoral response against the three influenza virus strains in controls, and only against A/H3N2 in HIV-1-infected children. The comparison of post-vaccination HI titers between HIV-1+ patients and HIV-1 negative controls showed significantly higher HI titers against the three strains in controls. In addition, post vaccination protective HI titers (defined as equal to or higher than 1:40) against the strains A/H3N2 and B were observed in a lower proportion of HIV-1+ children than in controls, while a similar proportion of individuals from each group achieved protective HI titers against the A/H1N1 strain. The CD4+ T cell count, CD4/CD8 T cells ratio, and serum viral load were not affected by influenza virus vaccination when pre- vs post-vaccination values were compared. These findings suggest that despite the fact that HAART is efficient in controlling HIV-1 replication and in increasing CD4+ T cell count in HIV-1-infected children, restoration of immune competence and response to cognate antigens remain incomplete, indicating that additional therapeutic strategies are required to achieve a full reconstitution of immune functions.

Abnormal humoral immune response to influenza vaccination in pediatric type-1 human immunodeficiency virus infected patients receiving highly active antiretroviral therapy

Given that highly active antiretroviral therapy (HAART) has been demonstrated useful to restore immune competence in type-1 human immunodeficiency virus (HIV-1)-infected subjects, we evaluated the specific antibody response to influenza vaccine in a cohort of HIV-1-infected children on HAART so as to analyze the quality of this immune response in patients under antiretroviral therapy. Sixteen HIV-1-infected children and 10 HIV-1 seronegative controls were immunized with a commercially available trivalent inactivated influenza vaccine containing the strains A/H1N1, A/H3N2, and B. Serum hemagglutinin inhibition (HI) antibody titers were determined for the three viral strains at the time of vaccination and 1 month later. Immunization induced a significantly increased humoral response against the three influenza virus strains in controls, and only against A/H3N2 in HIV-1-infected children. The comparison of post-vaccination HI titers between HIV-1+ patients and HIV-1 negative controls showed significantly higher HI titers against the three strains in controls. In addition, post vaccination protective HI titers (defined as equal to or higher than 1:40) against the strains A/H3N2 and B were observed in a lower proportion of HIV-1+ children than in controls, while a similar proportion of individuals from each group achieved protective HI titers against the A/H1N1 strain. The CD4+ T cell count, CD4/CD8 T cells ratio, and serum viral load were not affected by influenza virus vaccination when pre- vs post-vaccination values were compared. These findings suggest that despite the fact that HAART is efficient in controlling HIV-1 replication and in increasing CD4+ T cell count in HIV-1-infected children, restoration of immune competence and response to cognate antigens remain incomplete, indicating that additional therapeutic strategies are required to achieve a full reconstitution of immune functions.

Neumonía adquirida en la comunidad en lactantes y preescolares del municipio de Turbo, Antioquia / Community acquired neumonia in children aged 2-60 months in Colombia

Se estudiaron 110 niños entre los 2 y los 60 meses de edad, con diagnóstico de neumonía adquirida en la comunidad, en el Hospital Francisco Valderrama del municipio de Turbo, Antioquia, pertenecientes al programa Vida Infantil de la Universidad de Antioquia. Los criterios de inclusión fueron la taquipnea y el tiraje de acuerdo con las normas de la OMS para el diagnóstico de la infección respiratoria baja en lactantes y preescolares en países en vías de desarrollo. Los pacientes se estudiaron microbiológicamente mediante hemocultivos, prueba de látex para antígenos bacterianos en la orina, prueba de Elisa para Mycoplasma pneumoniae y panel respiratorio para los virus que causan más frecuentemente dicha enfermedad. Se hicieron además hemoleucogramas y radiografías pulmonares. Todas las muestras se tomaron bajo criterios protocolizados y se trasladaron por vía aérea a la ciudad de Medellín bajo normas estrictas de conservación, para ser procesadas en el Laboratorio de Investigaciones en Infectología Pediátrica de la Universidad de Antioquia. Los exámenes más adecuados para la comprobación del diagnóstico fueron las radiografías de tórax con 77 por ciento; los hemocultivos con una positividad de 11.1 por ciento, el panel respiratorio con 3.7 por ciento, la prueba de látex para los antígenos bacterianos con 7.4 por ciento y la prueba de ELISA con 0.9 por ciento. Los hemoleucogramas tuvieron un amplio margen de variabilidad. No se encontró relación estadística entre las variables epidemiológicas estudiadas y la gravedad de la infección. El estudio confirma la escasa sensibilidad de los exámenes paraclínicos y reafirma la importancia del diagnóstico clínico temprano como base para iniciar la terapia.

One hundred and ten children aged between 2 and 60 months with the diagnosis of communityacquired pneumoniae, were studied at Francisco Valderrama Hospital in the city of Turbo, Colombia; they belonged to the University of Antioquia Child Life program. Admission criteria were tachypnea and retraction according to the WHO guidelines for lower respiratory tract infection diagnosis in infants and preschool children in developing countries. Patients were studied microbiologically by means of blood cultures, urine latex aggutination test for bacterial antigens, ELISA test for Mycoplasma pneumoniae, and a panel for respiratory viruses that frequently cause this disease. Blood specimens and pulmonary radiographies were also taken under protocolized criteria and the former were transported by plane to Medellín under strict measures of preservation, in order to be processed at the Pediatric Investigation and Infectology Laboratory of the University of Antioquia. Radiographies were positive in 77% of cases, blood cultures in 11.1%, latex agglutination for bacterial antigens in 7.4%, respiratory viruses panel in 3.7%, and ELISA test in 0.9%. Hemoleucograms had a wide range of variability. Relationships between epidemiological variables and the severity of the infection were not found. The study confirms the scarce positivity of paraclinical tests and reaffirms the importance of early clinical diagnosis as the basis for starting therapy

Ganado Blanco Orejinegro (BON): Una alternativa para la producción en Colombia / BON cattle: an alternative for production in Colombia

El ganado Blanco Orejinegro descendiente del ganado traído por Colón durante su segundo viaje, ha sobrevivido durante casi 500 años en las áreas tropicales colombianas productoras de café. Además de su capacidad adaptativa este ganado ha mostrado otras características como: docilidad, habilidad para aprovechar forrajes de mala calidad, gran habilidad materna, mayor precocidad sexual, alta fertilidad, mayor productividad en cruces F1 (carne y leche) y marcada resistencia a ectoparásitos. Estas características, en conjunto con hallazgos moleculares recientes que sugieren alta variabilidad genética y resistencia a patógenos bacterianos y vírales demuestran que esta raza, que en la actualidad se encuentra en vía de extinción, es portadora de información genética importante que la convierte en una alternativa para la producción en las condiciones tropicales. El objetivo de esta revisión es hacer una recopilación de trabajos realizados con ganado BON; además, mostrar las perspectivas de investigación, basados en los trabajos actualmente llevados a cabo en la Universidad de Antioquia, con el fin de demostrar el potencial genético de esta raza, que quizás no ha podido ser expresado debido a las condiciones de manejo a que esta raza ha sido sometida.

Estandarización de un método de ELISA para citomegalovirus humano

En este informe se presenta la caracterización de un método de ELISA para la detección de IgG específica mediante un antígeno obtenido a partir de un sonicado de cultivos celulares infectados con CMV. La prueba se estandarizó con base en un ELISA comercial, encontrándose un coeficiente de correlación de 93 y 95 por ciento. Se practicaron 290 determinaciones con los sueros de 188 personas. El punto de corte para establecer la serorreactividad se determinó como la media aritmética (x) de los delta de densidad óptica de los seronegativos (considerados así por los sueros de referencia y los controles) más tres desviaciones estandar (S), correspondiendo a 0.3 con lo cual se obtiene un 99 por ciento de confiabilidad. El impacto de esta técnica se basa en la posibilidad de ampliar el diagnóstico y la investigación de la infección y la enfermedad por CMV a menor costo, a la vez que se adaptan tecnologías para hacer más factible el desarrollo sistemático y continuado de la investigación.

Frecuencia de infeccion por herpes virus en 129 ninos en edad escolar en Antioquia / Frequency of herpesvirus infection in 129 elementary school children in Antioquia, Colombia

Con el proposito de hacer una primera aproximacion al estudio de la frecuencia de las infecciones herpeticas del hombre en nuestro medio, se realizo una encuesta serologica entre estudiantes de primer ano de primaria de diferentes procedencias. A excepcion del herpes simplex tipo 2 y la varicela-zoster, que presentaron frecuencias de 0 y 44.5%, respectivamente, las demas infecciones herpeticas se encontraron ampliamente distribuidas: herpes simplex tipo 1, 78%; Epstein-Barr, 94%; citomegalovirus, 98% y Herpes humano 6 100%. No se encontro ninguna asociacion entre las frecuencias de infeccion y las diferentes variables analizadas: procedencia, sexo, edad, numero de personas en la familia y numero de orden del escolar en la familia; igualmente, se pudo apreciar que no existe ninguna asociacion entre la infeccion por los diferentes agentes estudiados

With the aim of making a preliminary approach to the frequency of human herpesviral infections in our local population, a serological survey was carried out among children entering school for the first time, in three different locations, namely: the city, the village and the countryside. Except for Herpes simplex type 2 and Varicella-Zoster viruses which presented infection frequencies of O and 44.5%, respectively, the other herpetic infections were widely distributed: Herpes simplex virus type 1, 78%; Epstein-Barr Virus, 94%; Cytomegalovirus, 98%; and Human Herspesvirus 6,100%. No association was found between the frequencies of infection and the following variables: procedency, age, sex, number of persons In the family, order number of the child within the family; also, there was no association between the frequencies of infection with the different types of virus