RESUMO
Introducción: Las infecciones respiratorias virales (IRV) son causa importante de morbilidad en adultos. Virus respiratorio sincicial (VRS) causa hasta 20 por ciento de las IRV en esta edad; sin embargo, su diagnóstico es subestimado debido a una menor sensibilidad de las técnicas diagnosticas convencionales (IF y ELISA). Objetivos: Evaluar el impacto del uso de reacción de la polimerasa en cadena en tiempo real (TR-RPC en tiempo real) en el diagnóstico de IRV por VRS en adultos y caracterizar su perfil clínico. Pacientes y Métodos: Durante ocho semanas del año 2005, los adultos hospitalizados en Hospital Clínico de la Universidad Católica con sospecha de IRV, e IFD negativa para VRS, FLU-A, -B, paraFLU-1, 2, 3 y ADV de muestra de hisopado nasofaríngeo, fueron sometidos a detección de VRS por TR-RPC en tiempo real. Se confeccionó una base de datos con los antecedentes clínicos, laboratorio y evolución de cada paciente. Resultados: De 114 pacientes con IFD negativa en 17 (14,9 por ciento) se detectó VRS. Fiebre, congestión faríngea, tos y signos de obstrucción bronquial, configuraron en más de 80 por ciento de los casos el perfil clínico de los pacientes. Treinta por ciento presentaba enfermedad crónica y 47 por ciento eran inmunocomprometidos. Tres de 17 (18 por ciento) presentaron descompensación de la enfermedad de base y 1/17 (6 por ciento) requirió ventilación mecánica. No hubo mortalidad asociada. Conclusiones: El uso de TR-RPC en tiempo real permitió duplicar la detección de infecciones por VRS en adultos hospitalizados respecto a las diagnosticadas por IFD. Se recomienda considerar el empleo la técnica de TR-RPC en tiempo real en aquellos pacientes con sospecha clínica de VRS durante la temporada de VRS y estudio viro lógico negativo por métodos convencionales.
Introduction: Viral respiratory infections (VRI) are a frequent cause of morbidity among adult population. Respiratory syncytial virus (RSV) produces 20 percent> of VRI, however diagnosis is limited for a low sensitivity of conventional (FDA and ELISA) tests. Aim: To assess the impact of real time reverse transcriptase-polymerase chain reaction (real time RT-PCR) technique in RSV diagnosis in adult hospitalized patients; to characterize RSV infection among these patients. Patients and Methods: All adults hospitalized in Hospital Clínico Universidad Católica during 8 weeks of winter season, with clinical picture of VRI, and with negative DFA for influenza A and B, parainfluenza 1, 2, 3 and adenovirus were included. Real time RT-PCR was performed from nasopharyngeal sample. Clinical information, general laboratory exams and chest X ray reports were collected. Results: Out of 114 patients with negative DFA, 17 (14.9 percento) Debe decir: RSV cases were demonstrated using real time RT- PCR. Fever, pharyngeal congestion, cough and bronchial obstruction were present in 80 percent> of patients. Thirty percent of them had a baseline chronic disease and 47 percent> were immunocompromised. One out of 17 patients (6 percent) required mechanical ventilation. No mortality was observed. Conclusions: Use of RT-PCR allowed increasing detection of RSV infection over 100 percent> among adults with VRI without virological diagnosis with conventional techniques. It is necessary to consider RSV RT-PCR test among patients with clinical picture of VRI during RSV season, with negative virological screening tests.
Assuntos
Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Vírus Respiratório Sincicial/diagnóstico , Vírus Sincicial Respiratório Humano/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Técnica Direta de Fluorescência para Anticorpo , Estudos Retrospectivos , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/imunologia , Sensibilidade e EspecificidadeRESUMO
UNLABELLED: Rickettsial infections in pets have not been documented in Chile. Some of those infections have relevant zoonotic potential. OBJECTIVES: To report two serologically confirmed cases of canine rickettsiosis. To determine seroprevalence to Rickettsia sp in a group of dogs. METHODS: IgG antibodies anti-R. conorii and anti-A. phagocitophilum by IFI in two dogs with clinical rickettsiosis. IgG antibodies anti-R. conorii in a group of 77 dogs. CLINICAL CASES: a dog presented with fever, myalgias and melena, another dog with bleeding and neurological involvement. Seroprevalence: 35% of the dogs had antibodies against Rickettsia. DISCUSSION: This is the first evidence of canine rickettsiosis in Chile, both clinical and serological. Co-infection with two tickborne agents: Rickettsia and Anaplasma, is documented. Molecular studies are needed to confirm the rickettsial species present in Chile. The zoonotic role of these infections must be also studied.
Assuntos
Anaplasma phagocytophilum , Anaplasmose/epidemiologia , Doenças do Cão/epidemiologia , Infecções por Rickettsia/veterinária , Rickettsia conorii/imunologia , Anaplasma phagocytophilum/imunologia , Anaplasma phagocytophilum/isolamento & purificação , Anaplasmose/diagnóstico , Animais , Anticorpos Antibacterianos/sangue , Chile/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/microbiologia , Cães , Feminino , Imunoglobulina G/sangue , Masculino , Prevalência , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/epidemiologia , Rickettsia conorii/isolamento & purificação , Estudos SoroepidemiológicosRESUMO
En Chile, no se han documentado infecciones por Rickettsias en mascotas; algunas de ellas tienen importante potencial zoonótico. Objetivos: Reportar dos casos de rickettsiosis canina con confirmación serológica y determinar seroprevalencia de Rickettsia sp un grupo de caninos. Métodos: IgG anti-Rickettsia conorii y anti-Anaplasma phagocitophilum por IFI en dos caninos con cuadro clínico sugerente de rickettsiosis. Determinación de IgG anti-R. conorii en 77 caninos. Resultados: Como casos clínicos hubo un canino con fiebre, mialgias y melena y otro con manifestaciones he-morrágicas y compromiso neurológico. Seroprevalencia: 35% de los caninos presentaban IgG anti-Rickettsia. Discusión: Se reporta por primera vez en Chile la presencia de rickettsiosis canina, tanto clínica como serológica. Se documenta co-infección por Rickettsia y Anaplasma, dos agentes transmitidos por garrapatas. Es necesario realizar estudios de biología molecular para confirmar la especie de rickettsia presente en Chile. Además, debe estudiarse el rol zoonótico de estas infecciones en nuestro medio.
Rickettsial infections in pets have not been documented in Chile. Some of those infections have relevant zoonotic potential. Objectives: To report two serologically confirmed cases of canine rickettsiosis. To determine seroprevalence to Rickettsia sp in a group of dogs. Methods: IgG antibodies anti-R. conorii and anti-A. phagocitophilum by IFI in two dogs with clinical rickettsiosis. IgG antibodies anti-R. conorii in a group of 77 dogs. Results: Clinical cases: a dog presented with fever, myalgias and melena, another dog with bleeding and neurological involvement. Seroprevalence: 35% of the dogs had antibodies against Rickettsia. Discussion: This is the first evidence of canine rickettsiosis in Chile, both clinical and serological. Co-infection with two tickborne agents: Rickettsia and Anaplasma, is documented. Molecular studies are needed to confirm the rickettsial species present in Chile. The zoonotic role of these infections must be also studied.
Assuntos
Animais , Masculino , Feminino , Cães , Anaplasma phagocytophilum/imunologia , Anaplasmose/epidemiologia , Doenças do Cão/microbiologia , Infecções por Rickettsia/veterinária , Rickettsia conorii/imunologia , Anaplasma phagocytophilum/isolamento & purificação , Anaplasmose/diagnóstico , Anticorpos Antibacterianos/sangue , Chile/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Técnica Indireta de Fluorescência para Anticorpo , Imunoglobulina G/sangue , Prevalência , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/epidemiologia , Rickettsia conorii/isolamento & purificação , Estudos SoroepidemiológicosRESUMO
BACKGROUND: During yearly influenza (FLU) season, FLU viruses are well represented among hospitalized patients as in the community. Also, other respiratory viruses could be represented among adult in-patients. AIM: to describe the presence and clinical- epidemiological characteristics of non-FLU respiratory virus infections (respiratory syncytial-RSV, parainfluenza and adenovirus-ADV) among hospitalized adults during FLU season and to compare with FLU-A (IA) or -B (IB) cases. PATIENTS AND METHODS: Adult patients hospitalized at Hospital Clínico Universidad Católica between May to July 2004 with a respiratory virus infections confirmed by rapid antigen test or direct immunofluorescence of IA, IB (Flu group) or RSV, parainfluenza (1-2-3) and ADV (non-Flu group) were included. RESULTS: 86 cases were identified: 73.5% FLU (48.2% IA, 25.3% IB) and 26.5% non-FLU (15.7% parainfluenza-2; 8.4% RSV; 1.2% parainfluenza-3; 1.2% ADV). No differences were observed in general characteristics and evolution of patients. In FLU-group were more frequently observed myalgia, cough, hospitalization due to febrile syndrome, higher values of C-reactive protein and band leukocytes count (p < 0.05). CONCLUSIONS: During 2004 FLU season a 26.5 % of respiratory viral infection were due to non-FLU viruses among adult hospitalized in our centre. The difficulty to difference FLU vs. non-FLU infections, suggest that it is necessary to include other respiratory virus in the viral etiological diagnosis, even in FLU season.
Assuntos
Infecções Respiratórias/virologia , Adenoviridae/isolamento & purificação , Adolescente , Idoso , Idoso de 80 Anos ou mais , Chile/epidemiologia , Surtos de Doenças , Feminino , Humanos , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Masculino , Pessoa de Meia-Idade , Vírus Sinciciais Respiratórios/isolamento & purificação , Infecções Respiratórias/epidemiologia , Respirovirus/isolamento & purificação , Estudos RetrospectivosRESUMO
El comportamiento epidemiológico del virus influenza (FLU) en la comunidad se refleja en el hospital, es planteable que la actividad comunitaria de otros virus respiratorios también se traduzca en un alza de las internaciones por estos agentes. Objetivo: describir la presencia y características clínico-epidemiológicas de infecciones por virus respiratorios no-FLU (virus respiratorio sincicial-VRS, parainfluenza y adenovirus-ADV) entre adultos hospitalizados durante la temporada de influenza y establecer una comparación con virus influenza-A (IA) o -B (IB). Pacientes y Método: Adultos internados en Hospital Clínico Universidad Católica, de mayo a julio de 2004, con infección por IA o IB, y VRS, parainfluenza (1-2-3) o ADV demostrada por test rápido o inmunofluorescencia directa. Resultados: Se identificaron 86 casos: 73,5 por ciento FLU (48,2 por ciento, IA y 25,3 por ciento IB) y 26,5 por ciento no-FLU. (15,7 por ciento parainfluenza-2; 8,4 por ciento VRS, 1,2 por ciento parainfluenza-3 y 1,2 por ciento ADV). El grupo con FLU presentó más frecuentemente mialgias, tos, hospitalización por síndrome febril, mayores valores de PCR y porcentaje de baciliformes (p < 0,05). Conclusiones: Durante la temporada de influenza 2004, 26,5 por ciento de las infecciones entre adultos hospitalizados fueron causadas por virus no-FLU. La dificultad en diferenciar infecciones por virus FLU de no-FLU, plantea la necesidad de ampliar el estudio de la etiología viral incluso durante la temporada de FLU.
Assuntos
Adolescente , Adulto , Humanos , Pessoa de Meia-Idade , Infecções Respiratórias/complicações , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Evolução Clínica , Chile/epidemiologia , Influenza Humana/epidemiologia , Hospitalização , Infecções por Adenoviridae/epidemiologia , Infecções por Paramyxoviridae/epidemiologia , Infecções por Vírus Respiratório Sincicial/epidemiologia , Estudos RetrospectivosRESUMO
El síndrome coqueluchoídeo es frecuente en el lactante menor siendo causa importante de morbilidad. Con el objeto de estudiar la importancia de bordetella pertussis como causa de este síndrome, las características clínicas de coqueluche y la sensibilidad y especificidad de las distintas técnicas para el diagnóstico de B. pertussis, se realizó un estudio con 66 niños hospitalizados con el diagnóstico de síndrome coqueluchoídeo. B. pertussis fue el principal agente causal (56 por ciento) seguido de varios virus respiratorios (14 por ciento) como adenovirus, virus respiratorio sincicial y parainfluenza. Las características clínicas que permitieron diferenciar a la coqueluche de las otras causas del síndrome coqueluchoídeo fueron la asociación de tos paroxística, emetizante y estridor inspiratorio. La linfocitosis absoluta sobre 10.000/mm elevado a 3, especialmente si se asoció a tos característica, tuvo buena especificidad con fines diagnósticos. La sensibilidad del cultivo, IFD y RPC para el diagnóstico de coqueluche fue de 32, 36 y 93 por ciento respectivamente. La especificidad de la IFD y la RPC fue de 87 y 98 por ciento respectivamente. El uso previo de antibióticos o la obtención de la muestra en estapas avanzadas de la enfermedad no modificó la sensibilidad de la técnica de RPC, no sucedió así con el cultivo e IFD. Por todo esto la RPC sería el método de elección para el diagnóstico de coqueluche
Assuntos
Humanos , Masculino , Feminino , Lactente , Bordetella pertussis/isolamento & purificação , Coqueluche/diagnóstico , Técnica Direta de Fluorescência para Anticorpo , Vacina contra Coqueluche/análise , Reação em Cadeia da Polimerase , Sensibilidade e EspecificidadeRESUMO
Freezing tolerance and avoidance were studied in several different sized species of the tropical high Andes (4200 m) to determine whether there was a relationship between plant height and cold resistance mechanisms. Freezing injury and supercooling capacity were determined in ground level plants (i.e. cushions, small rosettes and a perennial herb), intermediate height plants (shrubs and perennial herbs) and arborescent forms (i.e. giant rosettes and small trees). All ground-level plants showed tolerance as the main mechanism of resistance to cold temperatures. Arborescent forms showed avoidance mechanisms mainly through supercooling, while intermediate plants exhibited both. Insulation mechanisms to avoid low temperatures were present in the two extreme life-forms. We suggest that a combination of freezing tolerance and avoidance by insulation is least expensive and is a more secure mechanism for high tropical mountain plants than supercooling alone.
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The gas exchange and water relations of the hemiparasite Pthirusa maritima and two its mangrove host species, Conocarpus erectus and Coccoloba uvifera, were studied in an intertidal zone of the Venezuelan coast. Carbon uptake and transpiration, leaf osmotic and total water potential, as well as nutrient content in the xylem sap and leaves of mistletoes and hosts were followed through the dry and wet season. In addition, carbon isotope ratios of leaf tissue were measured to further evaluate water use efficiency. Under similar light and humidity conditions, mistletoes had higher transpiration rates, lower leaf water potentials, and lower water use efficiencies than their hosts. Potassium content was much higher in mistletoes than in host leaves, but mineral nutrient content in the xylem sap of mistletoes was relatively low. The resistance of the liquid pathway from the soil to the leaf surface of mistletoes was larger than the total liquid flow resistance of host plants. Differences in the daily cycles of osmotic potential of the xylem sap also indicate the existence of a high resistance pathway along the vascular connection between the parasite pathway along the vascular connection between the parasite and its host. P. maritima mistletoes adjust to the different physiological characteristics of the host species which it parasitizes, thus ensuring an adequate water and carbon balance.
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Freezing tolerance as a cold resistance mechanism is described for the first time in a plant growing in the tropical range of the Andean high mountains. Draba chionophila, the plant in which freezing tolerance was found, is the vascular plant which reaches the highest altitudes in the Venezuelan Andes (approximately 4700m). Night cycles of air and leaf temperature were studied in the field to determine the temperature at which leaf freezing began. In the laboratory, thermal analysis and freezing injury determinations were also carried out. From both field and laboratory experiments, it was determined that freezing of the leaf tissue, as well as root and pith tissue, initiated at a temperature of approximately-5.0°C, while freezing injury occurred at approximately-12.0°C for the pith, and below-14.0°C for roots and leaves. This difference in temperature suggests that the plant still survives freezing in the-5.0 to-14.0°C range. Daily cycles of leaf osmotic potential and soluble carbohydrate concentration were also determined in an attempt to explain some of the changes occurring in this species during the nighttime temperature period. A comparison between Andean and African high mountain plants from the point of view of cold resistance mechanisms is made.
RESUMO
Factors affecting supercooling capacity and cold hardiness were investigated in leaves of ten giant rosette species of the genus Espeletia (Compositae). These species grow along a 2,800-4,200 m elevation gradient in the Venezuelan Andes. In this high tropical environment, freezing frequently occurs every night, particularly above 3,300 m, but lasts for only a few hours. Supercooling capacty is linearly related to leaf water potential (Ψ L ) in all species; however supercooling is more responsive to Ψ L changes in Espeletia species from high paramos. The rate of change in the species-specific supercooling point and the rate of change of average annual minimum temperature along the elevation and climatic gradient follow the same trend (approximately -0.6 K per 100 m elevation). At a given elevation, the expanded leaves of the different species tend to supercool 8-10 K below minimum air temperatures. Experimentally-induced freezing was accompanied by the formation of intracellular ice and tissue damage. The relative apoplastic water content (RAWC) of the leaves, which may influence the ice nucleation rate or the facility by which ice propagates, was determined by pressure-volume methods. Species from higher sites tend to exhibit lower RAWC (2%-7%) than species from lower sites (7%-36%). A causal relationship between supercooling capacity and RAWC is suggested. In the high tropical Andes, the temperature oxotherm plateau of Espeletia leaves seems to be sufficiently fow to avoid freezing.