RESUMEN
BACKGROUND: With a conservatively estimated 1 million cases of leptospirosis worldwide and a 5-10% fatality rate, the rapid diagnosis of leptospirosis leading to effective clinical and public health decision making is of high importance, and yet remains a challenge. METHODOLOGY: Based on parallel, population-based studies in two leptospirosis-endemic regions in Brazil, a real-time PCR assay which detects lipL32, a gene specifically present in pathogenic Leptospira, was assessed for the diagnostic effectiveness and accuracy. Patients identified by active hospital-based surveillance in Salvador and Curitiba during large urban leptospirosis epidemics were tested. Real-time PCR reactions were performed with DNA-extracted samples obtained from 127 confirmed and 23 unconfirmed cases suspected of leptospirosis, 122 patients with an acute febrile illness other than leptospirosis, and 60 healthy blood donors. PRINCIPAL FINDINGS: The PCR assay had a limit of detection of 280 Leptospira genomic equivalents/mL. Sensitivity for confirmed cases was 61% for whole blood and 29% for serum samples. Sensitivity was higher (86%) for samples collected within the first 6 days after onset of illness compared to those collected after 7 days (34%). The real-time PCR assay was able to detect leptospiral DNA in blood from 56% of serological non-confirmed cases. The overall specificity of the assay was 99%. CONCLUSIONS: These findings indicate that real-time PCR may be a reliable tool for early diagnosis of leptospirosis, which is decisive for clinical management of severe and life-threatening cases and for public health decision making.
Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Epidemias , Leptospira/aislamiento & purificación , Leptospirosis/diagnóstico , Leptospirosis/epidemiología , Lipoproteínas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Adulto , Brasil/epidemiología , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Femenino , Humanos , Leptospira/genética , Leptospirosis/sangre , Leptospirosis/microbiología , Masculino , Persona de Mediana Edad , ARN Ribosómico 16S/genética , Sensibilidad y EspecificidadRESUMEN
This retrospective cohort study investigated the presence of bacteria in respiratory secretions of patients hospitalized with acute respiratory infections and analyzed the impact of viral and bacterial coinfection on severity and the mortality rate. A total of 169 patients with acute respiratory infections were included, viruses and bacteria in respiratory samples were detected using molecular methods. Among all samples, 73.3% and 59.7% were positive for viruses and bacteria, respectively; 45% contained both virus and bacteria. Bacterial coinfection was more frequent in patients infected by community respiratory viruses than influenza A H1N1pdm (83.3% vs. 40.6%). The most frequently bacteria detected were Streptococcus pneumoniae and Haemophilus influenzae. Both species were co-detected in 54 patients and identified alone in 22 and 21 patients, respectively. Overall, there were no significant differences in the period of hospitalization, severity, or mortality rate between patients infected with respiratory viruses alone and those coinfected by viruses and bacteria. The detection of mixed respiratory pathogens is frequent in hospitalized patients with acute respiratory infections, but its impact on the clinical outcome does not appear substantial. However, it should be noted that most of the patients received broad-spectrum antibiotic therapy, which may have contributed to this favorable outcome.
Asunto(s)
Infecciones Bacterianas/complicaciones , Coinfección , Infecciones del Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio/virología , Virosis/complicaciones , Enfermedad Aguda , Anciano , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Estudios de Cohortes , Femenino , Haemophilus influenzae/genética , Haemophilus influenzae/aislamiento & purificación , Haemophilus influenzae/patogenicidad , Humanos , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Masculino , Persona de Mediana Edad , Infecciones del Sistema Respiratorio/mortalidad , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación , Virosis/virología , Virus/genética , Virus/aislamiento & purificaciónRESUMEN
A correlaçäo entre trombocitose e atividade da doença de Crohn (DC) tem sido constatada por alguns autores. Entretanto, esta observaçäo näo tem sido extensamente utilizada pela existência de comprovaçöes limitadas. Assim, os autores analisaram, retrospectivamente, os dados dos últimos 30 pacientes atendidos na Disciplina de Gastroenterologia do Departamento de Clínica Médica do Hospital das Clínicas da Faculdade de Medicina da Universidade de Säo Paulo, e na clínica privada de um dos autores (A.B.). Levou-se em consideraçäo a contagem de plaquetas (método de Brecher-Cronkite; valores normais 200.000 a 400.000 plaquetas/mm3) e o índice clínico de atividade da DC segundo os critérios de Harvey e Bradshaw. Onze pacientes (37%) apresentaram trombocitose (x=500.818 + ou - 56.845) e o valor médio do índice clínico de atividade desse grupo foi 8,6 (intervalo de confiança: 6-13). Dezenove pacientes (63%) näo apresentaram trombocitose (267.789 + ou - 62.124) e o seu valor médio de atividade foi 5,7 (intervalo de confiança: 2-11). Diferença estatisticamente significante foi verificada entre os valores médios dos índices clínicos de atividade dos dois grupos (z=2,84, para alfa < ou = 0,05), bem como entre as médias do número de plaquetas/mm3 (z = 4,5, para alfa < ou = 0,05). Näo houve relaçäo estatisticamente significante entre trombocitose e formas íleo-cólica, jejuno-ileal e cólica da DC. Entretanto, dos nove pacientes da casuística com forma ileal, oito (88%) näo apresentaram trombocitose e tiveram índices de atividade < ou = 6. Os possíveis mecanismos fisiopatológicos da trombocitose na DC säo comentados e revisados. A relaçäo entre trombocitose e a atividade da DC, observada na presente casuística, näo constitui, certamente, elemento diagnóstico para a afecçäo, mas associadamente ao quadro clínico, pode representar importante parâmentro para indicar a atividade da doença