Dengue Patients Treated with Doxycycline Showed Lower Mortality Associated to a Reduction in IL-6 and TNF Levels.

OBJECTIVE: To determine the effect of doxycycline treatment on cytokine levels, including tumor necrosis factor (TNF) and interleukin 6 (IL-6), and mortality in dengue patients at high risk of complication. METHODS: A group of dengue hemorrhagic fever patients (n=231) were randomized to receive either standard supportive care or supportive care in addition to oral doxycycline twice daily for 7 days. Dengue virus infection was confirmed by PCR using multiple primers. Serum samples were obtained at days 0, 3, 5 and 7 and tested for levels of TNF and IL-6. RESULTS: Doxycycline-treated group presented a 46% lower mortality than that observed in the untreated group (11.2% [13/116] vs 20.9% [24/115], respectively, p=0.05). Moreover, administration of doxycycline resulted in a significant (p<0.01) decrease in levels of TNF and IL-6 versus controls in the tests performed during follow-up (day 3, 5 and 7). Patients who died in both groups possessed significantly (p<0.01) higher levels of TNF and IL-6 compared to those who survived at all-time points. CONCLUSION: The above findings suggest that doxycycline can provide a clinical benefit to dengue patients at high risk of complications. This effect could be mediated by decreasing pro-inflammatory cytokine levels.

Detection of human influenza virus in Yucatan, Mexico.

OBJECTIVE: Influenza virus is the most common cause of Acute Respiratory Infections (ARI) world wide. In patients with chronic condition, infection by the influenza virus can cause complications such as pneumonia which may have fatal outcome. The aim of this work was to determine the frequency of human influenza virus in outpatients with influenza-like illness (ILI) and in those patients admitted to hospital with community acquired pneumonia (CAP) in Yucatan, Mexico (October 1998-July 1999). MATERIALS AND METHODS: Throat swabs were collected from ILI and CAP patients and processed to detect respiratory viruses. All clinical samples were tested for seven respiratory viruses using a rapid indirect immunofluorescence test (IFI). Clinical samples with positive results for influenza virus by IFI were inoculated into chick embryo eggs and/or MDCK cells for viral isolation. All influenza virus isolates were typed using the WHO influenza Kit 1998-1999. RESULTS: A total of 288 clinical samples were collected. Influenza virus type A was diagnosed in 29 clinical samples (10%), no other respiratory viruses were identified. Influenza virus was present with 8.9% (17 out of 189) in ILI patients, whereas with 12.12% (12 out of 99) in CAP patients. Influenza virus was detected from December to July. Six viral isolates were obtained and identified as influenza A (H3N2). CONCLUSION: Human influenza virus is certainly a cause of ARI and pneumonia in Yucatan, Mexico. The results showed that influenza virus contributes to at least 8.9% of the ARI, and more importantly to 12% of CAP patients. Positive cases were present in a different pattern to temperate zones where the peak of incidence occurs during autumn and winter.

Golpe de calor: revisión de conceptos a propósito de un caso / Heat stroke: revision of concepts with regard to a case

Introducción. El "Golpe de Calor" (GC) se produce cuando la regulación de la temperatura es incapaz de disipar la acumulación del calor corporal. El GC ocurre ante la exposición de altas temperaturas (GC "postejercicio"). Caso clínico. Paciente masculino de 20 años de edad, sin antecedentes patológicos previos. Inició su padecimiento posterior a ejercicio físico intenso (carreras) durante 30 minutos, en una temperatura ambiental de 39º a 40ºC y presentando de manera súbita pérdida del estado de conciencia y fiebre de 40ºC. Diez y siete horas después del inicio del padecimiento, el paciente presentó estado de coma profundo (no había respuesta a estímulos), síndrome hemorrágico y alteraciones en la función renal. Se estableció el diagnóstico de GC con manifestaciones de coma metabólico e hipoxémico, insuficiencia renal aguda (IRA), coagulación intravascular diseminada (CID) y miocardiopatía. Discusión. El daño descrito en el GC es una degeneración celular genelarizada y hemorragias ampliamente distribuidas. Hay evidencias que señalan a las monoaminas y citoquinas como participantes en la disrregulación térmica y en el daño cerebral. La rabdomiolisis favorece el desarrollo de necrosis tubular aguda e IRA. Las alteraciones de la hemostasia y fibrinolisis descritas en el GC son compatibles con el diagnóstico de CID. La activación plaquetaria y el daño endotelial favorecen el desarrollo de la CID. Uno de los órganos afectados tempranamente en el GC es el corazón y se han documentado estados de hipotiroidismo, incrementos en la procalcitonina e hipersecresión de la hormona de crecimiento (HC). Se identifican como marcadores de mal pronóstico la elevación de la deshidrogenasa láctica, de la HC y disminución de Antitrombina III. Se debe reducir la temperatura en un plazo de una hora. La vigilancia de la permeabilidad de las vías aéreas, el control y prevención de crisis convulsivas, así como de arritmias cardiacas, son maniobras que aumentan la posibilidad de supervivencia de estos pacientes. Las secuelas más frecuentes son afectaciones del sistema nervioso central. Es importante la identificación de factores de riesgo y modificarlos para la prevención del GC