Seropositivity and history of hospitalisation for dengue in relation to anthropometric indices among Colombian children and adults.

The role of anthropometric status on dengue is uncertain. We investigated the relations between anthropometric characteristics (height, body mass index and waist circumference (WC)) and two dengue outcomes, seropositivity and hospitalisation, in a cross-sectional study of 2038 children (aged 2-15 years) and 408 adults (aged 18-72 years) from Bucaramanga, Colombia. Anthropometric variables were standardised by age and sex in children. Seropositivity was determined through immunoglobulin G antibodies; past hospitalisation for dengue was self-reported. We modelled the prevalence of each outcome by levels of anthropometric exposures using generalised estimating equations with restricted cubic splines. In children, dengue seropositivity was 60.8%; 9.9% of seropositive children reported prior hospitalisation for dengue. WC was positively associated with seropositivity in girls (90th vs. 10th percentile adjusted prevalence ratio (APR) = 1.19; 95% confidence interval (CI) 1.03-1.36). Among adults, dengue seropositivity was 95.1%; 8.1% of seropositive adults reported past hospitalisation. Height was inversely associated with seropositivity (APR = 0.90; 95% CI 0.83-0.99) and with hospitalisation history (APR = 0.19; 95% CI 0.04-0.79). WC was inversely associated with seropositivity (APR = 0.89; 95% CI 0.81-0.98). We conclude that anthropometry correlates with a history of dengue, but could not determine causation. Prospective studies are warranted to enhance causal inference on these questions.

Vitamin D serostatus and dengue fever progression to dengue hemorrhagic fever/dengue shock syndrome.

Vitamin D could modulate pathways leading to dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). We examined the associations of serum total 25-hydroxy vitamin D [25(OH)D] and vitamin D binding protein (VDBP) concentrations in patients with uncomplicated dengue fever (DF) with risk of progression to DHF/DSS. In a case-control study nested in a cohort of DF patients who were followed during the acute episode in Bucaramanga, Colombia, we compared 25(OH)D and VDBP at onset of fever between 110 cases who progressed to DHF/DSS and 235 DF controls who did not progress. 25(OH)D concentrations were also compared between the acute sample and a sample collected >1 year post-convalescence in a subgroup. Compared with 25(OH)D ⩾75 nmol/l, adjusted odds ratios (95% CI) for progression were 0·44 (0·22-0·88) and 0·13 (0·02-1·05) for 50 to 75 nmol/l (vitamin D insufficiency) and <50 nmol/l (vitamin D deficiency), respectively (P, trend = 0·003). Mean 25(OH)D concentrations were much lower post-convalescence compared with the acute episode, regardless of case status. Compared with controls, mean VDBP was non-significantly lower in cases. We conclude that low serum 25(OH)D concentrations in DF patients predict decreased odds of progression to DHF/DSS.

Clínica gastrointestinal y su asociación con la severidad en Dengue / Association between clinical gastrointestinal with severe severity in dengue

Objetivo: establecer el grado de asociación existente entre la clínica gastrointestinal de los pacientes con dengue y la severidad de la enfermedad. Diseño: observacional analítico de corte transversal. Población y métodos: pacientes hospitalizados con diagnóstico de dengue clásico (DC) y dengue hemorrágico (DH), en las instituciones de salud del departamento de Santander durante 1994 - 1998. Inicialmente se consideraron casos los pacientes con DH y controles aquellos con DC; luego, se definieron como casos los pacientes con DH más hipotensión, edemas o derrames serosos (Dengue Hemorrágico Severo) y controles a aquellos con DH sin los anteriores signos evaluados fueron: vómito, dolor abdominal, hemátemesis, hepatomegalia mediante una análisis estadístico univariado, bivariado y de regresión logística múltiple. Resultados: en total se incluyeron 1.132 pacientes, 487 con DC y 645 con DH. Todos los signos gastrointestinales evaluados se encontraron asociados con DH: vómito (OR=1.52; IC95 por ciento=1.11-2.07) dolor abdominal (OR=1-77; IC95 por ciento=1.19-2.63) hepatomegalia (OR=2.35; IC95 por ciento=1.55-3.59), y hematemesis (OR=3.93; IC95 por ciento=2.41-6.39); (p < 0.05). En el análisis multivariado para DH Severo, sólo hubo asociación con dolor abdominal. Los demás síntomas no se asociaron con una forma más grave de la enfermedad. conclusión: en el presente estudio se demuestra que síntomas y signos gastrointestinales se asocian con la severidad del dengue y que su presencia debe alertar al clínico acerca de un eventual deterioro de las condiciones clínicas del paciente

Virulence of a variant of Paracoccidioides brasiliensis that exists in the yeast form at room temperature.

Paracoccidioides brasiliensis (ATCC 60885) produces conidia that, when plated in enriched media and incubated at 21-25 degrees C, give rise to a yeast-form variant (YRT) (ATCC 46678). The virulence of this variant for BALB/c mice has been compared with that of the yeast and conidia produced by the parent isolate. Adult female mice were inoculated intravenously with 10(7) viable cells of YRT or yeast, or 5 x 10(5) viable conidia. Mice were weighed weekly, and three mice were sacrificed at 1, 2, 3, 4 and 8 weeks post-inoculation and their organs weighed and prepared for determination of viable counts (colony forming units; c.f.u.). Animals infected with yeast cells or with conidia exhibited little weight loss in comparison with that seen in the YRT-infected mice which began to lose weight 1 week post-challenge. Organ weights increased in the YRT group, while the changes in the remaining two groups were minor. The c.f.u. from these organs also increased in the YRT-infected mice, whereas the infection in the yeast-and conidia-infected mice was self-limiting. A proportion (16.6%) of the YRT-infected animals died during the observation period. Conversely, no deaths occurred in the remaining groups. These results indicate that the YRT variant possesses increased virulence.

Morphological study of a variant of Paracoccidioides brasiliensis that exists in the yeast form at room temperature.

Incubation of Paracoccidioides brasiliensis conidia at 20-25 degrees C (RT) results in two types of colonies, mycelial (M) and yeast (YRT). A study of the latter colonies was undertaken. Conidia were plated in complex (BHI) and chemically-defined media (CDCM), with and without fetal calf serum (FCS). Incubation was carried out at 21 degrees C for 4 weeks. The mean number of YRT colonies was approximately 18.5% on BHI agar. Selected YRT colonies were transferred to liquid CDCM, incubated 7 days at 21 degrees C and transferred to solid media; YRT appearance was preserved in 95% of the colonies if media were FCS-supplemented; otherwise, most colonies reverted to the M form. When FCS was replaced by bovine albumin or by alpha-globulin, 63% and 68% respectively of the colonies obtained after plating YRT cells, became mycelial. Comparative morphologic studies of both YRT and yeasts grown at 37 degrees C suggested that there were no major differences between these two types of yeast cells when size and budding were taken into consideration. The results indicate that in this particular variant, dimorphism is not exclusively temperature-dependent.

Cytomegalovirus infection with acute erosive esophagitis.

A healthy young adult is described in whom acute erosive esophagitis developed four weeks after undergoing splenectomy and receiving six units of blood because of trauma. Cytomegalovirus inclusion bodies were identified in esophageal mucosa, and cytomegalovirus was cultured from blood and throat. Within three weeks, the patient's anticytomegalovirus antibody had increased four-fold. The patient was initially anergic and had a titer of antinuclear antibody of 1:10,240. His symptoms and histopathologic findings disappeared over five weeks, and his immunologic abnormalities were partially corrected. It is suggested that cytomegalovirus was the primary cause of gastrointestinal disease in this nonimmunocompromised patient.

Brain abscess due to penicillin- and clindamycin-resistant Bacteroides melaninogenicus.

The case of a patient with severe anaerobic infection, a brain abscess, is presented. The causative organism was a penicillinase-producing, clindamycin-resistant strain of Bacteroides melaninogenicus. Treatment with adequate doses of penicillin G failed. Findings in this case suggest caution when basing therapy on the untested assumption that B. melaninogenicus is routinely susceptible to penicillin and clindamycin therapy.