Dynamics of dengue epidemics in urban contexts.

Dengue, similar to other arboviral diseases, exhibits complex spatiotemporal dynamics. Even at town or village level, individual-based spatially explicit models are required to correctly reproduce epidemic curves. This makes modelling at the regional level (province, country or continent) very difficult and cumbersome. We propose here a first step to build a hierarchized model by constructing a simple analytical expression which reproduces the model output from macroscopic parameters describing each 'village'. It also turns out to be a good approximation of real urban epidermic outbreaks. Subsequently, a regional model could be built by coupling these equations on a lattice.

Pulmonary valve endocarditis: mid-term follow up of pulmonary valvectomies.

Four males aged 20-37 years (three drug addicts and one with a congenital mixed pulmonary valve lesion) were diagnosed in 1989, 1991 and 1993 with pulmonary valve endocarditis without tricuspid infection. Three patients were positive for hepatitis B, C or both, and one patient was HIV-positive. The predominant organism in blood cultures was Staphylococcus aureus. Antibiotic treatment of pulmonary valve endocarditis had failed; thus partial or total valvectomies were performed. Postoperatively, all patients were cured of infection and initial recovery was good. At mid-term follow up (5-10 years) there were no recurrences, and tolerance of the resultant pulmonary insufficiency was good. Slight to severe tricuspid valve insufficiency developed, together with right ventricular dilatation, in all cases. Hepatomegaly was apparent in two cases and peripheral edema in one. Despite treatment, the latter patient remained in moderate right ventricular failure, and may require homograft valve replacement. The other three patients remained in good clinical condition. Eradication of the infection was achieved in all patients. It is concluded that pulmonary valve resection is the treatment of choice for pulmonary valve endocarditis when antibiotic treatment has failed. Complete resection of all affected tissue should be performed in these cases. Analysis of preoperative data did not permit differentiation of those patients likely to develop right heart failure.

Clinical significance of polymicrobial versus monomicrobial bacteremia involving Pseudomonas aeruginosa.

The objective of this study was to examine the clinical significance of polymicrobial bacteremia involving Pseudomonas aeruginosa. Two hundred forty-eight episodes of Pseudomonas aeruginosa bacteremia, 43 of which were polymicrobic, were studied prospectively over a 6-year period. Three sets of blood cultures were obtained for each patient. Positive results for all three blood cultures were found more frequently in patients with polymicrobial infection, who were older than those with monomicrobial infection. Patients with polymicrobial bacteremia also were worse clinically and developed shock more frequently. Crude mortality was higher in patients with polymicrobial infection. A multivariate analysis revealed three variables significantly and independently associated with polymicrobial Pseudomonas aeruginosa bacteremia: higher age, poor clinical status of the patient, and positive results for all blood cultures obtained.

Primary lymphomas of the heart in immunocompetent patients. Presentation of two cases with one 12 year survival. Analysis of surgical implications.

Two primary malignant lymphomas originating in the right heart cavities have been diagnosed and treated in our department: one, with additional right atrial and inferior vena cava thrombosis required emergency thrombectomy, incomplete excision and chemotherapy and survived 12 years, the other with extensive right ventricular infiltration and failure, died from mediastinitis and aplastic anaemia following surgery and chemotherapy. Quick diagnosis and treatment are indicated. If possible, surgery should be avoided.

[Detection of Brucella with an automatic hemoculture system: Bact/Alert]. / Detección de Brucella por un sistema automático de hemocultivos: Bact/Alert.

BACKGROUND: The ability of in vitro and in vivo detection of Brucella spp. with the Bact/Alert system was studied. METHODS: Three strains of Brucella melitensis and two of Brucella abortus were used. Different dilutions of the five strains were performed in trypticase soy broth (TSB), achieving concentrations of 1 cfu/ml, 5 cfu/ml, 10 cfu/ml and 100 cfu/ml. Ten ml of each dilution and strain were inoculated into 5 aerobic bottles Bact/Alert and 5 biphasic Hemóline bottles. Furthermore, over a 9 month period, 8,216 bottles of Bact/Alert bottles from hospitalized patients and from the emergency department were processed in the authors' laboratory. RESULTS: The mean detection time for Brucella growth was from 2 to 3 days with the Bact/Alert system, and 14 days in the biphasic bottles. Former bottles processed in the authors' laboratory, 11 aerobic bottles belonged to 5 patients in whom brucelosis was confirmed by bloodculture. The Bact/Alert system detected Brucella melitensis in only on bottle at 2.9 days of incubation. In 7 bottles Bact/Alert detected B. melitensis by a blind pass of these bottles at 10 to 20 days of incubation. CONCLUSIONS: These results suggest that the Bact/Alert system does not totally solve the diagnosis of brucellosis. Blind passes of the bloodcultures are required.

In vitro activity of cloconazole, sulconazole, butoconazole, isoconazole, fenticonazole, and five other antifungal agents against clinical isolates of Candida albicans and Candida spp.

The in vitro activity of several new imidazoles, cloconazole, sulconazole, butoconazole, isoconazole and fenticonazole, were compared with those of amphothericin B, flucytosine, and three azoles: econazole, miconazole and ketoconazole against isolates of pathogenic Candida. A total of 186 clinical isolates of 10 species of the genus Candida and two culture collection strains were tested by an agar-dilution technique. Isoconazole was the most active azole, followed by butoconazole sulconazole. Differences between some of the species in their susceptibility to the antifungal agents were noted. Sulconazole and cloconazole had the highest activity in vitro against 106 isolates of C. albicans. Butoconazole and isoconazole were also very active against isolates of C. albicans, and were the most active azole compounds against 80 isolates of Candida spp.

[Sensitivity of yeasts of the genus Candida to new antifungal agents]. / Sensibilidad de levaduras del género Candida a nuevos agentes antifúngicos.

We studied the in vitro activity of cloconazole, sulconazole, butoconazole, isoconazole, fenticonazole and ciclopirox, as well other classical antifungal agents against 188 Candida spp. strains. Minimum inhibitory concentrations (MIC) have been determined by dilution-agar technique. Of all the imidazole compound tested, isoconazole showed the greatest activity against 186 Candida strains isolates (MIC 90%: 4 micrograms/ml). Sulconazole and cloconazole showed their best activity against 106 Candida albicans isolates. Butoconazole and isoconazole had demonstrated good activity against C. albicans and also were the most active agents against 80 Candida spp. isolates. In vitro activity of ciclopirox against Candida is close to that of econazole (MIC 90%: 8 micrograms/ml).

In vitro activity of nitroxoline against clinical isolates of Candida species.

The in vitro antifungal activity of the quinoline nitroxoline has been compared with those of amphotericin B, flucytosine, and two azoles, miconazole and ketoconazole, against clinical isolates of Candida spp. A total of 186 isolates of 10 species of Candida and two culture collection strains were tested by an agar-dilution technique. Nitroxoline was highly active against Candida spp. MICs for nitroxoline ranged between 0.25-2 micrograms ml-1 for 186 representative strains. With MIC90 as the measure of antifungal activity, nitroxoline appeared to be superior to the imidazoles studied. Data for individual species of Candida revealed that the activities of nitroxoline and amphotericin B were generally just as effective against C. albicans, whereas flucytosine was the most active agent against Candida spp.