Long term evaluation of etiological treatment of Chagas disease with benznidazole

The aim of this article is to present an investigation of cure rate, after long follow up, of specific chemotherapy with benznidazole in patients with both acute and chronic Chagas disease, applying quantitative conventional serological tests as the base of the criterion of cure. Twenty one patients with the acute form and 113 with one or other of the various chronic clinical forms of the disease were evaluated, after a follow up period of 13 to 21 years, for the acute, and 6 to 18 years, for the chronic patients. The duration of the acute as well as the chronic disease, a condition which influences the results of the treatment, was determined. The therapeutic schedule was presented, with emphasis on the correlation between adverse reactions and the total dose of 18 grams, approximately, as well as taking into consideration precautions to assure the safety of the treatment. Quantitative serological reactions consisting of complement fixation, indirect immunofluorescence, indirect hemagglutination, and, occasionally, ELISA, were used. Cure was found in 76 per cent of the acute patients but only in 8 per cent of those with chronic forms of the disease. In the light of such contrasting results, fundamentals of the etiological therapy of Chagas disease were discussed, like the criterion of cure, the pathogenesis and the role of immunosuppression showing tissue parasitism in long standing chronic disease, in support of the concept that post-therapeutic consistently positive serological reactions mean the presence of the parasite in the patient's tissues. In relation to the life-cycle of T. cruzi in vertebrate host, there are still some obscure and controversial points, though there is no proof of the existence of resistant or latent forms. However, the finding over the last 15 years, that immunosuppression brings about the reappearance of acute disease in long stand chronic patients justifies a revision of the matter. Facts were quoted in favor of the treatment of chronic patients.

Evaluation of hemostasis disorders and anticardiolipin antibody in patients with severe leptospirosis

A prospective study was designed to evaluate disorders of hemostasis and levels of anticardiolipin antibodies (ACL) in 30 patients with severe leptospirosis and acute renal failure (ARF) (ARF was defined as serum creatinine > or = 1.5 mg/dL). The patients had been admitted to the Walter Cantídio University Hospital, São José Infectious Diseases Hospital and General Hospital of Fortaleza, Ceará, from August 1999 to July 2001. They all were male, with a mean age of 32 ± 14 years and with clinical and laboratory diagnoses of ARF leptospirosis. The time elapsed between onset of symptoms and the first hemorrhagic manifestation was 9 ± 4 days. Bleeding was observed in 86% of the patients. Laboratory tests showed significantly high levels of urea (181 ±95 mg/dl), fibrinogen, (515 ± 220 mg/dl), prothrombin time (13.3 ± 0.9 seconds) and low platelet counts (69 ± 65x10³/mm³) on admission. There was no elevation in activated partial thromboplastin time or thrombin time. Levels of IgM and IgG ACL concentrations were significantly increased (p < 0.05) in leptospirosis patients when compared to control patients (28.5 ± 32.4 vs. 11.5 ± 7.9MPL U/ml and 36.7 ± 36.1 vs. 6.5 ± 2.5 GPL U/ml), respectively. Vasculitis, thrombocytopenia and uremia should be considered important factors for the pathogenesis of hemorrhagic disturbances and the main cause of death in severe leptospirosis.

Evaluation of Etest and macrodilution broth method for antifungal susceptibility testing of Candida sp strains isolated from oral cavities of AIDS patients

A comparison of the Etest and the reference broth macrodilution susceptibility test for fluconazole, ketoconazole, itraconazole and amphotericin B was performed with 59 of Candida species isolated from the oral cavities of AIDS patients. The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines. Our data showed that there was a good correlation between the MICs obtained by the Etest and broth dilution methods. When only the MIC results at ± 2 dilutions for both methods were considered, the agreement rates were 90.4% for itraconazole, ketoconazole and amphotericin B and 84.6% for fluconazole of the C. albicans tested. In contrast, to the reference method, the Etest method classified as susceptible three fluconazole-resistant isolates and one itraconazole-resistant isolate, representing four very major errors. These results indicate that Etest could be considered useful for antifungal sensitivity evaluation of yeasts in clinical laboratories.

Evaluation of a rapid dipstick test, Malar-CheckTM, for the diagnosis of Plasmodium falciparum malaria in Brazil

The present study was carried out to evaluate the Malar-CheckTM Pf test, an immunochromatographic assay that detects Plasmodium falciparum Histidine Rich Protein II, does not require equipment, and is easy and rapid to perform. In dilution assays performed to test sensitivity against known parasite density, Malar-CheckTMwere compared with thick blood smear (TBS), the gold standard for diagnosis. Palo Alto isolate or P. falciparum blood from patients with different parasitemias was used. The average cut-off points for each technique in three independent experiments were 12 and 71 parasites/mm³ (TBS and Malar-CheckTM, respectively). In the field assays, samples were collected from patients with fever who visited endemic regions. Compared to TBS, Malar-CheckTMyielded true-positive results in 38 patients, false-positive results in 3, true-negative results in 23, and false-negative result in 1. Malar-CheckTMperformed with samples from falciparum-infected patients after treatment showed persistence of antigen up to 30 days. Malar-CheckTM should aid the diagnosis of P. falciparum in remote areas and improve routine diagnosis even when microscopy is available. Previous P. falciparum infection, which can determine a false-positive test in cured individuals, should be considered. The prompt results obtained with the Malar-CheckTM for early diagnosis could avoid disease evolution to severe cases.