Production and diagnostic application of recombinant domain III of West Nile envelope protein in Brazil

INTRODUCTION: West Nile virus (WNV) is a flavivirus with a natural cycle involving mosquitoes and birds. Over the last 11 years, WNV has spread throughout the Americas with the imminent risk of its introduction in Brazil. METHODS: Envelope protein domain III of WNV (rDIII) was bacterially expressed and purified. An enzyme-linked immunosorbent assay with WNV rDIII antigen was standardized against mouse immune fluids (MIAFs) of different flavivirus. RESULTS: WNV rDIII reacted strongly with St. Louis encephalitis virus (SLEV) MIAF but not with other flaviviruses. CONCLUSIONS: This antigen may be a potentially useful tool for serologic diagnosis and may contribute in future epidemiological surveillance of WNV infections in Brazil.

Evaluation of the diagnostic value of the tourniquet test in predicting severe dengue cases in a population from Belo Horizonte, State of Minas Gerais, Brazil

Introduction Dengue is prevalent in many tropical and sub-tropical regions. The clinical diagnosis of dengue is still complex, and not much data are available. This work aimed at assessing the diagnostic accuracy of the tourniquet test in patients with suspected dengue infection and its positivity in different classifications of this disease as reported to the Information System for Notifiable Disease in Belo Horizonte, State of Minas Gerais, Brazil between 2001 and 2006. Methods Cross-section analysis of the diagnostic accuracy of the tourniquet test for dengue, using IgM-anti-DENV ELISA as a gold standard. Results We selected 9,836 suspected cases, of which 41.1% were confirmed to be dengue. Classic dengue was present in 95.8%, dengue with complications in 2.5% and dengue hemorrhagic fever in 1.7%. The tourniquet test was positive in 16.9% of classic dengue cases, 61.7% of dengue cases with complications and 82.9% of cases of dengue hemorrhagic fever. The sensitivity and specificity of the tourniquet test were 19.1% and 86.4%, respectively. Conclusions A positive tourniquet test can be a valuable tool to support diagnosis of dengue where laboratory tests are not available. However, the absence of a positive test should not be read as the absence of infection. In addition, the tourniquet test was demonstrated to be an indicator of dengue severity.

Performance of a rapid diagnostic test for the detection of visceral leishmaniasis in a large urban setting

Introduction Rapid diagnostic tests (RDTs) may improve the early detection of visceral leishmaniasis (VL), but their real-world performance requires additional study. Therefore, we evaluated the performance of an rK39-based RDT (Kalazar Detect™) for the detection of VL in an endemic, large urban area. Methods Data were collected from a registry of rK39 RDT performed at 11 emergency care units in Belo Horizonte, Brazil, and from a national database of reportable communicable diseases of the Sistema de Informação de Agravos de Notificação (SINAN). Results The rapid rK39 test was performed in 476 patients, with 114 (23.9%) positive results. The analysis of rK39 RDT performance was based on 381 (80%) cases reported to the SINAN database, of which 145 (38.1%) were confirmed cases. Estimates for sensitivity and specificity were 72.4% (95% CI: 64.6-79%) and 99.6% (95%CI: 97.6-99.9%), respectively. Positive and negative predictive values were estimated at 99.1% (95%CI: 94.9-99.8%) and 85.5% (95%CI: 80.8-89.1%), respectively. In addition, close agreement between the rK39 RDT and indirect immunofluorescence was observed. Conclusions In summary, the rK39 RDT showed a high specificity but only moderate sensitivity. In endemic areas for VL, treatment may be considered in cases with clinical manifestations and a positive rK39 RDT, but those with a negative test should be subjected to further investigation.

Is autonomic function associated with left ventricular systolic function in Chagas heart disease patients undergoing treatment for heart failure?

Introduction The association between cardiac autonomic and left ventricular (LV) dysfunction in Chagas disease (ChD) is controversial. Methods A standardized protocol that includes the Valsalva maneuver, a respiratory sinus arrhythmia (RSA) test, and an echocardiographic examination was used. Spearman correlation coefficients (rho) were used to investigate associations. Results The study population consisted of 118 ChD patients undergoing current medical treatment, with an average LV ejection fraction of 51.4±2.6%. The LV ejection fraction and diastolic dimension were correlated with the Valsalva index (rho=0.358, p<0.001 and rho=-0.266, p=0.004, respectively) and the RSA (rho=0.391, p<0.001 and rho=-0.311, p<0.001, respectively). Conclusions The impairment of LV function is directly associated with a reduction of cardiac autonomic modulation in ChD.

Evaluation of diagnostic tests for Wuchereria bancrofti infection in Brazilian schoolchildren

Introduction Since the launch of the Global Programme to Eliminate Lymphatic Filariasis, more than 70% of the endemic countries have implemented mass drug administration (MDA) to interrupt disease transmission. The monitoring of filarial infection in sentinel populations, particularly schoolchildren, is recommended to assess the impact of MDA. A key issue is choosing the appropriate tools for these initial assessments (to define the best intervention) and for monitoring transmission. Methods This study compared the pre-MDA performance of five diagnostic methods, namely, thick film test, Knott's technique, filtration, Og4C3-ELISA, and the AD12-ICT card test, in schoolchildren from Brazil. Venous and capillary blood samples were collected between 11 pm and 1 am. The microfilarial loads were analyzed with a negative binomial regression, and the prevalence and associated 95% confidence intervals were estimated for all methods. The accuracies of the AD12-ICT card and Og4C3-ELISA tests were assessed against the combination of parasitological test results. Results A total of 805 schoolchildren were examined. The overall and stratified prevalence by age group and gender detected by Og4C3-ELISA and AD12-ICT were markedly higher than the prevalence estimated by the parasitological methods. The sensitivity of the AD12-ICT card and Og4C3-ELISA tests was approximately 100%, and the positive likelihood ratios were above 6. The specificity of the Og4C3-ELISA was higher than that of the AD12-ICT at different prevalence levels. Conclusions The ICT card test should be the recommended tool for monitoring school-age populations living in areas with ongoing or completed MDA.

An unusual case of heart failure due to Plasmodium vivax infection with a favorable outcome

Although malaria is one of the oldest types of parasitic infection, we have recently witnessed substantial changes in the outcome of malarial infections. Severe Plasmodium vivax infections have recently become more frequent, and are occasionally associated with fatal outcomes. Cardiac arrhythmia and myocardial failure have also been reported, typically in association with Plasmodium falciparum infections. We report a case of myocarditis and heart failure, due to Plasmodium vivaxinfection, along with the favorable outcome.

Acceptance and potential barriers to effective use of diagnostic tests for visceral leishmaniasis in an urban area in Brazil

Abstract: INTRODUCTION: Acceptance of the IT LEISH(r) and direct agglutination test- made in the Laboratório de Pesquisas Clínicas (DAT-LPC) by healthcare professionals and patients suspected of visceral leishmaniasis (VL) in Ribeirão das Neves was evaluated. METHODS: Ninety-two patients and 47 professionals completed three questionnaires. RESULTS: Eighty-eight (96%) patients considered fingertip blood collection a positive test feature, and 86% (37) and 91% of professionals considered the IT LEISH(r) easy to perform and interpret, respectively. All professionals classified the DAT-LPC as simple and easy. CONCLUSIONS: Patients and healthcare professionals in Ribeirão das Neves demonstrated a high degree of acceptance of the IT LEISH(r) and DAT-LPC.

Acute renal failure due to abdominal compartment syndrome: report on four cases and literature review

We report on 4 cases of abdominal compartment syndrome complicated by acute renal failure that were promptly reversed by different abdominal decompression methods. Case 1: A 57-year-old obese woman in the post-operative period after giant incisional hernia correction with an intra-abdominal pressure of 24 mm Hg. She was sedated and curarized, and the intra-abdominal pressure fell to 15 mm Hg. Case 2: A 73-year-old woman with acute inflammatory abdomen was undergoing exploratory laparotomy when a hypertensive pneumoperitoneum was noticed. During the surgery, enhancement of urinary output was observed. Case 3: An 18-year-old man who underwent hepatectomy and developed coagulopathy and hepatic bleeding that required abdominal packing, developed oliguria with a transvesical intra-abdominal pressure of 22 mm Hg. During reoperation, the compresses were removed with a prompt improvement in urinary flow. Case 4: A 46-year-old man with hepatic cirrhosis was admitted after incisional hernia repair with intra-abdominal pressure of 16 mm Hg. After paracentesis, the intra-abdominal pressure fell to 11 mm Hg.

Validity of the Brazilian Portuguese version of the bipolar spectrum diagnostic scale

OBJECTIVE: Bipolar spectrum disorders (BSDs) are prevalent and frequently unrecognized and undertreated. This report describes the development and validation of the Brazilian version of the bipolar spectrum diagnostic scale (B-BSDS), a screening instrument for bipolar disorders, in an adult psychiatric population. METHOD: 114 consecutive patients attending an outpatient psychiatric clinic completed the B-BSDS. A research psychiatrist, blind to the B-BSDS scores, interviewed patients by means of a modified version of the mood module of the Structured Clinical Interview for DSM-IV ("gold standard"). Subthreshold bipolar disorders were defined as recurrent hypomania without a major depressive episode or with fewer symptoms than those required for threshold hypomania. RESULTS: The internal consistency of the B-BSDS evaluated with Cronbach's alpha coefficient was 0.89 (95% CI; 0.86-0.91). On the basis of the modified SCID, 70 patients (61.4%) of the sample received a diagnosis of BSDs. A B-BSDS screening score of 16 or more items yielded: sensitivity of 0.79 (95% CI; 0.72-0.85), specificity of 0.77 (95% CI; 0.70-0.83), a positive predictive value of 0.85 (95% CI; 0.78-0.91) and a negative predictive value of 0.70 (95% CI; 0.63-0.75). CONCLUSION: The present data demonstrate that the B-BSDS is a valid instrument for the screening of BSDs.

Assessment of inotropic and vasodilating effects of milrinone lactate in patients with dilated cardiomyopathy and severe heart failure

OBJECTIVE: To assess the hemodynamic and vasodilating effects of milrinone lactate (ML) in patients with dilated cardiomyopathy (DCM) and New York Heart Association (NYHA) class III and IV heart failure. METHODS: Twenty patients with DCM and NYHA class III and IV heart failure were studied. The hemodynamic and vasodilating effects of ML, administered intravenously, were evaluated. The following variables were compared before and during drug infusion: cardiac output (CO) and cardiac index (CI); pulmonary capillary wedge pressure (PCWP); mean aortic pressure (MAP); mean pulmonary artery pressure (MPAP); mean right atrial pressure (MRAP); left ventricular systolic and end-diastolic pressures (LVSP and LVEDP, respectively); peak rate of left ventricular pressure rise (dP/dt); systemic vascular resistance (SVR); pulmonary vascular resistance (PVR); and heart rate (HR). RESULTS: All patients showed a significant improvement of the analysed parameters of cardiac performance with an increase of CO and CI; a significant improvement in myocardial contractility (dP/dt) and reduction of the LVEDP; PCWP; PAP; MAP; MRAP; SVR; PVR. Were observed no significant increase in HR occurred. CONCLUSION: Milrinone lactate is an inotropic dilating drug that, when administered intravenously, has beneficial effects on cardiac performance and myocardial contractility. It also promotes reduction of SVR and PVR in patients with DCM and NYHA class III and IV of heart failure.

Effects of propranolol on the QT dispersion in congestive heart failure

OBJECTIVE - Studies have shown that therapy with beta-blockers reduces mortality in patients with heart failure. However, there are no studies describing the effects of propranolol on the QT dispersion in this population. The objective of this study was to assess the electrophysiological profile, mainly QT dispersion, of patients with heart failure regularly using propranolol. METHODS - Fifteen patients with heart failure and using propranolol were assessed over a period of 12 months. Twelve-lead electrocardiograms (ECG) were recorded prior to the onset of beta-blocker therapy and after 3 months of drug use. RESULTS - A significant reduction in heart rate, in QT dispersion and in QTc dispersion was observed, as was also an increase in the PR interval and in the QT interval, after the use of propranolol in an average dosage of 100 mg/day. CONCLUSION - Reduction in QT dispersion in patients with heart failure using propranolol may explain the reduction in the risk of sudden cardiac death with beta-blocker therapy, in this specific group of patients.

Exercise and heart failure. Relation of the severity of the disease to the anaerobic threshold and the respiratory compensation point

OBJECTIVE - To identify, the anaerobic threshold and respiratory compensation point in patients with heart failure. METHODS - The study comprised 42 Men,divided according to the functional class (FC) as follows: group I (GI) - 15 patients in FC I; group II (GII) - 15 patients in FC II; and group III (GIII) - 12 patients in FC III. Patients underwent a treadmill cardiopulmonary exercise test, where the expired gases were analyzed. RESULTS - The values for the heart rate (in bpm) at the anaerobic threshold were the following: GI, 122±27; GII, 117±17; GIII, 114±22. At the respiratory compensation point, the heart rates (in bpm) were as follows: GI, 145±33; GII, 133±14; GIII 123±22. The values for the heart rates at the respiratory compensation point in GI and GIII showed statistical difference. The values of oxygen consumption (VO2) at the anaerobic threshold were the following (in ml/kg/min): GI, 13.6±3.25; GII, 10.77±1.89; GIII, 8.7±1.44 and, at the respiratory compensation point, they were as follows: GI, 19.1±2.2; GII, 14.22±2.63; GIII, 10.27±1.85. CONCLUSION - Patients with stable functional class I, II, and III heart failure reached the anaerobic threshold and the respiratory compensation point at different levels of oxygen consumption and heart rate. The role played by these thresholds in physical activity for this group of patients needs to be better clarified.