Mario Calvo

Value of Adenosine Deaminase (ada) in Ascitic Fluid for the Diagnosis of Tuberculous Peritonitis: A Meta-analysis

Background and Goals Adenosine deaminase (ADA) levels are used for diagnosing tuberculosis in several locations and although many studies have evaluated ADA levels in ascitic fluid. These studies have defined arbitrary cut-off points creating difficulties in the clinical application of the results. The goals of this study are: to determine the usefulness of ADA levels in ascitic fluid as a diagnostic test for peritoneal tuberculosis (PTB) and define the best cut-off point. Study A systematic review was done on the basis of 2 independent searches. We selected prospective studies that included consecutive patients. Diagnosis of PTB had to be confirmed by bacteriologic or histologic methods and ADA levels determined by the Giusti method. Inclusion/exclusion criteria were applied by 2 independent reviewers. A receiver operating characteristic curve was constructed to establish the optimal cut-off point and the likelihood ratios (LRs) estimated using fixed-effect pooled method. Results Twelve prospective studies were found. Four of them met the inclusion criteria and were thus included in the meta-analysis. They included 264 patients, of which 50 (18.9%) had PTB. ADA levels showed high sensitivity (100%) and specificity (97%) using cut-off values from 36 to 40 IU/L. The included studies were homogeneous. Optimal cut-off point was determined at 39 IU/L, and LRs were 26.8 and 0.038 for values above and below this cut-off. Conclusions This study supports the proposition that ADA determination is a fast and discriminating test for diagnosing PTB with an optimal cut-off value of 39 IU/L.

The International Study of Wheezing in Infants: Questionnaire Validation

Background: There are no internationally validated questionnaires to investigate the prevalence of infant wheezing. This study was undertaken to validate a questionnaire for the International Study on the Prevalence of Wheezing in Infants (Estudio Internacional de Sibilancias en Lactantes, EISL). Material and Methods: Construct and criterion validity were tested for the question ‘Has your baby had wheezing or whistling in the chest during his/her first 12 months of life?’. Construct validity (i.e. the ability of parents and doctors to refer to the same symptoms with the same words) was tested in a sample of 50 wheezing and 50 non-wheezy infants 12–15 months of age in each of 10 centres from 6 different Spanish- or Portuguese-speaking countries. Criterion validity (i.e. the ability of parents to correctly detect the symptom in the general population) was evaluated in 2 samples (Santiago, Chile and Cartagena, Spain) of 50 wheezing and 50 non-wheezing infants (according to parents) of the same age, randomly selected from the general population, who were later blindly diagnosed by a paediatric pulmonologist. Results: Construct validity was very high (ĸ test: 0.98–1) in all centres. According to Youden’s index, criterion validity was good both in Cartagena (75.5%) and in Santiago (67.0%). Adding questions about asthma medication did not improve diagnosis accuracy. Conclusions: The EISL questionnaire significantly distinguished wheezy infants from healthy ones. This questionnaire has a strong validity and can be employed in large international multicentre studies on wheezing during infancy.

Person-to-person household and nosocomial transmission of andes hantavirus, Southern Chile, 2011.

Four persons became ill after exposure to a patient infected with the virus; 2 cases involved hospital transmission.

High-Dose Intravenous Methylprednisolone for Hantavirus Cardiopulmonary Syndrome in Chile: A Double-Blind, Randomized Controlled Clinical Trial

BACKGROUND Andes virus (ANDV)-related hantavirus cardiopulmonary syndrome (HCPS) has a 35% case fatality rate in Chile and no specific treatment. In an immunomodulatory approach, we evaluated the efficacy of intravenous methylprednisolone for HCPS treatment, through a parallel-group, placebo-controlled clinical trial. METHODS Patients aged >2 years, with confirmed or suspected HCPS in cardiopulmonary stage, admitted to any of 13 study sites in Chile, were randomized by study center in blocks of 4 with a 1:1 allocation and assigned through sequentially numbered envelopes to receive placebo or methylprednisolone 16 mg/kg/day (≤1000 mg) for 3 days. All personnel remained blinded except the local pharmacist. Infection was confirmed by immunoglobulin M antibodies or ANDV RNA in blood. The composite primary endpoint was death, partial pressure of arterial oxygen/fraction of inspired oxygen ratio ≤55, cardiac index ≤2.2, or ventricular tachycardia or fibrillation within 28 days. Safety endpoints included the number of serious adverse events (SAEs) and quantification of viral RNA in blood. Analysis was by intention to treat. RESULTS Infection was confirmed in 60 of 66 (91%) enrollees. Fifteen of 30 placebo-treated patients and 11 of 30 methylprednisolone-treated patients progressed to the primary endpoint (P = .43). We observed no significant difference in mortality between treatment groups (P = .41). There was a trend toward more severe disease in placebo recipients at entry. More subjects in the placebo group experienced SAEs (P = .02). There were no SAEs clearly related to methylprednisolone administration, and methylprednisolone did not increase viral load. CONCLUSIONS Although methylprednisolone appears to be safe, it did not provide significant clinical benefit to patients. Our results do not support the use of methylprednisolone for HCPS. CLINICAL TRIALS REGISTRATION NCT00128180.

Childhood Asthma and Allergies in Urban, Semiurban, and Rural Residential Sectors in Chile

While rural living protects from asthma and allergies in many countries, results are conflicting in Latin America. We studied the prevalence of asthma and asthma symptoms in children from urban, semiurban, and rural sectors in south Chile. A cross-sectional questionnaire study was conducted in semiurban and rural sectors in the province of Valdivia (n = 559) using the ISAAC (International Study of Asthma and Allergies in Childhood) questionnaire. Results were compared to prevalence in urban Valdivia (n = 3105) by using data from ISAAC III study. Odds ratios (+95% confidence intervals) were calculated. No statistical significant differences were found for asthma ever and eczema symptoms stratified by residential sector, but a gradient could be shown for current asthma and rhinoconjunctivitis symptoms with urban living having highest and rural living having lowest prevalence. Rural living was inversely associated in a statistical significant way with current asthma (OR: 0.4; 95% CI: 0.2–0.9) and rhinoconjunctivitis symptoms (OR: 0.3; 95% CI: 0.2–0.7) in logistic regression analyses. Rural living seems to protect from asthma and respiratory allergies also in Chile, a South American country facing epidemiological transition. These data would be improved by clinical studies of allergic symptoms observed in studied sectors.

Características de los pacientes que reciben ventilación mecánica en unidades de cuidados intensivos: primer estudio multicéntrico chileno

Prospective cohort of consecutive adult patients admitted to 19 intensive care units(ICU) from 9 Chilean cities who received MV for more than 12 hours between September 1st, 2003,and September 28th, 2003. Demographic data, severity of illness, reason for the initiation of MV,ventilation modes and settings as well as weaning strategies were registered at the initiation and then,daily throughout the course of MV for up to 28 days. ICU and hospital mortality were recorded.

Environmental Risk Factors in the First Year of Life and Childhood Asthma in the Central South of Chile

Background. Childhood asthma has a high prevalence in South America—a region of the world currently undergoing a thorough modernization and transition process. Asthma in South America is mainly associated with poor urban environment, which actually may challenge the role of the hygiene hypothesis. We systematically assessed the impact of environmental factors in the first year of life on asthma. Methods. A case–control study including 188 asthmatics and 294 hospital-based controls aged 6–15 years was carried out in the Central South of Chile. Parents of study participants completed a computer-assisted interview on environmental factors (such as birth order, day-care attendance, pneumonia infection, regular animal and furry pet contact, and environmental tobacco smoke exposure) in the first year of life and potential confounders. Atopy was assessed using skin prick tests. Multivariate logistic regression models were calculated to assess the association between exposures and asthma, adjusting for potential confounders. Results. Day-care attendance (OR = 0.31; 95% CI: 0.10, 0.94) and regular farm animal contact (OR = 0.38; 95% CI: 0.17, 0.85) were inversely related to childhood asthma in the logistic regression models. Pneumonia infection (OR = 2.24; 95% CI: 1.21, 4.16) and mold or dampness in the home (OR = 1.87; 95% CI: 1.18, 2.97) in the first year of life were positively associated with asthma. Conclusion. Our results suggest that the hygiene hypothesis is also applicable in the Chilean setting, a South American country in epidemiological transition.

Asthma in changing environments - chances and challenges of international research collaborations between South America and Europe - study protocol and description of the data acquisition of a case-control-study

BackgroundAsthma in children is an emerging public health problem in South America. So far, research in this part of the world is limited. This paper presents the methodology and description of the data acquisition of an asthma case-control study conducted in the Central South of Chile.Methods/DesignA hospital-based case-control study about asthma (188 cases, 294 controls) in children (6-15 years) was carried out in Valdivia, Chile between November 2008 and December 2009. Data on asthma risk factors were collected by computer-assisted personal interview using validated questions from e.g. ISAAC phase II. Data on household dust exposure (endotoxin, allergen analyses), skin prick tests to most common allergens, stool examinations for parasitic infection, and blood samples (total IgE, genetics) were collected. Additionally, 492 randomly chosen blood donors were recruited in order to assess allele frequencies in the population of Valdivia.DiscussionOverall 1,173 participants were contacted. Response was 82% among cases and 65% among controls. Atopic sensitization was high (78% among cases, 47% among controls). Cases had a statistically significantly (p < .0001) increased self-reported 12-month prevalence of symptoms of rhinitis (82% vs. 51%) and wheeze (68% vs. 16%). The study is well placed to address current hypotheses about asthma and its correlates in the South American context. Results of this study might help develop novel, innovative and individualized prevention strategies in countries in transition with respect to the South American context.

Meningitis bacteriana aguda por Streptococcus suis en criadores de cerdos: comunicación de los primeros dos casos en Chile

UNLABELLED Human infection by Streptococcus suis is a zoonosis with a known occupational risk. Meningitis is its most frequent clinical manifestation. We present the first two cases in Chile. FIRST CASE 54-year-old female patient, pig-farmer. She presented headache, vomiting, confusion and meningismus. She presented septic shock. Second case: 48-year-old male patient, also pig farmer, presented headache, vomiting and meningismus. A Grams staining of cerebrospinal fluid (CSF) showed gram-positive cocci in both cases. Ceftriaxone and dexamethasone treatment was administered. The CSF cultures were positive for Streptococcus suis serotype 2. The patients experienced a good outcome, without neurological sequelae at the time of discharge. It is considerable to evaluate epidemiologic factors in order to suspect this etiological agent in cases of meningitis. These cases enhance the need of heighten awareness of potential for occupational exposure and infection by this emerging human pathogen. Educating population at risk about simple preventive measures must be considered.

Environmental factors in infancy and ulcerative colitis in the Central South of Chile: A case–control study☆

BACKGROUND AND AIMS Evidence for the role of the hygiene hypothesis and the development of Ulcerative Colitis (UC) is unclear. We aimed to explore the association between environmental factors in infancy and UC. METHODS A hospital-based case-control study (52 UC cases, response: 77%, 174 age- , sex and place of living matched controls, response: 62%) was carried out in the Central South of Chile in 2009/2010. Patients or parents underwent a personal interview about early life experiences. RESULTS High paternal education (adjusted Odds Ratio (aOR): 2.1; 95% CI: 1.0-4.5) as proxy for socioeconomic status was positively associated with case status in the final multivariate logistic regression model. Likewise, having older siblings was a risk factor for UC (aOR: 2.2; 95%CI: 1.1.-4.4). CONCLUSIONS The importance for some early life environmental factors in the development of UC was established. However, the role of the hygiene hypothesis could not be confirmed for all environmental factors.