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Biomedical subjects

R Palacio

Publications and source records attributed to R Palacio.

18 recordsLinked to original sources
PubMed2003

Invasive pneumococcal diseases in Uruguayan children: comparison between serotype distribution and conjugate vaccine formulations.

An on-going Streptococcus pneumoniae surveillance in Uruguay furnished national information on serotype distribution of isolates from invasive infections in children </=5 years. The adequacy of 7-, 9- and 11-valent conjugate vaccine formulations was evaluated, in comparison with the prevalence of the serotypes causing disease in this target population. From 1994 to 2001, 506 isolates were submitted to the National Reference Laboratory. The heptavalent vaccine would cover 49% of the invasive isolates, while the nonavalent vaccine would potentially prevent 76% of cases. The 11-valent vaccine would increase coverage to 86%. All the serotype/groups of penicillin-resistant isolates are included in the three conjugate vaccine formulations. The available data indicate that the 9- or the 11-valent vaccines, if affordable, are the most suitable formulations for Uruguayan children.

Child, Preschool↗
PubMed2003

Measurement of serum levels of eosinophil cationic protein in the diagnosis of acute gastrointestinal anisakiasis.

Thirty-two patients with abdominal pain and/or intestinal pseudo-obstruction who had consumed raw or undercooked fish in the previous 72 h, were included in a study of anisakiasis, a parasitation of the human gastrointestinal tract by third stage Anisakis simplex larvae. Skin prick test (SPT) against A. simplex were positive in all the patients. High median eosinophil cationic protein (ECP) serum concentrations (> 15 mg/L) at day 0 with normal serum levels at day 30 and a rise of median total and specific IgE against A. simplex at day 30, were observed. We conclude that a raised serum level of ECP in the first 72 h from the onset of symptoms coinciding with a positive SPT against A. simplex and high total and specific immunoglobulin (IgE) in the first month after the parasitation, could be a useful tool in the diagnosis of gastrointestinal anisakiasis, even if the parasite cannot be isolated.

Acute Disease↗
PubMed2001

Antibiotic resistance in Streptococcus pneumoniae in six Latin American countries: 1993-1999 surveillance.

The impact of invasive pneumococcal invasive disease is increased by the emergence of antibiotic resistance. We report regional and temporal variations in antibiotic resistance for 4,105 invasive Streptococcus pneumoniae isolates collected from Latin American children <5 years, between 1993 and 1999. Reduced susceptibility to penicillin was detected in 1,182 isolates (28.8%); 36% of these were resistant (> or = 2 microg/ml), including 12.6% with MIC > or = 4 microg/ml, occurring primarily in serotypes 14 and 23F. Reduced susceptibility to third-generation cephalosporins was detected in 12.1% of the collection. Mexico had the highest proportion of reduced susceptibility to penicillin (51.6%) and to third-generation cephalosporins (22%), whereas Brazil had the lowest at 20.9% and 0.7%, respectively. Isolates cultured from patients with pneumonia were more likely to have reduced susceptibility to third-generation cephalosporins than isolates from patients with meningitis (p < 0.0001). Susceptibility to trimethoprim-sulfamethoxazole, chloramphenicol, erythromycin, and vancomycin was tested by disk diffusion for 2.899 isolates. Reduced susceptibility was observed for 45.6%, 11.5%, 6.9%, and 0%, respectively. Thirty-one percent of the strains were resistant to > or = 2 drugs. High levels of antibiotic resistance in Latin America emphasize the need for the development of and adherence to rational antibiotic use guidelines. On-going surveillance will monitor the impact of these programs.

Age Factors↗
PubMed2001

Three-year assessment of methicillin-resistant Staphylococcus aureus clones in Latin America from 1996 to 1998.

Four hundred ninety-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from 1996 to 1998 from 22 hospitals in five countries of Latin America-Argentina, Brazil, Chile, Uruguay and Mexico-were examined for antimicrobial susceptibility and clonal type in order to define the endemic clones in those hospitals. The hybridization of ClaI restriction digests with the mecA- and Tn554-specific DNA probes combined with pulsed-field gel electrophoresis of chromosomal SmaI digests (ClaI-mecA::ClaI-Tn554::PFGE clonal types) documented not only the predominance and persistence of the Brazilian clone (XI::B::B) in Brazil (97%) and Argentina (86%) but also its massive dissemination to Uruguay (100%). Moreover, a close relative of the Brazilian clone (XI::kappa::B) was highly represented in Chile (53%) together with a novel clone (47%) (II::E'::F) resistant to pencillin, oxacillin, ciprofloxacin, chloramphenicol, clindamycin, erythromycin, and gentamicin. A unique clonal type (I::NH::M) was detected in Mexico among pediatric isolates and was resistant to penicillin, oxacillin, and gentamicin only. This study clearly documented the very large capacity for geographic expansion and the persistence of the Brazilian clone, contributing not only to the increasing uniformity of the MRSA in South America but worldwide as well.

Anti-Bacterial Agents↗
PubMed2000

Ten-year review of invasive pneumococcal diseases in children and adults from Uruguay: clinical spectrum, serotypes, and antimicrobial resistance.

OBJECTIVES: Since 1987, the Reference Laboratory of the Ministry of Health of Uruguay has been monitoring infections due to Streptococcus pneumoniae in patients under 5 years of age, in those between 5 to 14 years of age, and in adults. The purpose of the present study was to retrospectively analyze a 10-year collection of invasive S. pneumoniae isolates from children 5 to 14 years of age and adults. METHODS: The Reference Children's Hospital, Pasteur Hospital, and two private hospitals in Montevideo as well as four hospitals located in other representative areas of the country participated in the pneumococcal surveillance program. Based on the information available at the Microbiology Department of the Central Public Health Laboratory (demographic data, date and site of isolate, and clinical diagnosis), all patients with an invasive pneumococcal disease were recorded. Pneumonia was clinically and radiologically diagnosed and etiology was assessed by isolation of S. pneumoniae from blood or pleural fluid. All specimens were collected at the Emergency Service. Capsular serotyping and antimicrobial susceptibilities were determined for each isolate. RESULTS: During the 10-year period, 228 invasive S. pneumoniae were identified and included in the study (blood, n = 129; cerebrospinal fluid [CSF], n = 73; pleural fluid, n = 20; peritoneal fluid, n = 3; synovial fluid, n = 1; pericardic fluid, n = 1; abscess, n = 1). The most frequent clinical presentations were pneumonia (n = 71) and meningitis (n = 69). Thirty-five adults had an underlying condition including, four with malignancies, four with lupus, two with human immunodeficiency virus (HIV)-infected, and two patients in hemodialysis among others. Eighteen of the 228 patients died (7.9% fatality rate), but only four of these had an underlying condition. Eleven fatal cases were attributable to meningitis (2 children, 9 and 11 years old; 9 adults, mean age, 59 y). Four patients with pneumonia and three with sepsis died, including a splenectomized woman. Nine different capsular serotypes (1, 5, 7, 9, 12, 15, 19A, 20, and 23A) were identified among the 18 fatal cases. Resistance to penicillin, generally combined with trimethoprim-sulfamethoxazole, fluctuated annually, not surpassing 10%. CONCLUSIONS: The study results indicated that 96% of the serotypes involved in severe pneumococcal diseases were included in the 23-valent vaccine and that S. pneumoniae resistance to penicillin was moderate.

Adolescent↗
PubMed2000

Molecular typing of methicillin-resistant Staphylococcus aureus by pulsed-field gel electrophoresis: comparison of results obtained in a multilaboratory effort using identical protocols and MRSA strains.

Pulsed-field gel electrophoresis (PFGE) has become the gold standard of molecular methods in epidemiological investigations. In spite of its high resolving power, use of the method has been hampered by inadequate laboratory-to-laboratory reproducibility. In the project described here we have addressed this problem by organizing a multilaboratory effort in which the same bacterial strains (subtype variants of the Iberian and Brazilian methicillin-resistant Staphylococcus aureus--MRSA--clones) were analyzed by twenty investigators in thirteen different laboratories according to an indentical protocol, which is reproduced here in detail. PFGE patterns obtained were analyzed at a central laboratory in order to identify specific technical problems that produced substandard macrorestriction patterns. The results including the specific technical problems and their most likely causes are described in this communication. Also listed are seven major epidemic clones of MRSA which have been characterized by molecular fingerprinting techniques and the prototypes of which have been deposited at the American Type Culture Collection, from where they will be available for interested investigators for the purpose of typing MRSA isolates. It is hoped that this communication will contribute to the improvement of the reproducibility and technical/aesthetic quality of PFGE analysis.

Bacterial Typing Techniques↗
PubMed2000

[Impact of Streptococcus pneumoniae on pneumonia in Latin American children. SIREVA-Vigía Group].

Community-acquired pneumonia is one of the leading causes of infant morbidity and mortality. Studies conducted in developing countries indicate that the most serious symptoms of pneumonia are associated with bacterial causes, mainly Streptococcus pneumoniae, followed by Haemophilus influenzae type b. Managing those infections in children under two years of age is hindered by the lack of appropriate vaccines and by the decreased susceptibility of S. pneumoniae to penicillin and other antibiotics. In 1993, at the initiative of the Regional System for Vaccines of the Pan American Health Organization, and with funding from the Canadian International Development Agency, a study was designed to identify the S. pneumoniae capsular types that cause invasive disease in Latin American children under 5 years of age. The objective of the study was to determine the ideal composition of a conjugate vaccine that could be used in Latin America, and the penicillin susceptibility of the S. pneumoniae isolates. The initiative was undertaken in Argentina, Brazil, Chile, Colombia, Mexico, and Uruguay. This report analyzes the information that the participating countries generated on pneumococcal pneumonia. A total of 3,393 children were found with systemic S. pneumoniae infections, of which 1,578 corresponded to pneumonias. The analysis focused on 1,409 cases of pneumonia in Argentina, Brazil, Colombia, Mexico, and Uruguay. Of the children, 63.8% of them were under two years of age. Twelve prevalent capsular types were identified, of which serotypes 14, 5, and 1 were the three most common in the majority of the countries. At the beginning of the study the highest level of penicillin resistance was found in Mexico (47.0%), and the lowest in Colombia (12.1%). Over the 1993-1998 period, resistance to penicillin increased in the five countries. Penicillin resistance was associated with a small number of capsular serotypes, mainly 14 and 23F. The first of those serotypes was resistant to penicillin and to trimethoprim-sulfamethoxazole, and the second was multiresistant. The frequency of resistance to trimethoprim-sulfamethoxazole was high in all of the countries; Argentina had the highest level, 58.0%. A decrease in susceptibility to chloramphenicol was uncommon, except in Colombia, where there was a resistance level of 23.4%. Resistance to erythromycin was low in all the countries, and all the isolates were susceptible to vancomycin.

Child, Preschool↗
PubMed1999

Determination of trimethoprim-sulfamethoxazole resistance in Streptococcus pneumoniae by using the E test with Mueller-Hinton agar supplemented with sheep or horse blood may be unreliable. The Pneumococcal Study Group.

An international, multicenter study compared trimethoprim-sulfamethoxazole MICs for 743 Streptococcus pneumoniae isolates (107 to 244 isolates per country) by E test, using Mueller-Hinton agar supplemented with 5% defibrinated horse blood or 5% defibrinated sheep blood, with MICs determined by the National Committee for Clinical Laboratory Standards broth microdilution reference method. Agreement within 1 log2 dilution and minor error rates were 69.3 and 15.5%, respectively, on sheep blood-supplemented agar and 76.9 and 13.6%, respectively, with horse blood as the supplement. Significant interlaboratory variability was observed. E test may not be a reliable method for determining the resistance of pneumococci to trimethoprim-sulfamethoxazole.

Animals↗
PubMed1999

Risk factors and course of illness among children with invasive penicillin-resistant Streptococcus pneumoniae. The Streptococcus pneumoniae Working Group.

OBJECTIVES: To assess differences in risk factors, clinical presentation, and course of illness between children infected with penicillin-sensitive and drug-resistant Streptococcus pneumoniae (DRSP). DESIGN: A retrospective cohort study conducted in Uruguay and Argentina using information from a hospital-based surveillance system. Hospitalized children 5 years of age and younger who had S pneumoniae isolated from a normally sterile site between June 1993 and October 1996 were eligible. Hospital records were linked with surveillance data. Both stratified univariate analysis and logistic regression was completed. RESULTS: Of the 380 children eligible for the study, 274 records (72%) were available for review. Ninety-nine children (36%) had DRSP; 46 showed intermediate susceptibility (minimum inhibitory concentration, 0.12-1.0 microg/mL) and 53 showed high-level resistance (minimum inhibitory concentration >/=2.0 microg/mL). Children with meningitis were less likely to have DRSP than those with other forms of invasive disease (relative risk = 0. 5; 95% confidence interval [CI], 0.2-0.9). Risk factors associated with DRSP were use of penicillin or ampicillin in the 3 months before illness (odds ratio = 2.9; 95% CI, 1.5-5.7) and possession of private medical coverage (odds ratio = 2.4; 95% CI, 1.2-5.0). Response to therapy, including response to penicillin or ampicillin among children with nonmeningeal invasive disease, course of illness, and clinical outcome did not differ significantly between children infected with penicillin-susceptible or penicillin-resistant isolates. CONCLUSION: In this study, previous use of penicillin or ampicillin and private medical coverage were associated with having DRSP. Children with nonmeningeal invasive disease responded equally well to penicillin regardless of the penicillin susceptibility of their pneumococcal isolate.

Ampicillin↗
PubMed1998

Frequency, Type and Associated Diseases of Bacteria and Virus in The Oropharynx of Children Born to Human Immunodeficiency Virus-Infected Mothers.

HIV-infected children are more likely than other children to develop pneumonia, which in these children is often recurrent or persistent. The main reservoir of the major pathogens is the nasopharynx, but to date no data has been published on the frequency and biologic characteristics of S.pneumoniae, H.influenzae and respiratory viruses found in the upper respiratory tract of children born to human immunodeficiency virus-infected mothers. To document these aspects, 105 children was monitored by pharyngeal swab (PS) and nasopahryngeal aspirates (NPA) who attended an outpatient clinic for HIV-infection evaluation. Bacterial identification was performed by standard procedures. Serotype, biotype and beta-lactamase production was investigated in H.influenzae isolates. S.pneumoniae serotypes were recognized by "quellung" and the susceptibility to 4 antibiotics was assessed. Respiratory syncytial viruses, parainfluenza, influenza A and B, and adenoviruses were diagnosed by indirect immunofluorescence and/or viral isolation in cell cultures. Twenty-nine children were identified as infected by HIV as a result of maternal-child transmission. Seventy children born to HIV-positive mothers but who were not HIV-infected served as controls. Of 269 PS, 110 110 S. pneumoniae and 92 H.influenzae were identified. Also 31 viruses were detected in 188 NPA. After stratifying by age no differences were observed in the frequency of bacterial colonization or in the presence of viruses in the upper respiratory tract of the two groups. Some biologic characteristics of the agents were noteworthy such as the frequency of colonization by S.pneumoniae serotype 14, the predominance of H.influenzae biotype I and the high frequency of viruses in NPA of asymptomatic children. Of note, although colonization frequencies were similar, children presenting with acute respiratory illness (ARI) were more likely to have bacteria isolated if they also had HIV-infection than if they were HIV-negative. It is concluded that HIV-infection in infants as a result of maternal virus transmission have a similar frequency of bacteria and virus colonization of their respiratory tract, but a higher frequency of ARI and perhaps a higher frequency of types of bacteria with special characteristics.

Journal Article↗
PubMed1997

Capsular type distribution and susceptibility to antibiotics of Streptococcus pneumoniae clinical strains isolated from Uruguayan children with systemic infections. Pneumococcus Study Group.

Children under 24 months of age are at high risk for serious infection with Streptococcus pneumoniae but they do not elicit effective immune responses to the currently available capsular polysaccharide vaccines. A polysaccharide protein conjugated vaccine involving the most frequent types has become an urgent need. To produce such a vaccine for Latin America, information on type distribution is required. Recently, Uruguay was 1 of the 6 countries in Latin America where surveillance for invasive pneumococcal infections in children under the age of 5 years was carried out. Seventy percent of the 182 invasive S. pneumoniae isolates were recovered from patients under 24 months of age, and 19% were recovered from infants under 6 months. The 7 most frequent types were 14, 5, 1, 6B, 3, 7F, and 19A; representing 80% of invasive isolates. Twenty-one types were identified, 16 in pneumonia and 14 in meningitis. Resistance to penicillin increased during the study period, from 29% in 1994, to 40% in 1995-1996, mainly because of the spread of type 14 strains resistant to penicillin and trimethoprim/sulphamethoxazol (89% of resistant isolates). The high proportion of systemic pneumococcal infections recorded in patients under 24 months of age and the increasing resistance of these agents to first-choice antibiotics point to an urgent need for a capsular polysaccharide protein conjugated vaccine.

Drug Resistance, Microbial↗
PubMed1985

Psychiatric symptomatology among Mexican American farmworkers.

The paper presents findings from an epidemiologic field survey of 500 Mexican American farmworkers conducted in central California. The survey was intended as a health needs assessment of this population and the Health Opinion Survey was used to establish normative psychiatric symptom distributions. Analyses of the data by gender, age and income revealed that these socio-demographic variables were not important predictors of symptom levels, although the highest mean scores were reported in the 40-59 age group. Income levels were modest and fairly uniform, which contributed to the lack of mean score variation. Symptom distributions were analyzed for the variables age and sex using the HOS criteria of caseness and it was found that approx. 20% of the sample reached the criteria of caseness. A comparison of HOS mean scores with a national sample of surveys indicated that Mexican American farmworkers had symptom levels which resemble those of other low income socio-economic groups, such as southern blacks. Another analysis was conducted which reported a striking correspondence between self perception of health with psychiatric symptoms. A conclusion reached from the survey is that the Mexican American farmworkers in this sample appear to be experiencing psychiatric symptom levels which place them at extraordinary risk. Stresses associated with this group, i.e., limited social mobility, transience, poverty, discrimination and a high rate of traumatic life events were identified as possible contributors to this risk proneness.

Acculturation↗