Patricia Reyes

Fungal bloodstream infections in tertiary care hospitals in Colombia

BACKGROUND Fungal infections have increased in critical care patients, causing high morbidity and mortality. AIMS Describe the frequency and responsible fungal species involved in bloodstream fungal infection from 2001 to 2007 in tertiary care level hospitals belonging to a surveillance network in Colombian cities. METHODS Data were collected from a microbiology surveillance network based on 27 hospital laboratories in five Colombian cities. Data were entered into a Whonet® version 5.4 database. Fungemia data were analyzed according to location (Intensive care unit -ICU- vs. non-ICU services). Frequency over time was also described. RESULTS Fungal infections corresponded to 4.1% of all bloodstream infections. Candidemia represented 3.7% and 5.2% of all isolates in non-ICU and ICU services, respectively. Over 99% of the isolates were yeasts, and Candida albicans was the most frequently isolated organism in and out of the ICU, showing a decreasing trend in the last few years. In the adult ICU and non-ICU services, the second organism most frequently isolated was C. tropicalis, while C. parapsilopsis was the most frequent in the pediatric and neonatal ICU, also showing an overall decreasing trend. Cryptococcus neoformans was the fourth mycotic organism most frequently identified. CONCLUSIONS In Colombia, epidemiology of fungal infections seems to be changing. C. albicans is the principal agent causing bloodstream fungal infection, but an increase of non-albicans species has been observed as well as high frequency of C. neoformans.

Geographic distribution of human Blastocystis subtypes in South America.

Blastocystis is a cosmopolitan enteric protist colonizing probably more than 1 billion people. This protozoan exhibits genetic diversity and is subdivided into subtypes (STs). The aim of this study was to determine the distribution of Blastocystis STs in symptomatic and asymptomatic human samples from different countries of South America. A total of 346 fecal samples were genotyped by SSU rDNA showing ST1 (28.3%), ST2 (22.2%), ST3 (36.7%), ST4 (2%), ST5 (2.3%), ST6 (2%), ST7 (2.3%), ST8 (0.6%), ST12 (0.9%) and a novel ST (2.7%). These findings update the epidemiology of Blastocystis in South America and expand our knowledge of the phylogeographic differences exhibited by this stramenopile.

Clinical and epidemiological characteristics and risk factors for mortality in patients with candidemia in hospitals from Bogotá, Colombia

BACKGROUND Bloodstream infection by Candida species has a high mortality in Latin American countries. The aim of this study was to describe the characteristics of patients with documented bloodstream infections caused by Candida species in third level hospitals and determine the risk factors for in-hospital-mortality. METHODS Patients from seven tertiary-care hospitals in Bogotá, Colombia, with isolation of a Candida species from a blood culture were followed prospectively from March 2008 to March 2009. Epidemiologic information, risk factors, and mortality were prospectively collected. Isolates were sent to a reference center, and fluconazole susceptibility was tested by agar-based E-test. The results of susceptibility were compared by using 2008 and 2012 breakpoints. A multivariate analysis was used to determinate risk factors for mortality. RESULTS We identified 131 patients, with a median age of 41.2 years. Isolates were most frequently found in the intensive care unit (ICU). Candida albicans was the most prevalent species (66.4% of the isolates), followed by C. parapsilosis (14%). Fluconazole resistance was found in 3.2% and 17.6% of the isolates according to the 2008 and 2012 breakpoints, respectively. Fluconazole was used as empirical antifungal therapy in 68.8% of the cases, and amphotericin B in 22%. Hospital crude mortality rate was 35.9%. Mortality was associated with age and the presence of shock at the time of Candida detection. Fluconazole therapy was a protective factor for mortality. CONCLUSIONS Candidemia is associated with a high mortality rate. Age and shock increase mortality, while the use of fluconazole was shown to be a protective factor. A higher resistance rate with new breakpoints was noted.

Molecular Epidemiology of Giardia, Blastocystis and Cryptosporidium among Indigenous Children from the Colombian Amazon Basin

The incidence and prevalence of intestinal parasites in children is most likely due to lack of natural or acquired resistance and differences in behavior and habits closely related to environmental and socioeconomic determinants. The most important protozoa that parasitize humans are Giardia, Entamoeba, Blastocystis, and Cryptosporidium. These parasites present wide intraspecific genetic diversity and subsequently classified into assemblages and subtypes. The Amazon basin is the largest in the world and is the fifth freshwater reserve on the planet. Contradictorily, people living in these areas (Indigenous populations) have poor quality of life, which favors the infection of diseases of fecal-oral transmission. The aim of this work was to unravel the molecular epidemiology of Giardia, Blastocystis and Cryptosporidium across four communities (Puerto Nariño, San Juan del Soco, Villa Andrea and Nuevo Paraíso). We obtained 284 fecal samples from children under 15 years old that were analyzed by direct microscopy (261 samples) and Real Time PCR (qPCR) (284 samples). The positive samples for these protozoa were further characterized by several molecular markers to depict assemblages and subtypes. We observed a frequency of Giardia infection by microscopy of 23.7% (62 samples) and by qPCR of 64.8% (184 samples); for Blastocystis by microscopy of 35.2% (92 samples) and by qPCR of 88.7% (252 samples) and for Cryptosporidium only 1.9% (5 samples) were positive by microscopy and qPCR 1.8% (5 samples). Regarding the Giardia assemblages, using the glutamate dehydrogenase (gdh) marker we observed AI, BIII and BIV assemblages and when using triose phosphate isomerase (tpi) we observed assemblages AI, AII, BIII and BIV. In contrast, Blastocystis STs detected were 1, 2, 3, 4, and 6. Lastly, the species C. viatorum, C. hominis (with the subtypes IdA19 and IaA12R8) and C. parvum (with the subtype IIcA5G3c) were identified. We observed a high profile of zoonotic transmission regarding the Giardia assemblages and Blastocystis STs/alleles. Also, we highlight the elevated frequency of infection by these two protozoans suggesting an active transmission in the area. Our findings reinforces the need to deploy better epidemiological surveillance systems for enteric pathogens in the area.

Molecular Epidemiology of Entamoeba: First Description of Entamoeba moshkovskii in a Rural Area from Central Colombia

Background Entamoeba histolytica, E. dispar and E. moshkovskii are the most frequent species described in human infection where E. histolytica is the only true pathogen. The epidemiology of this infection is complex due to the absence of a routine exam that allows a correct discrimination of the Entamoeba species complex. Therefore, molecular methods appear as the unique epidemiological tool to accomplish the species discrimination. Herein, we conducted a cross-sectional study to determine the frequency of Entamoeba species infections in a group of asymptomatic individuals from a rural area in central Colombia. Methodology/Principal Findings A total of 181 fecal samples from asymptomatic children under 16 years old from the hamlet La Vírgen, Cundinamarca (Colombia) that voluntarily accepted to participate in the study were collected. The fecal samples were examined by light microscopy and DNA-extracted, subsequently submitted to molecular discrimination of E. dispar/E. histolytica/E. moshkovskii infection based on a multiplex PCR assay targeting the 18S rRNA fragment. To confirm the species description, twenty samples were randomly submitted to DNA sequencing of the aforementioned fragment. By direct microscopic examination, frequency of the complex E. histolytica/E. dispar/E. moshkovskii was 18.8% (34/181). PCR showed a frequency of 49.1% (89/181), discriminated as 23.2% (42/181) that were positive for E. dispar, 25.4% (46/181) for E. moshkovskii and 0.55% (1/ 181) for E. histolytica. Also, mixed infections were detected between E. dispar and E. moshkovskii at 4.42% (8/181) of the samples. Molecular barcoding confirmed the diagnosis depicted by the multiplex PCR assay. Conclusions/Significance This is the first description of E. moshkovskii in Colombia and the second report in South-America to our knowledge. Our results suggest the need to unravel the true epidemiology of Entamoeba infections around the world, including the real pathogenic role that E. moshkovskii may have.

Validez de los estudios de asociación entre geohelmintos e incidencia de malaria: ¿Debería impactar las políticas de salud?

INTRODUCCION: La distribucion mundial de las geohelmintiasis y la malaria se encuentra ampliamente sobrepuesta. Algunos estudios sugieren una asociacion entre las infecciones por geohelmintos y la incidencia de malaria. OBJETIVOS: Identificar la evidencia epidemiologica disponible y evaluar la validez de estos estudios. METODOLOGIA: Una revision sistematica fue realizada en bases de datos especializadas. Los estudios identificados fueron analizados criticamente y ordenados segun clasificacion de la U.S. Preventive Services Task Force. Se identificaron las principales limitaciones metodologicas de cada estudio. RESULTADOS: Se encontraron seis estudios publicados sobre el tema. Solo dos estudios tienen un alto nivel de evidencia (nivel I), tres de nivel II-2, y uno de nivel III-3. Existen importantes limitaciones metodologicas para aclarar la asociacion entre geohelmintos e incidencia de malaria. CONCLUSIONES: Es apresurado discutir las potenciales implicaciones en salud publica de estos hallazgos dada la escasez de estudios y la validez limitada de la evidencia existente. Futuros estudios con nuevas consideraciones metodologicas podrian mejorar el conocimiento acerca de esta asociacion. Sin embargo, es mas importante realizar acciones sobre los determinantes estructurales para controlar y prevenir la ocurrencia de ambas enfermedades.

Agreement of the Kato-Katz test established by the WHO with samples fixed with sodium acetate analyzed at 6 months to diagnose intestinal geohelminthes

The aim of this study was to evaluate the performance of the Kato-Katz test (WHO version) with stool samples from a rural area, fixed with sodium acetate (SAF). The Kato-Katz test was used to compare unfixed samples (conventional test) with the same samples containing SAF fixative at time 0 and at 6 months. The study included stools from 154 subjects. A marginally statistically significant decrease in prevalence was estimated only for hookworm, when comparing unfixed samples versus the SAF fixed samples read at 6 months (p=0.06). A significant reduction in parasite load was found for hookworm (p<0.01) and Trichuris trichiura (p<0.01) between the unfixed and the fixed sample read at 6 months, but not for Ascaris lumbricoides (p=0.10). This research suggests that the SAF fixative solution is a good option for transporting samples for diagnosis, especially in rural areas in developing countries.

Bacteriuria is not associated with surgical site infection in patients undergoing cardiovascular surgery

HighlightsNeither bacteriuria nor urinary tract infections cause infections in cardiac surgery patients.Any case with bacteriuria ended in surgical site infection.There would be no need for search of urinary infection in cardiac surgery patients. Background: Despite absence of evidence, in practice, asymptomatic bacteriuria is perceived as a risk factor for surgical site infection (SSI) among patients with cardiac surgery. We aimed to identify whether an association exists between the preoperative presence of asymptomatic bacteriuria or urinary tract infection and SSI in patients undergoing cardiovascular surgery. Methods: This is an analytical study with a retrospective cohort of patients undergoing coronary revascularization or valve replacement surgery. We identified cases of bacteriuria, urinary tract infection, and cardiovascular SSI and adjusted the results according to exposure to antibiotics and known risk factors for SSI using a multivariate logistic regression analysis. Results: A total of 840 patients were included in the study, of whom 33 (3.9%) had asymptomatic bacteriuria and 13 (1.5%) had urinary tract infections. The incidence of SSI was 9.5% (80 patients), with 2.3% of cases having mediastinitis. In the multivariate analysis, asymptomatic bacteriuria (relative risk, 0.83; 95% confidence interval, 0.26‐2.56; P = .74) and urinary tract infection (relative risk, 2.54; 95% confidence interval, 0.60‐10.69; P = .20) were not risk factors for SSI. Traditional risk factors were found to increase the risk of SSI. Conclusions: The presence of bacteriuria is not a risk factor for presenting SSI in cardiovascular surgery. Screening with urinalysis or urine culture would not be recommended for patients undergoing cardiac surgery.

Consenso de uso de antimicrobianos en pacientes críticamente enfermos con falla renal o en riesgo de padecerla

A growing number of critically ill patients are being taken care with sepsis secondary to bacterial or mycotic infections. In this group of patients, sepsis per se is a risk factor for the development of renal failure, which has been related to an increased risk of hospital mortality. An expert panel in infectious diseases, critical care and renal diseases prepared an evidence based consensus over the use of antimicrobials (antibacterial and antifungal agents) in critically ill patients with renal failure or at risk of suffering it. A sytematic review of the scientific literature was performed and recommendations were established by means of a consensus using the Delphi method. Recommendations proposed by this consensus are intended to be use by healthcare workers who are in charge of this kind of patients with the aim to identify the group of patients with higher risk of developing renal failure and to establish the therapeutic measures theat have the best outcome and lower frequency of severe side effects in renal function. An implementation strategy was added with the recommendations.

Perfiles de poliparasitismo intestinal en una comunidad de la Amazonia colombiana

INTRODUCTION Intestinal parasite infections and polyparasitism are highly prevalent in the most vulnerable populations of developing countries due to environmental, biological and social determinants common in the transmission of parasites. Children between 1 and 15 years of age are the most affected population. OBJECTIVE To describe the prevalence and profiles of intestinal polyparasitism in 1 to 15 year-old children from native communities in the Colombian Amazon region. MATERIALS AND METHODS We used a non-probability sampling of 300 children between 1 and 15 years of age from several rural settlements and the main urban area of Puerto Nariño, Amazonas, Colombia, who participated voluntarily in the study. We obtained fecal samples that were analyzed by the direct method (0.85% saline solution-lugol) and the Kato-Katz technique. The most prevalent polyparasitism profiles were identified using Cohens kappa coefficient with a 95% confidence interval. RESULTS The prevalence of polyparasitism, defined as the presence of at least two intestinal pathogenic parasites, was 84% (95 % CI: 79.35-87.96). Polyparasitism by two or three of the following parasites: Ascaris lumbricoides, Trichuris trichiura, Blastocystis sp., Ancylostoma duodenale and Necator americanus from the Ancylostomatidae family, and Entamoeba histolytica, E. dispar and E. moshkovskii of the Entamoeba complex, had the highest prevalence. CONCLUSION Several intestinal polyparasitism profiles were found, although in most cases fewer than six parasites were involved. Better prevalence estimations and identification of determinant factors will allow to priorize and direct resources to control these infections.