Bazo errante complicado: el caso de un lactante de 13 meses / Complicated wandering spleen: a 13 month old child case

El bazo errante es una patología infrecuente que se origina en una alteración congénita o adquirida de su soporte ligamentoso. La clínica es variable, abarcando desde pacientes asintomáticos hasta cuadros de abdomen agudo, según el grado de compromiso vascular del pedículo esplénico. La evolución generalmente es benigna, requiriendo de destorsión y pexia, al ser el bazo viable, y de esplenectomía en las situaciones contrarias. No hemos encontrado en la literatura la descripción de un bazo vagabundo con compromiso isquémico, que haya evolucionado hacia una sepsis, fulminante. Comunicamos el caso de un lactante con bazo errante que presentó una sepsis grave, secundaria a la torsión del pedículo vascular e infarto esplénico. Luego de la estabilización del cuadro infeccioso, se practicó la esplenectomía, evolucionando en forma satisfactoria

Inmunogenicidad y reactogenicidad de una vacuna de difteria, tétanos, pertussis acelular de contenido antigénico reducido, dTpa, en niños de 10 a 11 años de edad y en adultos / Immunogenicity and reactogenicity of a reduced antigen content diphteria, tetanus, acellular pertussis vaccine, dTpa, in 10 to 11 years old children and in adults

Background: New vaccination strategies are needed to control the increasing problem of pertussis in teenagers and adults. Aim: To determine the immunogenicity and reactogenicity of a diphtheria-tetanus-acellular pertussis (dTpa) vaccine with reduced antigen content. Material and Methods: A single dose of the dTpa vaccine was administered to 60 children 10 to 11 years old and 60 healthy adults. At the moment of vaccination and one month later, antibody levels were measured against 3 B pertussis antigens: anti-pertussis toxin (PT), anti-pertactin (PRN) and anti-filamentous hemagglutinin (FHA), as well as anti-tetanus and anti-diphtheria antibodies. Local and general symptoms were registered during 14 days following vaccine administration. Results: Antibody response for PT, FHA and PRN was 98.3 percent, 100 percent and 100 percent in adults and 98.2 percent, 100 percent and 98.2 percent in children. Seropositivity for all pertussis antigens was 100 percent in adults and in children one month after vaccination. Geometric mean titers (GMT) significantly increased in adults and children. The seroprotection level achieved for tetanus and diphtheria antibodies one month after vaccination was 96.7 percent for adults and 100 percent for children, respectively. No serious adverse events were reported during the study. Among local symptoms pain was the most frequent (88-90 percent), but it was mostly mild or moderate. Solicited general symptoms observed for children and adults, respectively, included headache (37 percent and 53 percent), fatigue (18 percent and 35 percent) gastrointestinal symptoms (18 percent and 25 percent) and fever (8 percent and 3 percent). Only one vaccinee had fever above 39­C. Conclusions: the dTpa vaccine showed an adequate safety profile and induced an intense immunological response to all antigens in adults and children aged 10-11

Complicaciones en niños con varicela en cuatro hospitales de Santiago-Chile: espectro clínico y estimación de costos directos / Varicella complications requiring hospitalization in four hospitals in Santiago, Chile: clinical spectrum and estimation of direct costs

Background: The knowledge of varicella complications and their associated cost may help for a better evaluation of varicella immunization benefits. Aim: To determine frequency, type, outcome and affected population of varicella complications in children requiring hospitalization, and to estimate their direct costs. Material and methods: Retrospective analysis of medical records of children admitted to four hospitals in Santiago, Chile, due to varicella complications between January 1997 and February 1999. Calculation of direct costs of hospitalizations in a sample of 30 patients. Results: One hundred fifty four patients were identified, 74 percent were younger than 5 years old, only one was immunocompromised. Complications identified were skin and soft tissue infections in 63 percent, invasive infections in 25,3 percent, neurological in 7.1 percent and miscellaneous in 4,5 percent. Staphylococcus aureus and Group A ß-haemolytic Streptococcus (GABS) were predominantly isolated. S. aureus was the main agent identified in superficial infections and GABS in invasive infections (sterile sites). Two patients died due to invasive infections (streptococcal toxic shock and S. aureus septicaemia) and 11 required surgical procedures. The average cost per hospitalization was US$ 600 in public hospitals and US$ 1,800 in the private hospital. Conclusions: Varicella complications requiring hospitalization are due mainly to bacterial infections and they affect immunocompetent toddlers. These complications can be severe and even fatal

Antrax / Anthrax

Agente: Bacillus anthracis. (Bacilo Gram positivo, aerobio estricto, esporulado, inmóvil). Reservorio: Herbívoros y sus subproductos, ambiente contaminado con esporas. Transmisión: Pasto con esporas ingestión por ganado esporas en carne, subproductos o suelo humano: contacto con piel, epitelio respiratorio, bucofaríngeo o intestinal. Laboratorio: Gram y cultivo en agar sangre de tejidos o líquidos infectados. Prevención: Vacuna y antimicrobianos Tratamiento: Penicilina V oral o g endovenosa, por un plazo variable de al menos 7 a 10 días. Alternativas: eritromicina, cloranfenicol, tetraciclina y ciprofloxacina

Epidemiología molecular del virus de inmunodeficiencia humana tipo 1 en Santiago, Chile / Molecular epidemiology of the human immunodeficiency virus tipe 1 in Santiago, Chile

Background: most of the studies of HIV-1 infection in South America have been limited to Brazil and little is known about the viral variants that are causing disease else where in the continent. Aim: to determine the characteristics of the viral variants present in Chile as well as patterns of viral transmission. Material and methods: viral sequences were obtained from 21 HIV-1 infected people from Santiago, Chile who were infected either via sexual contact or intravenous drug use. Cloned sequences obtained from both the third variable and conserved regions of the envelope as well as the viral protease were evaluated. Results: we found only clade B subtype viruses in Santiago. An evaluation of the envelope gene revealed no evidence that the sequences were monophyletic by risk group. A number of the protease sequences were predicted to encode amino acid substitutions commonly found during selection for protease inhibitor resistance. Conclusions: the HIV-1 strains studied in Chile, belong to the subtype B. There is no molecular evidence of separate introductions of the virus into the different risk groups. A number of substitutions in the protease gene that may confer resistance to protease inhibitors were found in patients with no previous exposure to this class of drugs

Parvovirus B19 / B19 parvovirus

Desde su descubrimiento hace menos de 25 años, mucho se ha progresado en el conocimiento de la infección causada por parvovirus B19, reconociéndose actualmente un amplio espectro de manifestaciones y la existencia de infecciones crónicas o persistentes. Este agente debe ser considerado en el diagnóstico diferencial de las variadas entidades clínicas que se describen en esta revisión. En este artículo se discuten también aspectos históricos, virológicos, epidemiológicos, de diagnóstico y manejo terapéutico de las infecciones por parvovirus B19

Resistencia del virus de inmunodeficiencia humano (VIH) a zidovudina (AZT): análisis genotípico en cepas aisladas de pacientes chilenos / Resistance of human immunodeficiency virus (VIH) to zidovudine: genotypic analysis in strains isolated from chilean patients

Background: Resistance of HIV to AZT is the result of mutations in the pol gene that codifies the enzyme reverse transcriptase. Aim: To asses the resistance to antiretroviral drugs in Chhilean patients infected with HIV. Material and methods: The presence of mutations was searched in 22 patients infected with HIV. The emergence or persistence of these mutations was studiend in sequential samples of 19 patients. The presence of the mutation that confers resistance to didanosine (ddi) was studied in those subjects exposed to the drug. Polymerase chain reaction techniques were used to analyze mutations in codons 41, 70 and 215 of the pol gene (resistance to AZT) and the mutation in codon 71 (resistance to DDI). Results: On admission, none of the patients without previous exposure to AZT had drug resistance mutations. Seven of 12 patients (58.3 percent) that had received AZT had mutations in codon 215. In two, they were associated to a mutation in codon 41 and in two, to a mutation in codon 70. After a mean follow up of 14 months, 13 of 15 patients (86 percent) that received AZT had viral strains genotypically resistant to the drug. In nine of these, the resistance was associated with disease progression. None of the 10 patients that received DDI had the mutation in codon 74 that confers resistance to the drug. However, in one of these patients, that never receided AZT, virus with a mutation in codon 215 was detected. Conclusions: A high percentage of patients that have received monotheraphy with AZT have genotypic resistance to the drug. This resistance is associated with clinical and immunological derangement in 70 percent of these subjects

Seroprevalencia de citomegalovirus y toxoplasma gondii en población sana menor de 30 años, en Santiago de Chile / Seroprevalence of cytomegalovirus y toxoplasma gondii in health population under 30 years old at Santiago, Chile

Subjects and methods: The prevalence of IgG antibodies against Cytomegalovirus and Toxoplasma gondii were studied in 560 subjetcs under 30 years old, using and ELISA technique. Age, socioeconomic level, breast feeding, assistance to nurseries and number of family members were considered as risk factors for these infections. Results: Infection by Cytomegalovirus and Toxoplasma gondii were studied in 560 subjetcs under 30 years old, using an ELISA technique. Age, socioeconomic level, breast feeding, assistance to nurseries and number of family members were considered as risk factors for these infections. Results: Infection by Cytomegalovirus had a global prevalence of 60 percent. It showed an epidemiological pattern of late adquisition in high socioeconomic levels and a pattern of early infection in medium and low socioeconomic levels. Eighty to 90 percent of sera were positive for the infection in adult subjetcs of the three socioeconomic levels. There was a positive correlation between the duration of breast feeding and the frequency of Cytomegalovirus infection. Infection by Toxoplasma gondii had a global prevalence of 24.6 percent. The rates of susceptible individuals were 80 and 50 percent in high and medium-low socioeconomic levels respectively. Conclusions: The knowledge about the frequency of these infections in high risk populations such as women during their reproductive years and immunodepressed individuals, will allow the implementation of preventive measures

Estudio microscópico de fenómenos biológicos asociados a infecciones por cateteres venosos centrales / Microscopic study of biological phenomenae associated to infections related to central venous catheters

Las complicaciones infecciosas son la principal limitación del uso de cateteres venosos centrales. Se presenta aquí un estudio descriptivo, mediante microscopía de barrido, de la formación de una matriz biológica en el interior y exterior del catéter como condicionante de la adherencia y crecimiento de bacterias, comprobándose que es un fenómeno que se presenta con alta frecuencia al permanecer estos dispositivos de poliuretano en el medio intravascular y subcutáneo. En este estudio preliminar se observa una adecuada correlación ente la observación de colonización del catéter por microscopía y el resultado de cultivo semicuantitativo de la punta de éste. La colonización del catéter, si bien representa uno de los eventos iniciales asociados a infección, no siempre se acompaña de signos clínicos o de bacteremia