Inmunodeficiencias primarias en niños gravemente enfermos: a propósito de 3 casos clínicos / Primary immunodeficiencies in seriously ill children: Report of 3 clinical cases

Las inmunodeficiencias primarias (IDP) son enfermedades congénitas causadas por alteraciones cuantitativas o funcionales de la respuesta inmunitaria. Se caracterizan por predisposición a infecciones, autoinmunidad, alergia y enfermedades linfoproliferativas. Objetivo: Reportar 3 casos de lactantes menores con IDP que se manifestaron como infecciones graves de curso inhabitual. Casos clínicos: Se presentan 3 pacientes diagnosticados como IDP en su estadía en la Unidad de Paciente Crítico Pediátrico. El primero corresponde a un lactante de 4 meses con neumonía multifocal extensa a quien se diagnosticó un síndrome de inmunodeficiencia combinada severa ligada a X; el segundo es un lactante de 8 meses que se manifestó como una adenitis mesentérica por Candida lusitaniae y que correspondió a enfermedad granulomatosa crónica, y el tercero se trata de un lactante de 6 meses que se presentó con un ectima por Pseudomona y se diagnosticó una agammaglobulinemia ligada a X. Conclusión: El diagnóstico de IDP debe sospecharse en presencia de una infección de evolución arrastrada que no responde a tratamiento habitual. Se discuten los casos y se presenta una puesta al día de las patologías diagnosticadas.

Primary immunodeficiency diseases (PID) are congenital disorders secondary to an impaired immune response. Infections, autoimmune disorders, atopy, and lymphoproliferative syndromes are commonly associated with this disorder. Objective: To present and discuss 3 infants diagnosed with PID. Clinical cases: The cases are presented of three patients with PID diagnosed during their first admission to a Paediatric Intensive Critical Care Unit. The first patient, a 4-month-old infant affected by a severe pneumonia, and was diagnosed as a Severe Combined Immunodeficiency Disease. The second patient was an 8-month-old infant with Candida lusitaniae mesenteric adenitis, and diagnosed with a Chronic Granulomatous Disease. The last patient, a 6-month-old infant presented with ecthyma gangrenosum and X-linked agammaglobulinaemia. Conclusion: PID should be suspected when an infectious disease does not responde to the appropriate therapy within the expected period. An update of each disease is presented.

La razón cintura estatura en escolares no varía con el género, la edad ni la maduración puberal / Waist-to-height ratio does not change with gender, age and pubertal stage in elementary school children

Background: Waist-to-height ratio (WHtR) is a cardiometabolic risk indicator in children. A value greater than or equal to 0.55 is an effective screening tool for identifying obese children with metabolic syndrome. However, it is unclear whether this cutoff can be applied equally to any age or gender. Aim: To analyze the variability of WHtR by age, gender and pubertal stage in elementary school children. Patients and Methods: Cross-sectional study in 2,980 school children (6-14 years old, 51% male) of Santiago, Chile. We measured weight, height and waist circumference and calculated body mass index and WHtR. Pubertal stage was assessed and classified as peripubertal (Tanner I and II) and pubertal (Tanner III, IV and V). Results: The mean age was 9.9 ± 2.3 years, with no gender difference (p = 0.5). Eighty one percent of boys and 59.4% of girls were peripubertal (p < 0.001). The association between age-adjusted WHtR by gender and pubertal stage was not significant (p = 0.409). Therefore mean, standard deviation and percentiles of WHtR were calculated without sex and pubertal stage segmentations. Conclusions: Since WHtR does not vary with age, gender and pubertal status in elementary school children, it is possible to use a single cutoff value, previously defined in this population, to identify children with cardiometabolic risk.

Patrones de susceptibilidad antimicrobiana de cepas de Shigella sonnei aisladas durante tres períodos diferentes en la Región Metropolitana, Chile / Antibiotic susceptibility patterns among Shigella sonnei, isolated during three different periods in Región Metropolitana, Chile

Background: Shigella sonnei gastroenteritis improves clinically and microbiologically with antibacterial treatment; however choosing a useful drug is a universal challenge because of in vitro susceptibility of S. sonnei frequently evolves to be resistant. Objective: To evaluate in vitro susceptibility of S. sonnei strains isolated from patients attending at the Chilean Región Metropolitana and to know the evolution that resistant patterns of S. sonnei have experienced. Material: In this study, the antimicrobial susceptibility profile of 277 isolates of Shigella sonnei was compared. The analyzed periods of time were: period I (1995-1997) 85 strains; period II (2004-2006) 92 strains and period III (2008-2009) 100 strains, in Santiago, Chile. The method performed to analyze susceptibility patterns was the disc diffusion (Kirby-Bauer). Results: The strains showed rates of resistance to ampicillin: period I, 85.8%; period II, 53.3%; period III, 100%, trimethoprim/sulfamethoxazole: period I, 50.5%; period, II 46.7%; period III, 100%, chloramphenicol: period I, 36.4%; period II, 12%; period III, 100% and tetracycline: period I, 38.8%; period II, 30.4%; period III, 100%. 98.9% of the strains showed susceptibility to quinolones. Significant differences were observed in patterns of antimicrobial resistance for both individuals and for multidrug resistance (≥ 3 antimicrobials) in the three periods (p < 0.001, χ2 test). Of all resistant strains, 17% were resistant to 1 or 2 antibiotics, while 65.7% showed a pattern of multidrug resistance; 100% of the period III strains presented multidrug resistance. Conclusion: These results showed the temporal resistance dynamics of S. sonnei circulating strains in the Chilean Región Metropolitana. Due to the endemic behavior of shigellosis in Chile, it is urgent to maintain permanent surveillance of antimicrobial resistance profiles to improve both prevention and treatment of shigellosis.

Introducción: La infección entérica producida por Shigella sonnei mejora clínicamente y microbiológicamente con antibioterapia; sin embargo, la elección del antimicrobiano es un problema universal pues la susceptibilidad in vitro de S. sonnei evoluciona frecuentemente hacia la resistencia. Objetivo: Evaluar la susceptibilidad in vitro a antimicrobianos de S. sonnei y conocer la evolución que han experimentado los patrones de resistencia de cepas aisladas de cuadros clínicos en pacientes de la Región Metropolitana, Chile. Material y Métodos: Se comparó el perfil de susceptibilidad a antimicrobianos, de 277 cepas clínicas de S. sonnei aisladas durante tres períodos: período I (1995-1997) 85 cepas; período II (2004-2006) 92 cepas y período III (2008-2009) 100 cepas, en Santiago, Chile. El perfil de susceptibilidad a antimicrobianos se determinó mediante test de difusión en agar. Resultados: Las tasas de resistencia de las cepas en los periodos I, II y III respectivamente fueron: ampicilina: 85,8%; 53,3%; 100%, cotrimoxazol: 50,5%; 46,7%; 100%, cloranfenicol: 36,4%; 12%; 100% y tetraciclina: 38,8%; 30,4%; 100%. El 98,9% de las cepas fue susceptible a quinolonas. Se observó diferencias significativas en los porcentajes de resistencia para antimicrobianos individuales y multi-resistencia (≥ 3 antimicrobianos) en los tres períodos (p < 0,001; Test de χ2). De las cepas resistentes, 17% presentó resistencia a uno ó dos antimicrobianos, 65,7% mostró multi-resistencia antimicrobiana. El 100% de las cepas del período III presentó multi-resistencia. Discusión: Estos resultados evidencian la dinámica temporal de la resistencia en cepas de S. sonnei circulantes en la Región Metropolitana. Dado que en Chile la shigelosis tiene un carácter endémico, es prioritario mantener una vigilancia constante de los perfiles de resistencia a antimicrobianos, para mejorar la prevención y el tratamiento de la shigelosis.

Prevalencia de hipertensión arterial y su asociación con la obesidad en edad pediátrica / Prevalence of hypertension in school age children and its association with obesity

Background: Hypertension in children is a frequently overlooked problem that is an important cardiovascular risk factor. Aim: To determine the prevalence of hypertension among school age children. Material and Methods: Cross-sectional study of 2980 children aged 10 ± 2years (48 percent females) from 10 schools of middle and lower class in Metropolitan Santiago. Blood pressure (BP) was measured in the sitting position on three occasions after a rest period, using a mercury sphygmomanometer with appropriate cuff arm diameter, averaging the results of the measurements. Systolic and diastolic hypertension were defined as blood pressure values over 95percentilefor age, sex and height. Results: The overall prevalence of hypertension was 12.2 percent in women and 15 percent in men (p < 0.05). According to nutritional status, the prevalence was 6.7, 8.9,13.6 and 26 percent in underweight, eutrophic, overweight and obese children, respectively (p < 0.01). Compared with normal weight children, the risk of being hypertensive for overweight children was 1.6 (95 percent confidence intervals (CI) 1.2-2.3) and for obese children was 3.6 (95 percent CI 2.8-4.7). Conclusions: The studied children had a high prevalence of hypertension, that was directly related to a higher body mass index.

Manifestaciones clínicas de la infección por virus influenza en niños inmunocompetentes / Clinical manifestation of influenza virus infection in immunocompetent children

Las manifestaciones clínicas de la infección por virus influenza en niños son inespecíficas. Recientes publicaciones han revelado el impacto -en términos epidemiológicos- de esta infección en niños, incluso con tasas superiores a los adultos. Los niños sanos representan un importante grupo de riesgo. Las manifestaciones clínicas son de inicio brusco caracterizadas por la presencia de fiebre. Los niños pequeños no presentan el cuadro clínico clásico, revelando un compromiso variable del estado general, con deshidratación y convulsiones. Si bien las complicaciones respiratorias son las más frecuentes (siendo el Streptococcus pneumoniae el agente mas importante) existe un sin número de reportes que describen otros órganos y sistemas comprometidos. Este artículo revisa las principales manifestaciones en niños inmunocompetentes.

Hantavirus y embarazo: aspectos hemodinámicos y respiratorios / Hanta virus and pregnancy: hemodynamic and respiratory aspects

The disease by Hanta virus has a recent diagnose in our country. 218 cases have been reported to date and given its high mortality of 44 percent, a great epidemiological campaign has been implemented, for its isolation and control. The most severe form of this disease, Hanta virus, is the cardio pulmonary syndrome which present characterics that difference it from other similar disorders. The more frequent hemodynamics patrons to find are low cardiac indexes (CI) with pulmonary vascular resistences and elevated (RVS) systemic. On the other hand, the respiratory disorders correspond to a pulmonary edema non cardiogenic, similar to acute respiratory distress syndrome (SDRA). There are few reports of Hanta in pregnant patients described in literature and case present a high rate of fetal and maternal mortality and there is not a clear description of the hemodynamic compromise, or certitude if there is vertical transmission of the virus from the infected mother to the fetus. We described the clinical case of a 12 weeks pregnant patient with cardio pulmonary syndrome due to Hanta virus (SCPH) which shws a different hemodynamics patron than which has been published and who survives both she as well as her child and do not present virus transmission to the fetus

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