[Human immunodeficiency virus infection in children and adolescents: more of 25 years in Chile]. / Infección por virus de inmunodeficiencia humana en niños y adolescentes: Más de 25 años en Chile.

In this article, the following topics about pediatric HIV infection and AIDS are summarized: a description of pathogenic and clinical aspects of HIV infection in children, the clues for its suspicion, the preventive strategies to avoid the vertical transmission of HIV, the study to certify or to rule out the HIV infection in infants and children, the main recommendations of antiretroviral treatment and how to prevent and treat manifestations of HIV infection. Besides, the evolution in Chile of the pediatric HIV infection is described with details, since the first child detected with AIDS in 1987, infected by transfusion and the first infants (twin) diagnosed in 1989, infected by vertical twins transmission, to 2014, with the progress obtained, snags, hopes and challenges addressed.

[Premastication: a new way of transmitting HIV. First pediatric case reported in Chile]. / Premasticación: una nueva forma de transmisión del virus de inmunodeficiencia humana. Primer caso pediátrico informado en Chile.

The incorporation of the protocol to prevent vertical transmission (PMTCT) of HV in pregnant women has reduced the rate of HV transmission in children to less than 2%. In Chile, currently the diagnosis of HIV infection in children is rare. Thus, one positive finding should lead us to audit compliance of the PMTCT and if this has been fully implemented should be reviewed other possible routes of HIV transmission. We present a case report that suggest that HV can be transmitted through the consumption of foods that have been premasticated by a person infected with HV. Premastication is a transmission path that had not been reported, being a possible explanation for some cases of late transmission of HIV in infants, so far attributed to breastfeeding. Understanding that premastication is a common behavior, you should educate people about the potential risk of transmission of diseases, including HIV, through this practice and advise HIV-infected caregivers against this practice.

[Evaluation of bone mineral density in children with vertical infection by HIV]. / Evaluación de la densidad mineral ósea en niños con infección vertical por VIH.

Changes in bone mineral density (BMD) are common in adults infected with human immunodeficiency virus (HIV). There are few studies evaluating bone involvement in children infected. OBJECTIVE: To evaluate BMD in vertically HIV-infected children. METHODS: We studied 53 infected children (8-18 years) from five hospitals. Disease status, nutritional assessment, vitamin D (25-OHD) levels and immunological status were recorded. BMD was measured by densitometry. Descriptive analysis, comparison of means and simple and multiple linear regression were used. RESULTS: 88.7% children were in stage B and C, 57% were eutrophic and 18.9% had short stature. 33.3% had 25-OHD levels < 20 ng / ml. 11%, 6% and 4% of the children had BMD <-2DE in hip, spine and whole body respectively. BMD was correlated with BMI, height, disease stage and years of treatment. Only protease inhibitors (PIs) maintained their significance when adjusted for other variables. CONCLUSION: children infected with HIV had lower BMD by age compared to NHANES III data. The severity of the disease, height, zBMI, years of treatment with antiretrovirals, mainly IP, are related to the reduction of bone mass.

[Cytomegalovirus disease in HIV-1 infected Chilean children]. / Enfermedad por citomegalovirus en niños chilenos infectados por el virus de la inmunodeficiencia humana-1.

UNLABELLED: Cytomegalovirus (CMV) is a frequent opportunistic infection in human immunodeficiency virus type 1 (HIV-1) infected children associated with significant morbidity and mortality. The aim of this study was to determine the frequency and impact of CMV disease in a prospective ly followed cohort of HIV-1 infected Chilean children. CMV disease was diagnosed in 28 out of 222 HIV infected children (12.6%); 92% of them were classified in category C and 61% in category 3 (CDC, 1994). Lung disease was the most common manifestation (25 children). Samples were obtained from the respiratory tract, blood, urine and tissue biopsies. Shell vial for CMV early antigen detection was the most commonly used diagnostic technique (20/ 28). All patients were treated with iv.ganciclovir and two children died during the CMV episode. The mean survival time for the remaining children is currently 42 months. CONCLUSION: CMV disease was frequent and caused mortality in HIV-1 infected Chilean children. Early diagnosis and treatment are key for clinical success.

[Young women with HIV infection acquired by vertical transmission: Expectations of having uninfected children]. / Mujeres jóvenes con infección por VIH adquirida por transmisión vertical: Expectativas de tener hijos no infectados.

INTRODUCTION: Pediatric antiretroviral therapy (ART), changed the prognosis of the disease, allowing young women infected by vertical transmission (TV) to be pregnant without risk for their fetus of acquiring this infection. AIM: To describe the clinical-immune status in pregnant women that acquired HV by vertical transmission, treatments received, monitoring of pregnancy and newborn characteristics. MATERIAL AND METHODS: A protocol was performed, evaluating clinical and immunological parameters during pregnancy, ART used, protocol preventing vertical transmission (PPTV), and follow up of children to 18 months of age. RESULTS: Of 358 HIV-positive patients vertically infected, five women became pregnant, between 14 and 24 years old. Pregnancies were controlled in clinical/immune-stage N2 C3. They had received two to five therapies. Full PPTV was performed in all binomials. Pre-natal undetectable viral loads ranged from 4,700 ARN copies/mL. Five living children were born by Caesarean section, four of them with 37 weeks of completed gestation and one of them with 34 weeks of gestation. All received zidovudine (AZT) for 6 weeks. CD4 at 72 hours of life ranged from 48% to 74.6%. All children were born uninfected with HIV. Only two had mild anemia. CONCLUSIONS: Expectations of HIV mothers vertically infected to have healthy children are similar to those infected by horizontal transmission, using PPTV.

[HIV/AIDS infection in children and adolescents: Chilean cohort 1987-2014]. / Infección por VIH/SIDA en niños y adolescentes: cohorte chilena 1987-2014.

The present document describes the Cohort of HIV/AIDS children detected in Chile from 1987 to August 2014 and the effectiveness of the Protocol for Prevention of Vertical Transmission (PPVT) of HIV infection. Of the 375 HIV infected children enrolled since 1987 to August 2014, 245 of them are still in pediatric control. From the analysis of the Cohort is inferred that: a) it has observed an improvement in the detection of the HIV infected child, in number and precocious time; b) the majority of these children continue to be detected by clinic symptoms and signs (mainly unspecific and infectious manifestations); c) the ARVT use has meant a clinic and immunologic improvement with diminution of the infections, principally opportunistic infections, with a better life quality, a prolongation of survival and a diminution of lethality; d) as more survival has been produced, cancer has begun to be detected, a very infrequent complication observed in them before the ARVT use. The PPVT started in 1995, and was reinforced in 2005 with the "Joint Norm of HIV and Syphilis Vertical Transmission Prevention" (MINSAL), both have meant a diminution of the HIV vertical transmission from > 35% (before 1995) to < 2% nowadays in the mother-child binomial; also have permitted a second generation of HIV exposed children born without infection. In spite this PPVT, still HIV infected child continue to be detected which imply failures in some points of the health system.

[Incidence of cancer in Chilean HIV-infected children]. / Incidencia de cáncer en niños chilenos infectados por VIH.

BACKGROUND: Pediatric HIV (+) patients have a 100 times greater risk of cancer than HIV (-) children. OBJECTIVE: To describe in Chilean HIV (+) children, cancer types, its appearance in relation to the stages of HIV disease and mortality. METHODS: A protocol was created to know some characteristics of these patients from the point of view of their HIV infection and cancer pathology. RESULTS: Of 360 HIV (+) children confirmed by the Institute of Public Health to May 2014, 9 patients with neoplastic disease (2.5%) were diagnosed. All the children were on ART, had more than three years of evolution of HIV infection and were in moderate to severe clinical/immunological stages. Lymphoma was the most common cancer. Five children, has received therapy according to Programa Infantil Nacional de Drogas Antineoplásicas (PINDA). There was no interaction between cancer treatment and antiretroviral therapy. Mortality was 13.8 x 1000 (5 cases). CONCLUSIONS: The incidence and type of neoplasia is consistent with the international literature, with less survival than HIV (+) children without tumors. The occurrence of cancer was observed in children with moderate to severe clinical and immunological compromise.

Linezolid versus vancomycin for treatment of resistant Gram-positive infections in children.

BACKGROUND: Pediatric infections caused by resistant Gram-positive infections are an increasing concern with limited treatment options. Linezolid, a new oxazolidinone, is active against staphylococci, streptococci and enterococci. OBJECTIVE: To assess clinical efficacy and safety of linezolid vs.vancomycin in antibiotic-resistant Gram-positive infections in children. DESIGN Hospitalized children (birth to 12 years of age) with nosocomial pneumonia, complicated skin/skin structure infections, catheter-related bacteremia, bacteremia of unknown source or other infections caused by Gram-positive bacteria were randomized 2:1 to receive linezolid intravenously followed by oral linezolid or vancomycin and then by an appropriate oral agent. Treatment duration was 10 to 28 days. RESULTS: There were 321 patients enrolled (linezolid 219, vancomycin 102). Clinical cure rates were 79% vs.74% (P = 0.36) and 89% vs.85% (P = 0.31) for linezolid and vancomycin in intent-to-treat and clinically evaluable patients, respectively. Cure rates were similar by age and infection diagnosis. Pathogen eradication rates in microbiologically evaluable patients were high for linezolid and vancomycin, respectively, for methicillin-susceptible S. aureus (95% vs.94%; P = 0.82), methicillin-resistant S. aureus (88% vs.90%; P = 0.89) and methicillin-resistant coagulase-negative staphylococci (85% vs.83%, P = 0.87). In clinically evaluable patients, linezolid-treated patients required significantly fewer days of intravenous therapy compared with vancomycin-treated patients (8.0 +/- 4.8; 10.9 +/- 5.8 days, respectively; P < 0.001). In addition significantly fewer linezolid-treated patients had drug-related adverse events than did vancomycin-treated patients (19% vs.34%, respectively; P = 0.003). Hematologic events were uncommon and similar between treatment groups. CONCLUSIONS: Linezolid was well-tolerated and as effective as vancomycin in treating serious Gram-positive infections in children.

Linezolid for the treatment of methicillin-resistant Staphylococcus aureus infections in children.

BACKGROUND: Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are becoming increasingly prevalent. Linezolid is effective and well-tolerated in the treatment of adults with MRSA infections. OBJECTIVE: To evaluate the clinical efficacy and safety of iv/oral linezolid in children with MRSA infections. METHODS: Data were obtained from two independent clinical trials. In an outpatient trial children (5 to 17 years of age) with uncomplicated skin and skin structure infections (SSSIs) were treated with linezolid or cefadroxil. In an inpatient trial hospitalized children (0 to 11 years of age) with pneumonia, bacteremia or complicated SSSI caused by resistant Gram-positive pathogens were administered iv linezolid with the option to switch to oral suspension (patients >90 days of age) or iv vancomycin. A subset of patients with MRSA infections from the two clinical trials is analyzed herein. RESULTS: In the outpatient trial children with skin infections caused by MRSA were treated with linezolid (15 patients) and cefadroxil (10 patients). In the microbiologically evaluable population, the clinical cure rate was 92.3% in the linezolid group and 85.7% in the cefadroxil group (P = 0.64). The pathogen eradication rate for MRSA was 92.3 and 85.7% in the linezolid and cefadroxil groups, respectively (P = 0.64). There were very few adverse events or drug-related adverse events and no serious adverse events in the outpatient trial. In the inpatient trial 20 children treated with linezolid and 14 treated with vancomycin had infections caused by MRSA. In the microbiologically evaluable population, the clinical cure rate was 94.1% in the linezolid group and 90.0% in the vancomycin group (P = 0.69). Pathogen eradication rates were 88.2 and 90.0% for the linezolid and vancomycin groups, respectively (P = 0.89). Susceptibility patterns of the MRSA isolates showed distinct patterns between the outpatient and inpatient trials. In the inpatient trial fewer patients in the linezolid group had drug-related adverse events than did those in the vancomycin group (20% vs. 43%; P = 0.15). CONCLUSIONS: Intravenous/oral linezolid is effective and well-tolerated in children with MRSA infections.

Evaluación de la densidad mineral ósea en niños con infección vertical por VIH / Evaluation of bone mineral density in children with vertical infection by HIV

Resumen Los cambios en la densidad mineral ósea (DMO) son comunes en adultos infectados con virus de la inmunodeficiencia humana (VIH). Existen pocos estudios que evalúen el compromiso óseo en niños. Objetivo: Evaluar la DMO en niños infectados verticalmente por VIH. Métodos: Se estudiaron 53 niños infectados (8-18) de cinco hospitales. Se registró severidad de enfermedad, evaluación nutricional, vitamina D (25-OHD) y estado inmunológico. La DMO se midió mediante densitometría. Se utilizó análisis descriptivo, comparación de medias y regresión lineal simple y múltiple. Resultados: El 88,7% estaban en estadio B y C, 57% eran eutróficos y 18,9% tenían talla baja. El 33,3% presentaba niveles de 25-OHD < 20 ng/ml. El 11%, 6% y 4% de los niños tenían DMO < 2DE en cadera, columna y cuerpo entero, respectivamente. La DMO se correlacionó con IMC, talla, severidad de enfermedad y años de tratamiento. Sólo inhibidores de las proteasas (IP) mantuvieron su significancia al ajustar por otras variables. Conclusión: Los niños infectados con VIH tuvieron DMO más baja por edad comparados con datos de NHANES III. La severidad de la enfermedad, talla, zIMC, los años de tratamiento con anti-retrovirales, principalmente IP, están relacionados con la reducción de la masa ósea.

Changes in bone mineral density (BMD) are common in adults infected with human immunodeficiency virus (HIV). There are few studies evaluating bone involvement in children infected. Objective: To evaluate BMD in vertically HIV-infected children. Methods: We studied 53 infected children (8-18 years) from five hospitals. Disease status, nutritional assessment, vitamin D (25-OHD) levels and immunological status were recorded. BMD was measured by densitometry. Descriptive analysis, comparison of means and simple and multiple linear regression were used. Results: 88.7% children were in stage B and C, 57% were eutrophic and 18.9% had short stature. 33.3% had 25-OHD levels < 20 ng / ml. 11%, 6% and 4% of the children had BMD <-2DE in hip, spine and whole body respectively. BMD was correlated with BMI, height, disease stage and years of treatment. Only protease inhibitors (PIs) maintained their significance when adjusted for other variables. Conclusion: children infected with HIV had lower BMD by age compared to NHANES III data. The severity of the disease, height, zBMI, years of treatment with antiretrovirals, mainly IP, are related to the reduction of bone mass.

Mujeres jóvenes con infección por VIH adquirida por transmisión vertical: expectativas de tener hijos no infectados / Young women with HIV infection acquired by vertical transmission: expectations of having uninfected children

Introduction: Pediatric antiretroviral therapy (ART), changed the prognosis of the disease, allowing young women infected by vertical transmission (TV) to be pregnant without risk for their fetus of acquiring this infection. Aim: To describe the clinical-immune status in pregnant women that acquired HV by vertical transmission, treatments received, monitoring of pregnancy and newborn characteristics. Material and Methods: A protocol was performed, evaluating clinical and immunological parameters during pregnancy, ART used, protocol preventing vertical transmission (PPTV), and follow up of children to 18 months of age. Results: Of 358 HIV-positive patients vertically infected, five women became pregnant, between 14 and 24 years old. Pregnancies were controlled in clinical/immune-stage N2 C3. They had received two to five therapies. Full PPTV was performed in all binomials. Pre-natal undetectable viral loads ranged from 4,700 ARN copies/mL. Five living children were born by Caesarean section, four of them with 37 weeks of completed gestation and one of them with 34 weeks of gestation. All received zidovudine (AZT) for 6 weeks. CD4 at 72 hours of life ranged from 48% to 74.6%. All children were born uninfected with HIV. Only two had mild anemia. Conclusions: Expectations of HIV mothers vertically infected to have healthy children are similar to those infected by horizontal transmission, using PPTV

Introducción: La terapia anti-retroviral en pediatría (TARV), cambió el pronóstico de la enfermedad, permitiendo embarazarse a mujeres jóvenes infectadas por transmisión vertical (TV). Objetivos: Conocer las características clínico-inmunológicas de las mujeres embarazadas, tratamientos recibidos, condición al embarazo y seguimiento de sus recién nacidos. Material y Método: Se efectuó un protocolo, evaluando etapas clínico-inmunológicas en el embarazo, TARV usadas, protocolo de prevención de transmisión vertical (PPTV) y seguimiento de los niños hasta 18 meses. Resultados: De 358 pacientes con infección por VIH adquirida por TV, cinco mujeres se embarazaron, con edades entre 14 a 24 años, embarazos que fueron controlados por el equipo de salud, encontrándose en etapa clínico-inmunológica N2 a C3. Habían recibido dos a cinco esquemas de TARV. Se efectuó PPTV completo en todos los binomios. Las cargas virales previas al parto fluctuaron entre indetectable y 4.700 copias ARN/ml. Nacieron por cesárea cinco niños vivos, cuatro de término y uno con 34 semanas de gestación. Todos recibieron zidovudina (AZT) durante seis semanas. Los CD4 a las 72 h de vida fluctuaron entre 48 y 74,6%. Ninguno de los niños adquirió la infección por VIH en forma vertical. Sólo dos presentaron anemia leve. Conclusiones: Las expectativas de madres con infección por VIH de adquisición vertical de tener hijos sanos son semejantes a las infectadas por transmisión horizontal, al usar PPTV.

Infección por VIH/SIDA en niños y adolescentes: cohorte chilena 1987-2014 / HIV/AIDS infection in children and adolescents: Chilean cohort 1987-2014

The present document describes the Cohort of HIV/AIDS children detected in Chile from 1987 to August 2014 and the effectiveness of the Protocol for Prevention of Vertical Transmission (PPVT) of HIV infection. Of the 375 HIV infected children enrolled since 1987 to August 2014, 245 of them are still in pediatric control. From the analysis of the Cohort is inferred that: a) it has observed an improvement in the detection of the HIV infected child, in number and precocious time; b) the majority of these children continue to be detected by clinic symptoms and signs (mainly unspecific and infectious manifestations); c) the ARVT use has meant a clinic and immunologic improvement with diminution of the infections, principally opportunistic infections, with a better life quality, a prolongation of survival and a diminution of lethality; d) as more survival has been produced, cancer has begun to be detected, a very infrequent complication observed in them before the ARVT use. The PPVT started in 1995, and was reinforced in 2005 with the "Joint Norm of HIV and Syphilis Vertical Transmission Prevention" (MINSAL), both have meant a diminution of the HIV vertical transmission from > 35% (before 1995) to < 2% nowadays in the mother-child binomial; also have permitted a second generation of HIV exposed children born without infection. In spite this PPVT, still HIV infected child continue to be detected which imply failures in some points of the health system.

Se presentan datos de la cohorte de niños con infección por VIH/SIDA detectados en Chile desde el año 1987 a agosto de 2014 y datos de la transmisión vertical (TV) del VIH con uso de protocolos de prevención de TV (PPTV). De los 375 niños infectados con VIH en este período, siguen en control pediátrico 245. Del análisis de la cohorte se desprende que: a) ha habido una mejoría en la pesquisa de los niños infectados con VIH, tanto en número como en precocidad; b) estos niños siguen detectándose, en su mayoría, por hechos clínicos (manifestaciones inespecíficas e infecciosas principalmente); c) el uso de TARV ha significado una mejoría clínica e inmunológica con disminución de las infecciones, principalmente las oportunistas, con una mejor calidad de vida, prolongación de la sobrevida, y disminución de la letalidad; d) por su mayor sobrevida, se ha observado el desarrollo de cánceres, muy infrecuentes en ellos antes del uso de terapia anti-retroviral. La aplicación de Protocolos de Prevención de la TV desde 1995, reforzada el 2005 con la “Norma Conjunta de la Prevención de la Transmisión Vertical del VIH y Sífilis” (MINSAL), ha significado una disminución de la TV del VIH desde más de 35% (antes de 1995) a < 2% actualmente en los binomios en prevención; además ha permitido que una segunda generación de niños expuestos al VIH nazca no infectada. A pesar de estos PPTV, aún siguen naciendo niños infectados con VIH, lo que implica fallas en algunos puntos del sistema de salud.

Infección por virus de inmunodeficiencia humana en niños y adolescentes: Más de 25 años en Chile / Human immunodeficiency virus infection in children and adolescents: More of 25 years in Chile

In this article, the following topics about pediatric HIV infection and AIDS are summarized: a description of pathogenic and clinical aspects of HIV infection in children, the clues for its suspicion, the preventive strategies to avoid the vertical transmission of HIV, the study to certify or to rule out the HIV infection in infants and children, the main recommendations of antiretroviral treatment and how to prevent and treat manifestations of HIV infection. Besides, the evolution in Chile of the pediatric HIV infection is described with details, since the first child detected with AIDS in 1987, infected by transfusion and the first infants (twin) diagnosed in 1989, infected by vertical twins transmission, to 2014, with the progress obtained, snags, hopes and challenges addressed.

En este artículo se describe en forma resumida la patogénesis y aspectos clínicos de la infección por VIH en niños, las claves para su sospecha, las medidas preventivas para evitar su transmisión vertical, el estudio necesario para certificar o descartar la infección en lactantes y niños mayores, y las principales recomendaciones para la terapia anti-retroviral y cómo tratar y prevenir las manifestaciones de la infección por VIH. Se relata a continuación, en forma detallada, la evolución que ha experimentado en Chile la infección por VIH en pediatría, desde el primer caso pesquisado en el año 1987, producto de una transfusión sanguínea, y los primeros lactantes (mellizos) detectados en 1989, que fueran infectados en forma vertical, hasta el año 2014, con el progreso obtenido, las trabas, esperanzas y desafíos enfrentados.

Incidencia de cáncer en niños chilenos infectados por VIH / Incidence of cáncer in Chilean HIV-infected children

Background: Pediatric HIV (+) patients have a 100 times greater risk of cancer than HIV (-) children. Objective: To describe in Chilean HIV (+) children, cancer types, its appearance in relation to the stages of HIV disease and mortality. Methods: A protocol was created to know some characteristics of these patients from the point of view of their HIV infection and cancer pathology. Results: Of 360 HIV (+) children confirmed by the Institute of Public Health to May 2014, 9 patients with neoplastic disease (2.5%) were diagnosed. All the children were on ART, had more than three years of evolution of HIV infection and were in moderate to severe clinical/immunological stages. Lymphoma was the most common cancer. Five children, has received therapy according to Programa Infantil Nacional de Drogas Antineoplásicas (PINDA). There was no interaction between cancer treatment and antiretroviral therapy. Mortality was 13.8 x 1000 (5 cases). Conclusions: The incidence and type of neoplasia is consistent with the international literature, with less survival than HIV (+) children without tumors. The occurrence of cancer was observed in children with moderate to severe clinical and immunological compromise.

Introducción: Los pacientes pediátricos con infección por VIH tienen un riesgo 100 veces mayor de presentar cáncer que los niños no infectados. Objetivos: Describir en niños chilenos con infección por VIH, los tipos de cáncer, su aparición en relación a las etapas de la enfermedad por VIH y la letalidad. Material y Métodos: Se creó un protocolo para conocer algunas características de estos pacientes desde el punto de vista de su infección por VIH y su patología oncológica. Resultados: De 360 niños infectados confirmados por el Instituto de Salud Pública a mayo de 2014, se diagnosticaron nueve casos con patología oncológica (2,5%).Todos los niños estaban con TARV, tenían una evolución de infección por VIH mayor a 3 años, en etapas clínicas/inmunológicas moderada a grave. Linfoma fue el cáncer más frecuente. Cinco niños, recibieron terapia de acuerdo al Programa Infantil Nacional de Drogas Antineoplásicas (PINDA). No hubo interacción entre tratamiento anti-neoplásico y terapia anti-retroviral. La mortalidad fue de 13,8 x 1.000 (5 casos). Conclusiones: La incidencia y tipo de neoplasias está de acuerdo con lo comunicado en la literatura científica internacional, con sobrevida inferior a los niños con infección por VIH sin neoplasias. La aparición de cáncer se observó en niños con larga evolución y compromiso clínico e inmunológico moderado a grave.

[Digestive pathology in children infected with the human immunodeficiency virus (HIV), in Santiago de Chile]. / Patología digestiva en niños infectados con el virus de inmunodeficiencia humana (VIH), en Santiago de Chile.

BACKGROUND: Human immunodeficiency virus (HIV) epidemiology has changed, affecting an increasing number of children. As in adults, the disease predominantly affects the digestive and respiratory systems. AIM: To report the gastrointestinal problems in HIV infected pediatric patients. PATIENTS AND METHODS: Twenty four HIV infected children (nine male, aged 1 to 12 years old, followed for 1 to 170 months), are reported. This group has been under care by a multiprofessional team. RESULTS: Oral candidiasis was present in 21 (88%), esophagic candidiasis in 3 (13%), oral ulcers in 4 (17%). Diarrhea was observed in 18 children (75%) and in eight, it had a chronic evolution. Cryptosporidium parvum was the most frequent agent found in six cases (1 with acute and 5 with chronic diarrhea). Schlerosing cholangiopathy was observed in one case, with a fatal outcome, in association to microsporidiosis. Upper endoscopy was done in 11 patients, demonstrating microscopic inflammatory changes in esophagic, gastric and duodenal epithelia in all. CONCLUSIONS: Digestive problems are common in HIV infected pediatric patients. They must be always sought actively. Endoscopy is a valuable tool for the early diagnosis of these problems.

[Verrucous endocarditis secondary to Saccharomyces cerevisiae. A case report]. / Endocarditis verrucosa secundaria a Saccharomyces cerevisiae. Caso clínico.

We report a preterm infant with 30 weeks of gestation, that received broad spectrum antimicrobials during the first days of life. At nine days of life, the infant appeared with abdominal distension and hematochezia. A systolic murmur with changing auscultatory features also appeared. An echocardiography showed an atrial vegetation. A yeast, that was identified as the emergent pathogen Saccharomyces cerevisiae appeared in two blood cultures. Treatment with amphotericin B was started, the dose was adjusted calculating the minimal inhibitory concentration of amphotericin B, and measuring plasma levels of the antimicrobial. Therefore the minimal effective dose was prescribed, avoiding its deleterious effects. After 14 days of antifungal therapy, a new echocardiography showed a reduction in the size of the atrial vegetation. At 35 days, it disappeared and amphotericin B was discontinued. On the outpatient follow up, the infant has shown a normal growth and a normal cardiac auscultation.

Virus oncogénicos y oncogenos / Oncogenic virus and oncogenes

En la primera parte de esta revisión se señalan las principales características de los virus ADN oncogénicos clásicos productores de tumores en animales. Estos virus "transformación" de cultivos de células, donde se demostró la integración de secuencias genómicas virales al genoma celular. Los estudios genéticos hechos con mutantes virales señalan la existencia de uno o varios genes virales que codifican y mantienen los rasgos fenotípicos propios de esta transformación. En el ser humano se presentan las principales evidencias que asocian al virus de Epstein-Barr con el linfoma de Burkitt y el carcinoma nasofaríngeo, al virus herpes simplex con cáncer cérviouterino y el virus de la hepatitis B (VHB) con el carcinoma hepático primario. De particular interés son los retrovirus, o virus ARN oncogénicos, en los que se demostró la existencia de la transcriptasa reversa, enzima que sintetiza ADN a partir de ARN, que permite la integración del genoma viral al genoma celular. Trabajando con mutantes temperatura sensibles del virus del sarcoma de Rous se logró aislar el gen transformante (v-src). La caracterización de este oncogen viral y de su producto, permitió la demostración de la existencia de su contrapartida celular, es decir de un gen celular "src", que está presente en células no-transformadas y que se ha detectado en el ADN de una variedad de especies animales, incluindo el hombre. El hallazgo del gen celular "src" fue el punto de partida para el estudio de los oncogenes celulares, de los cuales 16 ya han sido detectados en genomas de diferentes especies de vertebrados. Finalmente se presentan los posibles mecanismos de activación de estos oncogenes celulares los que se han preservado a lo largo de toda la evolución

Vacunas virales convencionales y del futuro / Conventional and future viral vaccines

Se revisa en forma concisa las ventajas y desventajas de las vacunas virales convencionales. El progreso de la ingeniería genética, así como el reconomiento de los sitos inmunogénicos presentes en la proteína de la superficia viral, han permitido el desarrollo de nuevas vacunas sintéticas y biosintéticas, las que son de gran utilidad cuando los agentes virales no pueden cultivarse en cantidad adecuada y/o cuando el virus muta rápidamente

Antivirales en infecciones por virus respiratorios / Antiviral drugs in viral respiratory infections

En esta revisión se comenta el espectro de acción y uso clínico de las sustancias biológicas con acción antiviral; la disponibilidad de vacunas virales y gammaglobulinas; las indicaciones del interferón en infecciones virales; las características que deben poseer los antivirales sintéticos. Se describen los principales antivirales sintéticos usados en infecciones respiratorias (amantadina, ribavirina) y se analizan sus indicaciones clínicas en profilaxis y tratamiento