Estudio multicéntrico, de seroprevalencia de IgG Toxoplasma gondii en niños con cáncer de la red del Programa Infantil Nacional de Drogas Antineoplásicas en la Región Metropolitana, Chile / Toxoplasma gondii IgG seroprevalence in children with cancer from National Children's Antineoplastic Drug Program network in the Metropolitan Region, Chile: a multicenter study

INTRODUCCIÓN: Toxoplasma gondii es un protozoo que afecta a un tercio de la población mundial y cuya seroprevalencia actualizada en niños con cáncer en nuestro medio, se desconoce. OBJETIVO: Describir la seroprevalencia de IgG anti-T. gondii en población pediátrica con cáncer atendida en hospitales públicos de la Región Metropolitana, Chile. MÉTODO: Estudio transversal de pacientes pediátricos oncológicos atendidos en la ciudad de Santiago. Se tomó una muestra de suero de 100 pacientes entre junio de 2016 y mayo de 2019. Se les realizó ELISA IgG T. gondii. RESULTADOS: Se analizaron 100 muestras, 51% de sexo masculino. Resultaron 12 positivas, 84 negativas y 4 indeterminadas. Los sueros de los pacientes se estratificaron por edad: 0-5 años 43%, 6-10 años 29%, 11-15 años 20% y > 15 años, 8%. El 61% eran pacientes con leucemia aguda. El porcentaje de mujeres con IgG positiva fue de 21% en comparación a 4% en hombres (P < 0,0011). CONCLUSIÓN: El 84% de los niños en tratamiento por cáncer son seronegativos para T. gondii, por lo que es importante educar en la prevención de la adquisición de este parásito en esta población, por el riesgo de desarrollar enfermedad grave con riesgo de muerte.

BACKGROUND: Toxoplasma gondii is a protozoan that affects a third of the world population and whose updated seroprevalence in children with cancer in our environment is unknown. AIM: To describe the seroprevalence of IgG anti-T. gondii in pediatric population with cancer treated in hospitals of the Metropolitan Region, Chile. METHOD: Cross-sectional study of the population of pediatric cancer patients treated in Santiago city, A serum sample was taken from 100 patients between June 2016 and May 2019. ELISA IgG T. gondii was performed. RESULTS: Of 100 children, 51% male. 12 were positive (12%), 84 negative (84%) and 4 indeterminate (4%). The stratification by age showed 43% patients between 0-5 years, 29% between 6-10 years, 20% in the group of 11-15 years and 8% in patients > 15 years. Sixty one percent of the samples came from patients with acute leukemia. The percentage of women who tested positive for IgG was 21% compared to 4% in men (P < 0.0011). CONCLUSION: 84% of children undergoing cancer treatment are seronegative for T. gondii, so it is important to educate on the prevention of the acquisition of this parasite in this population, due to the risk of developing serious and fatal disease.

Vacunas SARS CoV-2, estudios en fase III / SARS CoV-2 vaccine studies currently in phase III

Resumen La enfermedad por coronavirus 2019, causada por el virus SARS-CoV2, fue declarada pandemia en marzo de 2020 por la OMS. La proteína S, de la superficie viral ha sido identificada como antígeno óptimo para el desarrollo de vacunas. En pandemia, el proceso tradicional de desarrollo de vacunas ha debido acelerarse para avanzar en una respuesta adecuada al problema, acortando los tiempos. La seguridad, inmunogenicidad, protección frente a la infección, fenómeno de "aumento dependiente de anticuerpos", duración de la protección se estudian en paralelo, a diferencia de la manera tradicional en que se llevaba a cabo en etapas sucesivas. Actualmente en Fase III hay 4 tipos vacunas: inactivadas; en base a proteínas purificadas o recombinantes, en base a ácidos nucleicos ADN/ARN y en base a vectores virales. El objetivo de esta revisión es conocer los estudios que preceden a las vacunas que actualmente están en estudios de Fase III y describir las características principales de estos estudios. Actualmente el mundo se encuentra en una situación inédita en el último siglo. Dentro las opciones para enfrentar este hecho, una vacuna o idealmente varias, seguras, eficaces e inmunogénicas, parecen ser una de las mejores alternativas para retomar en un plazo razonable la normalidad perdida.

Abstract The coronavirus disease 2019, caused by the SARS-CoV2 virus, was declared a pandemic in March 2020 by the WHO. Protein S from the viral surface has been identified as the optimal antigen for vaccine development. In a pandemic, the traditional vaccine development process has had to be accelerated to advance in an adequate response to the problem, shortening the times. Safety, immunogenicity, protection against infection, antibody dependent enhancement phenomena and duration of protection are studied in parallel, unlike the traditional way in which it was carried out in successive stages. Currently in Phase III there are 4 types of vaccines: inactivated; based on purified or recombinant proteins, based on DNA / RNA nucleic acids and based on viral vectors. The objective of this review is to understand the studies that precede the vaccines that are currently in Phase III studies and to describe the main characteristics of these studies. Currently the world is in a situation unprecedented in the last century. Among the options to face this fact, one vaccine or, ideally, several, safe, effective and immunogenic, seem to be one of the best alternatives to regain lost normality within a reasonable time.

Infección micótica profunda en niños con cáncer, neutropenia y fiebre, en Chile / Invasive fungal infections in children with cancer and febrile neutropenia, in Chile

Background: Invasive fungal infections (IFI) cause prolonged hospitalizations and increase the possibility of death among patients with cancer and febrile neutropenia (FN). Up to 10 percent of febrile neutropenic episodes may be caused by IFI. Aim: To estimate the incidence of IFI among a large group of Chilean children with cancer and FN. Patients and Methods: Clinical and laboratory information was collected from a data base provided by the "Programa Infantil Nacional de Drogas Antineoplásicas" (PINDA) that included 445 FN episodes occurring in five hospitals in Santiago, Chile. This information was used to identify children that presented with signs and symptoms compatible with an IFI. According to predefined criteria based on a literature review, IFI episodes were categorized as "proven", "probable" or "possible". Results: A total of 41/445 episodes (9.2 percent) were compatible with an IFI of which 4 (0.9 percent) were proven, 23 (5.2 percent) probable, and 14 (3.1 percent) possible. Hospitalization was longer (27 vs 8 days, p <.01), new infectious foci appeared with higher frequency (71 vs 38 percent, p <.01), and mortality was higher (10 vs 1.6 percent, p <.001) in children with IFI compatible episodes, when compared to children who did not have an IFI. Conclusions: The estimated incidence of IFI in Chilean children with cancer and FN ranged between 6-9 percent depending on the stringency of criteria selection used for classification. This estimate is similar to that reported by other studies. The low detection yield of clinically compatible IFI underscores the need of improved diagnosis of fungal infections in this population

Neutropenia febril en el niño con cáncer: conceptos actuales sobre criterios de riesgo y manejo selectivo / Febrile neutropenia in children with cancer: risk assessment and risk based therapeutic strategies

The risk for invasive bacterial infection (IBI) in cancer pediatric patients with febrile neutropenia, is variable. Clinicians worldwide are increasingly considering selective strategies for children at low risk for IBI, including shortened antimicrobial course, early hospital discharge, oral antimicrobial treatment, and management as outpatients. These strategies would significantly benefit these children and health care systems. The critical issue is to identify the most reliable risk factors useful for selection of those individuals who are at low risk for IBI. In Chile, during the past 10 years, a group of physicians from the Subcommittee of Infectious Diseases of the National Child Program of Antineoplastic Drugs and the University of Chile have worked to develop more selective strategies for pediatric patients with cancer, fever and neutropenia. During 1996-1997 we identified risk factors of IBI in a group of 447 febrile neutropenic episodes. During 1999-2000 we validated these risk factors in a prospective study that included 263 febrile neutropenic episodes. A model of risk prediction was developed and is currently being evaluated for the selection of low risk patients who are treated as inpatients for 24 hours, followed by outpatient treatment

Sinusitis complicada / Complicated sinusitis

Se presenta el caso de una paciente boliviana quien acude con el diagnóstico de una osteomielitis de cadera, décima costilla y techo del etmoides, posiblemente secundario a una infección por bacterias anaerobias. Se revisa la evolución y tratamiento y se efectúa una revisión de las etiologías infectológicas que podrían explicar un cuadro de estas características

Agentes causantes de infecciones del torrente circulatorio en niños con cáncer, en cinco hospitales de Santiago, 1994-1998 / Causative agents of bloodstream infections in Chilean pediatric patients with cancer

Background: Pediatric patients in treatment for cancer can have fatal bacterial infections. Thus, in the presence of fever or other signs infection, antimicrobials have to be prescribed empirically. Aim: To know the causative agents of bacteremia in children with cancer, their changes with time and between different hospitals and their patterns of susceptibility. Material and methods: We reviewed the blood cultores of children with cancer in five hospitals of Santiago, from 1994 at 1998. Results: During the study period, 707 agents were isolated. The most frequently isolated species or genus were coagulase negative Staphylococcus (43 percent), Staphylococcus aureus (16 percent), Escherichia coli (9 percent), Klebsiella spp. (8 percent), Pseudomonas spp. (5 percent) and Candida spp. (4 percent). Coagulase negative Staphylococcus was 55 percent resistant to meticilin and S. aureus was 44 percent resistant. Enterobacteriae had 15 percent resistance to gentamicin and amikacin, 2 percent to imipenem, 26 percent to ceftriaxone, 21 percent to cefotaxim and 20 percent to ceftazidim. Among non fermenting agents resistance was 6 percent for imipenem, 9 percent for amikacin 10 percent for ciprofloxacin, 19 percent for ceftazidim and 22 percent for cefoperazone. The resistance of Streptococcus spp. (non pneumoniae) to penicillin reached 50 percent and that of Enterococcus spp. was of 33 percent. Conclusions: Treatment for pediatric patients with cancer must be modified and new guidelines including more active medications for patients at risk for bacteremia, should be devised