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Mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. Diagnosis of maternal infection and the newborn is achieved by a combination of serological tests, clinical features and ultrasound images. An early diagnosis of maternal infection allows treatment that offers a reduction both in transmission rate and risk of congenital damage. The aim of this expert consensus was to review the scientific literature which would enable an update of the clinical practice guideline of prevention, diagnosis and treatment of congenital toxoplasmosis in our country.La transmisión vertical de la infección por Toxoplasma gondii ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. El diagnóstico de la infección materna y la del recién nacido se logra con el conjunto de pruebas serológicas, hallazgos clínicos y ecográficos. El reconocimiento temprano de la infección materna permite un tratamiento que reduce la tasa de transmisión y el riesgo de daño en el producto de la concepción. El objetivo de este consenso de expertos fue revisar la literatura científica para actualizar las recomendaciones de práctica clínica respecto de la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita en nuestro país.

The Global Meningococcal Initiative (GMI) is an international group of scientists and clinicians with expertise in meningococcal disease (MD). It promotes MD prevention through education and research. Given geographic differences in disease epidemiology, prevention strategies (e.g., vaccination) should be country-specific to ensure local needs are met. However, regional policies/recommendations and standardized disease diagnostic criteria should be implemented to improve surveillance and control strategies, and allow for more robust data comparisons. Consequently, the GMI convened a meeting with Latin American representatives to discuss the burden of MD and vaccination practices/policies, and consider if the global GMI recommendations could be tailored. The group determined that as robust, uniform epidemiologic data are required to make informed health-policy decisions, it would be useful to first summarize the regional situation herein (including disease surveillance, case definitions, epidemiology, vaccination and outbreak control strategies) and then determine a consensus-based meningococcal case definition for use throughout the region.

In Argentina, the National Technical Advisory Group on Immunizations is represented by the National Immunization Commission (CoNaIn), an organization created by the Ministry of Health in 2000. Recently, the Argentine government has decided to prioritize vaccination as a state policy, emphasizing this strategy as a sign of social equity so CoNaIn was restructured to increase its capacity to formulate sound and evidence-based recommendations. The commission shall consist of a group of immunization experts, representatives of scientific societies, the immunization program and the Ministry of Health. Its functions include the formulation of recommendations on the introduction of vaccines into the immunization program. The recommendations are based on technical, programmatic and social criteria. This decision-making process transparent with the support and advice of experts and scientific societies and guided by available evidence decisions help strengthen the Ministry of Health immunization policy generating greater confidence and support from the population and health professionals.

OBJECTIVE. Several studies have evaluated dexamethasone for prevention of hearing loss in childhood bacterial meningitis, but results have varied. We compared dexamethasone and/or glycerol recipients with placebo recipients, and measured hearing at 3 threshold levels.METHODS. Children aged 2 months to 16 years with meningitis were treated with ceftriaxone but were double-blindly randomly assigned to receive adjuvant dexamethasone intravenously, glycerol orally, both agents, or neither agent. We used the Glasgow coma scale to grade the presenting status. The end points were the better ear's ability to detect sounds of >40 dB, ≥60 dB, and ≥80 dB, with these thresholds indicating any, moderate-to-severe, or severe impairment, respectively. All tests were interpreted by an external audiologist. Influence of covariates in the treatment groups was examined by binary logistic regression.RESULTS: Of the 383 children, mostly with meningitis caused by Haemophilus influenzae type b or Streptococcus pneumoniae, 101 received dexamethasone, 95 received dexamethasone and glycerol, 92 received glycerol, and 95 received placebo. Only the presenting condition and young age predicted impairment independently through all threshold levels. Each lowering point in the Glasgow scale increased the risk by 15% to 21% (odds ratio: 1.20, 1.21, and 1.15 [95% confidence interval: 1.06–1.35, 1.07–1.37, and 1.01–1.31]; P = .005, .003, and .039) for any, moderate-to-severe, or severe impairment, respectively. Each increasing month of age decreased the risk by 2% to 6% (P = .0001, .0007, and .041, respectively). Neither dexamethasone nor glycerol prevented hearing loss at these levels regardless of the causative agent or timing of antimicrobial agent.CONCLUSIONS: With bacterial meningitis, the child's presenting status and young age are the most important predictors of hearing impairment. Little relief is obtained from current adjuvant medications.

Background The aim of this study was to describe the frequency of minority populations of viruses carrying mutations K103N and M184V in drug-naive HIV type-1 (HIV-1)-infected children, and to further evaluate their effect on the selection of drug-resistant viruses within highly active antiretroviral therapy (HAART). Methods Newly diagnosed vertically HIV-1-infected children were evaluated. The HIV-1 pol gene was sequenced for subtyping and antiretroviral drug resistance analysis. Standard genotypic sequencing and sequence-selective real-time PCR (SPCR) to quantify minority viral populations were used. Results From December 2004 to July 2006, we included 35 children who were studied at baseline and during their first HAART regimen (follow-up median time 29.4 months). Of them, 82.9% were infected with intersubtype B/F recombinant variants. At baseline, all children had a drug-susceptible viral population that was studied by bulk sequencing. SPCR showed that 4 children had between 2–10% of M184V, 11 had 20% in less time than those with 0.1–0.6% or without minority populations ( P=0.01). Conclusions It was shown that having 2–10% of M184V at baseline enhanced its selection in high percentages in a short time after HAART initiation. Further research regarding the presence of minority quasispecies before initiation of HAART in large paediatric populations should be undertaken to evaluate their clinical effect during HAART.

La transmisión de la infección por Toxoplasma gondii de la madre al hijo ocurre cuando la madre se infecta por primera vez en el transcurso del embarazo. Tanto el diagnóstico prenatal, como el del primer año de vida se basa en pruebas serológicas; y la mayoría de las veces es necesario realizar más de una de estas pruebas ya que tienen distintos porcentajes de sensibilidad y/o especificidad así como distintos niveles de complejidad. El recién nacido requiere seguimiento serológico en el primer año de vida o hasta que se descarte el diagnóstico de toxoplasmosis congénita. El diagnóstico temprano de la infección, en la mujer embarazada, permite un tratamiento oportuno y se indica con el propósito de reducir la tasa de transmisión y el daño congénito. Es posible que con un programa activo, de prevención y tratamiento temprano, se pueda reducir la tasa de incidencia de la toxoplasmosis congénita de alrededor del 5 por mil nacimientos a 0.5 por mil. El objetivo de este consenso fue revisar la literatura científica para la prevención, el diagnóstico y el tratamiento de la toxoplasmosis congénita, para que se pueda implementar en nuestro país.The mother-to-child transmission in Toxoplasma gondii infection occurs only when the infection is acquired for the first time during pregnancy. The prenatal and early postnatal diagnosis can only be achieved by serological testing. Serologic tests have different sensitivities, specificities and complexities, so that different tests in more than one blood sample are necessary for the diagnosis. Serological follow-up of the infants should be conducted during the first year of life or until the diagnosis of congenital toxoplasmosis can be ruled out. Treatment recommendations try to reduce the transmission rate and the risk of congenital damage. Congenital toxoplasmosis incidence rate is approximately 5 per 1000 births, but can be reduced to 0.5 per 1000 with an active screening program. The aim of this consensus group was to review the scientific literature on congenital toxoplasmosis and prepare a statement on prevention, diagnosis and treatment that should be implemented in our country.

In spite of active measles virus (MV) vaccination strategies, reemergence continues to occur, impairing global eradication programs. The immune status against measles was evaluated in 350 vaccinated healthy Argentine children and teenagers who received a single dose of the MV Schwarz strain Lirugen vaccine (Aventis Pasteur). Sera were assessed for immunoglobulin G (IgG) antibodies by a commercial enzyme immunoassay (EIA) (Enzygnost; Behring), an in-house EIA, and neutralization EIA. Results obtained with these methods showed a marked decline in IgG level with increasing age. At 1 to 4 years of age, 84% of children had IgG antibodies above 200 mIU/ml, conventionally accepted as protective levels, whereas only 32% of older children and teenagers had antibody levels exceeding 200 mIU/ml. Moreover, the MV IgG content in the teenage group was significantly lower than the IgG antibody level of the group of younger children ( P < 0.0001). In contrast, screening for IgG antibody levels to inactivated tetanus vaccine showed that, on average, 80% of this population was fully protected and that this high level of protection remained through the teenage years. This study suggests that within this population a considerable proportion of individuals had low measles antibody levels that may be insufficient to protect against reinfections or clinical disease.

HIV-1 infection in children less than 15 years of age is mainly due to mother-to-child transmission. The aim of this work was to investigate molecular evidence to prove father-to-be horizontal transmission in two possible events of transmission. In the first event a boy was identified as HIV infected at 2-3 years of age. At the same time infection was confirmed in the father, while mother and siblings were negative. In the second event a girl was negative for HIV at age 1 and identified as HIV-1 infected at age 6. The father's HIV infection was diagnosed in the same period while the mother was repeatedly negative. No evidence of sexual assault or transfusion was recorded in any case. Peripheral blood mononuclear cells were obtained from both fathers and children. After PCR amplification, the C2V3 region of the envelope gene and the region coding for amino acid 132 of p24 up to amino acid 40 of p7 of the gag gene were sequenced. Genetic distance measurements and phylogenetic tree analysis showed that in both cases the father's and child's viral sequences were closely related. They were distinct when compared to Argentina sequences including sequences from the same geographic region. Epidemiological and molecular data strongly suggest that horizontal transmission had occurred, probably related to the close father-to-child contact.

BACKGROUND AND AIMS Shiga-like toxin (Stx)-producing Escherichia coli (STEC) infection is an ongoing health issue that can lead to serious complications, including hemolytic uremic syndrome (HUS) and death. This study assessed demographic and epidemiologic information of STEC infection among Argentinean children. METHODS A prospective surveillance of 2435 screened children (age, 0.5-15 years) presenting with watery diarrhea and/or bloody diarrhea was undertaken to evaluate the clinical course of STEC infection. RESULTS Prevalence of STEC infection was 4.1% among subjects presenting with watery diarrhea for ≤ 5 days' duration, bloody diarrhea for ≤ 36 hours' duration, or both. Incidence of STEC infection was significantly higher in the subjects with bloody diarrhea. Ninety-three STEC+ children underwent further evaluation, of whom 8 (8.6%) developed HUS. White blood cells, particularly neutrophils, were abnormally elevated at screening in 5 of 8 HUS subjects. Quantifiable serum Stx-2 values were noted within 24 to 48 hours after the onset of bloody diarrhea in 3 HUS subjects using a validated chemiluminescence assay, with levels quickly dissipating by HUS onset. CONCLUSIONS Results suggest that young STEC-positive children with bloody diarrhea and exhibiting neutrophilic leukocytosis in the early course of their diarrhea are at risk for HUS progression. The observation of measurable concentrations of Stx-2 levels in the early post-bloody-diarrhea period and rapid dissipation at the time of HUS onset requires further evaluation.

A post hoc analysis of 654 children with bacterial meningitis showed that the level of consciousness is the most important predictor of death and/or neurological sequelae, more than is etiology per se. This finding emphasizes the need of including a measurement of the presenting status in all studies examining treatment efficacy.

IntroductionThe aim of our study was to analyse the frequency of primary mutations associated with HIV drug resistance in a population of children born to HIV-infected mothers.DesignA prospective study included newly HIV-diagnosed children treated at two public paediatric hospitals.Patients and methodsClinical and antiretroviral therapy (ART) data were collected in mother-child pairs. HIV-1 subtyping and ART resistance mutations were assayed in children by sequencing a region of HIV pol gene.Results: A total of 67 children were enrolled22 less than 12 months of age, 20 between 1 and 5 years and 25 between 6 and 14 years. Six (9.0%) children had viral strains with at least one primary mutation associated with resistance to reverse transcriptase and protease inhibitors. A significantly ( P=0.019) higher frequency of resistance (22.7%, n=5/22) was found among children aged DiscussionA high percentage of recently diagnosed infants were found to carry primary ART resistance mutations. Limited options for ART of HIV-infected children might lead to increased HIV-associated morbidity and mortality. Thus, consideration should be given to mandatory screening for primary ART resistance before initiating therapy for infants aged

We have studied the epidemiology of pertussis in two countries, Argentina and France, which have similar histories of long-term mass vaccination with a whole-cell vaccine. Both countries display a comparable epidemiology, with an increase of the incidence of the disease in non-vaccinated newborns. We used pulsed-field gel electrophoresis (PFGE) analysis and genotyping to compare Bordetella pertussis clinical isolates recovered in Argentina and France in 2001-2004. The majority of the isolates harbors prn2 allele and belongs to PFGE IVbeta group. Isolates were found to be very similar genetically suggesting a common evolution of the disease in these two countries using the same vaccine.

Despite favorable meta-analyses, no study involving third-generation cephalosporins for the treatment of childhood bacterial meningitis has documented a benefit of adjuvant dexamethasone therapy if the outcomes are examined individually.We conducted a prospective, randomized, double-blind trial comparing adjuvant dexamethasone or glycerol with placebo in children aged from 2 months through 16 years in Latin America. Ceftriaxone was administered to all children; children were randomized to also receive dexamethasone intravenously, glycerol orally, both agents, or neither agent. Primary end points were death, severe neurological sequelae, or deafness, with the first 2 end points forming a composite end point. A subgroup analysis for Haemophilus influenzae type b meningitis was undertaken. Intention-to-treat analysis was performed using binary logistic regression models.H. influenzae type b, pneumococci, and meningococci were the main agents found among 654 patients; dexamethasone was given to 166, dexamethasone and glycerol were given to 159, glycerol was given to 166, and placebo was given to 163. No adjuvant therapy significantly affected death or deafness. In contrast, glycerol and dexamethasone plus glycerol reduced severe neurological sequelae, compared with placebo; the odds ratios were 0.31 (95% confidence interval [95% CI], 0.13-0.76; P=.010) and 0.39 (95% CI, 0.17-0.93; P=.033), respectively. For neurological sequelae and death, the odds ratios were 0.44 (95% CI, 0.25-0.76; P=.003) and 0.55 (95% CI, 0.32-0.93; P=.027), respectively. Dexamethasone therapy prevented deafness in patients with H. influenzae type b meningitis only if patients were divided grossly into dexamethasone recipients and nonrecipients and if timing between dexamethasone and ceftriaxone administration was not taken into account (odds ratio, 0.27; 95% CI, 0.09-0.77; P=.014).Oral glycerol therapy prevents severe neurological sequelae in patients with childhood meningitis. Safety, availability, low cost, and oral administration also add to its usefulness, especially in resource-limited settings.

Las infecciones invasivas por Streptococcus pneumoniae (Spn) producen mortalidad elevada en países en desarrollo, con tasas entre 4 y 100 veces mayores que las de Estados Unidos o Canadá. Es el primer agente causal de neumonía en la infancia y de meningitis fuera de los brotes epidémicos por Neisseria meningitidis. La OPS, a través del grupo SIREVA, dedicado al desarrollo de vacunas en Latinoamérica, organizó un programa de vigilancia de infecciones invasivas por Spn en seis países: Argentina, Brasil, Chile, Colombia, México y Uruguay, iniciado en 1993 y que continúa actualmente. En Argentina participan en la actualidad más de 20 centros hospitalarios distribuidos en todas las áreas geográficas del país, actuando como Centro Nacional de referencia para la serotipificación y determinación de la resistencia a los antibióticos el Instituto ANLIS "Dr. Carlos G. Malbrán". Objetivos: 1) Determinar los serotipos predominantes, su resistencia a los antibióticos y los cambios temporales en infecciones invasivas por Spn de niños menores de 5 años de edad; 2) Obtener información confiable para la formulación de una vacuna conjugada adecuada para la región. Metodología: Diseño prospectivo observacional. Se incluyeron todos los niños menores de 6 años de edad internados por infecciones invasivas (neumonía, meningitis, sepsis o bacteriemia), en los que se aisló Spn de un sitio previamente estéril. Se realizó control externo de confiabilidad de los resultados, inicialmente en el laboratorio de referencia de Canadá y actualmente en el Instituto Adolfo Lutz de San Pablo. El análisis estadístico se realizó con EPIINFO 6 y con el programa WHONET de OMS. Resultados: Se destacan los siguientes hallazgos: Se aisló Spn en 1 390 muestras clínicas. La edad media (N = 1 175) fue de 19,5 meses, con 74,4% - 2 años; fueron neumonías 60,5%; meningitis 26,6%, sepsis 8,2%. Se halló sensibilidad disminuida a penicilina en 32,1% (414/1 288), con resistencia alta 16,1% e intermedia 16%. La resistencia a los antibióticos betalactámicos se incrementó en el período 1993-8. Los serotipos prevalentes fueron: 14 (32,5%), 6A/6B, 9V, 23F, 19F, 18C, 4, 5, 1. Los serotipos 14 y 6AB prevalecieron en menores de 2 años mientras que el 5 y el 1 prevalecieron en mayores de 2 años (p < 0,001). El serotipo 14, la neumonía y la edad menor de 2 años fueron los factores de riesgo para resistencia a penicilina. La representatividad para las vacunas conjugadas 7-valente, 9-valente y 11-valente fue de 53,3%, 77,4% y 82,6% respectivamente, mayor para la 7-valente en los menores de 2 años (61,2%) y en los menores de 2 años con neumonía (71,2%). Más del 90% de los serotipos aislados con algún grado de resistencia estuvieron contenidos en las tres vacunas analizadas. Conclusiones: Un programa nacional de vigilancia de Spn invasivo fue desarrollado en Argentina y otros países latinoamericanos. Se identificaron por primera vez los serotipos predominantes en infecciones invasivas y se comprobó el incremento significativo de la resistencia a penicilina y otros antibióticos, similar a lo informado en casi todos los países del mundo. Se obtuvo información epidemiológica válida para evaluar estrategias de prevención con nuevas vacunas Since 1993, the PAHO, through the Regional Vaccine System (SIREVA Group) organized a surveillance protocol of invasive Streptococcus pneumoniae (Spn) infections in children less than 5 years old in six Latin-American countries: Argentina, Brazil, Chile, Colombia, Mexico and Uruguay. In Argentina more than 20 hospitals are now participating in this project. Objectives: 1) To determine the predominant serotypes, the antibiotic resistance and changes along the time. 2) To know the representativity of the serotypes isolated in the new conjugated vaccines. Methodology: Children less than 6 years old hospitalized by Spn invasive infections were included (pneumonia, meningitis, bacteremia o sepsis). The ANLISS "Dr. Carlos G. Malbrán" Institute was the reference center for Spn serotyping and antibiotic resistance determination. Results: Spn was isolated from 1 390 clinical samples. The average age was 19.5 months, 74.4% belonged to children equal or less than 2 years of age. The main clinical diagnosis were: pneumonia 60.5%, meningitits 26.6%, fever without foccus (bacteremia) or sepsis 8.2%. Decreased penicillin sensitivity (DPS) was found in 32.1% of the cases, with high resistance in 16.1% and intermediate resistance in 16%; the increase of DPS in the 1993-98 period was significant, like in other countries. The more frequent serotypes were: 14 (32.5%), 6A/6B, 9V, 23F, 19F, 18C, 4, 5, and 1. Serotypes 14 and 6AB were prevalent in children less than 2 years old and serotypes 5 and 1, in children than 2 years older (p < 0.001). Serotype 14, pneumonia and age less than 2 years were risk factors for penicillin resistance. Finally, the representativity of the serotypes in the new conjugated vaccines 7-valent, 9-valent and 11-valent was: 53.3%, 77.4% and 82.6% respectively. For the 7-valent vaccine, was higher in the less than 2 years old group (61.2%), and for this age group with pneumonia (71.2%). More than 90% of penicillin resistant serotypes were included in the three conjugated vaccines. Conclusions: A national surveillance program was developped in Argentina and other Latin-American countries. Prevalent invasive Spn serotypes were identified; a significative increase in penicillin and other antibiotic resistance was found, like in almost all countries. This epidemiologic information is of great importance for evaluating the new conjugated vaccines

Background The ready availability of HIV prevention, testing and treatment services has lowered HIV mother-to-child transmission (MTCT) rates to less than 2% in high-income countries. Argentina has laws that guarantee universal and free antiretroviral therapy (ART) to every HIV-infected person and makes the offering of an HIV test to every pregnant woman mandatory. In spite of this, HIV MTCT is still present. The aim of this report is to call the attention of general paediatricians of belated HIV diagnoses in children.

In this article we describe two lethal cases of MTCT of HIV and T.cruzi in the province of Buenos Aires, Argentina. Child 1 was admitted to the hospital being 1 month old with respiratory difficulty and diarrhoea. Being six months old he was released but being 22 months old he presented sepsis and died. The mother was not treated during pregnancy, while the child was treated with combined HAART and benznidazol. Child 2 was admitted to a provincial Hospital being 20 days old, and referred to the Children´s Hospital. After 39 days at the ICU the child died with sepsis. His mother received ZDV late in her pregnancy. The child received was treated with HAART, interrupted at 3 months due to severe organic failure. The lack of diagnosis of T. cruzi in both mothers worsened the prognosis of these two children, since treatment with antiparasitic drugs is used since birth. Fil: Agosti, Maria Rosa. Hospital de Niños Sor María Ludovica, la Plata; Argentina Fil: Ercoli, Pablo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina Fil: Dolcini, Guillermina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina Fil: Andreani, Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología. Centro Nacional de Referencia para el Sida; Argentina Fil: Martinez Peralta, Liliana A.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Microbiología; Argentina Fil: Gonzalez Ayala, Silvia Elena. Hospital de Niños Sor María Ludovica, la Plata; Argentina