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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.

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.