Oropharyngeal meningococcal carriage in children and adolescents, a single center study in Buenos Aires, Argentina.

BACKGROUND: Neisseria meningitidis (Nm) pharyngeal carriage is a necessary condition for invasive disease. We present the first carriage study in children in Buenos Aires, Argentina, considering 2017 as a transition year. Aims: to assess the rate of Nm carriage, to determine genogroup, clonal complex and outer membrane protein distribution, to determine carriage risk factors by age. METHODS: Cross-sectional study including children 1-17 yrs, at Ricardo Gutiérrez Children's Hospital in Buenos Aires 2017. Oro-pharyngeal swabs were taken and cultured within a short time after collection. Genogroup was determined by PCR and clonal complex by MLST. Categorical variables were analyzed. RESULTS: A total of 1,751 children were included. Group 1: 943 children 1-9 yrs, 38 Nm were isolated; overall carriage 4.0%. Genogroup distribution: B 26.3%, W 5.3%, Y 2.6%, Z 5.3%, other groups 7.9% and capsule null (cnl) 52.6%. Participating in extracurricular activities was the only independent predictor of Nm carriage. Group 2: 808 children 10-17 yrs, 76 Nm were isolated; overall carriage 9.4%. Genogroup distribution: B 19.7%, C 5.3%, W 7.9%, Y 9.2%, Z 5.3%, other groups 7.9% and cnl 44.7%. Independent predictors of carriage: attending pubs/night clubs and passive smoking (adjusted OR: 0.55, 95%CI = 0.32-0.93; p = 0.025). CONCLUSIONS: Overall carriage was higher in 10-17 yrs. The isolates presenting the cnl locus were prevalent in both age groups and genogroup B was the second most frequent.

Episodios de Hipotonía Hiporrespuesta (EHH) postvacunación: reporte de una serie de casos / Post-vaccination hypotonic-hyporesponsive episodes: report of a series of cases

Objetivo: Describir características clínicas, antecedentes de vacunación, recursos médicos utilizados y continuidad del esquema de vacunación de los casos de Episodio de Hipotonía Hiporrespuesta (EHH) que consultaron al Vacunatorio del Hospital de Niños Ricardo Gutiérrez (HNRG). Materiales y métodos: Estudio descriptivo de serie de casos. Se incluyeron los niños con diagnóstico de EHH, según los Criterios de Brighton, que consultaron entre Enero 2010 y Agosto 2017. Resultados: Se registraron 14 casos, 1 se descartó por datos insuficientes (n= 13). La media de edad fue 5 meses, sin predominio de sexo. Diez casos se presentaron luego de la 1° dosis y todos antes de las 24hs. Recibieron quíntuple celular 12 pacientes, hexavalente 1; recibieron otras vacunas 11 casos. Síntomas concomitantes más frecuentes: fiebre e irritabilidad. Realizaron consulta médica 12 y se internaron 9. Doce tuvieron recuperación total, de 1 no hay datos. Ocho continuaron el esquema con vacuna acelular, uno con celular y ninguno presentó complicaciones. Conclusiones: Todos presentaron el EHH dentro de las 24hs post vacunación con componente pertussis, con recuperación completa. La mayoría luego de la primera dosis. Más del 80% requirió consulta médica y casi el 70% internación. La continuidad del esquema no se asoció con complicaciones

Objective: To describe the clinical manifestations, vaccination history, medical resources used and the continuity of the vaccination schedule in all the cases of hypotonic-hyporesponsive episodes (HHE) seen in the immunization center of Ricardo Gutierrez Children´s Hospital. Materials and methods: Descriptive study of a retrospective case series. All children diagnosed with HHE according to the Brighton Criteria, who were seen between January 2010 and August 2017, were included. Results: There were 14 cases, one of which was dismissed due to insufficient data (n= 13). The mean age was 5 months, with no predominance of sex. Ten of the episodes occurred after the 1st dose and all of them within 24 hs. Twelve patients received pentavalent whole-cell vaccines, one received the hexavalent vaccine and eleven received other vaccines. The most frequent concomitant symptoms were fever and irritability. Twelve required medical consultation and nine, hospitalization. Evolution: 12 recovered completely and data were missing from 1. Eight of the patients who were followed up continued with acellular vaccines, one with pentavalent whole-cell vaccine. None presented complications. Conclusions: All patients presented the HHE within 24 hours after the administration of pertussis component vaccines, recovering completely HHE has been observed mainly after the first dose More than 80% required medical consultation and almost 70%, hospitalization. The continuity of the schedule was not associated with complications

Enfermedad por virus Dengue: su prevención / Dengue disease: its prevention

El Dengue al igual que el zika y el chikungunya son enfermedades trasmitidas por vectores Más del 80% de la población mundial vive en zonas de riesgo de contraer al menos una de estas enfermedades. El dengue es transmitido por la picadura del mosquito hembra vector del género Aedes, especie A. aegypti que circula con mayor frecuencia en las Américas. La carga de enfermedad por dengue es sin duda un problema global que afecta a gran parte de la población mundial y el número de casos se ha incrementado considerablemente en los últimos 50 años. El período de incubación de la enfermedad varía de 3 a 15 días con una media de 4 a 6 días pero existe una gran proporción de casos asintomáticos estimada en alrededor del 75%.1 Las intervenciones de control de vectores ofrecen uno de los mejores rendimientos de inversiones en el ámbito de la salud pública. Los programas eficaces de control de vectores que reducen enfermedades pueden impulsar el desarrollo humano y económico. Actualmente se encuentran en desarrollo 4 vacunas para controlar esta enfermedad y una vacuna ya se encuentra aprobada en algunos países del mundo, fundamentalmente indicada para sujetos con infección previa por Dengue

Dengue as well as Zika and Chikungunya are diseases transmitted by vectors. More than 80% of the world population lives in areas at risk of contracting at least one of these diseases. Dengue is transmitted by the female vector mosquito of the genus Aedes species A. Aegypti, which circulates most frequently in the Americas. The burden of Dengue disease is undoubtedly a global problem that affects a large part of the world population and the number of cases has increased considerably in the last 50 years. The incubation period of the disease varies from 3 to 15 days with an average of 4-6 days, but there is a large proportion of asymptomatic cases, estimated to be around 75%. Vector control interventions offer one of the best investment returns in the field of public health. Effective vector control programs that reduce diseases can boost human and economic development. At present, 4 vaccines are being developed to control this disease and one vaccine has been approved in some countries, mainly indicated for subjects previously infected with Dengue

Immunogenicity and reactogenicity of a combined fully liquid DTPw-HepB-Hib pentavalent vaccine in healthy infants: no clinically relevant impact of a birth dose of hepatitis B vaccine.

OBJECTIVES: In this open-label, non-randomized phase II study, the safety and immunogenicity of a fully liquid diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type b (DTPw-HepB-Hib) combination vaccine (Quinvaxem(®)) were assessed in infants who had or had not received a birth dose of hepatitis B (HepB) vaccine. STUDY DESIGN: Two groups of infants, 'HepB at birth' (n=110) and 'no HepB at birth' (n=108), were enrolled and received a primary vaccination course using a 2-4-6 months schedule. RESULTS: Seroprotection/seroconversion rates of >95% were achieved against all antigens included in the combination vaccine for both study groups. Although significantly higher anti-hepatitis B virus (p<0.001) and anti-tetanus (p=0.031) antibody titers were achieved in group 'HepB at birth' when compared with group 'no HepB at birth', the proportion of 'no HepB at birth' subjects achieving protective titers was non-inferior to the proportion of subjects in group 'HepB at birth'. The birth dose of HepB vaccine did not seem to influence the safety pattern of the DTPw-HepB-Hib combination vaccine. CONCLUSIONS: The present study demonstrated that the fully liquid DTPw-HepB-Hib vaccine was safe and immunogenic when administered using a 2-4-6 months immunization schedule, regardless of whether or not infants had received a dose of HepB vaccine at birth.

Mercury levels in newborns and infants after receipt of thimerosal-containing vaccines.

OBJECTIVES: Thimerosal is a mercurial preservative that was widely used in multidose vaccine vials in the United States and Europe until 2001 and continues to be used in many countries throughout the world. We conducted a pharmacokinetic study to assess blood levels and elimination of ethyl mercury after vaccination of infants with thimerosal-containing vaccines. METHODS: Blood, stool, and urine samples were obtained before vaccination and 12 hours to 30 days after vaccination from 216 healthy children: 72 newborns (group 1), 72 infants aged 2 months (group 2), and 72 infants aged 6 months (group 3). Total mercury levels were measured by atomic absorption. Blood mercury pharmacokinetics were calculated by pooling the data on the group and were based on a 1-compartment first-order pharmacokinetics model. RESULTS: For groups 1, 2, and 3, respectively, (1) mean +/- SD weights were 3.4 +/- 0.4, 5.1 +/- 0.6, and 7.7 +/- 1.1 kg; (2) maximal mean +/- SD blood mercury levels were 5.0 +/- 1.3, 3.6 +/- 1.5, and 2.8 +/- 0.9 ng/mL occurring at 0.5 to 1 day after vaccination; (3) maximal mean +/- SD stool mercury levels were 19.1 +/- 11.8, 37.0 +/- 27.4, and 44.3 +/- 23.9 ng/g occurring on day 5 after vaccination for all groups; and (4) urine mercury levels were mostly nondetectable. The blood mercury half-life was calculated to be 3.7 days and returned to prevaccination levels by day 30. CONCLUSIONS: The blood half-life of intramuscular ethyl mercury from thimerosal in vaccines in infants is substantially shorter than that of oral methyl mercury in adults. Increased mercury levels were detected in stools after vaccination, suggesting that the gastrointestinal tract is involved in ethyl mercury elimination. Because of the differing pharmacokinetics of ethyl and methyl mercury, exposure guidelines based on oral methyl mercury in adults may not be accurate for risk assessments in children who receive thimerosal-containing vaccines.