Search

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.

Background Neisseria meningitidis (Nm) pharyngeal carriage is a necessary condition for invasive meningococcal disease. In 2017, Argentina introduced a tetravalent meningococcal conjugated vaccine (MenACYW) to the National Immunization Program for children. We present the first carriage study in children in the prevaccine era. Aims: 1) to assess the rate of Nm carriage in healthy children and adolescents attending a public hospital in Buenos Aires city; 2) to determine serogroup and clonal complex distribution; 3)to determine carriage risk factors by age. Methods Cross-sectional study including children 1–17 years, stratified in two age groups (1–9 years and 10–17 years) assisted at Ricardo Gutiérrez Children Hospital between March-December 2017. Oro-pharyngeal swabs were plated and meningococci identified by conventional microbiology methods. Serogroup was determined by PCR. Clonal complex was determined by MLST. Results A total of 1751 children were included. Group aged 1–9 years: 38 Nm were isolated from 943 samples collected: overall carriage 4.0%. Serogroups distribution: B 26.3%, Y 2.6%, W 5.3%, Z 5.3%, non-groupable 7.9% and non-capsulated 52.6%. Clonal complex was determined for 25 isolates. Attendance at social venues was the only independent predictor of Nm carriage (adjusted OR: 2.02, CI 95% = 1.01–4.03; P = 0.04). Group aged 10–17 years: 76 Nm were isolated from 808 samples: overall carriage 9.4%. Serogroups distribution: B 19.7%, C 5.3%, W 7.9%, Y 9.2%, Z 5.3%, non-groupable 7.9% and non-capsulated 44.7%. Clonal complex was determined for 58 isolates. Independent predictor of Nm carriage: attendance at night clubs (adjusted OR: 3.38, CI95% = 1.28–8.93; P = 0.013); passive smoking at home (adjusted OR: 0.55, CI 95% = 0.32–0.93; P = 0.025). Preliminary data show a total of 10 different clonal complexes present among all serogroups in the 1–9 years group aged and 13 in 10–17 years. Conclusion Overall carriage was higher in the 10–17 years population. The non-encapsulated Nm was prevalent in both groups and serogroup B was the most frequent among the encapsulated. The results demonstrated a high diversity of N. meningitis in pharyngeal carriage. Disclosures All authors: No reported disclosures.

Poster: "18th ICID / Fri_Station_01.2 / Is Haemophilus Influenzae type b (Hib) reemerging? 25 years of meningitis surveillance in a Pediatric Hospital in Buenos Aires metropolitan area" by: "M. D. V. Juarez1, M. F. Lucion1, M. S. Areso1, M. Ana Clara1, A. Rainelli1, M. P. Della Latta2, M. Turco2, J. Bakir1, A. Gentile2; 1Buenos Aires, CABA/AR, 2Buenos Aires/AR"

Background Neisseria meningitides (Nm) cause different types of invasive infections.Nm pharyngeal carriage is a necessary condition for invasive meningococcal disease. In 2017 Argentina introduced a tetravalent meningococcal conjugated vaccine (MenACYW) to the National Immunization Program.Aims To assess the rate of Nm carriage in healthy children and adolescents attending a public hospital in Buenos Aires city, to determine genogroup and clonal complex distribution,to describe genogroup distribution of Nm isolated from ID in Argentina, during the same period. Methods Between March and December 2017, a single-center, cross-sectional study was performed among 1,751 children 1–17 years old attending Ricardo Gutiérrez Children Hospital in Buenos Aires, Argentina. From oro-pharyngeal swabs, genogroup and clonal complex (CC) were identified. We analyzed Nm ID genogroups data reported to the Regional Surveillance Program (SIREVA II) in the same year. at the same period were relevated. Results 114Nm were isolated from the carriage study, with an overall carriage of 6.5%.Genogroups distribution: B 25(21.9%), W 9(7.8%), Y 7(6.1%), Z 6(5.2%), C 4(3.5%), non-groupable 9(7.8%) and non-capsulated (NC)54 (47.3%). 105 Clonal complex (CC) were determined: Genogroup B isolates belonged to ST-41/44, ST-35, ST-32 and ST-865. Genogroup W was associated to ST-11 and ST-35. SIREVA reported 76 strains of Nminvasive infections in 2017, 53.9% meningitis, 11.8% meningitis and sepsis, 22.4% sepsis, and 11.8% others. Genogroupsdistribution: B59.2% (45), W 23.6% (18), C 10.5% (8), Y 6.5% (5). Conclusion Genogroup B is the most frequent cause of ID followed by W in our country. In the pharyngeal carriage study we found that NmNC was prevalent and genogroup B was the most frequent among the encapsulated.Genogroup B CCs detected in our carriage study coincided with those found previously in ID in Argentina. Genogroup W carriage was low and hypervirulent CC ST-11 was detected. Although genogroup Z does not cause ID in our country it was found in carriage. Disclosures All authors: No reported disclosures.

Haemophilus influenzae type B (Hib) used to be the main cause of bacterial meningitis in children younger than 5 years old. Following the introduction of the Hib vaccine in the immunization schedule (1998), its incidence reduced significantly but it has increased over the last years. The objectives of this study included describing the characteristics and analyzing the epidemic curve of Haemophilus influenzae type B (Hib) meningitis by comparing the pre- and postimmunization periods.Time-series study. All patients hospitalized with Hib meningitis at Hospital de Niños "R. Gutiérrez" (January 1992-May 2016). Hospitalization rates were compared before (pre-immunization) and after (post-immunization) the introduction of the Hib vaccine. The post-immunization period was divided into three similar periods.Eighty-five patients with Hib meningitis were admitted (73.3% in the pre-immunization period). No differences were observed in relation to the clinical and sociodemographic characteristics of cases in both periods. Pre-immunization: 10.5 cases/year; postimmunization: 0.7 cases/year. As of 2014, the rate has increased. Lethality rate: 4.8% (all preimmunization). Post-immunization data (n= 15): 40% had completed their primary immunization schedule, 40% were delayed on the immunization schedule for their age. Overall reduction in the hospital rate of Hib meningitis by 89.8% (95% confidence interval: -82.79-93.96%, p0.001) in the post-immunization period. The analysis of the different post-immunization periods shows a decline in reduction over time.A very significant reduction in hospitalizations due to Hib meningitis was observed after the Hib vaccine was introduced; however, over the past years, the number of cases has increased although no changes have been observed in patient characteristics.Haemophilus influenzae b era la principal causa de meningitis bacteriana en menores de 5 años. Después de la introducción de la vacuna al calendario (1998), se observó un descenso significativo de la incidencia, pero, en los últimos años, hubo un aumento. Los objetivos de este estudio fueron describir las características y analizar la curva epidémica de los casos de meningitis por Haemophilus influenzae b (MHib) comparando los períodos pre- y posvacunación.Estudio de series temporales. Se incluyeron todos los pacientes internados por MHib en el Hospital de Niños "R. Gutiérrez" (enero de 1992-mayo de 2016). Se compararon las tasas de hospitalización antes (prevacunación) y después (posvacunación) de la introducción de la vacuna. Se dividió la etapa posvacunación en tres períodos similares.Fueron admitidos 85 pacientes con MHib (73,3% prevacunación). Las características clínicas y sociodemográficas de los casos en ambos períodos no mostraron diferencias. Prevacunación: 10,5 casos/año; y posvacunación: 0,7 casos/año. A partir de 2014, se observó un aumento. Tasa de letalidad: 4,8% (todos prevacunación). Datos posvacunación (n= 15): 40% del esquema primario completo, 40% del esquema atrasado para la edad. Reducción global de la tasa hospitalaria de MHib de 89,8% (IC 95%: -82,79-93,96%; p0,001) en el período posvacunación. Al analizar los diferentes períodos posvacunación, se observa una caída en la reducción a lo largo del tiempo.Se observó una disminución muy importante de las hospitalizaciones por MHib pos introducción de la vacuna, pero, en los últimos años, se evidenció un aumento de estos casos sin modificaciones en las características de los pacientes.

Background Human enteroviruses are one of the major causes of central nervous system (CNS) infections in pediatrics. Study design We have studied 1242 children under 15 years old with suspicion of CNS infection from January 1998 to December 2003. CSF was obtained and molecular typing of human enterovirus B serotypes was performed by RT-PCR and sequencing of the N-terminal part of VP1 gene. Results According to the clinical syndromes, patients were grouped as aseptic meningitis ( n = 654, 52.6%), encephalitis ( n = 239, 19.2%), febrile seizures ( n = 153, 12.3%), febrile infant ( n = 84, 6.7%), neonatal disease ( n = 70, 5.6%),), acute flaccid paralysis ( n = 31, 2.4%) and acute disseminated encephalomyelitis ( n = 11, 0.9%). HEV was detected in 335/1242 CSF samples (26.97%) and was associated to aseptic meningitis ( n = 243, 72.5%); febrile infant ( n = 31, 9.2%); neonatal infection ( n = 26, 7.7%); encephalitis ( n = 25, 7.5%), febrile seizures ( n = 9, 2.68%); acute flaccid paralysis ( n = 1, 0.3%). Seasonal incidence of HEV-B species was analyzed showing that in Buenos Aires infections occur mainly during late spring and summer. Molecular serotyping was completed in 60/335 samples. Echovirus 30, Echovirus 9, Coxsackie B3 to B5 and Echovirus 33 were the most frequently identified. Conclusions We showed that HEV are responsible for a considerable proportion of hospitalizations in children with central nervous system compromise reaching 27% of overall etiology.