Laboratory surveillance of invasive Haemophilus influenzae disease in Argentina, 2011-2019.

The incorporation of Haemophilus influenzae type b (Hib) vaccine into the Argentine National Immunization Program in 1998 resulted in a dramatic decrease in the incidence of invasive disease due to this serotype. We assessed 1405 H. influenzae (Hi) isolates causing invasive infections referred to the National Reference Laboratory between 2011 and 2019.

Invasive Streptococcus pneumoniae isolates from pediatric population in Argentina for the period 2006-2019. Temporal progression of serotypes distribution and antibiotic resistance.

Streptococcus pneumoniae is a major cause of severe invasive disease associated with high mortality and morbidity worldwide. A total of 2908 pneumococcal isolates were analyzed between 2006 and 2019. Gold standard pneumococcal serotyping (the Neufeld-Quellung reaction) was performed to identify the serotypes associated with infection in children < 5 years in Argentina and agar dilution method was carried out to determine their profiles to 14 antimicrobial agents.

Population genetic structure, serotype distribution and antibiotic resistance of causing invasive disease in children in Argentina.

Invasive disease caused by (IPD) is one of the leading causes of morbidity and mortality in young children worldwide. In Argentina, PCV13 was introduced into the childhood immunization programme nationwide in 2012 and PCV7 was available from 2000, but only in the private market. Since 1993 the National IPD Surveillance Programme, consisting of 150 hospitals, has conducted nationwide pneumococcal surveillance in Argentina in children under 6 years of age, as part of the SIREVA II-OPS network.

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.

The direct effect of pneumococcal conjugate vaccines on invasive pneumococcal disease in children in the Latin American and Caribbean region (SIREVA 2006-17): a multicentre, retrospective observational study.

Background: Streptococcus pneumoniae isolated from patients with invasive pneumococcal disease has been subjected to laboratory-based surveillance in Latin American and Caribbean countries since 1993. Invasive pneumococcal diseases remain a major cause of death and disability worldwide, particularly in children. We therefore aimed to assess the direct effect of pneumococcal conjugate vaccines (PCVs) on the distribution of pneumococcal serotypes causing invasive pneumococcal disease in children younger than 5 years before and after PCV introduction.

Distribution of PCV13 and PPSV23 Streptococcus pneumoniae serotypes in Argentinean adults with invasive disease, 2013-2017.

Streptococcus pneumoniae is a major cause of severe invasive disease associated with high mortality and morbidity worldwide. To identify the serotypes most commonly associated with infection in adults in Argentina, 791 pneumococcal isolates from 56 hospitals belonging to 16 provinces and Buenos Aires city were serotyped. The isolates were submitted as part of a National Surveillance Program for invasive pneumococcal disease in adults, which started in 2013.

Community acquired pneumonia incidence among children less than 5 years of age in Concordia, Argentina: vaccination impact.

Objective: To measure the effectiveness of pneumococcal conjugated vaccine (PCV13) against Community Acquired Pneumonia (CAP) and invasive pneumococcal disease, 2 years after the vaccine (2+1) was included into the National Immunization Program of Argentina, and to describe variables associated with bacterial pneumonia and hospitalization.

Methods: This was a prospective, population-based surveillance study of CAP incidence (ambulatory and hospitalized) among children less than 5 years of age in the Department of Concordia (Entre Rios, Argentina) from April 2014 - March 2016. The diagnosis of probable bacterial pneumonia (PBP) was determined following the standardized WHO protocol.

Characterization of Streptococcus pneumoniae invasive serotype 19A isolates from Argentina (1993-2014).

The aim of this study was to characterize Streptococcus pneumoniae serotype 19A isolates causing invasive pneumococcal disease in children, collected in Argentina between 1993 and 2014. A total of 176 isolates serotype 19A were analyzed. There was an increase in the proportion of serotype 19A isolates from 3% in 1993 to 6% in 2011, prior to the introduction of PCV13 in 2012, and from 2012 to 2014 its proportion gradually decreased.

[Infection by Bordetella pertussis and bordetella parapertussis in cases of suspected whooping cough (2011-2015) in Mar del Plata, Argentina].

Objectives: . To classify the study population in the Argentinian National Health Surveillance System framework, determine the proportion of infection by Bordetella pertussis and Bordetella parapertussis, and identify factors associated with the cases of suspected whooping cough attended to in the city of Mar del Plata and its outskirts during the period 2011- 2015.

Materials And Methods: An observational and descriptive study was carried out.

Meningococcal Disease in Children in Argentina A 3-year Active Sentinel Hospital Surveillance Study.

Background: Meningococcal disease (MD) is a medical emergency and a serious public health problem. As new meningococcal vaccines become available, MD surveillance is crucial to provide baseline epidemiologic data before implementing preventive measures. We estimated MD incidence and epidemiology in Argentina using hospital-based surveillance.

[Pneumococcal meningitis in children under 15 years of age in Misiones (Argentina). Sixteen year's epidemiological surveillance].

We report the results of pneumococcal meningitis surveillance conducted at the Provincial Pediatric Hospital of Posadas, Misiones (Argentina), before the conjugate vaccine was introduced into the national vaccination schedule. Between January 1994 and December 2009, 167 cases of Streptococcus pneumoniae meningitis were diagnosed in children aged 1 month to 15 years. The attack rate/100,000 children ranged from 19.

[Surveillance of Haemophilus influenzae serotypes in Argentina from 2005 to 2010 during the Haemophilus influenzae type b conjugate vaccine era].

The introduction of the Haemophilus influenzae type b vaccine in the immunization programs of many countries has greatly reduced this invasive disease and the carriage caused by this serotype, also increasing other capsular types and non-capsular isolations. There were 313 isolations of H. influenzae under study, which were recovered from a sterile site coming from pediatric and adult patients carrying the invasive disease.

Serotype distribution of pneumococci isolated from pediatric patients with acute otitis media and invasive infections, and potential coverage of pneumococcal conjugated vaccines.

A 16-month prospective, descriptive study was conducted on pneumococcal serotype distribution isolated from children with acute otitis media (AOM) and invasive infections (INV). Eighty-nine children with pneumococcal INV and 324 with a first episode of AOM were included. Bacterial pathogens (N = 326) were isolated from the middle-ear fluid of 250 patients.

Phenotypic and genotypic characteristics of Neisseria meningitidis disease-causing strains in Argentina, 2010.

Phenotypic and genotypic characterization of 133 isolates of Neisseria meningitidis obtained from meningococcal disease cases in Argentina during 2010 were performed by the National Reference Laboratory as part of a project coordinated by the PAHO within the SIREVA II network. Serogroup, serotype, serosubtype and MLST characterization were performed. Minimum Inhibitory Concentration to penicillin, ampicillin, ceftriaxone, rifampin, chloramphenicol, tetracycline and ciprofloxacin were determined and interpreted according to CLSI guidelines.

Laboratory-based surveillance of Neisseria meningitidis isolates from disease cases in Latin American and Caribbean countries, SIREVA II 2006-2010.

Background: Published data on the epidemiology of meningococcal disease in Latin America and the Caribbean region is scarce and, when available, it is often published in Spanish and/or in non-peer-reviewed journals, making it difficult for the international scientific community to have access.

Methods: Laboratory data on 4,735 Neisseria meningitidis strains was collected and reported by the National Reference Laboratories in 19 Latin American countries and the Caribbean Epidemiology Centre (CAREC) between 2006 and 2010 as part of the work carried out by the SIREVA II network. Serogroup and MIC to penicillin, rifampin and chloramphenicol were determined.

Impact of vaccination against Haemophilus influenzae type b with and without a booster dose on meningitis in four South American countries.

To inform World Health Organization recommendations regarding use of Haemophilus influenzae type b (Hib) vaccines in national immunization programs, a multi-country evaluation of trends in Hib meningitis incidence and prevalence of nasopharyngeal Hib carriage was conducted in four South American countries using either a primary, three-dose immunization schedule without a booster dose or with a booster dose in the second year of life. Surveillance data suggest that high coverage of Hib conjugate vaccine sustained low incidence of Hib meningitis and low prevalence of Hib carriage whether or not a booster dose was used.

Dissemination of an erythromycin-resistant penicillin-nonsusceptible Streptococcus pneumoniae Poland(6B)-20 clone in Argentina.

Prevalence of serotype 6B penicillin (PEN)-nonsusceptible Streptococcus pneumoniae significantly increased from 15.8% (1993-1997) to 67.3% (1998-2002) (p<0.

[Pneumococcal surface protein A (PspA) families. Relation with serotypes and clinical site of infection].

PspA, a pneumococcal surface protein, is highly immunogenic and common to all serotypes. Although pspA gene shows a great heterogeneity at the N-terminal region, PspA protein has conserved epytopes which are able to elicit protective cross-reaction against various serotypes presenting different PspA. In spite of the high polimorfism of the PspA, three majority families can be identified.

[Whooping cough: clinical and epidemiological characteristics of 20 confirmed cases of the Paediatric Hospital of Misiones province].

Pertussis or whooping cough is a respiratory disease that has emerged in recent years in several countries including Argentina. The aim is to retrospectively describe clinical and epidemiological characteristics of 20 patients in the Pediatric Hospital of Misiones with confirmed diagnosis of whooping cough, according to criteria set by WHO and CDC, during the years 2005 and 2006. The median age was 4 months, 13 were male (65%).

Laboratory-based surveillance of Streptococcus pneumoniae invasive disease in children in 10 Latin American countries: a SIREVA II project, 2000-2005.

Background: For the last 14 years the Pan American Health Organization has been promoting surveillance of invasive pneumococcal disease in Latin American children for better understanding of the disease tendencies regarding capsular types circulation in each country and susceptibility to antimicrobials.

Methods: Laboratory-based surveillance data from 10 Latin American countries collected from 2000 to 2005 were analyzed, including serotype distribution and susceptibility to beta-lactam antibiotics.

Results: Although 61 different capsular types were identified during the 6-year surveillance, 13 serotypes accounted for 86% of all isolates.

Molecular characterization of invasive serogroup Y Neisseria meningitidis strains isolated in the Latin America region.

Objectives: To improve the understanding of serogroup Y invasive meningococcal disease (IMD) in Latin America, particularly IMD molecular epidemiology; 166 Y serogroup isolates received at the National Reference Laboratories of Argentina, Brazil, Chile, Colombia, and Costa Rica during 2000-2006 were characterized by their molecular markers.

Methods: This analysis included serological assays to determine serogroup/serotype/serosubtype, DNA sequencing and genotyping of the porB and/or porA genes, multilocus sequence typing (MLST) and fetA allele determination.

Results: Sixteen different antigenic combinations were observed.

[Resistance to non-beta-lactam antibiotics in the clinical isolates of Streptococcus pneumoniae of children in Latin America. SIREVA II, 2000-2005].

Objective: To examine the development of resistance to erythromycin, chloramphenicol, trimethoprim-sulfamethoxazole (TMP-SMZ), and vancomycin of the invasive isolates of Streptococcus pneumoniae obtained from children in 10 Latin American/Caribbean countries during six years of surveillance.

Methods: Analysis of 8 993 isolates of S. pneumoniae recovered in 2000-2005 from children with invasive infections, who were less than 6 years of age, and from Argentina, Brazil, Chile, Colombia, Cuba, Dominican Republic, Mexico, Paraguay, Uruguay, or Venezuela.

Characterization of in vitro-generated and clinical optochin-resistant strains of Streptococcus pneumoniae isolated from Argentina.

Optochin susceptibility is a key test used for pneumococcal diagnosis, but optochin-resistant (Opt(r)) pneumococci have been reported in the last 2 decades. In this work, we characterized eight Opt(r) clinical strains which presented a new mutation, G47V, a predominant A49S mutation (recently reported in Brazil) and A49T. These mutations were found in the c subunit of the F(0)F(1) ATPase encoded by the atpC gene, and W206C was found in the a subunit encoded by the atpA gene.

PorA types in Neisseria meningitidis serogroup B isolated in Argentina from 2001 to 2003: implications for the design of an outer membrane protein-based vaccine.

Identification of Neisseria meningitidis PorA types remains important, as the PorA protein is a major immunogenic component of several meningococcal vaccines under development. In this study, 191 N. meningitidis serogroup B isolates collected in Argentina through active laboratory-based surveillance from 2001 to 2003 were serosubtyped.