Colonização de orofaringe por Streptococcus pneumoniae em crianças de creches municipais de Taubaté-SP: correlação entre os principais sorotipos e a vacina pneumocócica conjugada heptavalente

Abstract

Objective: Streptococcus pneumoniae usually colonizes the oropharynx of healthy people. Oropharyngeal carriage is related to the invasion of adjacent structures and to the development of invasive disease. A descriptive cross-sectional study was performed aiming at verifying the prevalence of oropharyngeal colonization by S. pneumoniae in children attending day care centers in the city of Taubaté -SP; verifying the frequency of S. pneumoniae serotypes in isolated strains; and relating the most frequent serotypes to the composition of the conjugated heptavalent pneumococcal vaccine currently in use.Methods: from June 29 to December 15 1998, samples of oropharyngeal material were collected from 987 children, ranging from 8 to 71 months old, enrolled in day care centers in Taubaté -SP. The identification of S. pneumoniae was based on the observation of the colonies that presented partial hemolysis in agar-blood and agarblood with gentamycin plates and on the observation of inhibited growth around the optochin disc. Serotyping was performed by the Quellung reaction, using specific antiserum, provided by the Centers for Disease Control and Prevention (Atlanta, GA/USA), and the Danish nomenclature system.Results: as a result, S. pneumoniae was isolated from the oropharynx in 209 out of 987 children (colonization rate of 21.2%). Twenty eight serotypes were identified. The seven most frequent serotypes were: 6A/6B (21.5%), 19F (14.8%), 18C (7.4%), 23F (7.4%), 9V (6.7%), 14 (5.2%), 10A (4.4%). Except for serotype 10A, all the other six are included in the vaccine. The only vaccine serotype which was not found was serotype 4.Conclusion: agreement of 63% between the oropharynx colonizer serotypes and the serotypes present in the vaccine was found. ResumoObjetivos: o Streptococcus pneumoniae habitualmente coloniza a orofaringe de pessoas sadias. O estado de portador assintomático está relacionado à invasão de estruturas adjacentes e ao surgimento de doença invasiva. Foi realizado estudo transversal, descritivo, objetivando verificar a prevalência de colonização de orofaringe pelo S. pneumoniae em crianças que freqüentam creches no município de Taubaté, SP, verificar a freqüência de sorotipos de Streptococcus pneumoniae nas cepas isoladas e relacionar os sorotipos mais freqüen-tes com os sorotipos presentes na composição da vacina pneumocócica heptavalente conjugada atualmente em uso.Métodos: foram coletados, de 29 de junho a 15 de dezembro de 1998, 987 swabs de orofaringe de crianças entre 8 e 71 meses de idade, matriculadas nas creches municipais de Taubaté, SP. A identificação do S. pneumoniae foi baseada na observação das colônias que apresentassem hemólise parcial nos meios AS e AS-G, e pela observação da inibição do crescimento ao redor do disco de optoquina. A sorotipagem foi realizada pela reação de Quellung, utilizando anti-soros específi-cos, e adotado o sistema de nomenclatura dinamarquês.Resultados: o Streptococcus pneumoniae foi isolado em 209 das 987 crianças (taxa de colonização= 21,1%). Vinte e oito s...

Doença pneumocócica invasiva em crianças e adolescentes soropositivos para HIV

“…The majority of these refer to colonization of the airways by Sp, since the difficulties in isolating the bacteria from cultures from people with pneumonia are well known. 4,[9][10][11][12][13] The only study published in Brazil on Sp serotypes identified from HIV+ children demonstrated that nasopharyngeal colonization of 112 children was no greater than that described in the literature for healthy children. 3 In our study, serotype 14 was the most frequent (four cases) and was also the serotype that exhibited greatest resistance to penicillin, which confirms data published in Brazilian literature.…”

Impacto da vacina conjugada contra Streptococcus pneumoniae em doenças invasivas

“…In Brazil, several studies have shown a colonization rate of about 40% in children less than 2 years of age. [31][32][33][34] Conjugate vaccines reduce the pneumococcus colonization rates and consequently the transmission of these bacteria in the community, thus playing a relevant role in herd immunity. This is important, although there is antibiotics.…”

“…In addition to this, it should be pointed out that over 95% of the strains resistant to penicillin are represented in this vaccine. [28][29][30][31][32][33][34][35][36][37][38][39][40] Therefore, it is expected that Pnc7 vaccine implementation could reduce not only the incidence of IPD, but also the dissemination of resistant strains (mainly ST14).…”

Impact of the antipneumococcal conjugate vaccine on the occurrence of infectious respiratory diseases and hospitalization rates in children

“…Global pneumococcal resistance to antibiotics is approximately 19%, according to the international criteria of the Clinical and Laboratory Standards Institute (CLSI) (9) . In Brazil, the reported resistance rate ranges from 21.2% to 55% for children 8-71 months of age and 19% to 43% in the general population (10) , with a reported pneumococcal colonization rate of 21% and 35.8% in children in States of São Paulo and Goiás, respectively (11) (12) . Other publications have reported colonization rates of 40% in children younger than 2 years old, with highest prevalence during the fi rst year of life (10) (11) (13) .…”