AUTHOR=Horácio Andreia N. , Silva-Costa Catarina , Lopes Joana P. , Ramirez Mário , Melo-Cristino José , Portuguese Group for the Study of Streptococcal Infections , Vaz Teresa , Gião Marília , Ferreira Rui , Fonseca Ana Buschy , Oliveira Henrique , Silva Ana Cristina , Costa Hermínia , Silva Maria Fátima , Afonso Maria Amélia , Pinto Margarida , Chantre Odete , Marques João , Peres Isabel , Daniel Isabel , Canas Ema , Ferreira Teresa , Marcelo Cristina , Monteiro Lurdes , Lito Luís Marques , Martins Filomena , Ana Pessanha Maria , Gonçalves Elsa , Morais Teresa , Marques Teresa , Toscano Cristina , Lopes Paulo , Felício Luísa , Lameirão Angelina , Mota Vieira Ana Paula , Tomaz Margarida , Bento Rosa , Ramos Maria Helena , Ana Paula Castro , Fonseca Fernando , Castro Ana Paula , Ribeiro Graça , Tomé Rui , Pontes Celeste , Boaventura Luísa , Chaves Catarina , Reis Teresa , Canhoto Nuno , Afonso Teresa , Pina Teresa , Peres Helena , Fontes Ilse , Martinho Paulo , Domingos Ana , Marrão Gina , Grossinho José , Ribeiro Manuela , Gonçalves Helena , Faustino Alberta , Alves Adelaide , Iglesias Maria Cármen , Pinheiro Maria Paula , Semedo R. , Coutinho Adriana , Cabral Luísa , Neto Olga , Sancho Luísa , Diogo José , Rodrigues Ana , Nascimento Isabel , Ramalheira Elmano , Bessa Fernanda , Diaz Raquel , Vale Isabel , Carvalho Ana , Ribeiro José Miguel , Read Maria Antónia , Alves Valquíria , Monteiro Margarida , Raposo Engrácia , Magalhães Maria Lurdes , Rochas Helena , Silva Anabela , Rodrigues Margarida , Mota Freitas José , Vieira Sandra , Meneses Maria Favila , de Sousa José Germano , Viana Mariana Bettencourt , Terra Isaura , Rodrigues Vitória , Pereira Patrícia , Duarte Jesuína , Pinto Paula , Moreira Ezequiel , Ferreira João Ataíde , Vicente Adília , Paixão Paulo , Novais Natália TITLE=Serotype 3 Remains the Leading Cause of Invasive Pneumococcal Disease in Adults in Portugal (2012–2014) Despite Continued Reductions in Other 13-Valent Conjugate Vaccine Serotypes JOURNAL=Frontiers in Microbiology VOLUME=7 YEAR=2016 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01616 DOI=10.3389/fmicb.2016.01616 ISSN=1664-302X ABSTRACT=

Since 2010 the 13-valent pneumococcal conjugate vaccine (PCV13) replaced the 7-valent vaccine (PCV7) as the leading pneumococcal vaccine used in children through the private sector. Although, neither of the PCVs were used significantly in adults, changes in adult invasive pneumococcal disease (IPD) were expected due to herd protection. We characterized n = 1163 isolates recovered from IPD in adults in 2012–2014 with the goal of documenting possible changes in serotype prevalence and antimicrobial resistance. Among the 54 different serotypes detected, the most frequent, accounting for half of all IPD, were serotypes: 3 (14%), 8 (11%), 19A (7%), 22F (7%), 14 (6%), and 7F (5%). The proportion of IPD caused by PCV7 serotypes remained stable during the study period (14%), but was smaller than in the previous period (19% in 2009–2011, p = 0.003). The proportion of IPD caused by PCV13 serotypes decreased from 51% in 2012 to 38% in 2014 (p < 0.001), mainly due to decreases in serotypes 7F and 19A. However, PCV13 serotype 3 remained relatively stable and the most frequent cause of adult IPD. Non-PCV13 serotypes continued the increase initiated in the late post-PCV7 period, with serotypes 8 and 22F being the most important emerging serotypes. Serotype 15A increased in 2012–2014 (0.7% to 3.5%, p = 0.011) and was strongly associated with antimicrobial resistance. However, the decreases in resistant isolates among serotypes 14 and 19A led to an overall decrease in penicillin non-susceptibility (from 17 to 13%, p = 0.174) and erythromycin resistance (from 19 to 13%, p = 0.034). Introduction of PCV13 in the NIP for children, as well as its availability for adults may further alter the serotypes causing IPD in adults in Portugal and lead to changes in the proportion of resistant isolates.