@entity328 Serotypes Identified in Mexican XXXX with Invasive Disease before and After the Introduction of PCV7 (1993-2012).

@entity1 @entity295 @entity697 @entity55 @entity2260 @entity5686 @entity693 @entity3 @entity328
BACKGROUND AND AIMS: @entity328 is the leading cause of @entity697 , @entity55 , @entity693 , and @entity295 . The heptavalent pneumococcal conjugate vaccine (PCV7) was incorporated into the national immunization program in Mexico in 2008. The aim of the study was to analyze the frequency of @entity2260 serotypes isolated from @entity1  <=5  years of age with @entity3 before and after the introduction of PCV7. METHODS: Isolates from sterile fluids, tissues and other body fluids were obtained from 1993 to 2012. Isolates collected in hospitals for the surveillance network were sent to the Instituto Nacional de Salud Publica. Serotyping was done using the Quellung reaction. The pre-vaccination period was considered from 1993-2007. RESULTS: A total of 1346 isolates were collected during 1993-2012. In the pre-vaccination era, serotypes included in PCV7 accounted for 59.7% of the strains, whereas in 2012 they represented only 21% of cases. There was a significant decrease in all PCV7-included serotypes. A gradual increase of the @entity5686 serotype was detected during the vaccination period from 7% in 2008 to 39% of the isolates in 2012. In this year, 29% of the serotypes causing invasive disease were not included in any of the pneumococcal conjugate vaccines. CONCLUSION: The emergence of PCV7 non-included serotypes after vaccination demands increased surveillance. Currently in Mexico, the 13-valent conjugate vaccine (PCV13) offers better coverage than the 10-valent pneumococcal conjugate vaccine (PCV10).
