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In 1993 the Pan American Health Organization initiated a laboratory-based surveillance system, called the SIREVA project, to learn about Streptococcus pneumoniae invasive disease in Latin American children. In 1994, National Laboratories in six countries were trained to perform serotyping and antibiotic susceptibility testing using broth microdilution to determine the MIC for specified antibiotics. An international External Quality Assurance (EQA) program was developed to monitor and support ongoing laboratory performance. The EQA program was coordinated by the National Centre for Streptococcus (NCS), Edmonton, Canada, and included external proficiency testing (EPT) and a validation process requiring regular submission of a sample of isolates from each laboratory to the NCS for verification of the serotype and MIC. In 1999, the EQA program was decentralized to use three of the original laboratories as regional quality control centers to address operational concerns and to accommodate the growth of the laboratory network to more than 20 countries including the Caribbean region. The overall EPT serotyping accuracies for phase I (1993 to 1998) and phase II (1999 to 2005) were 88.0 and 93.8%, respectively; the MIC correlations within ؎1 log 2 dilution of the expected result were 83.0 and 91.0% and the interpretive category agreements were 89.1 and 95.3%. Overall, the validation process serotyping accuracies for phases I and II were 81.9 and 88.1%, respectively, 80.4 and 90.5% for MIC agreement, and 85.8 and 94.3% for category agreement. These results indicate a high level of testing accuracy in participating National Laboratories and a sustained increase in EQA participation in Latin America and the Caribbean.The impact of childhood pneumonia caused by Streptococcus pneumoniae in the developing world is well recognized; however, until recently, the epidemiology of invasive pneumococcal disease in Latin America was poorly documented (3, 4, 8). The growing rates of antibiotic-resistant S. pneumoniae worldwide, combined with the promise of new conjugate pneumococcal vaccines, prompted the Pan American Health Organization/World Health Organization (PAHO/WHO) to initiate an international laboratory-based surveillance network that would provide prospective regional serotype prevalence data, antibiotic resistance rates, and epidemiology of invasive pneumococcal disease in Latin American children. In 1993, with significant funding from the Canadian International Development Agency, the National Centre for Streptococcus (NCS), Edmonton, Alberta, Canada, and the Laboratory Centre for Disease Control, Ottawa, Ontario, Canada, were recruited to provide laboratory and epidemiological support for this new project (3,4,8). As part of the PAHO/WHO Sistema Regional de Vacunas, the project became known as SIREVA (8).The establishment of specific goals to guide the SIREVA project was integral to successful development of the quality program: (i) to produce study data accepted as valid by the international community; (ii) to create an ...

A percentage of annual decline of serotypes causing IPD and NIPD included in PCV was detected among groups not targeted to receive the vaccine, probably due to herd effect. Considering pneumococcal serotype distribution is a dynamic process, we highlight the importance of surveillance programs.

No abstract

During a surveillance study to determine the relative prevalence of capsular types of Streptococcus pneumoniae and antimicrobial susceptibility of invasive isolates in children <5 years old in Mexico City, 220 isolates were collected. The serotype 23F was the most common found, followed by types 6A + B, 14, 19F, and 19A. Diminished susceptibility to penicillin was detected in 106 isolates (48.2%), and high penicillin resistance was found in 49 strains (22.2%), 31 belonging to type 23F. Resistance was also observed to erythromycin (13.1%), to chloramphenicol (43.1%), and to cefotaxime (10.9%). No strains were resistant to ofloxacin or vancomycin. Forty-four of the highly penicillin resistant isolates (penicillin MIC > or =2.0 microg/ml) were examined with molecular fingerprinting techniques; 29 (65.9%) of these isolates (all except two strains) were serotype 23F and shared subtype variants of PFGE type A characteristic of the internationally spread Spanish/USA clone of S. pneumoniae. These strains were also resistant to trimethoprim/sulfametoxasole (TMP/SMX), chloramphenicol, and tetracycline, and most of them were susceptible to erythromycin. Another 6 of the highly penicillin-resistant strains (serogroups 9 and 14) showed PFGE fingerprints and antimicrobial susceptibility pattern characteristic of a second internationally spread clone (French/Spanish clone) and carried resistance to penicillin and TMP/SMX. The rest of the 9 penicillin-resistant isolates were represented by 7 distinct additional PFGE types. The findings suggest that almost 80% of all highly penicillin resistant strains may have been "imported" into Mexico.