Evolution of Streptococcus pneumoniae serotypes and penicillin susceptibility in Latin America, Sireva-Vigia Group, 1993 to 1999

Background. Since 1993 the Pan American Health Organization has coordinated a surveillance network with the National Reference Laboratories of Argenti na, Brazil, Chile, Colombia, Mexico and Uruguay aimed at monitoring capsula r types and antimicrobial susceptibility of Streptococcus pneumoniae causin g invasive disease in children <6 years of age. Methods. The surveillance system included children 6 years of age and young er with invasive disease caused by S. pneumoniae. The identification, capsu lar typing and susceptibility to penicillin of the isolates were conducted using a common protocol, based on standard methodologies. Results. By June, 1999, 4105 invasive pneumococcal isolates had been collec ted mainly from pneumonia (44.1%) and meningitis (41.1%) cases. Thirteen ca psular types accounting for 86.1% of the isolates (14,6A/6B, 5,1,23F, 19F, 18C, 19A, 9V, 7F, 3, 9N and 4) remained the most common types during the su rveillance period. Diminished susceptibility to penicillin was detected in 28.6% of the isolates, 17.3% with intermediate and 11.3% with high level re sistance. Resistance varied among countries and increased during this perio d in Argentina, Colombia and Uruguay. Serotypes 14 and 23F accounted for 66 .6% of the resistance. Conclusion. These surveillance data clearly demonstrate the potential impac t of the introduction of a conjugate vaccine on pneumococcal disease and th e need for more judicious use of antibiotics to slow or reverse the develop ment of antimicrobial resistance.