Epidemiological Surveillance Study ofStreptococcus pneumoniaein Latin America: Serotype Distribution. A Pan American Health Organization Initiative

Streptococcus pneumoniae causes a variety of clinical conditions, including pneumonia, meningitis, bacteremia and otitis media. This micro-organism is the most common single bacterial agent responsible for respiratory tract infections . Each year, more than one million children are estimated to die each year from pneumococcal pneumonia , half of whom are infants younger than one year of age. Current efforts to prevent mortality and morbidity due to pneumococcal infections in children are focused on early diagnosis and prompt antimicrobial therapy; however, the spread of antimicrobial resistance is leading to the research of new complementary strategies, such as vaccination. Unfortunately, the available 23-valent pneumococcal vaccine is not recommended for children younger than two years of age due to the vaccine's poor immunogenicity. The development of an adequate pneumococcal vaccine for a particular region will depend on the existence of detailed , reliable and representative data on the prevalence and serotype distribution of S pneumoniae. In Latin America, published data on this issue are scarce. Recognizing this problem, the Pan American Health Organization, through its Special Program for Vaccines and Immunization and Sistema Regional de Vacunas, with major funding from the Canadian International Development Agency, designed and implemented an intercountry and multiinstitutional collaborative study in six Latin American countries . The objectives of the collaborative study were to determine the prevalence of capsular types of S pneumoniae that cause invasive disease, particularly pneumonia, in children younger than five years of age; to monitor the patterns of susceptibility to penicillin and other antibiotics; to establish and strengthen regional laboratory facilities and epidemiological capabilities for monitoring capsular types, subtypes and antimicrobial susceptibility; and to create a bank of isolates that could be used for further research.