Impacto de Streptococcus pneumoniae en las neumonias del niño latinoamericano
Impact of Streptococcus pneumoniae in Latin American children
Rev. panam. salud pública; 8 (3), 2000
Publication year: 2000
La neumonia adquirida en la comunidad es una de las principales causas de morbilidad y mortalidad en la infancia. Estudios realizados en paises en desarrollo indican que los cuadros de neumonia mas graves se asocian a causas bacterianas, con predominio de Streptococcus pneumoniae, seguido por Haemophilus influenzae tipo b. El manejo de esas infecciones en los menores de 2 años se ve dificultado por la carencia de vacunas apropiadas y por la disminucion de la susceptibilidad de S. pneumoniae a la penicilina y a otros antibioticos. En 1993, por iniciativa del Sistema Regional de Vacunas (SIREVA) de la Organizacion Panamericana de la Salud y con la financiacion de la Agencia Canadiense para el Desarrollo Internacional (Canadian International Development Agency: (CIDA), se diseño un estudio para identificar los tipos capsulares de S. pneumoniae que causan enfermedad invasora en los niños latinoamericanos menores de 5 años, con el proposito de determinar tanto la composicion ideal de una vacuna conjugada que pudiera emplearse en la Region como la susceptibilidad a la penicilina de los aislados de S. pneumoniae. La iniciativa fue aceptada por Argentina, Brasil, Colombia, Chile, Mexico y Uruguay. En este informe se analiza la informacion sobre la neumonia por S. pneumoniae generada en los paises participantes. Se captaron 3.393 niños con infecciones sistemicas por S. pneumoniae, de las cuales 1.578 correspondian a neumonias. El analisis se concentro en los 1.409 casos de neumonia de Argentina, Brasil, Colombia, Mexico y Uruguay. La distribucion por edades evidencio un franco predominio de los menores de 2 años (63.8 por ciento). Se identificaron 12 tipos capsulares prevalentes, de los cuales los serotipos 14, 5 y 1 ocuparon los tres primeros lugares en la mayoria de los paises
Community-acquired pneumonia is one of the leading causes of infant morbidity and
mortality. Studies conducted in developing countries indicate that the most serious
symptoms of pneumonia are associated with bacterial causes, mainly Streptococcus
pneumoniae, followed by Haemophilus influenzae type b. Managing those infections in
children under two years of age is hindered by the lack of appropriate vaccines and
by the decreased susceptibility of S. pneumoniae to penicillin and other antibiotics. In
1993, at the initiative of the Regional System for Vaccines of the Pan American Health
Organization, and with funding from the Canadian International Development
Agency, a study was designed to identify the S. pneumoniae capsular types that cause
invasive disease in Latin American children under 5 years of age. The objective of the
study was to determine the ideal composition of a conjugate vaccine that could be
used in Latin America, and the penicillin susceptibility of the S. pneumoniae isolates.
The initiative was undertaken in Argentina, Brazil, Chile, Colombia, Mexico, and
Uruguay. This report analyzes the information that the participating countries generated on pneumococcal pneumonia. A total of 3 393 children were found with systemic
S. pneumoniae infections, of which 1 578 corresponded to pneumonias. The analysis
focused on 1 409 cases of pneumonia in Argentina, Brazil, Colombia, Mexico, and
Uruguay. Of the children, 63.8% of them were under two years of age. Twelve prevalent capsular types were identified, of which serotypes 14, 5, and 1 were the three
most common in the majority of the countries. At the beginning of the study the highest level of penicillin resistance was found in Mexico (47.0%), and the lowest in
Colombia (12.1%). Over the 1993–1998 period, resistance to penicillin increased in the
five countries. Penicillin resistance was associated with a small number of capsular
serotypes, mainly 14 and 23F. The first of those serotypes was resistant to penicillin
and to trimethoprim-sulfamethoxazole, and the second was multiresistant. The frequency of resistance to trimethoprim-sulfamethoxazole was high in all of the countries; Argentina had the highest level, 58.0%. A decrease in susceptibility to chloramphenicol was uncommon, except in Colombia, where there was a resistance level of
23.4%. Resistance to erythromycin was low in all the countries, and all the isolates
were susceptible to vancomycin.