ABSTRACT

1. High Case Fatality Rates of Invasive Pneumococcal Disease (IPD) in Hospitalized Children in Lima, Perú Theresa Ochoa1, Martha Egoavil1, María Castillo2, Isabel Reyes3, Eduardo Chaparro4, Roger Hernandez4, Wilda Silva5, Francisco Campos6, Humberto Guerra1 and the Peruvian Research Group on Pneumococcus (GPIN). 1Univ.Peruana Cayetano Heredia, 2Inst. Nacional de Salud del Niño, 3Hosp. Emergencias Pediátricas, 4Hosp. Cayetano Heredia, 5Hosp. Rebagliati-EsSalud, 6Hosp. San Bartolomé. ABSTRACT Background. It has been estimated that 2 children die every hour due to pneumococcal disease in Latin America.It is important to determine the burden of invasive pneumococcal disease (IPD) in order to develop locally apropiate vaccine strategies.Methods. We conducted a 2-year multicenter, passive surveillance study in 16 hospitals in Lima, Perú. Data were collected from patients <16 yr of age with sterile site cultures yielding pneumococcus. Antibiotic susceptibility was performed by E-test. Strains were serotyped by the Quellung reaction.Results. From May 2006 to April 2008, 101 IPD episodes were analyzed; 68% were in children < 2 yrs of age; 87% in children < 6 yrs. Diagnoses were pneumonia 48%, meningitis 39% and sepsis 8%. The overall mortality rate was 22%; 32% in meningitis, 25% in sepsis, and 16% in pneumonia. Resistance rates were as follows: cotrimoxazole (63% high-level resistance [HLR] and 13% intermediate resistance [IR]), penicillin (10% HLR and 13%IR), erythromycin (25% HLR and 0% IR), ceftriaxone (3% HLR and 9% IR). Considering the new penicillin breakpoints for non-meningeal isolates, the percent of susceptible strains increased from 43% to 88% (p<0.001). The most common serotypes were 14 (26%), 6B (20%), 19F (11%), 5 (6%), 23F (6%), 19A (4%) and 6A (4%). Coverage by the heptavalent conjugate vaccine (PCV7) was 69%.Conclusion. IPD in hospitalized children in Lima was associated with high mortality. Antibiotic resistance was common, although with the new penicillin breakpoints for non-meningeal isolates, most strains were susceptible. Therefore, penicillin remains the drug of choice for the treatment of non-meningeal hospitalized pneumococcal infections in Lima. Children in Lima may benefit from vaccination with PCV7. • RESULTS • From May 2006 to April 2008, 101 invasive pneumoccocal disease episodes were studied. • The rate of IPD hospitalizations for children less 2 years of age in Lima was 34/100,000. • Patient age ranged from 1m to 15.8 years with a median of 1.2y; 68% of episodes were in children < 2y , 19% in children 2-6y and 13% in children 6-16y. • The main diagnoses were pneumonia 48%, meningitis 39%, sepsis-bacteremia without a focus 8% and peritonitis 3%. • Isolates were obtained from blood in 58%, CSF in 29%, pleural fluid in 7%. TAB 4. Estimated percent serotype coverage with PCV7 and the investigational 10 and 13-valent pneumococcal conjugate vaccines FIG 1. Susceptibility pattern of S.pneumoniae among meningeal and non-meningeal isolates* FIG 2. Serotypes among penicillin resistant S. pneumoniae* TAB 1. Fatal cases of IPD ** * 39 meningeal strains and 62 non-meningeal strains. TAB 3. Serotype distribution of S. pneumoniae isolatesin 99 patients with IPD ** p<0.05 OBJECTIVE To determine the burden of IPD, the antibiotic susceptibility and serotype distribution of S. pneumoniae in pediatric patients in Lima, Perú. *All isolates n=99, penicillin non-susceptible isolates n=23. • CONCLUSIONS • The rate of IPD in hospitalized children in Lima was high. • IPD was associated with high case fatality rate (22%) especially among meningitis cases (32%). • Penicillin non-susceptible strains accounted for 8% of non-meningeal isolates and 46% of meningeal isolates. • The most common serotypes were 14, 6B, 19F, 23F, 5, 6A and 19A, which accounted for 77% of all strains and 99% of all penicillin resistant strains. • The estimated coverage with PCV-7 for children less than 6y was 69% and 72% for children less than 2y. * Follow up data were available in 91 patients • The overall case fatality rate was 22%. Among patients who died, 35% had an underlying illness but only 20% had a penicillin non-susceptible strain. • METHODS • We conducted a 2-year passive multicenter surveillance of IPD in 11 public hospitals and 5 private clinics and laboratories in Lima. • Data was collected from patients <16 yr of age from whom S. pneumoniae was isolated from sterile site cultures. • Antibiotic susceptibility was determined for ceftriaxone, choramphenicol, penicillin, erythromycin and TMP/SMX using E-test. Interpretation was according to 2008 CLSI standards. • Serotyping was performed using the Quellung reaction. TABLE 2. Streptococcus pneumoniae MIC (101 strains) *Other serotypes: Omni negative (3 strains); 11A, 15A, 24F, 25 (2 strains each); 9N, 12F, 13, 16F, 23A, 34, 38 (1 strain each). Contact Information: Theresa.J.Ochoa@uth.tmc.edu