Abstract

Abstract: Introduction: Invasive bacterial infections (IBI) represent a clinical feature of primary immunodeficiencies (PIDs). The American Academy of Pediatrics does not suggest evaluating immunologically children who present a first IBI. We tested if immunologic evaluation of children with a first episode of IBI could help identify patients with PIDs earlier. Methods: A prospective study was carried out between 2012 and 2015 at Roberto del Río Hospital among children 1 month to 13 years of age who were hospitalised with IBI (S. pneumoniae, H. influenzae, N. meningitidis, condensing pneumonia or pleuropneumonia). Immunoglobulins, complement, HIV status and pneumococcal antibodies to 10 serotypes were measured. Results: Seventy-one patients were evaluated with average age of 38 months. One HIV+, one IgA deficient and one patient with low IgG levels were identified. Within the 0–24 months group (n = 32) 28 patients received ≥2 doses of PCV10 vaccine. Only 10 patients showed titers ≥1.3 ug/ml for ≥5 serotypes. Of 24 2–5 year old patients, 6 received ≥2 doses of PCV10 but only 3 had titers ≥1.3 ug/ml to ≥5 of the 10 serotypes. Of 11 patients (15 %) who received a polysaccharide vaccine, 9 had a poor response with titers ≤1.3 ug/ml for ≥5 serotypes. Conclusion: Our study revealed a high percentage of patients who had poor or weak responses to both PCV and PPV vaccines. These results justify immunological evaluation of patients that present with a single invasive bacterial infection.