Haemophilus influenzae type b invasive infections in children hospitalized between 2000 and 2017 in a Pediatric Reference Hospital (PRH)

Abstract

Background: Uruguay incorporated the conjugate vaccine against Haemophilus influenzae b (Hib) in 1994. In 2008, the vaccine was changed from one with natural conjugated capsular polysaccharide to one with a synthetic polysaccharide component. We describe the frequency and characteristics of invasive Hib infections in children hospitalized in a Pediatric Reference Hospital (PRH) between January 1st, 2000 and December 31st, 2017. Methods: Sterile site Hib isolations from hospitalized children were included. Clinical and microbiological characteristics were analyzed. Favorable conditions for the infection were considered: incomplete immunization, immunodeficiencies and associated pathologies. Two periods are described: 1, prior to vaccine change (1/1 st/ 2000-12/31/08) and 2, post-change (1/1 st/09-12/31st/17). Results: 45 children were hospitalized: 5 in the first period and 40 in the second. The hospitalization rate per 10,000 discharges was 0.41 (95% CI 0.05-0.77) and 4.2/10,000 (95% CI 2.89-5.48), respectively (p < 0.01). The diagnoses at discharge were: meningitis/ventriculitis (20), pneumonia (16), bacteremia (3), epiglottitis (1), arthritis (1), cellulitis (3) and obstruction of the upper airway (1). Four children presented comorbidities. Twenty seven received less than 3 doses of anti-Hib vaccination and 18 were properly vaccinated (2 were immunodeficient). The median hospitalization was 14 days, 18 children required intensive therapy. Conclusions: Observed change may be due to: incomplete primary series, inhomogeneous vaccine coverage and immunogenicity of the synthetic polysaccharide. To reduce this public health problem, epidemiological surveillance.

Interactions of Bacteriophages and Bacteria at the Airway Mucosa: New Insights Into the Pathophysiology of Asthma

“…H. influenzae isolates can be divided into encapsulated (serotypes a-f) and non-encapsulated strains designated also as typable or non-typable isolates accordingly. Colonization of nasopharynx with typable b serotype (<3% of population) causes, in most of the cases, serious invasive disease such as meningitis ( 119 , 120 ), while colonization with non-typable serotypes (80% of adults and 40% of children) may result in sinusitis, exacerbation of COPD, conjunctivitis and otitis media ( 121 ).…”