Invasive Haemophilus influenzae Disease at Texas Children’s Hospital, 2011 to 2018

Abstract

Background: Universal vaccination with Haemophilus influenzae type b conjugate vaccines has significantly changed the epidemiology of invasive H. influenzae disease in the United States. We reviewed the epidemiology, clinical features, and outcomes in 61 patients with invasive H. influenzae disease evaluated at Texas Children’s Hospital (TCH). Methods: Cases of invasive H. influenzae disease, defined as isolation of the organism from cerebrospinal fluid, blood, synovial fluid or pleural fluid, during 2011 to 2018 among children cared for at TCH in Houston, TX, were included. Results: We identified 61 cases of invasive H. influenzae disease in children ≤18 years of age. The overall hospitalization rate due to invasive H. influenzae disease increased between 2011 and 2018 (0 vs. 0.64/1000 hospitalizations; P = 0.019). The majority (80%) of infections occurred in children <5 years of age. Of the 61 H. influenzae infections, 24 (39.3%) infections were caused by nontypeable H. influenzae strains, 18 (29.5%) infections were caused by H. influenzae type a, 12 (19.7%) infections were caused by H. influenzae type f, 3 (4.9%) infections were caused by H. influenzae type e and 4 (6.6%) isolates were not typed. A total of 78.7% of the isolates were β-lactamase negative. The most common clinical presentations were bacteremia without a source, pneumonia and meningitis. Conclusions: The hospitalization rate for H. influenzae invasive disease increased over an 8-year period at TCH. The overall trend was mainly driven by an increasing number of invasive infections caused by nontypeable H. influenzae and H. influenzae type a. Morbidity was substantial, especially in meningitis cases.

Invasive Haemophilus influenzae Type F Infection Complicated by Subarachnoid Phlegmon and Cortical Venous Thrombosis

“…6 Since the Hif conjugate vaccine was introduced in 1990, most invasive illnesses in US children, specifically bacteremia and meningitis, have been due to either nontypeable strains or non-Hif capsular serotypes. 1,7,11,14 Viral respiratory coinfections, like with influenza B virus seen in our patient, can have a synergistic effect to increase the virulence of these bacteria, facilitating both the focal spread and systemic invasion, and increasing morbidity and mortality. 4…”

“…2,3,7 In 1994, invasive Hif was reported to occur at frequency of 1.9 cases per 1 million children with pneumonia and meningitis being the most common presentations. 9 The percentage of Hif infections has declined with universal introduction of the conjugate vaccine.10 With this decline, the incidence of invasive infections caused by nontypeable or other strains of H influenzae, 5,7,11 particularly serotype f, has grown in the United States as well as other countries. [12][13][14] In the pediatric population, pneumonia and meningitis are the most common forms of severe Hif infection.…”

“…The bacteremia in turn may have seeded the pre-existing prominent subarachnoid spaces after being introduced into the CSF by passing through the choroid plexus. 17 An oral antibiotic was predictably insufficient to fully treat the Hif meningitis, 11,18 and complications ensued.…”

Case Report: Invasive Non Type b Haemophilus influenzae in Immunocompromised Children

“…The decline of Hib cases after the development of the vaccine raises the question of clinical relevance of nontype b serotypes. With the emergence of nontype b serotypes, importance should be stressed on its burden, especially in the pediatric population [10,11]. Identification of the specific serotype, as well as further research into each serotype, will help determine overall disease burden.…”

<p>Acute Hematogenous Osteomyelitis in Children: Clinical Presentation and Management</p>

“…25 In young infants who acquire infection with pathogens which are also known as common causes of meningitis (e.g., pneumococcus, Group B Streptococcus or Haemophilus influenzae), consideration may need to be given towards performing a lumbar puncture to obtain a CSF culture; meningitis has been described concomitantly, albeit rarely, in such patients. [26][27][28] Beyond traditional culture methods, increasing interest has developed in molecular diagnostics for AHO. A number of multiplex PCR-based panels exist to help identify major AHO pathogens from either bone exudates, purulent collections or synovial fluid; in some cases, these studies are able to identify select antibiotic resistance genes.…”