Oman study reports rising invasive Haemophilus influenzae infections in children

A multicenter retrospective study in The Pediatric Infectious Disease Journal examined invasive Haemophilus influenzae infections in children younger than 13 years at five tertiary and secondary hospitals in Oman from January 2010 through June 2024. Researchers identified 142 microbiologically confirmed infections from sterile body sites and assessed incidence, serotypes, clinical features and outcomes. Median age was 12 months, and 45.1% of patients were younger than one year.

Reported incidence increased from 0.60 per 100,000 children in 2017 to 2.43 per 100,000 in 2023 (rate ratio 4.05; P = 0.016). Bacteremia accounted for 51.4% of presentations, meningitis for 22.5% and pneumonia for 11.9%. Among typed isolates, the authors reported type b as most frequent (29.6%), followed by nontypeable strains (17.6%) and type a (16.9%). Most children had received three doses of Hib-containing vaccine.

Neurological complications occurred in 53.1% of meningitis cases. Seizures at presentation were associated with poor neurological outcomes (P = 0.0066), while 89.4% of all children recovered without sequelae. The findings support continued surveillance and improved serotyping. Interpretation is limited by the retrospective, hospital-based design; the supplied report does not specify serotyping completeness or vaccination status by serotype. These data therefore do not establish vaccine effectiveness or explain the incidence increase.