Haemophilus influenzae serotype a as a cause of purulent meningitis in a six-month-old infant

Czech version

Authors: Vladimír Mihál ¹; Marie Rohanová ¹; Andrea Lysáková ²; Pavla Kučová ³
Authors‘ workplace: Dětská klinika LF UP a FN v Olomouci ¹; Dětské a novorozenecké oddělení Nemocnice Šumperk, a. s. ²; Ústav mikrobiologie LF UP a FN v Olomouci ³
Published in: Čes. slov. Farm., 2026; 75, 87-90
Category: Current Pharmacotherapy

Overview

Haemophilus influenzae serotype b (Hib) has historically been the most significant pathogen causing invasive infections. In recent decades, an increase in the incidence of other Haemophilus influenzae serotypes has been observed, particularly serotypes e+ f, as well as, most notably, invasive infections caused by non-typeable strains. Invasive disease caused by Hia, similarly to Hib, affects primarily young children and represents a significant cause of morbidity and mortality. To better understand the clinical and epidemiological characteristics of Hia, epidemiological studies and active microbiological surveillance of invasive disease across all age groups worldwide are needed. We describe a six-month-old, previously healthy but incompletely vaccinated infant who was hospitalized with suspected sepsis and purulent meningitis following a four-day history of intermittent fever associated with chills, vomiting, drowsiness progressing to apathy, and gradual development of dehydration. Haemophilus influenzae was confirmed from both blood culture and cerebrospinal fluid, and capsular antigen identification at the National Reference Laboratory for Haemophilus infections determined serotype a (Hia). A two-week course of parenteral antibiotic therapy with cefotaxime led to recovery without significant neurological complications.

Keywords:

Meningitis – children – Haemophilus influenzae serotype a

Sources

1. Murphy TF. Haemophilus species, Including H. influenzae and H. ducreyi (chancroid). In: Mandell, Douglas, and Bennett‘s Principles and Practice of Infectious Diseases, 8th ed, Bennett JE, Dolin R, Blaser MJ (Eds), Elsevier, Philadelphia. 2015; p.2575.

2. Nováková L, Šebestová H, Křížová P, et al. Invazivní onemocnění způsobená Haemophilus influenzae v České republice v období 2008–2022. Zprávy CEM (SZÚ, Praha). 2023;32(8):290-296.

3. Soeters HM, Blain A, Pondo T, et al. Current epidemiology and trends in invasive Haemophilus influenzae disease –⁠ United States, 2009-2015. Clin Infect Dis. 2018;67(6):881-889.

4. Slack MPE, Cripps AW, Grimwood K, et al. Invasive Haemophilus influenzae infections after 3 decades of Hib protein conjugate vaccine use. Clin Microbiol Rev. 2021;34(3):e0002821.

5. Russo DO, Torres BR, Romanelli RMC, et al. Haemophilus influenzae serotype a as a cause of meningitis in children in Brazil. Pediatr Infect Dis J. 2022;41(2):108-111.

6. Ulanova M, Tsang RSW. Haemophilus influenzae serotype a as a cause of serious invasive infections. Lancet Infect Dis. 2014;14(1):70-82.

7. Lima JBT, Ribeiro GS, Cordeiro SM, et al. Poor clinical outcome for meningitis caused by H. influenzae serotype a strains containing the IS1016-bexa deletion. J Infect Dis. 2010; 202(10):1577-1584.

8. Ladhani S, Slack MP, Heath PT, et al. and the European Union invasive bacterial infection surveillance participants. Invasive Haemophilus influenzae disease, Europe, 1996–2006. Emerg Infect Dis. 2010;16 : 455-463.

9. Ulanova M. Invasive Haemophilus influenzae serotype a disease in the H. influenzae serotype b conjugate vaccine era: Where are we going? Clin Infect Dis. 2021;73(2):e380-e382.

10. Ulanova M, Tsang RS. Invasive Haemophilus influenzae disease: changing epidemiology and host-parasite interactions in the 21st century. Infect Genet Evol. 2009;9(4):594-605.

11. Probst V, Shahoud F, Osborne AF, et al. Report of Haemophilus Influenzae serotype a intracranial infections in older children. Pediatr Investig. 2023;7(2):132-136.

12. Plumb ID, Lecy D, Singleton R, et al. Invasive Haemophilus influenzae serotype a infection in children: clinical description of an emerging pathogen –⁠ Alaska, 2002–2014. Pediatri Infect Dis J. 2018;37 : 298-303.