Haemophilus influenzaenon-type b Invasive Disease in Children ≤ 5 yearsof age: A Case Report and Review of Literature

Abstract

Background: Haemophilus influenzae type b (Hib) was the leading cause of invasive disease in children <5 years of age before the introduction of Hib conjugate vaccines. Invasive disease due to non-type H. influenzae has been increasingly reported. Aims: To describe a case of invasive non-type b Haemophilus influenzae and review the literature. Case and Methods: We describe a case of a 4-month-old male presented with fever and lethargy, subsequently diagnosed with bacteremia and meningitis due to Haemophilus influenzae type a (Hia). His clinical course was complicated by subdural empyema (figure 1) and seizures with complete recovery following surgical drainage and prolonged antibiotic therapy. We searched PubMed and Embase from 2010 to 2020 for case reports of non-type b Hi invasive disease in children ≤ 5 years. Results: Out of 138 articles screened, 17 were selected for review. 31 individual cases were summarized with 25% reported in the US. Calculated mean age was 1.5 years (range 0-5 years). Most common presentation was bacteremia (80%, 25) and meningitis (55%, 17). Most cases caused by Hia (52%, 16). About 29% (9) has underlying combordities, and additional 13% (4) were later diagnosed with immunodeficiency condition. Subdural collection and seizures occurred separately in 16% (5) Majority of patients recovered, and 3 (10%) died. Conclusion: Non-type b Hi invasive disease can lead to high morbidity and mortality in children. Epidemiologic surveillance and serotyping are crucial to monitor changing epidemiology of Hi invasive disease. Inclusion of non-type b strains in the Hib conjugate vaccine may be necessary to protect against H. influenzae invasive disease .