Clinical characteristics and serological typing of invasive Haemophilus influenzae infection in children

Abstract:

Objective To analyze the clinical and serological typing characteristics of invasive Haemophilus influenzae (Hin) infection in children. Methods Clinical data of 34 children with invasive Hin infection admitted to Children's Hospital of Shanxi from 2015 to 2021 were analyzed retrospectively. According to clinical diagnosis, they were divided into meningitis infection group and non-meningitis infection group. General data, symptoms, signs, laboratory serological indicators, and Hin serum typing characteristics of children, as well as differences in inflammatory factor level between the two groups were analyzed. Results Among the 34 patients, 22 were males and 12 were females, with a male to female ratio of 1.83 ∶1. Children aged ≤36 months accounted for 82.35%. The levels of procalcitonin (PCT) (23.71 [4.10, 77.80]) ng/mL and C-reactive protein (CRP) (200.00 [164.55, 200.00]) mg/L in children in the meningitis infection group were higher than those in the non-meningitis group (1.08 [0.49, 6.00] ng/mL, 69.46 [48.09, 125.63] mg/L, respectively), with statistically significant differences(both P < 0.05). The platelet (PLT) count in the non-meningitis group ([312.56±186.81]×10⁹/L) was higher than that in the meningitis group ([183.28±165.67]×10⁹/L), with statistically significant difference (P < 0.05). There was no statistically significant difference in white blood cell (WBC) count and neutrophil (NEUT) percentage between two groups (both P>0.05). Among the isolated Hin strains, 27, 2, and 2 strains were type b (Hib), e and f, respectively; 3 strains were not typed; serotype a, c and d strains were not found. There was no statistically significant difference in the distribution of typeable Hin strains between the two groups(χ² =0.25, P>0.05). There was no statistically significant difference in the constituent rate of typeable Hin strains between male and female children (67.74% vs 32.26%, χ² =1.42, P>0.05). Conclusion The majority of invasive Hin infection cases are children under 3 years old, and the predominant strain is type b. CRP and PCT levels of infected children increased significantly, while PLT is significantly lower than that of non-infected children, which has certain clinical diagnostic value and can provide effective support for early classified diagnosis and anti-infection treatment of invasive infectious diseases combined with other clinical testing items.