Haemophilus influenzae type b carriage and burden of its related diseases in Chinese children: Systematic review and meta-analysis.

BACKGROUND: Haemophilus influenzae type b (Hib) is an important cause of invasive bacterial disease in children worldwide. The limited awareness of disease burden is a major barrier to the introduction of Hib vaccine into China's National Immunization Program. Therefore, we conducted a systematic review and meta-analysis to estimate carriage of Hib and burden of its related diseases in Chinese children. METHODS: We systematically searched Pubmed, Web of Science, Ovid, Chinese National Knowledge Infrastructure (CNKI), and Wanfang databases for studies published up to December 31, 2016, reporting Hib carriage and burden of Hib diseases among children in Mainland China. Pooled estimates were obtained using random-effects models. RESULTS: We included 27 studies with 15783 children across 14 provinces. The pooled carriage of Hib was 5.87% (95% CI 3.42-8.33) for healthy children. The pooled proportion of disease due to Hib were 4.06% (95% CI 3.29-4.83) for acute lower respiratory tract infection (ALRI) and 27.32% (95% CI 0.41-54.24) for bacterial meningitis. The proportion of ALRI caused by Hib was higher in northern China than that in the south. Significant heterogeneity was noted across and within regions (P<0.001). After the induction of Hib vaccine, meta-regression showed that carriage of Hib changed little (P=0.725), but the proportion of ALRI caused by Hib in children decreased (P<0.001). CONCLUSIONS: Hib carriage persists at low levels among children in China. The proportion of ALRI due to Hib infection decreased with year. Incorporation of Hib vaccine into the National Immunization Program could reduce the burden of Hib disease in China.