Comparison of Haemophilus influenzae Seroprevalence in Serum Samples Collected from 0-5-year-old Children in Japan in 1980, 1995, 2010, and 2012.

Comparison of Haemophilus influenzae Seroprevalence in Serum Samples Collected from 0-5-year-old Children in Japan in 1980, 1995, 2010, and 2012. Jpn J Infect Dis. 2019 Aug 30;: Authors: Arai S, Satoh H, Okuno H, Morino S, Oishi K, Tanaka-Taya K Abstract Haemophilus influenzae type b (Hib) causes various invasive infections, such as meningitis, septic arthritis, and pneumonia, especially in children under 5 years of age. Despite Hib vaccines protect Hib infection, seroepidemiological surveys of Hib infections have not been conducted systematically in Japan thus far. We analyzed 1,338 serum samples from 0-5-year-old children that were provided by the National Serum Reference Bank of the National Institute of Infectious Diseases (Tokyo, Japan). Serum levels of the anti-polyribosylribitol phosphate (PRP) IgG antibody against the Hib were determined using an anti-H. influenzae IgG enzyme immunoassay kit. We revealed that in samples from 1,168 (87.3%) children, anti-PRP IgG antibody levels were ≥0.15 µg/mL, i.e., at the minimal natural immunity level. Titers expected to provide long-term protection (≥1 µg/mL) were increased from 2.7% to 51.6% of <1 year of age after introduction of Hib vaccine (1980: 5.3%, 1995: 2.7%, 2010: 22.0%, 2012: 51.6%). Our data confirmed that the introduction of Hib vaccination under 5 years of age increased the proportion of children with high anti-PRP IgG titers that ensured long-term protection. ...
Source: Japanese Journal of Infectious Diseases - Category: Infectious Diseases Authors: Tags: Jpn J Infect Dis Source Type: research