Levels of anti-Haemophilus influenzae type B antibody in Turkey before routine vaccination

Abstract number: R2541

Sonmez C., Coplu N., Kurtoglu D., Esen B., Crowley-Luke A., Ransley L.

Objectives:Haemophilus influenzae type b (Hib) vaccine was introduced into the routine vaccination schedule in Turkey on January 1st, 2007. This study investigated immunity to Hib before vaccination.

Methods: Serum samples collected from Samsun, Antalya and Diyarbakir provinces between 2000–2001 were tested in this study. A total of 1713 serum samples from patients aged 6 months to more than 60 years from 26 health centres were tested. A commercial ELISA (Immunozym Hib IgG, Progen Biotechnik GmhB, Heidelberg, Germany) test was used to measure antibody concentration of anti-Hib IgG. For quality control, 30 sera were selected and retested at the Health Protection Agency (HPA)(Salisbury, U.K) using an in-house ELISA. For evaluation of the concentration of anti-Hib antibody, leqslant R: less-than-or-eq, slant0.15 mg/ml was accepted as non-protective, >0.15 to <1.0 mg/ml as short term protection and geqslant R: gt-or-equal, slanted1.0 mg/ml as long term protective. Chi-square test and logistic regression were used for statistical analysis.

Results: Results of the commercial ELISA and the HPA in-house ELISA correlated well (correlation coeficient 0.87). The distribution of antibody concentrations according to age, gender and location by protection levels is shown in the Table. Between 38.1 to 79.3% of children under five years of age had antibody levels lower than those considered protective, and 15.2 to 61.9% had antibody levels cosistent with short term protection. These children should be considered at risk of Hib infection. Protection against Hib infection increased by age in all three provinces (Antalya: OR 1.028, 95.0% CI; 1.070–1.038, Diyarbakir: OR 1.027, 95.0% CI; 1.060–1.038, Samsun: OR 1.041, 95.0% CI; 1.030–1.052). There were no statistically significant differences between provinces when Diyarbakir was considered as the reference province (Samsun: OR 1.800, 95.0% CI; 0.617–1.036, Antalya: OR 1.212, 95.0% CI; 1.930–1.579).

Conclusion: Children under five years of age in Turkey were at high risk for Hib infection before the introduction of vaccination. The impact of the vaccination programme should be monitored at frequent intervals to ensure the maximum benefit is obtained from immunisation.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Location: Barcelona, Spain
Presentation type:
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