| Abstract: | The aim of the present study was to assess the prevalence of Haemophilusinfluenzae type b (Hib) nasopharyngeal (NP) colonisation among healthychildren where Hib vaccination using a 3p+0 dosing schedule has been routinelyadministered for 10 years with sustained coverage (> 90%). NP swabs were collectedfrom 2,558 children who had received the Hib vaccine, of whom 1,379 were 12-< 24months (m) old and 1,179 were 48-< 60 m old. Hi strains were identified bymolecular methods. Hi carriage prevalence was 45.1% (1,153/2,558) and the prevalencein the 12-< 24 m and 48-< 60 m age groups were 37.5% (517/1,379) and 53.9%(636/1,179), respectively. Hib was identified in 0.6% (16/2,558) of all children inthe study, being 0.8% (11/1,379) and 0.4% (5/1,179) among the 12-< 24 m and48-< 60 m age groups, respectively. The nonencapsulate Hi colonisation was 43% (n= 1,099) and was significantly more frequent at 48-< 60 m of age (51.6%, n = 608)compared with that at 12-< 24 m of age (35.6%, n = 491). The overall resistancerates to ampicillin and chloramphenicol were 16.5% and 3.7%, respectively; theco-resistance was detected in 2.6%. Our findings showed that the Hib carrier rate inhealthy children under five years was very low after 10 years of the introduction ofthe Hib vaccine. |
