Abstract

CASTILLO-FEBRES, Olga et al. Oropharyngeal Carriers in Venezuelan Children in two Child care Settings, Vaccinated or not with Haemophilus Influenzae type b Tetanus Toxoid Conjugate Vaccine (PRP-T). Invest. clín [online]. 2005, vol.46, n.1, pp.15-24. ISSN 0535-5133.

The objective was to estimate the oropharyngeal carrier rate of Haemophilus influenzae type b (Hib) and non typeable (NTHi) in unvaccinated and vaccinated children, with PRP/T vaccine, both cared at home and attending day care centers. Healthy children of either sex, younger of 7 years, excluding those that received antibiotics one month prior to the inclusion, were recruited from control clinics for healthy babies, and assigned to Group I fully immunized and Group II unimmunized. Both, children cared at home and attending day care centers were included. Parents provided an informed consent. Specimens were obtained from the oropharynx for culture, identification and serotyped by slide agglutination (Phadebact Haemophilus test). P values were obtained with Chi-square, Fisher’s and Z test. Odds ratio was obtained when appropriated. Results were as following: a total of 320 children were enrolled, 99 in group I (49 cared at home, 50 attending day care) and 221 in group II (94 cared at home, 127 attending day care) the percentage of carriers was 22.8% (17.8% NTHi and 5% Hib). The carriage rate of NTHi was similar in groups I and II cared at home (18%vs 19%), and for those attending day care were 16% vs 17%. Carriage rate of Hib in children attending day care of group II was 12% vs 1% of those cared at home (p=0.002). None of the children in group I was colonized by Hib. The Hib carrier rate was more similar to that of industrialized countries in the pre vaccine era in children cared at home, however, attendance to a day care center significantly increases its risk. The PRP/T vaccine appears to prevent the carrier state in both care settings.

Keywords : Haemophilus influenzae; orpharingeal carriage; PRP-T vaccine.