The Study On The Pharyngeal Carriage Of Haemophilus Influenzae In Healthy Children

Haemophilus influenzae (Hi) is an important pathogen colonized in the nasopharynx of healthy children. The carriage of Haemophilus influenzae is closely related to the diseases of Haemophilus influenzae. So, it is important and necessary to make an investigation on the nasopharyngeal carriage of Haemophilus influenzae in healthy children. For this,from 09/1998 to 06/1999(two semesters),we took two representative kindergartens in Fuzhou as the research subjects. Samples were obtained from pharynx in healthy children by the method of oropharyngeal swab in the first month of each season. Samples taken totals 2053 specimens, including: 522 of autumn,520 of winter,503 of spring and 508 of summer. Samples were cultured on Improved Columbia chocolated agar (ICCA).All isolated strains were biotyped and tested for drug susceptibility,and some isolated strains from healthy children in the period of autumn and winter were serotyped at random. Results: the average positive rate of Haemophilus influenzae is 19.63% of the year.which is 18.0 1%(94/522) in autumn, 36.73%(1911520) in winter, l0.93%(55/503) in spring and 12.40%(63/508) in summer, respectively. Except no significant difference between summer and spring , there is a statistically significant difference in the detection of Haemophilus influenzae among others seasons (p<0.001) .The season of the highest carriage rate is winter, followed by autumn ,summer and spring . But no statistically significant difference was found in the detection of Haemophilus influenzae among different kindergartens ,ages and sexes(p>0.05). Among the biotype distribution of Haemophilus influenzae ,the rate of biotype is4.71% (type I), 12.16%(type II), 1 1.66%(typelll), 6.95%(typelV), 6.45% (type V), 8.19% (typeVl), 15.14% (typeVll)and 34.74%(typeVlfl), respectively. Among them the highest rate is type Viii. The rate of type I , II ,II1,JV, V A~I in winter is apparently higher than that of other seasons(p<0.00l) .However , the rate of type VIII in the winter is apparently lower than that of other season(p<0.05) ,and the rate of type VII is not statistically significantly different in different ssons(P>O.05). Among the serotypes distribution of Haemophilus influenzae, NTHi(iiin-typeable HacmQphilua influenzae) is the type with the highest rate of 31 .25(30/96 the secund is Hib(type b) with 21.88%(21/96), the third is type d with 13.S4%(13196), the forth is type e with 13.54%(13/96), the fifth is type f with I0.75%(l0/96), the sixth is type c with 9.3 8%(9/96)and no type a was detected. There is a statistically significant difference in the serotypes distribution in autumn and in winter.The distribution rate of NTHi in winter is apparently higher than in autumn(p<0.01). However, the distribution rate of Hib in autumn is apparently higher than in winter(p