杭州某幼儿园健康儿童流感嗜血杆菌携带状况及其血清分型

Carriage and serotypes of haemophilus influenza in young children attending a kindergarten in Hangzhou

目的了解健康儿童不同月份流感嗜血杆菌的携带状况及血清分型。方法对2002年9月至2003年6月杭州某甲级幼儿园2～5岁的入托儿童随机进行每周1次的咽拭子培养,用V因子、X因子试验鉴定流感嗜血杆菌,用玻片凝集法进行血清分型,用纸片扩散法进行药敏试验。结果连续10个月中受检儿童848例,217例(占25.6%)携带流感嗜血杆菌,其中1月份的携带率最高,达34.8%,6月份的携带率最低,为12.6%,儿童在12月、1月、2月、3月4个月中的总携带率显著高于其他6个月(χ2=10.95,P<0.001)。217例携带者共分离到223株流感嗜血杆菌,不可分型菌株180株,占80.7%;可分型菌株占19.3%(43株),包括a型4株,c型2株,d型35株,e型1株和f型1株,未分离到b型流感嗜血杆菌。61株(27.4%)菌株产生β内酰胺酶,28.6%的菌株对氨苄西林耐药,且不可分型菌株对氨苄西林的耐药率显著高于可分型菌株(χ2=4.19,P<0.05)。结论本研究中健康儿童对流感嗜血杆菌的携带率以12月、1月、2月和3月份为高,可分型流感嗜血杆菌以d型占绝对优势,新型菌苗的研制已成为一项紧迫的任务。

Objective To investigate the carriage and serotyping of Haemophilus influenzae(H. influenza)in children attending kindergarten in consecutive months in Hangzhou.Methods During the 10-month period, September 2002 through June 2003, pharyngeal cultures were obtained every week from kindergarten attendees between 2 to 5 years. Identification of isolates as H.influenza was confirmed by V factor and X factor test. Serotyping was performed by slide agglutination method and the sensitivities of antibiotics to H.influenza strains were determined in vitro with disk diffusion methods.Results During the consecutive10 months, 217 of 848 children (25.6%)carried H.influenza strains. More carriers were found in December , January, February and March than in the remained months(χ~2=10.95,P<0.001).223 strains were isolated from 217 carriers, 80.7%of them were non-typable and 19.3% ( 43 strains) were typable,which including type a(4strains), type c (2 strains), type d (35 strains), type e (1strains) and type f (1strains). No type b strain was identified in the study.61(27.4%) strains were β-lactamase positive and 28.6% of 182 strains tested successfully were resistant to ampicillin. Resistance rate to ampicillin in non-typable H.influenza was significantly higher than that in typable strains(χ~2=4.19,P<0.05).Conclusions Strains of H.influenza were adept to colonize in pharyngeal of children mainly in December, January , Feburary, and March in Hangzhou and Type d was the most common type in typable strains.To develop a new vaccine to prevent infection of type d or nontypeable H.influenza is urgent.