杭州地区儿童病毒性肠炎病原学分析

Etiology of viral enteritis and molecular epidemiology of rotavirus in children in Hangzhou area

目的 探讨杭州地区儿童病毒性肠炎的病原和轮状病毒 (RV)分子流行病学特点。方法 用酶联免疫吸附测定 (ELISA)、透射电子显微镜 (TEM)、逆转录聚合酶链反应 (RT PCR)及聚丙烯酰胺凝胶电泳 (PAGE)方法 ,对 1999年 1月 ,在本院就诊的 83例拟诊为急性病毒性肠炎患儿的粪便标本进行了病毒检测和RV组、亚组及血清、基因型测定。结果 RV检出率为 60 2 %( 5 0 / 83 ) ,均为A组、P1A(P[8])基因型 ,主要为Ⅱ亚组 ,G1血清型 ,基因群均为G1P[8]。同时还检测到萼状病毒 (CV)、诺沃克病毒 (NLV)各 3例 ,星状病毒 2例 (此 2例同时检测到RV)。RV检出率以 3～ 2 4个月年龄组最高为 63 2 %( 4 8/ 76) ,RV阳性组的临床表现较阴性组重。结论 1999年 1月杭州地区儿童急性肠炎的主要病原是RV ,属A组、P1A(P[8])基因型、G1P[8]基因群 ,其主要亚组和血清型为Ⅱ亚组、G1血清型。儿童病毒性肠炎存在着多种病原 (除轮状病毒外还有CV、NLV及星状病毒 )并有双重病毒感染存在。RV肠炎好发于 2岁以内婴幼儿 ,且临床表现较非RV感染组重。

Objective To search into the pathogens of viral enteritis and molecular epidemiology of rotavirus (RV) in children in Hangzhou area. Methods Stool specimens of 83 children with suspected acute viral enteritis in Hangzhou in January 1999 were collected. RV, astrovirus and enteric adenovirus were detected for all specimens by enzyme linked immunosorbent assay (ELISA). Then the subgroup, VP7 serotype and VP4 genotype were determined in RV positive specimens by ELISA, polyacrylamide gel electrophoresis (PAGE) and reverse transcriptase polymerase chain reaction (RT-PCR). RV, astrovirus, calicivirus (CV), small round structured virus (SRSV) and enteric adenovirus were detected by using transmission electron microcopy (TEM) and Norwalk virus (NLV) was detected with both TEM and RT-PCR in RV negative specimens. Results RV was detected in 50 of 83 (60.2%) specimens; all the 50 strains belonged to group A. Further analysis showed that among 50 RV-infected cases, 47 were subgroup Ⅱ, 1 case was subgroup Ⅰ+Ⅱ, in 2 cases the virus was of unknown subgroup. Of the 50 cases, 38 were G1, 9 were not identified, the remaining 3 were G3, G4 and G1+G2+G4, respectively. Genotype (P serotype) analysis showed that all RV positive specimens were P1A (P) genotype and G1P genogroup . Other viruses were also detected in 8 specimens by using various methods: CV was found by TEM in 3 (3.6%), NLV by RT-PCR in 3 (3.6%) and astrovirus by ELISA in 2 (2.4%) (these 2 cases was RV positive at the same time), respectively. The highest frequency of group A RV detected was 63.2% (48/76) in patients aged 3～24 months. Conclusion The major pathogen of acute viral enteritis in children in Hangzhou area in January 1999 was group A RV, P1A(P) genotype and G1P genogroup. Subgroup Ⅱ and G1 serotype were predominant. Besides RV, some pathogens, such as CV,NLV and asterovirus were also detected and there were double viral infections in some children with acute enteritis. Children under the age of 2 years seemed to be more susceptible to RV infection than those of other age groups. The symptoms of RV enteritis were more severe than those of other viral enteritis.