为了探讨局部地区暴发流行的因素，对2004年与2005年间在贵州省安龙县及其周边发生的人间狂犬病进行个案调查，用直接免疫荧光法检测犬脑组织中的狂犬病毒抗原，用RT-PCR法扩增G基因片段，测定核苷酸序 列并构建系统发生树进行遗传特征分析。自1994-2003年安龙县报告无人间狂犬病疫情，但于2004与2005年分别报告44例与27例人狂犬病。71例狂犬病患者中68人被犬所伤，3人被猫所伤。在有完整记录的69例患者中，潜伏期平均为47.5d（10～282），13例狂犬病患者的潜伏期≤15d（18.84％）；32例的潜伏期≤30d（46.38％），尤其是在2004年的患者中，潜伏期≤20d的病例有13例，占30％。2005年在疫点周围采集的85只犬脑组织中，5只犬脑组织狂犬病毒抗原阳性，阳性率为5.88 %。A13株与A48株病毒之间的G基因核苷酸序列同源性为86.5％，与已报道病毒株比较发现，A13株与广西分离株有最高的同源性，而A48株却与印度尼西亚分离株SN01-23的同源性最高。比较分析两株病毒G基因编码的氨基酸序列，发现包括GⅠ、GⅡ，以及GⅢ抗原位点内的区间，A13与A48分别有19和28个氨基酸位点发生了氨基酸的替代。用全G基因核苷酸序列进行系统分析发现，两株毒株全为Ⅰ型狂犬病毒。结果表明引起安龙县的狂犬病流行的病毒不是新型狂犬病毒，犬饲养量大与病毒携带率高是狂犬病发病暴发流行的直接原因。

This study was aimed to analyze human rabies cases that occurred from 2004 to 2005 in Anlong County in Guizhou province, and to explore the possible factors causing the epidemics. Each case of rabies was investigated. Canine brains were collected, and an immunofluorescence assay was used to detect rabies virus antigen. The G gene was amplified by RT-PCR, and then sequenced. Phyologenetic trees were constructed to analyze the genetic relatedness of rabies viruses. From 1994 to 2003, no human rabies case occurred in Anlong. But 44 and 27 cases of human rabies were reported in 2004 and 2005, respectively. In 71 cases, 68 were attributed to dog bites, and 3 patients were reported to have been bitten by cats. The median incubation period was 47.5 days (10～282) for the 69 cases with clear history records. However, it was noticed that 13 (18.84%) and 32 (46.38%) of 69 cases developed the disease within 15 days and 30 days of exposure, respectively, and particularly, 13 of 44 cases developed the disease within 20 days in 2004. In the spring of 2005, a total of 85 dog brains were examined for rabies viral antigen by DFA and confirmed by RT-PCR, 5 (5.88%) were positive. Analysis of the sequences of G gene of the two isolates showed the identity of the nucleotides sequences was 86.5% between the two isolates. Furthermore, A13 strain has high identity with the known isolates from Guangxi, while A48 strain shares high identity with the strain SN01-23 from Indonesia. Both strains are diverse from vaccine strains, aG, PV and ERA. The phylogenetic tree constructed with the entire G gene sequence showed the two isolates were rabies virus. Comparison of the deduced amino acid sequences of the two isolates, 19 and 28 of amino acid residues including the residues in the antigenic site Ⅰ, Ⅱ and Ⅲ were substituted for A13 and A48, respectively. The results suggested that the virus caused the outbreak in Anlong is not an emerging rabies virus, and the increasing number of dogs and the high rate of virus carriers in dogs might be responsible for the outbreak.