Rand P W, Lacombe E H, Smith R P, Gensheimer K, Dennis D T
Maine Medical Center Research Institute, South Portland, USA.
Am J Trop Med Hyg. 1996 Aug;55(2):160-4. doi: 10.4269/ajtmh.1996.55.160.
To investigate a low rate of reported human Lyme disease adjacent to an area where the vector tick had become well established, we performed human and canine serosurveys and gathered data on environmental factors related to the risk of transmission. In March 1993, we obtained serum samples and conducted questionnaires that included information on outdoor activities, lot size, and frequency of deer sightings from 272 individuals living within a 5-km strip extending 12 km inland from a study site in south coastal Maine where collections revealed an abundant population of deer ticks. Serologic analysis was done using a flagellin-based enzyme-linked immunosorbent assay (ELISA) followed by Western immunoblot of positive and equivocal samples. Sera from 71 unvaccinated dogs within the study area were also analyzed for anti-Borrelia antibodies by ELISA. Human seropositivity was limited to two individuals living within 1.2 km of the coast. The frequency of daily deer sightings decreased sharply outside this area. Canine seropositivity, 100% within the first 0.8 km, decreased to 2% beyond 1.5 km. Canine serology appears to correlate with the entomologic indicators of the risk of Lyme disease transmission. Possible explanations for the low human seroprevalence are offered.
为调查在媒介蜱虫已大量繁殖的区域附近报告的人类莱姆病发病率较低的情况，我们开展了人类和犬类血清学调查，并收集了与传播风险相关的环境因素数据。1993年3月，我们从居住在缅因州南部沿海一个研究地点向内陆延伸12公里、宽5公里地带内的272个人那里获取了血清样本并进行问卷调查，问卷内容包括户外活动、地块面积以及目击鹿的频率，该研究地点的采集结果显示有大量的鹿蜱。血清学分析采用基于鞭毛蛋白的酶联免疫吸附测定（ELISA），随后对阳性和疑似阳性样本进行Western免疫印迹分析。研究区域内71只未接种疫苗的犬的血清也通过ELISA分析了抗伯氏疏螺旋体抗体。人类血清阳性仅局限于居住在距海岸1.2公里范围内的两个人。在此区域之外，每日目击鹿的频率急剧下降。犬类血清阳性率在最初的0.8公里范围内为100%，在1.5公里以外降至2%。犬类血清学似乎与莱姆病传播风险的昆虫学指标相关。文中还提供了人类血清阳性率较低的可能解释。
