Ohara Y, Sato T, Homma M
Department of Microbiology, Kanazawa Medical University, Ishikawa, Japan.
J Med Entomol. 1998 Jul;35(4):471-3. doi: 10.1093/jmedent/35.4.471.
Sixteen cases of tularemia transmitted by arthropods are used to characterize arthropod-borne tularemia in Japan. Arthropod-borne tularemia accounted for 1.2% of a total of 1,374 cases of tularemia observed between 1924 and 1996. The number of cases reported in Japan was low when compared with the number of cases reported in the United States. Arthropod-borne tularemia, however, is increasing and has reached 10.1% incidences during the last 16 yr. No arthropod-borne cases were reported prior to 1951. The occurrence of tularemia infection caused by contact with diseased hares was diphasic with the higher peak occurring during the winter, whereas the occurrence of arthropod-borne tularemia was common from spring to autumn. Among the 16 cases that we studied, 5 were initiated by tick-bites, 5 by the crushing of ticks found on domestic dogs, and 1 by an unidentified insect. In the remaining 5 cases, the vectors were not identified although arthropod bites were confirmed. These arthropod-borne cases were observed exclusively in the northeastern area of Honshu, the main island of Japan, and the age of patients ranged from 23 to 74 yr. The arthropod vectors associated with tularemia and factors influencing incidence of arthropod-borne tularemia in Japan are discussed.
16例由节肢动物传播的兔热病病例被用于描述日本节肢动物传播的兔热病特征。在1924年至1996年期间观察到的1374例兔热病病例中，节肢动物传播的兔热病占1.2%。与美国报告的病例数相比，日本报告的病例数较少。然而，节肢动物传播的兔热病正在增加，在过去16年中发病率已达10.1%。1951年之前未报告过节肢动物传播的病例。因接触患病野兔引起的兔热病感染呈双相性，较高的峰值出现在冬季，而节肢动物传播的兔热病在春季至秋季较为常见。在我们研究的16例病例中，5例由蜱叮咬引发，5例由碾碎在家犬身上发现的蜱引发，1例由不明昆虫引发。在其余5例中，尽管确认有节肢动物叮咬，但未确定传播媒介。这些节肢动物传播的病例仅在日本主岛本州岛的东北部地区观察到，患者年龄在23岁至74岁之间。本文讨论了与兔热病相关的节肢动物传播媒介以及影响日本节肢动物传播兔热病发病率的因素。
