FIELD SURVEY ON TSUTSUGAMUSHI DISEASE IN TAIWAN IN CONNECTION WITH THE INCREASE OF TSUTSUGAMUSHI DISEASE CASES IN RECENT JAPAN

1986年7月24日至8月17日在台湾对恙虫病进行了流行病学实地调查。收集到的数据和材料于1987年带回日本进行分析。从统计资料可知，台湾每年约有100例恙虫病病例。患者多为澎湖岛上的农民和军人。（澎湖岛）和台东县，多数病例发生在夏季，现场调查也显示患者在其居住地周围的灌木丛和耕地中感染。采用间接荧光抗体试验和免疫过氧化物酶试验检测了本调查收集的40例患者血清对Gilliam、Karp和Kato原型菌株的反应性，结果表明血清对Gilliam和Karp原型菌株反应强烈。在免疫印迹分析中，这些患者的血清与所有原型的45-65K多肽反应明显，这些多肽被认为是菌株特异性抗原。对原型菌株的特异性较低，说明台湾立克次体可能具有与原型菌株不同的抗原性。在澎湖群岛、台东、屏东两州共捕获鼠鼠31只、粘鼠8只、黄鼠4只、斑鼠15只，共捕获恙螨7395只。细粒螨为优势种，占各调查地区螨类总数的90%以上。未检出细恙虫亚属其他种，提示恙虫病的主要媒介是迪利塞恙虫病。从6只啮齿类动物中分离到棘齿蚴，目前正在对其多肽组成和抗原成分进行详细的分析。

An epidemiological field research on tsutsugamushi disease in Taiwan was carried out during the period from 24 July to 17 August, 1986. The data and materials collected were brought back to Japan and analysed in 1987.From the statistical data, it was known that about 100 cases of tsutsugamushi disease were recorded yearly in Taiwan. Most of the patients were farmers and military soldiers on Peng-hu Isls. (Pescador Isls.) and in Tai-tung Prefecture, and most of the cases occurred in summer, By the field surveys, it was also demonstrated that the patients had acquired the infection in bushes aroud their residing sites and cultivated fields.The reactiveities of 40 patients' sera collected in the present survey to the prototype strains of Gilliam, Karp and Kato were examined by the indirect fluorescent antibody test and the immunoperoxidase test, and it was shown that the sera reacted strongly with Gilliam and Karp strains. In immunoblotting assay, these patients' sera reacted clearly with 45-65K polypeptides of all prototypes which were considered to be a strain specific antigen. The relatively low specificity in the reactivities to the prototype strains suggests that the rickettsiae in Taiwan might have antigenic properties distinctive from the prototypes.A total of 58 mammals comprising of 31 Suncus murinus, 8 Mus muculus, 4 Rattus losea and 15 Bandicota indica were trapped on Peng-hu Isls, and in Tai-tung and Ping-tung Prefectures, and 7,395 trombiculid mites were collected from them. Leptotrombidium (L.) deliense was the predominant species occupying more than 90% of mites popolations collected in every area surveyed. No other species of the subgenus Leptotrombidium was detected suggesting that L.(L.) deliense is the main vector of tsutsugamushi disease in these areas. Rickttiae were isolated from 6 rodents, and their polypeptide composition and antigenic components are now being examined in detail.