- 學位論文
台灣北部地區蚤傳立克次體病之血清流行病學研究
Seroepidemiology of Flea-borne Rickettsiosis in Northern Taiwan
摘要
立克次體病為一常見的不明熱來源。在台灣，本土流行的立克次體病包括恙蟲病以及地方性斑疹傷寒。在過去五年內，每年約有300至400個恙蟲病的個案以及30到40個地方性斑疹傷寒的個案發生。然而，立克次體病的檢出率在近幾年內皆不太高。2008年時，發表了台灣第一個人類感染Rickettsia felis的個案。由於R. felis在臨床上的表徵與其他立克次體病十分相似，包括發燒、頭痛、肌肉痛、關節痛、皮膚紅疹等，造成臨床判斷上的不易。再加上使用血清學方法檢驗時，R. felis和R. typhi會有交叉反應產生，易導致檢驗結果誤判。因此R. felis感染所造成的個案數量可能被低估。為了解台灣蚤傳立克次體病的流行病學，本研究採用於2009年至2010年間由國立臺灣大學附設醫院通報至衛生署疾病管制局疑似為恙蟲病、地方性斑疹傷寒以及Q熱經檢出結果為陰性之血清檢體，共有221個樣本來自127為病人。利用免疫螢光染色法，針對R. felis 、 R. typhi 及 R. japonica 之三種病原進行檢驗。而檢出結果共有23為病人為Rickettsia 感染，其中8位為台灣蚤傳立克次體感染陽性，7位為其他斑點熱群之立克次體感染，另8位因病原之血清學交叉反應而無法確定感染源，須以吸收式西方墨點法(absorb Western blot)再加以確認。另外並針對其中三位為台灣蚤傳立克次體感染之病患進行病例的回顧，三位的臨床症狀包括發燒、皮膚紅疹、腹痛、淋巴結腫大、肝炎、急性腎衰竭而導致休克以及肺炎造成之急性呼吸衰竭而死亡。研究結果顯示了台灣蚤傳立克次體病在北台灣的確是個潛在的病原，而其他斑點熱群立克次體的感染可能也被忽視而需更多的研究及了解。
並列摘要
Rickettsioses are common agent as a cause of fever of unknown origin. In Taiwan, endemic rickettsial diseases including scrub typhus and murine typhus which brought about 300 to 400 and 30 to 40 annual cases separately in the past five years. However, positive rate of diagnosis in rickettsial diseases remained low in the past few years. In 2008, first human case of Rickettsia felis was reported in Taiwan. Clinical symptoms of R. felis are similar to other rickettsial diseases including fever, headache, myalgia, and macular rash, which make clinical diagnosis difficult. Also, R. felis may have cross reaction with R. typhi in serologic tests which may lead to misdiagnosis. Human cases of R. felis infection may be underestimated. To realize the epidemiology of R. felis infection in Taiwan, we analyzed 221 serological samples sent from National Taiwan University Hospital to the Centers for Disease Control (Taiwan CDC) for rickettsioses diagnosis during 2009 (86 samples) and 2010 (135 samples) which collected from 127 patients have negative diagnostic results of scrub typhus, murine typhus and Q fever. Three whole cell antigens were tested in immunofluorescence assay including R. felis which isolated from the cat flea, R. typhi and R. japonica. A total of 23 patients were positive for Rickettsia infection, 8 were positive for R. felis infection, 7 were positive for other spotted rickettsiae infection, because of the cross reaction in immunofluorescence assay, source of infection in 8 patients are further examined by absorb Western blot. Medical records of 3 cases are examined, clinical symptoms including fever, skin rash, chills, abdominal dullness, lymphadenopathy, hepatitis, septic shock with acute renal failure, and pneumonia with acute respiratory distress syndrome. The results confirm that R. felis is a potential pathogen in northern Taiwan, and other spotted rickettsiae infection may need further studies.