Case report 14

Reporter I1 賴俊甫

Present illness

A 24-year-old male medical student from West Africa had lived in the United States for several years and had made periodic visits home to visit his family.

When he fell ill with symptoms of severe myalgia, abdominal discomfort, vomiting, diarrhea, fever, chills, and sweats, he presented to the emergency room, where he was noted to have an itchy rash and a tender, indurated, erythematous lesion on his left fore-arm. He had a diminished reaction to pain. Enlarged posterior cervical lymph nodes were apparent on physical examination.

Lab finding

Blood was drawn for laboratory studies. Based on clinical symptoms and the patient's former residence in West Africa, the laboratory was asked to look for blood parasites.

Thick and thin blood smears were prepared and stained by the Giemsa method. A lymph node aspirate was also stained by the Giemsa method. Slender protozoan forms having long, free flagella, were seen in both blood smears and lymph node prepa rations.

溼血液抹片 這個方法是在顯微鏡玻片上置一滴血液然後覆上蓋玻片。用 x40 倍物鏡的顯微鏡來檢查。可以看到錐蟲在紅血球之間的活動。

厚血液抹片 將一滴血液置於玻片上，然後再用玻片的邊緣將之抹開成直徑約 2 公分的範圍。在空氣中搖動使之加速乾燥，不需加以固定。用緩衝溶液配成的 4% Giemsa 染色液染色 30 分鐘 ( 根據製造廠商和操作人員技術的不同而有不同的染色時間和染色液稀釋濃度。以製造的說明為標準做各種不同時間和濃度的比較來找出最合適的結果 ) 。將玻片洗淨之後用 x100倍油鏡來檢查。由錐蟲的特徵性形態可在顯微鏡下很容易地就看出來，但錐蟲可能在染色過程中受到損傷，而增加品種判斷的困難。

薄血液抹片 這個方法主要是用來鑑別錐蟲的品種。它是先置一小滴血液於玻片上然後將之抹於另一片玻片。塗抹的方法是用一玻片置於另一玻片之邊緣上並使其成30° 的角度，兩玻片的接觸點平均沾著血液之後，將玻片往上拉到玻片的另一端，而使血液成一層均勻而且薄的膜。在空氣中搖動使之乾燥，用甲醇固定 3 分鐘，再用和厚血液抹片一樣的方法來染色。染色後用水龍頭水輕輕洗過，待其乾燥之後用 x100 倍油鏡的顯微鏡下檢查 ( 另一方法是固定 2 分鐘後再加入 May-Grunwald 染色液後放置 2 分鐘，然後加入等量的緩衝液後放置 8 分鐘，最後讓溶液流乾 ) 。這個方法可以看出錐蟲的特徵性形態。

Question 1

Which infection does this patient have? What is the name of the hemoflagellatecausing his infection?

非洲錐蟲症 (African Trypanosomiasis) 岡比亞錐蟲 (Trypanosoma gambiense) 洛締斯錐蟲 (Trypanosoma rhodesiense)

睡眠病 (sleeping sickness) 錐蟲進入腦幹之後造成破壞，產生 acute hemorr

hagic leukocephalopathy ，而使病人產生昏睡

岡比亞錐蟲 gambiense 洛締斯錐蟲 rhodesiense

分部地區 西非、中非 東非、南非 位置 水邊、人口聚集處 大草原、最近才砍過的

灌木叢 主要宿主 人類 大角羚羊、水牛 Disease 慢性，晚期入侵 CNS 急性，早期就入侵 CNS 持續期間 數月到數年 (時間長 ) 數週到數月 (時間短 ) 辨別方式 淋巴結 (慢性傳染所以

在淋巴結可發現 )CSF測試

血液檢查、 CSF測試

Question 2

Describe the life cycle of this hemoflagellate.

Tsetse fly(采采蠅 ) ，一般蚊子只有雌的會吸血，但是采采蠅雌、雄都會吸血，血液為最主要的食物

經由吸取患者的血液來完成傳播

Question 3

What is the term given to the lymphadenopathy noted in this patient?

感染錐蟲的臨床表徵：Winterbottom’s sign後頸三角淋巴結腫大

Question 4

What is the term used to describe the delayed sensation to pain?

隨血液跑到中樞神經後，會出現Kerendel sign 長期會出現 CNS 的傷害 ,包括運動 ,感覺及神智 . 加壓於手掌或是尺神經 ,解除壓力後會引發劇烈疼痛 。

Question 5

How is the diagnosis of this infection made?

直接診斷 : 血液抹片 : 適用於絡締斯錐蟲之診斷 淋巴腺穿刺 ：適用於岡比亞錐蟲之診斷 骨髓穿刺：適用於感染早期 腦脊髓液檢查

間接診斷： 血清學檢查 (Card agglutination test for tr

ypanosomiasis, CATT)

在血液、淋巴液或 CSF 中找到蟲體 .

Question 6

Which form of this parasite is the diagnostic stage seen in clinical specimens?

Describe the morphological appearance of this form.

非洲錐蟲呈現 slender form南美洲錐蟲在血液中呈現 C form

Slender protozoan forms having long, free flagella, were seen in both blood smears and lymph node prepa rations.

非洲錐蟲 slender form

南美洲錐蟲 C form

Question 7

How does the patient's travel history aid in the diagnosis of this infection?

West Africa

Question 8

Discuss the treatment for this infection.

岡比亞錐蟲感染： 早期 (未侵犯神經中樞 )： Suramine 晚期 (已侵犯神經中樞 ) ：Melarsoprol

(砷 ) (DL-alpha-difluoromethylornithine, DFMO, ef

lornithine)絡締斯錐蟲感染： 早期 (未侵犯神經中樞 )： Pentamidine 晚期 (已侵犯神經中樞 ) ： Melarsoprol

Reference

寄生蟲學科 : 詹益欣老師教學檔醫學快紀：

http://medicine.zh-tw.org/index.php/%E9%A6%96%E9%A0%81

Thanks for your attention!!