Hong In S, Zaidi Syed Y, McEvoy Peter, Neafie Ronald C
Department of Pathology, College of Medicine, Howard University, 520 W. Street, N.W., Washington, D.C. 20059, USA.
Acta Cytol. 2004 Mar-Apr;48(2):211-4. doi: 10.1159/000326318.
Strongyloides stercoralis, a nematode parasite in humans with free-living and autoinfective cycles, is often an asymptomatic infection of the upper small intestine. If the host becomes immunocompromised, autoinfection may increase the intestinal worm burden and lead to disseminated strongyloidiasis. The parthenogenetic adult female larvae can remain embedded in the mucosa of the small intestine for years, producing eggs that develop into either rhabditiform, noninfective larvae or filariform, infective larvae. Manifestations of dissemination occur when the filariform larvae penetrate the intestinal wall and migrate into the blood. Pulmonary involvement is common, and the central nervous system may be affected. Blood eosinophilia is typical, and gram-negative sepsis from enteric bacteria may occur. Much less commonly described is invasion of the peritoneal cavity with peritoneal effusion.
A 49-year-old man who came to the United States from Liberia 4 years earlier presented with sudden onset of severe abdominal distention, generalized weakness and marked pedal edema. Diagnostic paracentesis showed numerous filariform larvae of S stercoralis. Stool examination confirmed the presence of both rhabditiform and filariform larvae. Subsequently the patient was found to be HIV seropositive, with a CD4 lymphocyte count of 59.
Early detection of S stercoralis may alter the often-fatal course of infection. The present case is the second reported one in the English-language literature of the diagnosis of S stercoralis in ascitic fluid.
粪类圆线虫是一种寄生于人体的线虫寄生虫,具有自由生活和自身感染周期,通常是上小肠的无症状感染。如果宿主免疫功能受损,自身感染可能会增加肠道蠕虫负担并导致播散性类圆线虫病。孤雌生殖的成年雌性幼虫可在小肠黏膜中嵌入数年,产生的卵可发育为杆状、无感染性的幼虫或丝状、有感染性的幼虫。当丝状幼虫穿透肠壁并进入血液时,就会出现播散表现。肺部受累很常见,中枢神经系统也可能受到影响。典型表现为血液嗜酸性粒细胞增多,可能会发生肠道细菌引起的革兰氏阴性败血症。较少被描述的是伴有腹腔积液的腹腔感染。
一名49岁男性,4年前从利比里亚来到美国,出现突然发作的严重腹胀、全身无力和明显的足部水肿。诊断性腹腔穿刺术显示有大量粪类圆线虫丝状幼虫。粪便检查证实存在杆状和丝状幼虫。随后发现该患者HIV血清学呈阳性,CD4淋巴细胞计数为59。
粪类圆线虫的早期检测可能会改变通常致命的感染病程。本病例是英文文献中第二例报道的在腹水中诊断粪类圆线虫的病例。