类圆线虫感染

粪便显微镜检的敏感性取决于执行检查的实验室的经验。对于富有经验的实验室，3 份阳性样本的敏感性为 50%~75%。[2]Genta RM. Global prevalence of strongyloidiasis: critical review with epidemiologic insights into the prevention of disseminated disease. Rev Infect Dis. 1989;11:755-767.http://www.ncbi.nlm.nih.gov/pubmed/2682948?tool=bestpractice.com[7]Boulware DR, Stauffer WM, Hendel-Paterson BR, et al. Maltreatment of Strongyloides infection: case series and worldwide physicians-in-training survey. Am J Med. 2007;120:545.e1-545.e8.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17524758http://www.ncbi.nlm.nih.gov/pubmed/17524758?tool=bestpractice.com[10]Caruana SR, Kelly HA, Ngeow JY, et al. Undiagnosed and potentially lethal parasite infections among immigrants and refugees in Australia. J Travel Med. 2006;13:233-239.http://onlinelibrary.wiley.com/doi/10.1111/j.1708-8305.2006.00045.x/fullhttp://www.ncbi.nlm.nih.gov/pubmed/16884406?tool=bestpractice.com

琼脂板粪便培养更敏感，但不常用于微生物学实验室。[26]Salazar SA, Gutierrez C, Berk SL. Value of the agar plate method for the diagnosis of intestinal strongyloidiasis. Diagn Microbiol Infect Dis. 1995;23:141-145.http://www.ncbi.nlm.nih.gov/pubmed/9407219?tool=bestpractice.com

粪便检查可见类圆线虫幼虫

敏感性为 80~85%。[7]Boulware DR, Stauffer WM, Hendel-Paterson BR, et al. Maltreatment of Strongyloides infection: case series and worldwide physicians-in-training survey. Am J Med. 2007;120:545.e1-545.e8.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17524758http://www.ncbi.nlm.nih.gov/pubmed/17524758?tool=bestpractice.com[11]Loutfy MR, Wilson M, Keystone JS, et al. Serology and eosinophil count in the diagnosis and management of strongyloidiasis in a non-endemic area. Am J Trop Med Hyg. 2002;66:749-752.http://www.ajtmh.org/cgi/reprint/66/6/749http://www.ncbi.nlm.nih.gov/pubmed/12224585?tool=bestpractice.com

无症状性嗜酸粒细胞增多症可见于 10%~15% 的新到达难民。[27]Seybolt LM, Christiansen D, Barnett ED. Diagnostic evaluation of newly arrived asymptomatic refugees with eosinophilia. Clin Infect Dis. 2006;42:363-367.http://cid.oxfordjournals.org/content/42/3/363.fullhttp://www.ncbi.nlm.nih.gov/pubmed/16392081?tool=bestpractice.com

当患者接受皮质类固醇治疗和出现重度感染时，通常不会出现嗜酸粒细胞增多症 (40%)。[16]Lim S, Katz K, Krajden S, et al. Complicated and fatal Strongyloides infection in Canadians: risk factors, diagnosis and management. CMAJ. 2004;171:479-484.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15337730http://www.ncbi.nlm.nih.gov/pubmed/15337730?tool=bestpractice.com[17]Newberry AM, Williams DN, Stauffer WM, et al. Strongyloides hyperinfection presenting as acute respiratory failure and gram-negative sepsis. Chest. 2005;128:3681-3684.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1941746/http://www.ncbi.nlm.nih.gov/pubmed/16304332?tool=bestpractice.com

嗜酸粒细胞增多症在感染儿童中通常比在成人中更严重。

＞0.4 x 10^9 个嗜酸性粒细胞/L（＞ 400 个嗜酸性粒细胞/μL）或相对嗜酸性粒细胞计数 ＞ 5%。

对于可能需要紧急使用皮质类固醇以治疗急症（如哮喘）（尤其是存在嗜酸粒细胞增多症时）且来自流行地区的移民，建议采取经验性伊维菌素。

在接受伊维茵素治疗 6~12 月后，三分之二的患者会出现血清学结果阴性或定量滴度将下降 40% 或更多。对于成功治疗的患者，嗜酸粒细胞增多症会在 6 个月随访时消退。[7]Boulware DR, Stauffer WM, Hendel-Paterson BR, et al. Maltreatment of Strongyloides infection: case series and worldwide physicians-in-training survey. Am J Med. 2007;120:545.e1-545.e8.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17524758http://www.ncbi.nlm.nih.gov/pubmed/17524758?tool=bestpractice.com

对于成功治疗的患者，嗜酸粒细胞增多症会在治疗后 6 个月随访时消退。

在重度感染病例中，可能在痰液虫卵和寄生虫检查中检测出幼虫。[7]Boulware DR, Stauffer WM, Hendel-Paterson BR, et al. Maltreatment of Strongyloides infection: case series and worldwide physicians-in-training survey. Am J Med. 2007;120:545.e1-545.e8.http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17524758http://www.ncbi.nlm.nih.gov/pubmed/17524758?tool=bestpractice.com

可见类圆线虫幼虫

在另一种临床样本（非粪便或痰）或活组织检查中（非肺部和胃肠道样本，肺部和胃肠道是常规类圆线虫生命周期涉及的部位）识别出类圆线虫幼虫时，可诊断为播散性类圆线虫感染。

可见类圆线虫幼虫

如嗜酸粒细胞增多症移民（来自流行地区）的粪便样本呈阴性，应考虑血清学检查。[11]Loutfy MR, Wilson M, Keystone JS, et al. Serology and eosinophil count in the diagnosis and management of strongyloidiasis in a non-endemic area. Am J Trop Med Hyg. 2002;66:749-752.http://www.ajtmh.org/cgi/reprint/66/6/749http://www.ncbi.nlm.nih.gov/pubmed/12224585?tool=bestpractice.com

根据需要，获得参考实验室的酶联免疫吸附法 (ELISA) 血清学检查。

血清学检查结果阳性

可能由皮肤活组织检查偶然发现。[Figure caption and citation for the preceding image starts]: 组织中的粪类圆线虫幼虫由明尼苏达州大学的 David Boulware 提供；经获准使用 [Citation ends].

在活组织检查中（非肺部和胃肠道样本，肺部和胃肠道是常规类圆线虫生命周期涉及的部位）识别出类圆线虫幼虫时，可诊断为播散性类圆线虫感染。

组织活检可见杆状蚴

PCR 是一种新兴的分子诊断工具，用于诊断类圆线虫感染。已经证明 PCR 检测的敏感性高于传统的虫卵和寄生虫检查。[25]Repetto SA, Ruybal P, Solana ME, et al. Comparison between PCR and larvae visualization methods for diagnosis of Strongyloides stercoralis out of endemic area: a proposed algorithm. Acta Trop. 2016;157:169-177.http://www.ncbi.nlm.nih.gov/pubmed/26868702?tool=bestpractice.com用于类圆线虫感染的商业 PCR 检测目前正在开发中。

DNA 检测