Service Fraternel d'Entraide, Vientiane, Lao People's Democratic Republic.
PLoS Negl Trop Dis. 2011 May;5(5):e1048. doi: 10.1371/journal.pntd.0001048. Epub 2011 May 17.
We evaluated the Ziehl-Neelsen staining (ZNS) technique for the diagnosis of paragonimiasis in Laos and compared different modifications of the ZNS techniques.
WE APPLIED THE FOLLOWING APPROACH: We (1) examined a paragonimiasis index case's sputum with wet film direct examination (WF) and ZNS; (2) re-examined stored ZNS slides from two provinces; (3) compared prospectively WF, ZNS, and formalin-ether concentration technique (FECT) for sputum examination of patients with chronic cough; and (4) compared different ZNS procedures. Finally, we assessed excess direct costs associated with the use of different diagnostic techniques.
Paragonimus eggs were clearly visible in WF and ZNS sputum samples of the index case. They appeared brownish-reddish in ZNS and were detected in 6 of 263 archived ZNS slides corresponding to 5 patients. One hundred sputum samples from 43 patients were examined with three techniques, which revealed that 6 patients had paragonimiasis (13 positive samples). Sensitivity per slide of the FECT, ZNS and the WF technique was 84.6 (p = 0.48), 76.9 (p = 0.25) and 61.5% (p = 0.07), respectively. Percentage of fragmented eggs was below 19% and did not differ between techniques (p = 0.13). Additional operational costs per slide were 0 (ZNS), 0.10 US$ (WF), and 0.79 US$ (FECT). ZNS heated for five minutes contained less eggs than briefly heated slides (29 eggs per slide [eps] vs. 42 eps, p = 0.01). Bloodstained sputum portions contained more eggs than unstained parts (3.3 eps vs. 0.7 eps, p = 0.016).
CONCLUSIONS/SIGNIFICANCE: Paragonimus eggs can easily be detected in today's widely used ZNS of sputum slides. The ZNS technique appears superior to the standard WF sputum examination for paragonimiasis and eliminates the risk of tuberculosis transmission. Our findings suggest that ZNS sputum slides should also be examined routinely for Paragonimus eggs. ZNS technique has potential in epidemiological research on paragonimiasis.
我们评估了在老挝用于诊断并殖吸虫病的萋-尼氏染色（ZNS）技术，并比较了该技术的不同改良方法。
我们采用了以下方法：（1）对一名并殖吸虫病索引病例的痰液进行湿片直接镜检（WF）和 ZNS 检查；（2）重新检查来自两个省份的储存 ZNS 载玻片；（3）前瞻性比较 WF、ZNS 和福尔马林-乙醚浓缩技术（FECT）对慢性咳嗽患者痰液的检查；（4）比较不同的 ZNS 程序。最后，我们评估了使用不同诊断技术所带来的额外直接成本。
在索引病例的 WF 和 ZNS 痰液样本中，明显可见并殖吸虫卵。在 ZNS 中，它们呈棕红色，在 263 张存档 ZNS 载玻片中有 6 张与 5 名患者相对应，共检测到 6 张。用三种技术检查了 43 名患者的 100 份痰液样本，结果显示 6 名患者患有并殖吸虫病（13 个阳性样本）。FECT、ZNS 和 WF 技术的每张载玻片的灵敏度分别为 84.6%（p=0.48）、76.9%（p=0.25）和 61.5%（p=0.07）。碎裂卵的百分比低于 19%，且在不同技术之间无差异（p=0.13）。每张载玻片的额外运营成本分别为 0（ZNS）、0.10 美元（WF）和 0.79 美元（FECT）。加热 5 分钟的 ZNS 载玻片比短暂加热的载玻片含有的卵少（每张载玻片 29 个卵[eps]与 42 eps，p=0.01）。血污部分的痰液比未血污部分含有更多的卵（3.3 eps 与 0.7 eps，p=0.016）。
结论/意义：在现今广泛使用的 ZNS 痰液载玻片上，很容易检测到并殖吸虫卵。ZNS 技术似乎优于标准 WF 痰液检查，可消除结核病传播的风险。我们的研究结果表明，ZNS 痰液载玻片也应常规检查是否存在并殖吸虫卵。ZNS 技术在并殖吸虫病的流行病学研究中具有潜力。
