本帖最後由 lsc0019 於 2009-8-19 00:39 編輯
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
July 28, 2009 — 根據7月29日英國醫學期刊(British Medical Journal)的前溯世代研究結果，一種可快速獲得結果的簡單驗尿方法，有助於男性感染砂眼披衣菌(Chlamydia trachomatis)的診斷。雖然此一感染一般沒有症狀而未被診斷，卻是在美國和英國最常見之性行為傳染的細菌感染症。若未加治療，衣原體會引起婦女骨盆發炎疾病、不孕、子宮外孕、男性也會不孕。
英國劍橋科學園區、Diagnostics for the Real World歐洲公司的Elpidio-Cesar Nadala等人寫道，我們評估了劍橋大學診斷發展部研發之新的衣原體快速檢測的表現。這項分析與一個蒐集男性尿液的裝置一起使用，特別適用於收集含有較多病原菌的初次淨排小便，不到1小時即可獲得檢測結果。這項分析發展用於幫助衣原體感染的診斷，提供篩檢工具以檢測有性行為的年輕男性是否有此類感染。
研究目標是評估衣原體快速檢測對於男性初次淨排小便樣本的偵測表現，看是否可以作為男性衣原體感染之診斷與篩檢的工具。研究對象包括年紀在16至73歲的1,211名男性，來自英國的青年性教育中心(來源1)或生殖祕尿醫學門診(來源2)。
衣原體快速檢測的敏感度、專一度、陽性與陰性預測值都與聚合酶連鎖反應相當，也測量衣原體快速檢測的目視訊號和有機體負載之間的關聯。
至於聚合酶連鎖反應，砂眼披衣菌的感染偵測率，來源1為4.4% (20/454)、來源2為11.9% (90/757)。至於衣原體快速檢測和聚合酶連鎖反應的比較，解析敏感度為82.6% (90/109)、專一度為98.5% (1085/1102)、陽性預測值為84.1% (90/107)、陰性預測值為98.3% (1085/1104)。
初次淨排小便樣本的有機體負載呈現衣原體陽性者，與衣原體快速檢測的目視訊號有顯著關聯(r，0.7897；P < .001)，範圍從7.28 × 102到6.93 × 106 plasmids/mL。
研究作者寫道，新的衣原體快速檢測對於男性初次淨排小便樣本的偵測表現顯示，它可作為男性衣原體感染之有效診斷工具。在1小時內可獲得檢測結果，將有助於立即治療與性關係之追蹤，可降低持續感染和傳染的風險。這項檢驗也可作為高流行性族群的男性衣原體尿液篩檢所用的核酸複製分析之簡單而可信的替代方法。
研究限制包括，來源1的衣原體盛行率低，無法控制某些尿液樣本中可能驗出的禁用物質。
研究作者結論表示，後續研究應聚焦在確認是否推廣衣原體快速檢測，用於篩檢高流行性族群之男性的衣原體感染，看是否有助於預防其女性伴侶的後遺症。此外，需要更多研究以確認衣原體快速檢測是否可更快速、簡單、非侵犯性的對年輕男性進行檢測，以增加接受度。快速檢測也可用於確認有症狀的非淋菌性尿道炎男性在接受照護時的衣原體狀態，可以更有效的進行性接觸史追蹤，且在檢測時就讓這些個案獲得健康促進資源。
Wellcome Trust支持本研究，另外有國家健康研究中心劍橋生物醫學研究中心的支持。3名研究作者、劍橋大學、Wellcome Trust 共同持有Diagnostics for the Real World公司，該公司生產劍橋大學研發這項快速檢測技術。
Urine Test May Help Diagnose Chlamydia in Men
By Laurie Barclay, MD
Medscape Medical News
July 28, 2009 — A simple urine test giving rapid results could help diagnose Chlamydia trachomatis infection in men, according to the results of a prospective cohort study reported in the July 29 issue of the British Medical Journal. Although this infection is typically asymptomatic and remains undiagnosed, it is the most common sexually transmitted bacterial infection in the United States and United Kingdom. If not treated, chlamydia may cause pelvic inflammatory disease, infertility, and ectopic pregnancy in women, as well as infertility in both sexes.
"We have evaluated the performance of a new Chlamydia Rapid Test, developed at the diagnostics development unit of the University of Cambridge," write Elpidio-Cesar Nadala, from Diagnostics for the Real World (Europe), Cambridge Science Park, United Kingdom, and colleagues. "The assay is used in conjunction with a collection device for male urine...specifically designed to collect the first voided urine that contains a higher organism load, and test results are available in less than an hour. This assay was developed to aid in the diagnosis of chlamydial infection and to provide a screening tool for the detection of such infection among young sexually active males."
The goal of this study was to assess the performance of Chlamydia Rapid Test with first-void male urine samples as a potential tool for the diagnosis and screening of chlamydial infection in men. The study cohort consisted of 1211 men aged 16 to 73 years attending a sexual health center for young people (site 1) or a genitourinary medicine clinic (site 2) in the United Kingdom.
The sensitivity, specificity, and positive and negative predictive value of the Chlamydia Rapid Test were compared with those of the polymerase chain reaction assay, and the association between the visual signal of the Chlamydia Rapid Test and organism load was also determined.
For the polymerase chain reaction assay, detection rates for C trachomatis infection were 4.4% (20/454) at site 1 and 11.9% (90/757) at site 2. For the Chlamydia Rapid Test vs polymerase chain reaction assay, the resolved sensitivity was 82.6% (90/109), specificity was 98.5% (1085/1102), positive predictive value was 84.1% (90/107), and negative predictive value was 98.3% (1085/1104).
The organism load in first-void urine samples that were positive for chlamydia correlated significantly with the visual signal of the Chlamydia Rapid Test (r, 0.7897; P < .001) and ranged from 7.28 × 102 to 6.93 × 106 plasmids/mL.
"The performance of the new Chlamydia Rapid Test with first void male urine samples indicates that it would be an effective diagnostic tool for chlamydial infection in men," the study authors write. "The availability of test results within an hour allows for immediate treatment and contact tracing, potentially reducing the risks for persistent infection and onward transmission. The test could also provide a simple and reliable alternative to nucleic acid amplification assays for testing of male urine in chlamydial screening programmes in high prevalence settings."
Limitations of this study include the low prevalence of chlamydia at site 1 and the inability to control for inhibitory substances potentially present in some urine specimens.
"Future studies should focus on determining whether the widespread use of the Chlamydia Rapid Test in screening young men for chlamydial infection in high prevalence settings can help prevent sequelae among their female sexual partners," the study authors conclude. "In addition, more studies are warranted to verify whether the Chlamydia Rapid Test would reassure young men that testing can be quick, simple, and non-invasive, and this might increase uptake. The rapid test might also be used to confirm the chlamydia status in men with symptomatic non-gonococcal urethritis at the point of care, thus allowing more efficient contact tracing and focusing the health promotion resources on these individuals at the time of testing."
The Wellcome Trust supported this study, with additional support from the National Institute for Health Research Cambridge Biomedical Research Centre. Three of the study authors, the University of Cambridge, and the Wellcome Trust are equity holders in Diagnostics for the Real World, which markets the rapid test technologies developed at the University of Cambridge.
BMJ. 2009;339:b2655. |
|
