沙眼防治研究取得新进展

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沙眼防治研究取得新进展


美国趣味科学网站12月21日报道：美国加州大学旧金山分校进行的一项研究显示，一种治疗有失明危险的眼部感染的方法每年使用一次的效果与每6个月使用一次相同。有关沙眼的这项随机性研究有望在利用同等药量的情况下使比原先多一倍的患者得到治疗。沙眼是世界上导致感染性失明的头号原因。

弗朗西斯·普罗克托眼科研究基金会助理教授布鲁斯·盖纳说：“关键是我们可以用更少的药物治疗更多的患者。鉴于成本问题和大规模治疗的不便性，我们将设法让药物尽可能派上最大的用场。”

研究人员的论文发表在本月出版的医学杂志《柳叶刀》上。他们在这项研究中开展了群体随机试验，利用一种名叫阿奇霉素的抗生素对埃塞俄比亚的沙眼患者进行治疗，埃塞俄比亚是世界上沙眼发病率最高的国家。他们挑选了24个村子并随机分成两组：12个村子的患者每6个月使用一次阿奇霉素，另外12个村子的患者则每12个月使用一次。

盖纳说：“我们发现，一开始沙眼的发病率很高。这些村庄里有40%-50%的儿童有这种病。他们是最容易感染的人群，而且沙眼会通过直接或间接接触方式迅速在人群之间传播。”

研究人员对两个患者群体都进行了跟踪，发现沙眼发病率都出现了明显下降。盖纳说：“我们发现，不管是一年治疗两次还是一年治疗一次，沙眼的发病率都跟原先的高达40%相比有了大幅下降，在一些村子甚至完全绝迹了。真的可以用较少的药办同样的事情。”

由于沙眼极易传播，因此这一研究成果具有重要意义。健康人与沙眼感染者发生密切接触，碰到了后者的眼睛或鼻子之后就会被传染。沙眼还可以通过患者使用过的毛巾或穿过的衣服传播。甚至苍蝇也会传播沙眼。

全球有大约4100万人感染沙眼，其中有800万人会由于得不到治疗而失明。全世界每年发放大约1.5亿份剂量的阿奇霉素用于治疗这种疾病。尚未发现衣原体沙眼菌存在对阿奇霉素的抗药性，这是阿奇霉素与其他抗生素的不同之处。阿奇霉素的这一特点以及此项重大研究成果给沙眼依旧肆虐的非洲、亚洲、中东乃至拉丁美洲和澳大利亚的部分地区带来了希望。盖纳说：“我们现在可以把治疗的覆盖面扩大一倍，这将对减少全球与沙眼有关的失明产生重大影响。”

Comparison of annual versus twice-yearly mass azithromycin treatment for hyperendemic trachoma in Ethiopia: a cluster-randomised trial

Background In trachoma control programmes, azithromycin is distributed to treat the strains of chlamydia that cause ocular disease. We aimed to compare the effect of annual versus twice-yearly distribution of azithromycin on infection with these strains. Methods We did a cluster-randomised trial in 24 subdistricts in northern Ethiopia, which we randomly assigned to receive annual or twice-yearly treatment for all residents of all ages. Random assignment was done with the RANDOM and SORT functions of Microsoft Excel. All individuals were offered their assigned treatment of a single, directly observed, oral dose of azithromycin. A 6 week course of topical 1% tetracycline ointment, applied twice daily to both eyes but not directly observed, was offered as an alternative to azithromycin in patients younger than 12 months, and in patients with self-reported pregnancy, with allergy, or who refused azithromycin. Our primary, prespecified outcome was the prevalence of ocular chlamydial infection in a random sample of children aged 0—9 years at baseline and every 6 months for a total of 42 months within sentinel villages. Our analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00322972. Findings Antibiotic coverage of children aged 1—9 years was greater than 80% (range 80·9 to 93·0) at all study visits. In the groups treated annually, the prevalence of infection in children aged 0—9 years was reduced from a mean 41·9% (95% CI 31·5 to 52·2) at baseline to 1·9% (0·3 to 3·5) at 42 months. In the groups treated twice yearly, the prevalence of infection was reduced from a mean 38·3% (29·0 to 47·6) at baseline to 3·2 % (0·0 to 6·5) at 42 months. The prevalence of ocular chlamydial infection in children aged 0—9 years in groups treated annually was not different from that of the groups treated twice yearly at 18, 30, and 42 months (pooled regression p>0·99, 95 % CI −0·06 to 0·06). The mean elimination time in the twice-yearly treatment group was 7·5 months earlier (2·3 to 17·3) than that of the annual group (p=0·10, Cox proportional hazards model). Interpretation After 42 months of treatment, the prevalence of ocular infection with chlamydia was similar in the groups treated annually and twice yearly. However, elimination of infection might have been more rapid in the groups of villages that received treatment twice yearly.

四叶草

据我们医院眼科大夫介绍我国有近80%的人有沙眼，看来，阿奇霉素新疗法对中国沙眼患者是一大福音。不知道国内有没有阿奇霉素滴眼液。