沙眼

title: 症状.
content: 人体感染后的潜伏期为5-14天。之后衣原体在角膜和结膜处生长,造成双眼结膜充血、结膜乳头增生、流泪、怕光、疼痒或异物感,眼部分泌物增多等类似细菌性结膜炎的症状,多见于上眼睑。患者睑结膜上皮组织的淋巴细胞聚集,形成突出的增生,此为外观可见的沙样颗粒。持续感染造成睫毛倒生、结膜结疤,角膜浑浊、眼睑内翻等症状,在有些患者身上可导致视力减退甚至失明。感染可以重复进行,最终各病态增生组织被瘢痕代替。  慢性沙眼:可因反复感染,病程迁延数年至十多年。充血程度虽减轻,但与皮下组织有弥漫性细胞浸润,结膜显污秽肥厚,同时有乳头增生及滤泡形成,滤泡大小不等,可显胶样,病变以上穹隆及睑板上缘结膜显著。同样病变亦见于下睑结膜及下穹隆结膜,严重者甚至可侵及半月皱壁。角膜血管翳:它是由角膜缘外正常的毛细血管网,越过角膜缘进入透明角膜,影响视力,并逐渐向瞳孔区发展,伴有细胞浸润及发展为浅的小溃疡,痊愈后可形成角膜小面。细胞浸润严重时可形成肥厚的肉样血管翳)。
title: 治疗和预防.
content: 砂眼的预防主要是以清洗用品、消灭苍蝇等方法来改善卫生,切断传播渠道。一些抗生素也可以用来预防传染。  以局部用药为主,常用利福平、金霉素、红霉素、四环素或磺胺滴眼液,需连续用药1～3个月。急性或严重沙眼,除局部用药外可口服四环素或磺胺,7～10天为一疗程,停药一周后再服用,一般需2～4个疗程。若乳头、滤泡严重时,可行沙眼滤泡挤压术。沙眼为接触性传染,故除治疗外应做好预防工作,如加强卫生宣传,改善环境卫生,培养良好的卫生习惯等。

Summary: 砂眼(英语:Trachoma),又称颗粒性结膜炎(英语:Granular conjunctivitis)、埃及眼炎(英语:Egyptian ophthalmia)和致盲性砂眼(英语:blinding trachoma)是由砂眼披衣菌感染导致的传染病。感染砂眼会造成眼睑内侧肉芽组织,可能导致眼睛痛、角膜表层受损或失明。未治疗而反复感染砂眼可能造成眼睑内翻而失明。 导致砂眼的病原体可因为直接以及间接接触到患者的眼睛或鼻子而传播。直接接触包括借由碰触衣物或苍蝇,而这些物体都曾和已感染病患的眼睛或鼻子触碰过。许多感染可能要长达几年的时间,才会让眼睑疤痕肿大到让睫毛开始摩擦眼睛的程度。孩童散播砂眼的几率高于成人。卫生条件不良、居住环境拥挤,以及缺乏干净水源和厕所等,都可能助长砂眼的传播。 预防的方法包括提升清水的获得及利用抗生素作治疗,包括一次治疗整个砂眼感染常见的族群。自行清洗不足以预防砂眼,但若配合其他措施,可能是有效的方法 。药物治疗包含口服阿奇霉素,及涂抹四环霉素。通常较偏好使用阿奇霉素,因为只需一次给药。如眼睑上已产生疤痕,可能必须进行手术矫正睫毛的位置,以预防失明。 全球统计,约有8,000万人有主动侵染的情形。在部分地区,幼童的感染率高达60-90%,且女性的发病率较男性高,推测可能和幼童频繁接触有关。砂眼是导致220万人视力衰退的原因,当中有120万人甚至已全盲。在非洲53个国家、亚洲、中南美洲约有2.3亿人暴露在得病的高危险中。每年可造成80亿美元的经济损失。砂眼被归类于「被忽视热带病」之一。

Trachoma: Trachoma is an infectious disease caused by bacterium "Chlamydia trachomatis". The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness. Untreated, repeated trachoma infections can result in a form of permanent blindness when the eyelids turn inward. The bacteria that cause the disease can be spread by both direct and indirect contact with an affected person's eyes or nose. Indirect contact includes through clothing or flies that have come into contact with an affected person's eyes or nose. Children spread the disease more often than adults. Poor sanitation, crowded living conditions, and not enough clean water and toilets also increase spread. Efforts to prevent the disease include improving access to clean water and treatment with antibiotics to decrease the number of people infected with the bacterium. This may include treating, all at once, whole groups of people in whom the disease is known to be common. Washing, by itself, is not enough to prevent disease but may be useful with other measures. Treatment options include oral azithromycin and topical tetracycline. Azithromycin is preferred because it can be used as a single oral dose. After scarring of the eyelid has occurred, surgery may be required to correct the position of the eyelashes and prevent blindness. Globally, about 80 million people have an active infection. In some areas, infections may be present in as many as 60–90% of children. Among adults, it more commonly affects women than men – likely due to their closer contact with children. The disease is the cause of decreased vision in 2.2 million people, of whom 1.2 million are completely blind. It commonly occurs in 53 countries of Africa, Asia, and Central and South America, with about 230 million people at risk. It results in US$8 billion of economic losses a year. It belongs to a group of diseases known as neglected tropical diseases.