Department of Parasitology, Research Institute of Ophthalmology, El-Giza, Egypt.
Department of Parasitology, Faculty of Medicine, Fayoum University, Egypt.
J Infect Public Health. 2018 May-Jun;11(3):377-383. doi: 10.1016/j.jiph.2017.09.013. Epub 2017 Sep 28.
Acanthamoeba keratitis (AK) is a severe corneal infection that may occur as a serious outcome of improper use of contact lenses (CL).
The study aimed to diagnose AK in soft CL users presenting with infectious keratitis, and to identify the prevalent genotypes isolated from different cases. Another aim was to determine the CL hygiene-related risk behaviors, and to explore the risk of water exposure for developing AK.
A cross sectional study was performed. A questionnaire was carried out including 260 clinically diagnosed cases as infectious keratitis (170 females and 90 males); all of them were soft CL users for the suspected risk factors. Corneal scrapes from the affected eyes were cultured to diagnose bacterial and AK. PCR was performed and the amplified products were sequenced and compared with GenBank data.
The parasite was positively amplified from 32 samples (12.3%). Acanthamoeba T4 genotype was identified in 27/32 (84.4%) of isolates. Other detected genotypes belonged to T5 and T3 genotypes at rates of 9.4%, and 6.25%, respectively. The most important risk factors associated with development of AK were female sex, sleeping while wearing CL, and exposure to water resources through different practices. These practices included rinsing the CL case in tap water, swimming and/or showering while wearing CL, using multipurpose solution for cleaning the lenses, using water from over-building tanks. Rubbing the eyes due to discomfort when applying CL was an additional important risk factor associated with AK. The protective factor was regular hand washing before using CL.
CL users were more exposed to AK and should gain enough health education regarding proper lens hygiene and dangers of tap water exposure.
棘阿米巴角膜炎（AK）是一种严重的角膜感染，可能是由于隐形眼镜（CL）使用不当而导致的严重后果。
本研究旨在诊断软性 CL 使用患者中出现的感染性角膜炎中的 AK，并确定从不同病例中分离出的常见基因型。另一个目的是确定与 CL 卫生相关的风险行为，并探讨接触水与 AK 发病的风险。
进行了一项横断面研究。进行了一项问卷调查，包括 260 例临床诊断为感染性角膜炎的病例（170 名女性和 90 名男性）；所有这些患者都是软性 CL 的使用者，具有可疑的危险因素。从受影响的眼睛刮取角膜标本，进行细菌和 AK 的培养。进行 PCR，扩增产物测序，并与 GenBank 数据进行比较。
从 32 个样本中（12.3%）阳性扩增出寄生虫。在 27/32（84.4%）的分离株中鉴定出棘阿米巴 T4 基因型。其他检测到的基因型分别为 T5 和 T3 基因型，比例分别为 9.4%和 6.25%。与 AK 发展相关的最重要的危险因素是女性、戴隐形眼镜睡觉以及通过不同的实践接触水资源。这些做法包括在自来水中冲洗 CL 盒、戴隐形眼镜游泳和/或洗澡、使用多用途溶液清洁镜片、使用水箱中的水。因戴隐形眼镜而感到不适时揉眼睛是与 AK 相关的另一个重要危险因素。保护因素是戴隐形眼镜前经常洗手。
CL 用户更容易受到 AK 的影响，应该获得足够的健康教育，包括正确的镜片卫生和接触自来水的危害。
