Clinical Research Unit, Department of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom.
PLoS Negl Trop Dis. 2010 Nov 2;4(11):e861. doi: 10.1371/journal.pntd.0000861.
Blinding trachoma, caused by ocular infection with Chlamydia trachomatis, is targeted for global elimination by 2020. Knowledge of risk factors can help target control interventions.
METHODOLOGY/PRINCIPAL FINDINGS: As part of a cluster randomised controlled trial, we assessed the baseline prevalence of, and risk factors for, active trachoma and ocular C. trachomatis infection in randomly selected children aged 0-5 years from 48 Gambian and 36 Tanzanian communities. Both children's eyes were examined according to the World Health Organization (WHO) simplified grading system, and an ocular swab was taken from each child's right eye and processed by Amplicor polymerase chain reaction to test for the presence of C. trachomatis DNA. Prevalence of active trachoma was 6.7% (335/5033) in The Gambia and 32.3% (1008/3122) in Tanzania. The countries' corresponding Amplicor positive prevalences were 0.8% and 21.9%. After adjustment, risk factors for follicular trachoma (TF) in both countries were ocular or nasal discharge, a low level of household head education, and being aged ≥ 1 year. Additional risk factors in Tanzania were flies on the child's face, being Amplicor positive, and crowding (the number of children per household). The risk factors for being Amplicor positive in Tanzania were similar to those for TF, with the exclusion of flies and crowding. In The Gambia, only ocular discharge was associated with being Amplicor positive.
CONCLUSIONS/SIGNIFICANCE: These results indicate that although the prevalence of active trachoma and Amplicor positives were very different between the two countries, the risk factors for active trachoma were similar but those for being Amplicor positive were different. The lack of an association between being Amplicor positive and TF in The Gambia highlights the poor correlation between the presence of trachoma clinical signs and evidence of C. trachomatis infection in this setting. Only ocular discharge was associated with evidence of C. trachomatis DNA in The Gambia, suggesting that at this low endemicity, this may be the most important risk factor.
ClinicalTrials.gov NCT00792922.
由沙眼衣原体眼部感染引起的致盲性沙眼，目标是在 2020 年之前在全球消除。了解危险因素有助于确定控制干预的目标。
方法/主要发现：作为一项整群随机对照试验的一部分，我们评估了随机选择的来自冈比亚 48 个和坦桑尼亚 36 个社区的 0-5 岁儿童中活动性沙眼和眼部沙眼衣原体感染的基线患病率和危险因素。按照世界卫生组织（WHO）简化分级系统检查了所有儿童的双眼，并从每个儿童的右眼采集眼拭子，用 Amplicor 聚合酶链反应进行处理，以检测沙眼衣原体 DNA 的存在。在冈比亚，活动性沙眼的患病率为 6.7%（335/5033），在坦桑尼亚为 32.3%（1008/3122）。相应的 Amplicor 阳性率在这两个国家分别为 0.8%和 21.9%。调整后，两个国家滤泡性沙眼（TF）的危险因素均为眼部或鼻部分泌物、家庭主要负责人教育水平低和年龄≥1 岁。在坦桑尼亚，增加的危险因素还有儿童面部有苍蝇、Amplicor 阳性和拥挤（每个家庭的儿童人数）。坦桑尼亚与 Amplicor 阳性相关的危险因素与 TF 相似，只是排除了苍蝇和拥挤。在冈比亚，只有眼部分泌物与 Amplicor 阳性相关。
结论/意义：这些结果表明，尽管两个国家的活动性沙眼和 Amplicor 阳性率存在很大差异，但活动性沙眼的危险因素相似，而 Amplicor 阳性的危险因素不同。在冈比亚，Amplicor 阳性与 TF 之间缺乏关联，这突出表明在这种低流行环境下，沙眼临床体征的存在与沙眼衣原体感染的证据之间相关性较差。在冈比亚，只有眼部分泌物与沙眼衣原体 DNA 的存在相关，这表明在这种低流行程度下，这可能是最重要的危险因素。
ClinicalTrials.gov NCT00792922。
