West Sheila K, Zambrano Andrea I, Sharma Shekhar, Mishra Sailesh K, Muñoz Beatriz E, Dize Laura, Crowley Kathryn, Gaydos Charlotte A, Rotondo Lisa A
Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, The Johns Hopkins School of Medicine, Baltimore, Maryland.
Nepal Netra Jyoti Sangh, Kathmandu, Nepal.
JAMA Ophthalmol. 2017 Nov 1;135(11):1141-1146. doi: 10.1001/jamaophthalmol.2017.3062.
To verify districts for elimination of blinding trachoma, the World Health Organization requires a population-based surveillance survey for follicular trachoma (TF) and trachomatous trichiasis (TT) 2 years after mass drug administration (MDA) activities have ceased. However, it is unknown if 2 years provides enough time to discover reemergence.
To determine the prevalence of trachoma from surveys among 4 districts in Nepal (Dailekh, Dang, Surkhet, and Kanchanpur) that had surveillance intervals of 2, 4, 8, and 10 years, respectively, after cessation of MDA.
DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional surveys were carried out in 2015 and 2016. Data analyses were done from March to September 2016. Among 20 clusters randomly selected from each district, 15 were randomly selected for infection and antibody testing: TF and TT were assessed, conjunctival swabs were tested for chlamydial infection, and blood spots were collected on filter paper to test for antibodies to Chlamydia trachomatis pgp3 using a multiplex bead assay. The study setting was 4 districts previously endemic for trachoma in Nepal. Participants were randomly selected and included 50 children aged 1 to 9 years and 100 adolescents and adults 15 years and older from each of the 20 clusters; this investigation reports on the children.
Length of time since the last round of MDA and the prevalence of TF among children aged 1 to 9 years and the prevalence of TT among adolescents and adults 15 years and older.
Of 3024 children surveyed in the clusters, 48.0% (n = 1452) were female. The mean (SD) age of the children was 5.4 (2.6) years. Eleven cases of TF were found, with a TF prevalence less than 1% in all 4 districts. Three cases of infection were found. Seropositivity for pgp3 antibody varied from 1.4% (95% CI, 0.7-2.6) in the district with a 10-year surveillance interval to 2.5% (95% CI, 1.3-4.5) in the district with a 4-year surveillance interval. Seropositivity increased slightly with age in only one district. The TT prevalence was less than 1 case per 1000 among the total population in all 4 districts after accounting for cases known to the health system and cases with no scarred conjunctiva.
This study found no evidence of reemergence of trachoma up to 10 years after cessation of MDA in 4 districts in children in Nepal. The recommendation for a surveillance survey at 2 years, as proposed by the World Health Organization, is supported by these data. Determining if individuals with TT had scarring or are known to the health system was critical for meeting elimination criteria of blinding trachoma.
为核实沙眼消除地区，世界卫生组织要求在大规模药物给药（MDA）活动停止2年后开展基于人群的滤泡性沙眼（TF）和沙眼性倒睫（TT）监测调查。然而，尚不清楚2年时间是否足以发现疾病再次出现。
确定尼泊尔4个地区（代莱赫、当、苏尔凯特和坎昌普尔）在MDA停止后分别间隔2年、4年、8年和10年进行调查时的沙眼患病率。
设计、地点和参与者：于2015年和2016年开展横断面调查。2016年3月至9月进行数据分析。从每个地区随机抽取的20个群组中，随机选取15个进行感染和抗体检测：评估TF和TT，检测结膜拭子中的衣原体感染，在滤纸上采集血斑，采用多重微珠分析法检测沙眼衣原体pgp3抗体。研究地点为尼泊尔之前沙眼流行的4个地区。参与者为随机选取，每个20个群组中包括50名1至9岁儿童以及100名15岁及以上青少年和成年人；本调查报道儿童情况。
自上一轮MDA以来的时间长度，以及1至9岁儿童中TF的患病率和15岁及以上青少年和成年人中TT的患病率。
在群组中接受调查的3024名儿童中，48.0%（n = 1452）为女性。儿童的平均（标准差）年龄为5.4（2.6）岁。发现11例TF病例，所有4个地区的TF患病率均低于1%。发现3例感染病例。pgp3抗体血清阳性率在监测间隔为10年的地区为1.4%（95%CI，0.7 - 2.6），在监测间隔为4年的地区为2.5%（95%CI，1.3 - 4.5）。仅在一个地区，血清阳性率随年龄略有增加。在计入卫生系统已知病例和无结膜瘢痕病例后，所有4个地区总人口中的TT患病率均低于每1000人1例。
本研究未发现尼泊尔4个地区MDA停止后长达10年儿童沙眼再次出现的证据。这些数据支持了世界卫生组织提议的2年进行一次监测调查 的建议。确定患有TT的个体是否有瘢痕或卫生系统是否已知对于满足致盲性沙眼消除标准至关重要。
