Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States.
Kongwa Trachoma Project, Kongwa, United Republic of Tanzania.
PLoS Negl Trop Dis. 2020 Oct 5;14(10):e0008708. doi: 10.1371/journal.pntd.0008708. eCollection 2020 Oct.
Trachoma is the leading infectious cause of blindness. Repeated or persistent ocular infection with Chlamydia trachomatis in childhood leads to conjunctival scarring, usually in adulthood but often earlier in areas with greater disease burden. There are limited longitudinal data examining change in scarring in children, especially where trachoma rates are low.
METHODOLOGY/PRINCIPAL FINDINGS: A cohort of children, ages 1-9 years, were randomly selected at baseline from 38 communities in Kongwa, Tanzania and followed for 2 years. Rates of trachomatous inflammation-follicular (TF) were <5% over the survey period. At baseline, 1,496 children were recruited and 1,266 (85%) were followed-up. Photographs were obtained at baseline and follow-up and graded for the presence and severity of scarring using a four-point scale ranging between S1-S4. In children without scarring at baseline, 1.6% (20/1,246) were found to have incident scarring, and incident scarring was more common among girls compared to boys. Among children with scarring at baseline, 21% (4/19) demonstrated progression.
CONCLUSIONS/SIGNIFICANCE: In this formerly hyper-endemic district, the incidence of new scarring in children ages 1-9 years is low, although 21% of those who had scarring at baseline progressed in severity over the 2-year follow-up period. These data provide support for the thesis that while incident scarring more closely reflects ongoing exposure, progression may involve factors independent of ongoing transmission of trachoma.
沙眼是导致失明的主要传染性病因。儿童时期反复或持续的沙眼衣原体眼部感染会导致结膜瘢痕形成，通常在成年期发生，但在疾病负担较重的地区往往更早。目前只有有限的纵向数据研究儿童瘢痕形成的变化，尤其是在沙眼发病率较低的地区。
方法/主要发现：在坦桑尼亚 Kongwa 的 38 个社区中，从基线开始，随机选择了年龄在 1-9 岁的儿童作为队列进行研究，并随访了 2 年。在整个调查期间，沙眼滤泡性炎症（TF）的发生率<5%。在基线时，共招募了 1496 名儿童，其中 1266 名（85%）接受了随访。在基线和随访时采集了照片，并使用 4 分制（S1-S4）对瘢痕的存在和严重程度进行分级。在基线时无瘢痕的儿童中，有 1.6%（20/1246）发现有新的瘢痕形成，且女孩的新瘢痕发生率高于男孩。在基线时有瘢痕的儿童中，有 21%（4/19）的瘢痕严重程度加重。
结论/意义：在这个曾经高度流行的地区，1-9 岁儿童中新发瘢痕的发生率较低，尽管 21%的基线有瘢痕的儿童在 2 年随访期间严重程度加重。这些数据支持了这样一种观点，即虽然新的瘢痕形成更能反映持续暴露，但进展可能涉及与沙眼持续传播无关的因素。
