Long COVID represents an unprecedented case of patient-led illness definition, emerging through Twitter in May 2020 when patients began collectively naming, documenting, and legitimizing their condition before medical institutions recognized it. This study examines 2.8 million tweets containing #LongCOVID to understand how contested illness communities construct knowledge networks and respond to epistemic injustice. Through topic modeling, reflexive thematic analysis, and exponential random graph modeling (ERGM), we identify seven discourse themes spanning symptom documentation, medical dismissal, cross-illness solidarity, and policy advocacy. Our analysis reveals a differentiated ecosystem of user roles -- including patient advocates, research coordinators, and citizen scientists -- who collectively challenge medical gatekeeping while building connections to established ME/CFS advocacy networks. ERGM results demonstrate that tie formation centers on epistemic practices: users discussing knowledge sharing and community building formed significantly more network connections than those focused on policy debates, supporting characterization of this space as an epistemic community. Long COVID patients experienced medical gaslighting patterns documented across contested illnesses, yet achieved WHO recognition within months -- contrasting sharply with decades-long struggles of similar conditions. These findings illuminate how social media affordances enable marginalized patient populations to rapidly construct alternative knowledge systems, form cross-illness coalitions, and contest traditional medical authority structures.

翻译：长新冠代表了患者主导疾病定义的前所未有案例，该概念于2020年5月通过Twitter平台浮现——患者在医疗机构尚未承认其病症时，便开始集体命名、记录并确证自身状况。本研究通过分析280万条包含#长新冠标签的推文，探讨争议性疾病社群如何构建知识网络并应对认知不公。借助主题建模、反思性主题分析与指数随机图模型（ERGM），我们识别出七大话语主题，涵盖症状记录、医学漠视、跨疾病团结和政策倡导。分析揭示了一个差异化的用户角色生态系统——包括患者倡导者、研究协调员和公民科学家——他们共同挑战医学知识垄断，同时与既有的肌痛性脑脊髓炎/慢性疲劳综合征（ME/CFS）倡导网络建立联结。ERGM结果表明，连接形成以认知实践为核心：讨论知识共享和社区建设的用户形成的网络连接显著多于聚焦政策辩论者，这支持了将该空间界定为认知共同体的特征。长新冠患者经历了争议性疾病中普遍存在的医学否定模式，却在数月内获得世界卫生组织（WHO）的官方认可——这与类似病症长达数十年的抗争形成鲜明对比。这些发现阐明了社交媒体如何赋能边缘化患者群体快速构建替代性知识体系、形成跨疾病联盟，并挑战传统医学权威结构。