美国在 2025 年报告了 2,242 例麻疹确诊病例，创 30 多年来新高。进入 2026 年，形势仍在恶化。南卡罗来纳州自 10 月以来已报告超过 600 例病例，且增长速度可能超过此前的西德克萨斯州疫情。全国范围内，疫苗接种率持续下降，被认为是病例回升的关键背景因素。

南卡罗来纳州疫情于 10 月 2 日以最初的 8 例开始，年底前增至 176 例。截至 1 月 20 日，确诊病例达到 646 例，其中 10 人住院治疗，另有 538 人被认定为潜在暴露并被要求居家隔离。病例主要集中在该州西北部，每天新增病例保持在两位数，并已波及两所大学校园，公共暴露地点仍在持续增加。

对比来看，西德克萨斯州疫情共造成 762 例确诊、99 例住院和 2 名未接种疫苗的学龄儿童死亡，历时约 7 个月。南卡罗来纳州 646 例中，563 例未接种疫苗，12 例仅接种 1 剂，13 例完成接种，58 例接种状态不明。麻疹群体免疫通常需要至少 95% 的两剂接种率，但疫情中心斯帕坦堡县仅为 90%，而某些学校低至 21%，显示出持续暴发的结构性风险。

The United States reported 2,242 confirmed measles cases in 2025, the highest level in more than 30 years. Entering 2026, conditions are worsening. South Carolina has reported more than 600 cases since October, and the pace suggests it could surpass the previous West Texas outbreak. Nationwide, steadily declining vaccination rates are widely viewed as a key factor behind the resurgence.

The South Carolina outbreak began on October 2 with an initial 8 cases and rose to 176 by the end of the year. As of January 20, confirmed cases reached 646, with 10 hospitalizations and 538 additional people identified as potentially exposed and instructed to quarantine at home. Cases are concentrated in the northwestern part of the state, with new infections reported in double digits each day, affecting two college campuses and an expanding list of public exposure sites.

By comparison, the West Texas outbreak caused 762 confirmed cases, 99 hospitalizations, and 2 deaths among unvaccinated school-age children over roughly 7 months. Of South Carolina’s 646 cases, 563 are unvaccinated, 12 received only 1 dose, 13 are fully vaccinated, and 58 have unknown status. Measles control generally requires at least 95% two-dose vaccination coverage, yet Spartanburg County is at 90%, and some schools are as low as 21%, indicating sustained structural risk for continued outbreaks.