Alumnus at Critical Care Department, Cardiff University, Cardiff, UK
Medical Department, EpiConsult Biomedical Consulting and Medical Communications Agency, Dover, UK.
Postgrad Med J. 2020 Nov;96(1141):686-692. doi: 10.1136/postgradmedj-2020-137673. Epub 2020 Jun 18.
In the summer of 2019, the Center for Disease Control and Prevention (CDC) declared an emergency of electronic cigarettes and/or vaping (vaping)-associated lung injury (EVALI) in the USA. The outbreak abated by January 2020, which the CDC attributed to heightened public awareness, 'user actions to reduce risk' and potentially the removal of vitamin E acetate (VEA) from vaping products (VEA is an oily chemical cutting agent, strongly associated with the disease). Even though the EVALI outbreak appears to be over, numerous epidemiological and medical questions are left still open. First, why were there practically no cases outside the USA, which represents nearly a quarter of the global vaping market? Comparative studies to map the differences in device/fluids/user habits between countries might be needed urgently. Second, what is the pathomechanism that sickens vapers irrespective of VEA exposure? VEA was only confirmed in about half of the cases and the presumed toxicity is yet to be determined. Aetiology/epidemiology focused research is needed to investigate/interpret the broader context to explain the outbreak. Third, could any socioeconomic/environmental factors have influenced the course of the outbreak? Finally, what should we expect in the years to come? Was EVALI a serious but reversible emergency medicine condition or is vaping as detrimental to long-term health as smoking? Besides the complex legislative, regulatory, ethical aspects of EVALI, biomedical research is also difficult: in-vitro experiments have limited inferential value to real real-life vaping due to its complexity; user habits are self-reported and under-researched; there is an active black market pouring unknown quality counterfeit products and, in the USA, federal restrictions limit cannabis research. Vaping is a toxicological, multidimensional conundrum; therefore, stringent quality control, transparent legal/ethical boundaries, meticulous international research and user education are paramount to prevent potential future outbreaks and determine the parameters safe vaping (if these exist).
2019 年夏天，美国疾病控制与预防中心（CDC）宣布电子烟和/或蒸气相关肺损伤（EVALI）为公共卫生紧急事件。到 2020 年 1 月，疫情得到缓解，CDC 将其归因于公众意识的提高、“用户采取行动降低风险”以及蒸气产品中可能去除维生素 E 醋酸盐（VEA）（VEA 是一种油性化学切割剂，与该疾病密切相关）。尽管 EVALI 疫情似乎已经结束，但仍有许多流行病学和医学问题尚未解决。首先，为什么美国以外的国家几乎没有病例，而美国占全球蒸气市场的近四分之一？可能需要紧急进行比较研究，以绘制各国之间设备/液体/用户习惯差异的图谱。其次，无论是否接触 VEA，使蒸气者生病的发病机制是什么？只有大约一半的病例中确认了 VEA，而假定的毒性仍有待确定。需要针对病因/流行病学的研究来调查/解释更广泛的背景，以解释疫情的爆发。第三，任何社会经济/环境因素是否会影响疫情的进程？最后，我们在未来几年中应该期待什么？EVALI 是一种严重但可逆转的急诊医学病症，还是像吸烟一样对长期健康有害？除了 EVALI 复杂的立法、监管、伦理方面外，生物医学研究也很困难：由于其复杂性，体外实验对真实的蒸气使用的推断价值有限；用户习惯是自我报告的，研究不足；有一个活跃的黑市充斥着未知质量的假冒产品，而且在美国，联邦限制限制了对大麻的研究。蒸气是一个毒理学的、多维度的难题；因此，严格的质量控制、透明的法律/伦理界限、细致的国际研究和用户教育对于防止潜在的未来疫情并确定安全蒸气的参数（如果存在的话）至关重要。
