PDF(Pubmed)
Abstract：
Legionnaires\' disease (LD) is a severe form of pneumonia (∼10-25% fatality rate) caused by inhalation of aerosols containing Legionella, a pathogenic gram-negative bacteria. These bacteria can grow, spread, and aerosolize through building water systems. A recent dramatic increase in LD incidence has been observed globally, with a 9-fold increase in the United States from 2000 to 2018, and with disproportionately higher burden for socioeconomically vulnerable subgroups. Despite the focus of decades of research since the infamous 1976 outbreak, substantial knowledge gaps remain with regard to source of exposure and the reason(s) for the dramatic increase in LD incidence. Here, we rule out factors indicated in literature to contribute to its long-term increases and identify a hitherto unexplored explanatory factor. We also provide an epidemiological demonstration that the occurrence of LD is linked with exposure to cooling towers (CTs). Our results suggest that declining sulfur dioxide air pollution, which has many well-established health benefits, results in reduced acidity of aerosols emitted from CTs, which may prolong the survival duration of Legionella in contaminated CT droplets and contribute to the increase in LD incidence. Mechanistically associating decreasing aerosol acidity with this respiratory disease has implications for better understanding its transmission, predicting future risks, and informed design of preventive and interventional strategies that consider the complex impacts of continued sulfur dioxide changes.
摘要：
军团菌病（LD）是由吸入含有军团菌的气雾剂引起的严重形式的肺炎（~10-25％的死亡率），一种致病性革兰氏阴性菌.这些细菌可以生长，传播，并通过建造水系统雾化。最近在全球范围内观察到LD发病率急剧增加，从2000年到2018年，美国增加了9倍，社会经济脆弱的亚组的负担不成比例地增加。尽管自臭名昭著的1976年爆发以来数十年的研究重点，关于暴露源和LD发病率急剧增加的原因，仍然存在大量的知识差距。这里,我们排除了文献中指出的导致其长期增长的因素，并确定了迄今为止尚未探索的解释因素。我们还提供了流行病学证明，LD的发生与暴露于冷却塔（CT）有关。我们的研究结果表明，减少二氧化硫空气污染，它有许多公认的健康益处，导致CT排放的气溶胶酸度降低，这可能延长军团菌在污染的CT液滴中的存活时间，并有助于LD发病率的增加。将降低的气溶胶酸度与这种呼吸系统疾病的机制联系起来，对更好地理解其传播具有重要意义。预测未来风险，考虑到二氧化硫持续变化的复杂影响的预防和干预策略的知情设计。
