Service of Pneumology, University Clinical Hospital of Santiago de Compostela, Santiago de Compostela, Spain.
Department of Preventive Medicine and Public Health, University of Santiago de Compostela, Santiago de Compostela, Spain.
Can Respir J. 2019 Mar 17;2019:4301039. doi: 10.1155/2019/4301039. eCollection 2019.
Influenza A H1N1 community-acquired pneumonia (CAP) is a quite frequent respiratory disease. Despite being considered more serious than other CAPs, there are very few studies comparing its characteristics with noninfluenza CAP. We aim to establish the differences between pneumonia due to H1N1 virus and pneumonia not caused by H1N1 influenza virus and to determine the probability that a pneumonia is due to an H1N1 virus infection based on the most relevant variables.
We used a case-control study where cases were H1N1 CAP patients with confirmed microbiological diagnosis and controls were patients with CAP admitted to hospital. H1N1 and other influenza types were discarded among controls. We calculated the probability of being a case or control using multivariate logistic regression.
We included 99 cases and 270 controls. Cases were younger than controls (53 vs 71 years, respectively). Mortality was much higher for H1N1 patients (13% vs 0.3%), and admission to intensive care unit was more frequent for H1N1 cases. The variables most associated with presenting H1N1 CAP were bilateral affectation on chest X-rays (OR: 5.70; 95% CI 2.69-10.40), followed by presence of arthromyalgias, with cases presenting close to three times more arthromyalgias compared to controls. Low leukocytes count and high AST values were also significantly associated with H1N1 CAP. H1N1 CAPs are characterized by bilateral affectation, low leukocyte count, presence of arthromyalgias, and high AST.
A few and easy to obtain clinical parameters might be extremely useful to distinguish H1N1 CAP from CAPs of other origin.
甲型 H1N1 流感社区获得性肺炎（CAP）是一种相当常见的呼吸道疾病。尽管它被认为比其他 CAP 更严重，但很少有研究将其特征与非流感 CAP 进行比较。我们旨在确定 H1N1 病毒引起的肺炎与非 H1N1 流感病毒引起的肺炎之间的差异，并根据最相关的变量确定肺炎是否由 H1N1 病毒感染引起的可能性。
我们使用了病例对照研究，其中病例是经微生物学确诊的 H1N1 CAP 患者，对照组是住院的 CAP 患者。在对照组中排除了 H1N1 和其他流感类型。我们使用多变量逻辑回归计算病例或对照的概率。
我们纳入了 99 例病例和 270 例对照。病例组比对照组年轻（分别为 53 岁和 71 岁）。H1N1 患者的死亡率高得多（13%比 0.3%），H1N1 病例更频繁地入住重症监护病房。与 H1N1 CAP 相关的最主要变量是胸片上的双侧受累（OR：5.70；95%CI 2.69-10.40），其次是存在关节痛，病例组的关节痛接近对照组的三倍。白细胞计数低和 AST 值高也与 H1N1 CAP 显著相关。H1N1 CAP 的特征是双侧受累、白细胞计数低、存在关节痛和 AST 值高。
一些易于获得的临床参数可能非常有助于将 H1N1 CAP 与其他来源的 CAP 区分开来。
