Influenza A (H1N1): outbreak management in a dialysis unit and clinical outcomes of infection in chronic hemodialysis patients

ABSTRACT Introduction: Chronic hemodialysis (HD) patients are considered to be at high risk for infection. Here, we describe the clinical outcomes of chronic HD patients with influenza A (H1N1) infection and the strategies adopted to control an outbreak of influenza A in a dialysis unit. Methods: Among a total of 62 chronic HD patients, H1N1 infection was identified in 12 (19.4%). Of the 32 staff members, four (12.5%) were found to be infected with the H1N1 virus. Outcomes included symptoms at presentation, comorbidities, occurrence of hypoxemia, hospital admission, and clinical evaluation. Infection was confirmed by real-time reverse transcriptase polymerase chain reaction. Results: The 12 patients who had H1N1 infection did not differ significantly from the other 50 non-infected patients with respect to age, sex, dialysis vintage, dialysis modality, or proportion of comorbidities. Obesity was higher in the H1N1-infected group (41.5 vs. 4%, p<0.002). The most common symptoms were fever (92%), cough (92%), and rhinorrhea (83%). Early empirical antiviral treatment with oseltamivir was started in symptomatic patients and infection control measures, including the intensification of contact-reduction measures by the staff members, antiviral chemoprophylaxis to asymptomatic patients undergoing HD in the same shift of infected patients, and dismiss of staff members suspected of being infected, were implemented to control the spread of infection in the dialysis unit. Conclusion: The clinical course of infection with H1N1 in our patients was favorable. None of the patients developed severe disease and the strategies adopted to control the outbreak were successful.

摘要
引言：慢性血液透析（chronic hemodialysis, HD）患者被认为具有较高的感染风险。本研究旨在描述合并甲型H1N1（influenza A (H1N1)）感染的慢性HD患者的临床结局，以及透析单元内控制甲型流感暴发所采取的防控策略。

方法：本研究纳入共计62例慢性HD患者，其中12例（19.4%）确诊甲型H1N1感染。32名医护人员中，4名（12.5%）检测出H1N1病毒阳性。研究结局指标包括就诊时症状、合并症、低氧血症发生情况、住院率及临床评估结果。感染确诊采用实时反转录聚合酶链反应（real-time reverse transcriptase polymerase chain reaction）检测。

结果：12例甲型H1N1感染患者与其余50例未感染患者在年龄、性别、透析龄、透析方式及合并症占比方面均无显著差异。但感染组患者的肥胖比例更高（41.5% vs 4%，p<0.002）。最常见的症状为发热（92%）、咳嗽（92%）及流涕（83%）。针对有症状患者，早期予以奥司他韦（oseltamivir）经验性抗病毒治疗；同时采取多项感染防控措施，包括强化医护人员的接触隔离措施、为与感染患者同班次接受透析的无症状患者实施抗病毒药物化学预防，以及对疑似感染的医护人员离岗隔离，以遏制透析单元内的感染扩散。

结论：本研究中慢性HD患者的甲型H1N1感染临床进程较为平稳，无患者出现重症疾病，且本次暴发所采取的防控策略取得了成功。