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（hemodialysis，以下简称HD）患者被认为具有较高的感染风险。本研究旨在描述感染甲型H1N1流感的慢性HD患者的临床转归，以及透析单元内控制甲型流感暴发的防控策略。
方法：本研究共计纳入62例慢性HD患者，其中12例（19.4%）确诊甲型H1N1流感感染；32名医护人员中，4名（12.5%）检测出H1N1病毒阳性。本研究的观察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。感染确诊采用实时逆转录聚合酶链反应（real-time reverse transcriptase polymerase chain reaction，以下简称RT-PCR）方法。
结果：12例甲型H1N1流感感染患者与其余50例未感染患者在年龄、性别、透析龄、透析方式及合并症比例方面均无显著差异。但感染组患者的肥胖发生率显著更高（41.5% vs 4%，p<0.002）。最常见的临床症状为发热（92%）、咳嗽（92%）及流涕（83%）。针对有症状患者尽早启动奥司他韦经验性抗病毒治疗，并实施一系列感染防控措施，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HD治疗的无症状患者给予抗病毒药物化学预防，以及对疑似感染的医护人员暂停在岗，以此遏制流感在透析单元内的传播。
结论：本研究中慢性HD患者感染甲型H1N1流感后的临床进程良好，所有患者均未发展为重症疾病，且本次暴发的防控策略取得了成功。