Harish M M, Ruhatiya Radhika Shriprakash
Department of Critical Care Medicine, Narayana Hrudayalaya, Bengaluru, Karnataka, India.
Lung India. 2019 Jul-Aug;36(4):330-336. doi: 10.4103/lungindia.lungindia_464_18.
Influenza A (H1N1) infection has a propensity to infect an immunocompromised host (ICH). These patients experience more severe manifestations and related complications with increased mortality. Influenza A (H1N1) infection in ICH differs from non-ICH in terms of clinical features, range of complications, radiological features, treatment response, and outcome. Radiology may show higher number of lesions but with no or minimal corresponding clinical manifestations. Coinfection with streptococci, staphylococci, and Aspergillus further increases mortality. Antiviral resistance compounds the overall picture despite optimal regimen. Use of steroids is detrimental. Extracorporeal membrane oxygenation (ECMO) is usually avoided in ICH. However, ICH groups with influenza A (H1N1) infection complicated by acute respiratory distress syndrome who have received ECMO have recorded mortality up to 61%. Nevertheless, evidence-based recommendation on use of ECMO in ICH is lacking. Annual inactivated influenza vaccine is recommended for most ICH groups with a few exceptions and for their close contacts. Hygiene measures greatly contribute to reducing disease burden. High index of suspicion for influenza A (H1N1) infection in ICH, early antiviral therapy, and treatment of coinfection is recommended. With the threat of transmission of resistant viral strains from ICH to the community, apart from treatment, preventive measures such as vaccination and hygienic practices have a significant role. Through this review, we have attempted to identify clinical and radiological peculiarities in ICH with influenza A (H1N1) infection, treatment guidelines, and prognostic factors. Influenza A (H1N1) infection in ICH may remain clinically silent or mild.
甲型H1N1流感感染易于侵袭免疫功能低下宿主（ICH）。这些患者会出现更严重的症状及相关并发症，死亡率也会升高。ICH患者的甲型H1N1流感感染在临床特征、并发症范围、放射学特征、治疗反应及预后方面与非ICH患者不同。放射学检查可能显示病灶数量较多，但相应的临床表现却不明显或仅有轻微表现。与链球菌、葡萄球菌及曲霉菌的合并感染会进一步增加死亡率。尽管采用了最佳治疗方案，但抗病毒耐药性使整体情况更加复杂。使用类固醇有害。ICH患者通常避免使用体外膜肺氧合（ECMO）。然而，接受ECMO治疗的合并急性呼吸窘迫综合征的甲型H1N1流感感染ICH患者的死亡率高达61%。尽管如此，目前仍缺乏关于ICH患者使用ECMO的循证推荐。对于大多数ICH患者群体（有少数例外情况）及其密切接触者，建议每年接种灭活流感疫苗。卫生措施对减轻疾病负担有很大帮助。建议对ICH患者的甲型H1N1流感感染保持高度怀疑指数，尽早进行抗病毒治疗并治疗合并感染。鉴于存在耐药病毒株从ICH患者传播至社区的威胁，除治疗外，诸如接种疫苗和卫生习惯等预防措施也发挥着重要作用。通过本综述，我们试图确定ICH患者甲型H1N1流感感染的临床和放射学特点、治疗指南及预后因素。ICH患者的甲型H1N1流感感染在临床上可能没有症状或症状轻微。
