Leekha Surbhi, Zitterkopf Nicole L, Espy Mark J, Smith Thomas F, Thompson Rodney L, Sampathkumar Priya
Department of Internal Medicine, Mayo School of Graduate Medical Education, Mayo Clinical College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
Infect Control Hosp Epidemiol. 2007 Sep;28(9):1071-6. doi: 10.1086/520101. Epub 2007 Jul 6.
To assess the duration of shedding of influenza A virus detected by polymerase chain reaction (PCR) and cell culture among patients hospitalized with influenza A virus infection.
Mayo Clinic (Rochester, Minnesota) hospitals that cater to both the community and referral populations.
Patients 18 years old and older who were hospitalized between December 1, 2004, and March 15, 2005, with a laboratory-confirmed (ie, PCR-based) diagnosis of influenza A virus infection were consecutively enrolled. Additional throat swab specimens were collected at 2, 3, 5, and 7 days after the initial specimen (if the patient was still hospitalized). All specimens were tested by PCR and culture (both conventional tube culture and shell vial assay). Information on demographic characteristics, date of symptom onset, comorbidities, immunosuppression, influenza vaccination status, and receipt of antiviral treatment was obtained by interview and medical record review. Patients were excluded if informed consent could not be obtained or if the date of symptom onset could not be ascertained.
Of 149 patients hospitalized with influenza A virus infection, 50 patients were enrolled in the study. Most patients were older (median age, 76 years), and almost all (96%) had underlying chronic medical conditions. Of 41 patients included in the final analysis, influenza A virus was detected in 22 (54%) by PCR and in 12 (29%) by culture methods at or beyond 7 days after symptom onset. All 12 patients identified by culture also had PCR results positive for influenza A virus.
Hospitalized patients with influenza A virus infection can shed detectable virus beyond the 5- to 7-day period traditionally considered the duration of infectivity. Additional research is needed to assess whether prolonging the duration of patient isolation is warranted to prevent nosocomial outbreaks during the influenza season.
评估甲型流感病毒感染住院患者中，通过聚合酶链反应（PCR）和细胞培养检测到的甲型流感病毒 shedding 持续时间。
梅奥诊所（明尼苏达州罗切斯特）的医院，服务社区和转诊人群。
连续纳入2004年12月1日至2005年3月15日期间因实验室确诊（即基于PCR）的甲型流感病毒感染而住院的18岁及以上患者。在初始标本采集后2、3、5和7天（如果患者仍住院）采集额外的咽拭子标本。所有标本均通过PCR和培养（传统试管培养和空斑试验）进行检测。通过访谈和病历审查获取人口统计学特征、症状发作日期、合并症、免疫抑制、流感疫苗接种状况以及抗病毒治疗情况等信息。如果无法获得知情同意或无法确定症状发作日期，则排除患者。
在149例甲型流感病毒感染住院患者中，50例患者纳入研究。大多数患者年龄较大（中位年龄76岁），几乎所有患者（96%）都有潜在慢性疾病。在最终分析的41例患者中，症状发作后7天及以上，22例（54%）通过PCR检测到甲型流感病毒，12例（29%）通过培养方法检测到。通过培养鉴定的所有12例患者PCR结果也为甲型流感病毒阳性。
甲型流感病毒感染住院患者可在传统认为具有传染性的5至7天期限之后排出可检测到的病毒。需要进一步研究以评估延长患者隔离时间是否有助于预防流感季节的医院内暴发。
