广州市成人流感样疾病882例病原学及临床特征分析

A pathogenic and clinical study of 882 cases of adult influenza-like illness in Guangzhou

目的 探讨引起广州地区成人流感样疾病（influenza like illness,ILI）的呼吸道病毒病原学分布及其临床特征.方法 2009年1-9月份采集882例成人ILI患者的鼻和（或）咽拭子,应用小瓶离心法进行病毒分离与鉴定,并对患者的临床特征进行分析.结果 （1）病原学分布：882份鼻和（或）咽拭子标本中,病毒培养阳性385份（43.7%）,共检测出9种病毒,以季节性甲型流感病毒为主,共259例（67.3%）,其余分别为乙型流感病毒107例（27.8%）;人副流感病毒（HPIV）1～3型5例（1.3%）;腺病毒、单纯疱疹病毒1型（HSV-1）及肠道病毒各2例（0.5%）;混合感染8例（2.1%）,其中季节性甲型流感和乙型流感病毒混合感染6例,乙型流感病毒与HPIV-3混合感染1例,腺病毒与呼吸道合胞病毒（RSV）混合感染1例.2009年3-5月份以乙型流感病毒为优势毒株,6-8月份则以季节性甲型流感病毒为主;（2）临床特征：ILI患者以18～30岁人群为主（49.7%）,中度发热、咽喉痛及咳嗽为主要临床症状,上呼吸道感染和肺炎的比例为88.4%（727/882）和10.7%（95/882）.季节性甲型流感和乙型流感的临床症状相似,流感病毒检测阳性组的白细胞和淋巴细胞平均数均较病毒阴性组低.腺病毒、HPIV及RSV感染者年龄较低,肠道病毒与疱疹病毒感染者未出现皮疹.结论 （1）引起2009年广州地区成人ILI的病原以季节性甲型流感和乙型流感病毒为优势病毒,其他呼吸道病毒散发,病毒病原体多样化特征不明显,呈季节性流行;（2）不同病毒感染的成人ILI患者发热程度不同,伴有明显的全身和上呼吸道症状,肺炎少见.

Objective This study was undertaken to describe the viral etiology and clinical features in patients with influenza-like illness （ILI） in Guangzhou. Methods The nasopharyngeal and throat swabs were collected from 882 patients presenting with ILI between January and September, 2009. Viral pathogens were cultured and identified by immunofluorescence technique using the Shell-Vial method. The clinical data were statistically analyzed. Results （1） Viral etiology. Of the 882 samples, 385 （43.7%） were confirmed to have at least one of the 9 different respiratory viruses detected. Among these viral isolates,67. 3% （259/385） were seasonal influenza A virus, 27. 8% （107/385） were influenza B virus, and 1.3%（5/385） were human parainfluenza virus （PHIV） 1, 2, or 3. In addition, 2 cases （0.5%） of each adenovirus, HSV-1, enterovirus and respiratory syncytial virus （RSV） were also found in the samples. Coinfections with more than one virus were revealed in 8 （2. 1% ） of 385 samples tested, among them 6 samples were mixture of influenza A and influenza B, 1 sample was positive for both influenza B virus and HPIV-3, and 1 was for both adenovirus and RSV. Seasonal influenza B virus appeared endemic between March and May, and seasonal influenza A virus became dominant between June and August. （2） Clinical features. The percentage of patients aged from 18 -30 years was much higher than that of other age groups.The most common symptoms were moderate fever and sore throat, followed by cough. The percentage of upper respiratory infection and pneumonia was 88.4% （ 727/882 ） and 10. 7% （ 95/882 ） respectively.Clinical features did not discriminate between patients with seasonal influenza A and those with influenza B virus infection. The average numbers of leukocytes and lymphocytes were lower in the group positive for influenza viruses than in virus negative group. The patients with adenovirus, HPIV and RSV infection were significantly younger. No rash was observed in patients with enterovirus or HSV infection. Conclusions （ 1 ） Seasonal influenza virus was the major viral etiologic agent of ILI in Guangzhou during the first 9 months in 2009. Influenza B and A viruses seasonally prevailed in spring and summer, respectively, while other viral etiologic agents appeared to be sporadic. （2） The analysis of clinical features in patients with ILI indicated that fever was the most common symptom, with body temperature varying greatly, and may be associated with evident respiratory and occasionally systemic symptoms. Among the cases with viral infection, the upper respiratory presentation was universal, and pneumonia was frequently noticed.