Clinical Features of the Initial Cases of 2009 Pandemic Influenza A (H1N1) Virus Infection in China

• Published in: The New England journal of medicine Vol. 361; no. 26; pp. 2507 - 2517
• Main Authors: Cao, Bin, Li, Xing-Wang, Mao, Yu, Wang, Da-Yan, Wang, Chen, Wang, Jian, Lu, Hong-Zhou, Lu, Lian-He, Chen, Yu-Sheng, Liang, Zong-An, Liang, Lirong, Zhang, Bin, Zhang, Su-Juan, Gu, Li
• Format: Journal Article
• Language: English
• Published: United States Massachusetts Medical Society 24.12.2009
• Subjects: Adolescent; Adult; Aged; Anti-Bacterial Agents - adverse effects; Anti-Bacterial Agents - therapeutic use; Antiviral Agents - adverse effects; Antiviral Agents - therapeutic use; Azithromycin - adverse effects; Azithromycin - therapeutic use; Child; Child, Preschool; China - epidemiology; Disease control; Disease Outbreaks - statistics & numerical data; Drug Therapy, Combination; Female; Humans; Incidence; Infant; Infections; Influenza A Virus, H1N1 Subtype - genetics; Influenza A Virus, H1N1 Subtype - isolation & purification; Influenza, Human - complications; Influenza, Human - drug therapy; Influenza, Human - epidemiology; Influenza, Human - virology; Logistic Models; Lymphopenia - epidemiology; Lymphopenia - etiology; Male; Middle Aged; Ofloxacin - adverse effects; Ofloxacin - therapeutic use; Oseltamivir - adverse effects; Oseltamivir - therapeutic use; Pandemics; Public health; Reverse Transcriptase Polymerase Chain Reaction; Risk Factors; Swine flu; Teaching hospitals; Time Factors; Virus Shedding; Young Adult; China
• ISSN: 0028-4793; 1533-4406
• DOI: 10.1056/NEJMoa0906612

The first case of 2009 pandemic influenza A (H1N1) infection in China was identified on May 10, 2009. An initial policy of quarantine was instituted, and the early cases were systematically monitored. In these early 426 cases, the incubation period (2 days), spectrum of illness (67.4% with fever), and duration of viral shedding by PCR (6 days) were determined. In China an initial policy of quarantine was instituted and early cases of H1N1 were systematically monitored. In these early cases, the incubation period was 2 days, 67.4% of the patients had fever, and the duration of viral shedding was 6 days. In early April 2009, cases of human infection with 2009 pandemic influenza A (H1N1) virus were identified in the United States 1 , 2 and Mexico, 3 and the virus then spread rapidly to other regions of the world. 4 , 5 The 2009 H1N1 virus is a triple-reassortant influenza virus containing genes from human, swine, and avian influenza viruses. 6 – 8 After documentation of human-to-human transmission of the virus in at least three countries in two of the six world regions defined by the World Health Organization (WHO), the WHO raised the pandemic level from 5 to 6, the highest level. 9 The first three cases . . .