A comparison of clinical and epidemiological characteristics of fatal human infections with H5N1 and human influenza viruses in Thailand, 2004-2006

• Published in: PloS one 2011-04, Vol.6 (4), p.e14809-e14809
• Main Authors: Shinde, Vivek, Hanshaoworakul, Wanna, Simmerman, James M, Narueponjirakul, Ubolrat, Sanasuttipun, Wiwan, Kaewchana, Suchada, Areechokechai, Darin, Ungchusak, Kumnuan, Fry, Alicia M
• Format: Article
• Language: English
• Subjects: Algorithms; Animals; Antiviral agents; Avian flu; Avian influenza; Avian influenza viruses; Birds; Blood; Cohort Studies; Communicable Disease Control; Diagnostic systems; Epidemics; Epidemiology; Exposure; Fatalities; Fever; Geography; Health aspects; Humans; Identification methods; Infectious Diseases; Infectious Diseases/Epidemiology and Control of Infectious Diseases; Infectious Diseases/Respiratory Infections; Infectious Diseases/Viral Infections; Influenza; Influenza A; Influenza A Virus, H5N1 Subtype - metabolism; Influenza in Birds - epidemiology; Influenza in Birds - mortality; Influenza in Birds - virology; Influenza, Human - epidemiology; Influenza, Human - mortality; Influenza, Human - virology; Laboratories; Leukocytes; Liver; Medical records; Oseltamivir; Polymerase Chain Reaction; Public Health and Epidemiology/Global Health; Public Health and Epidemiology/Infectious Diseases; Respiratory failure; Retrospective Studies; Risk analysis; Risk Factors; Seasons; Thailand; Viruses; Vomiting; White blood cell count
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0014809

The National Avian Influenza Surveillance (NAIS) system detected human H5N1 cases in Thailand from 2004-2006. Using NAIS data, we identified risk factors for death among H5N1 cases and described differences between H5N1 and human (seasonal) influenza cases. NAIS identified 11,641 suspect H5N1 cases (e.g. persons with fever and respiratory symptoms or pneumonia, and exposure to sick or dead poultry). All suspect H5N1 cases were tested with polymerase chain reaction (PCR) assays for influenza A(H5N1) and human influenza viruses. NAIS detected 25 H5N1 and 2074 human influenza cases; 17 (68%) and 22 (1%) were fatal, respectively. We collected detailed information from medical records on all H5N1 cases, all fatal human influenza cases, and a sampled subset of 230 hospitalized non-fatal human influenza cases drawn from provinces with ≥1 H5N1 case or human influenza fatality. Fatal versus non-fatal H5N1 cases were more likely to present with low white blood cell (p = 0.05), lymphocyte (p