Background The first human infections with influenza A(H1N1)pdm09 virus were confirmed in April 2009. We describe the clinical and epidemiological characteristics of influenza A(H1N1)pdm09-associated pneumonia deaths in Thailand from May 2009-January 2010. Methods We identified influenza A(H1N1)pdm09-associated pneumonia deaths from a national influenza surveillance system and performed detailed reviews of a subset. Results Of 198 deaths reported, 49% were male and the median age was 37 years; 146 (73%) were 20–60 years. Among 90 deaths with records available for review, 46% had no identified risk factors for severe influenza. Eighty-eight patients (98%) received antiviral treatment, but only 16 (18%) initiated therapy within 48 hours of symptom onset. Conclusions Most influenza A(H1N1)pdm09 pneumonia fatalities in Thailand occurred in adults aged 20–60 years. Nearly half lacked high-risk conditions. Antiviral treatment recommendations may be especially important early in a pandemic before vaccine is available. Treatment should be considered as soon as influenza is suspected.
Santa-Olalla Peralta P, Cortes-Garcia M, Vicente-Herrero M, Castrillo-Villamandos C, Arias-Bohigas P, et al.. (2010) Risk factors for disease severity among hospitalised patients with 2009 pandemic influenza A (H1N1) in Spain, April - December 2009. Euro Surveill 15.
Pebody RG, McLean E, Zhao H, Cleary P, Bracebridge S, et al.. (2010) Pandemic Influenza A (H1N1) 2009 and mortality in the United Kingdom: risk factors for death, April 2009 to March 2010. Euro Surveill 15.
Bassetti M, Parisini A, Calzi A, Pallavicini FM, Cassola G, et al.. (2010) Risk factors for severe complications of the novel influenza A (H1N1): analysis of patients hospitalized in Italy. Clin Microbiol Infect.
Champunot R, Tanjatham S, Kerdsin A, Puangpatra P, Wangsai S, et al. (2010) Impact of pandemic influenza (H1N1) virus-associated community-acquired pneumonia among adults in a tertiary hospital in Thailand. Jpn J Infect Dis 63: 251–256.
de Silva UC, Warachit J, Waicharoen S, Chittaganpitch M (2009) A preliminary analysis of the epidemiology of influenza A(H1N1)v virus infection in Thailand from early outbreak data, June-July 2009. Euro Surveill 14.
Hanshaoworakul W, Simmerman JM, Narueponjirakul U, Sanasuttipun W, Shinde V, et al. (2009) Severe human influenza infections in Thailand: oseltamivir treatment and risk factors for fatal outcome. PLoS One 4: e6051.
WHO (2009) Clinical management of human infection with pandemic (H1N1) 2009, revised guidance. Available: http://www.who.int/csr/resources/publica？tions/swineflu/clinical_management_h1n1.？pdf. Accessed 2011 Jan 10.
Reichert T, Chowell G, Nishiura H, Christensen RA, McCullers JA (2010) Does Glycosylation as a modifier of Original Antigenic Sin explain the case age distribution and unusual toxicity in pandemic novel H1N1 influenza? BMC Infect Dis 10: 5.
Santa-Olalla Peralta P, Cortes Garcia M, Limia Sanchez A, Andres Prado J, Pachon Del Amo I, et al. (2010) [Critically ill patients with 2009 pandemic influenza A (H1N1) infection in Spain: Factors associated with death, April 2009-January 2010.]. Rev Esp Salud Publica 84: 547–567.
Nguyen-Van-Tam JS, Openshaw PJ, Hashim A, Gadd EM, Lim WS, et al. (2010) Risk factors for hospitalisation and poor outcome with pandemic A/H1N1 influenza: United Kingdom first wave (May-September 2009). Thorax 65: 645–651.
Fiore AE, Fry A, Shay D, Gubareva L, Bresee JS, et al. (2011) Antiviral agents for the treatment and chemoprophylaxis of influenza – recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 60: 1–24.
Bassetti M, Parisini A, Calzi A, Pallavicini FM, Cassola G, et al. (2011) Risk factors for severe complications of the novel influenza A (H1N1): analysis of patients hospitalized in Italy. Clin Microbiol Infect 17: 247–250.
Garcia-Garcia L, Valdespino-Gomez JL, Lazcano-Ponce E, Jimenez-Corona A, Higuera-Iglesias A, et al. (2009) Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City. BMJ 339: b3928.