Skip to main content
    • Aa
    • Aa

Delayed oseltamivir treatment is associated with longer viral shedding of pandemic (H1N1) 2009 virus

  • Y. H. LEUNG (a1), W. L. LIM (a2), M. H. WONG (a1) and S. K. CHUANG (a1)

During the early phase of the influenza pandemic in 2009, all cases of laboratory-confirmed pandemic (H1N1) 2009 (pH1N1) infection required compulsory isolation in hospital. These cases were offered oseltamivir treatment and only allowed to be discharged from the hospital when three consecutive respiratory specimens were negative for the virus by reverse transcription–polymerase chain reaction (RT–PCR). We reviewed the case records of these patients to assess the viral shedding kinetics of the pH1N1 virus. We defined viral shedding duration as the interval from illness onset date to the date of collection of the last positive specimen from the patients. Fifty-six patients were included in the study, of whom 96% received oseltamivir. The median viral shedding duration of pH1N1 virus by viral culture and RT–PCR were 3 days and 4 days, respectively. Patients who started oseltamivir treatment >48 h after onset had a significantly longer median viral shedding duration by viral culture than those who started treatment within 48 h of onset (4 days vs. 2 days, P=0·014).

Corresponding author
*Author for correspondence: Y. H. Leung, Field Epidemiology Training Programme, Centre for Health Protection, Department of Health, Room 325, 147C Argyle Street, Kowloon, Hong Kong. (Email:
Hide All
1.Centers for Disease Control and Prevention. Swine influenza A (H1N1) infection in two children – southern California, March–April 2009. Morbidity and Mortality Weekly Report 2009; 58: 400402.
2.Centers for Disease Control and Prevention. Outbreak of swine-origin influenza A (H1N1) virus infection – Mexico, March–April 2009. Morbidity and Mortality Weekly Report 2009; 58: 463466.
3.World Health Organization. Press statement by WHO Director-General. 11 June 2009 ( Accessed 1 February 2011.
4.Couch RB, Kasel JA. Influenza. In: Lennette EH, Lennette DA, Lennette ET, eds. Diagnostic Procedures for Viral, Rckettsial and Chlamydial infections, 7th edn. Washington: American Public Health Association, 1995, pp. 431446.
5.Centre for Health Protection. CHP molecular diagnostic protocols for the detection of human swine influenza virus type A (subtype H1) revision 2 (26 December 2009). ( Accessed 1 February 2011.
6.Ling LM, et al. Effects of early oseltamivir therapy on viral shedding in 2009 pandemic influenza A (H1N1) virus infection. Clinical Infectious Diseases 2010; 50: 963969.
7.Witkop CT, et al. Novel Influenza A (H1N1) outbreak at the U.S. Air Force Academy: epidemiology and viral shedding duration. American Journal of Preventive Medicine 2010; 38: 121126.
8.Aoki FY, et al. Early administration of oral oseltamivir increases the benefits of influenza treatment. Journal of Antimicrobial Chemotherapy 2003; 51: 123129.
9.Kawai N, et al. Factors influencing the effectiveness of oseltamivir and amantadine for the treatment of influenza: a multicenter study from Japan of the 2002–2003 influenza season. Clinical Infectious Diseases 2005; 40: 13091316.
10.Cao B, et al. Clinical features of the initial cases of 2009 pandemic influenza A (H1N1) virus infection in China. New England Journal of Medicine 2009; 361: 25072517.
11.Yu H, et al. Effectiveness of oseltamivir on disease progression and viral RNA shedding in patients with mild pandemic 2009 influenza A H1N1: opportunistic retrospective study of medical charts in China. British Medical Journal 2010; 341: c4779.
12.Li CC, et al. Correlation of pandemic (H1N1) 2009 viral load with disease severity and prolonged viral shedding in children. Emerging Infectious Diseases 2010; 16: 12651272.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Epidemiology & Infection
  • ISSN: 0950-2688
  • EISSN: 1469-4409
  • URL: /core/journals/epidemiology-and-infection
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 1
Total number of PDF views: 9 *
Loading metrics...

Abstract views

Total abstract views: 120 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 21st October 2017. This data will be updated every 24 hours.