Recognizing true H5N1 infections in humans during confirmed outbreaks

  • Mukhtiar Zaman Khyber Teaching Hospital, Khyber Medical University, Peshawar, Pakistan
  • Viktor Gasimov Sanitary-Epidemiological Surveillance, Ministry of Health, Baku, Azerbaijan
  • Ahmet Faik Oner Yuzuncu Yil University, Van, Turkey
  • Nazim Dogan Ataturk University Medical School, Erzurum, Turkey
  • Wiku Adisasmito University of Indonesia, Depok, Indonesia
  • Richard Coker London School of Hygiene and Tropical Medicine, Bangkok, Thailand
  • Ebun L Bamgboye St. Nicholas Hospital, Lagos, Nigeria
  • Paul KS Chan The Chinese University of Hong Kong, Hong Kong
  • Wanna Hanshaoworakul Ministry of Public Health, Nonthaburi, Thailand
  • Nelson Lee The Chinese University of Hong Kong, Hong
  • Bounlay Phommasack Ministry of Health, Lao People's Democratic Republic
  • Sok Touch Ministry of Health, Cambodia
  • Owen Tsang Princess Margaret Hospital, Hong Kong
  • Anna Swenson Real-World and Late Phase Research, Quintiles, Cambridge, MA, United States
  • Stephen Toovey Academic Centre for Travel Medicine and Vaccines, London, United Kingdom
  • Nancy A Dreyer Real-World and Late Phase Research, Quintiles, Cambridge, MA, United States
Keywords: influenza, human, avian influenza, oseltamivir, antiviral agents


Introduction: The goal of this study was to evaluate whether any characteristics that are evident at presentation for urgent medical attention could be used to differentiate cases of H5N1 in the absence of viral testing.

Methodology: Information about exposure to poultry, clinical signs and symptoms, treatments, and outcomes was abstracted from existing data in the global avian influenza registry ( using standardized data collection tools for documented and possible cases of H5N1 infection who presented for medical attention between 2005-2011 during known H5N1 outbreaks in Azerbaijan, Indonesia, Pakistan and Turkey.

Results: Demography, exposure to poultry, and presenting symptoms were compared, with only the common symptoms of fever and headache presenting significantly more frequently in confirmed H5N1 cases than in possible cases. Reported exposure to  infected humans was also more common in confirmed cases. In contrast, unexplained respiratory illness, sore throat, excess sputum production, and rhinorrhea were more frequent in possible cases. Overall, oseltamivir treatment showed a survival benefit, with the greatest benefit shown in H5N1 cases who were treated within two days of symptom onset (51% reduction in case fatality).

Conclusion: Since prompt treatment with antivirals conferred a strong survival benefit for H5N1 cases, presumptive antiviral treatment should be considered for all possible cases presenting during an outbreak of H5N1 as a potentially life-saving measure.


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Author Biography

Nancy A Dreyer, Real-World and Late Phase Research, Quintiles, Cambridge, MA, United States

Global Chief of Scientific Affairs

PhD in Epidemiology

Fellow of the International Society of Pharmacoepidemiology

How to Cite
Zaman M, Gasimov V, Oner AF, Dogan N, Adisasmito W, Coker R, Bamgboye EL, Chan PK, Hanshaoworakul W, Lee N, Phommasack B, Touch S, Tsang O, Swenson A, Toovey S, Dreyer NA (2014) Recognizing true H5N1 infections in humans during confirmed outbreaks. J Infect Dev Ctries 8:202-207. doi: 10.3855/jidc.3329
Original Articles