Pandemic (H1N1) 2009 influenza virus spread throughout the world since most people did not have immunity against the virus. In the post pandemic phase when many humans might possess immunity against the pandemic virus, one of the concerns is infection in immunocompromised people. Therefore, we used an immunosuppressed macaque model to examine pathogenicity of the pandemic (H1N1) 2009 virus unde...

BACKGROUND In April, 2009, a new influenza pandemic caused by a swine-origin H1N1 subtype influenza virus was imminent. We thereby carried out an emergency surveillance study in a Chinese city of Qingdao. METHODS Pharyngeal swab samples were collected from four targeted groups and tested by reverse-transcription polymerase chain reaction. Each laboratory-confirmed pandemic H1N1 case or cluste...

The study was aimed at determining the prevalence of pandemic influenza (H1N1) 2009 among patients with respiratory tract diseases during July-December 2009 using real-time reverse transcription polymerase chain reaction. Haemagglutination inhibition (HI) assay was performed to detect antibody titres against pandemic influenza in 255 medical personnel, 307 members of the general population duri...

There is uncertainty whether the 2009 seasonal influenza vaccination influences the risk of infection with the 2009 pandemic influenza A(H1N1) virus. This issue was investigated in 548 healthcare workers from Capital and Coast District Health Board, Wellington, New Zealand, presenting with influenza-like illness during the influenza pandemic between June and August 2009. All workers completed a...

OBJECTIVE To compare the patient characteristics, clinical features and outcomes of adult patients hospitalised with pandemic (H1N1) 2009 influenza and seasonal influenza. DESIGN AND SETTING Retrospective medical record review of all patients admitted to Liverpool Hospital, Sydney, with laboratory-confirmed influenza from the initiation of the "PROTECT" phase of the pandemic response on 17 Ju...

The emergence of H1N1 in 2009 shows that it is a mistake to regard the scenario of having to implement pandemic plans as merely hypothetical. This recent experience provides an opportunity to inquire into the current state of pandemic preparedness plans with regard to their ethical adequacy. One aspect that deserves consideration in this context is the disclosure of ethical reasoning. According...

Although influenza A/H1N1pdm09 is not causing a pandemic anymore, we recently observed two critically ill pregnant women infected by this virus. We present these cases to illustrate the possible severe complications of an - at that moment - seasonal influenza in pregnancy. We discuss the epidemiological differences between the pandemic and post pandemic phase and try to explain the high virulen...

A human influenza pandemic generally occurs every 30-40 years, and many experts believe that the next pandemic is overdue. There are a number of requirements for a new pandemic to begin: i) emergence of a new viral strain to which general populations lack sufficient immunity, ii) ability of this new strain to infect humans and to cause severe disease, and, iii) capability to transmit efficientl...

On June 11, 2009 the World Health Organization (WHO) declared a new H1N1 influenza pandemic. This pandemic strain is as transmissible as seasonal H1N1 and H3N2 influenza A viruses. Major concerns facing this pandemic are whether the new virus will replace, co-circulate and/or reassort with seasonal H1N1 and/or H3N2 human strains. Using the ferret model, we investigated which of these three poss...

BACKGROUND During the wave 1 of the influenza A(H1N1)pdm09 virus, Norway appeared to be suffering from high mortality rates. However, by the end of the pandemic, it was widely reported that the number of deaths were much lower than previous years. OBJECTIVES The mortality burden from influenza is often assessed by two different approaches: counting influenza-certified deaths and estimating th...