Influenza and other respiratory viruses
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Influenza Other Respi Viruses · Sep 2013
ReviewBrief literature review for the WHO global influenza research agenda--highly pathogenic avian influenza H5N1 risk in humans.
Highly pathogenic avian influenza A H5N1 viruses remain a significant health threat to humans given the continued rare occurrence of human cases with a high case fatality rate. This brief literature review summarizes available evidence of risk factors for H5N1 infection in humans and updates a recent systematic review published in early 2011. Several epidemiologic studies have been published to evaluate the risk factors for H5N1 infection in humans, including contact with poultry and poultry products and non-poultry-related contact such as from H5N1-contaminated water. ⋯ This suggests that there may be a threshold of virus concentration needed for effective transmission and that circulating H5N1 strains have not yet mutated to transmit readily from either poultry to human or from human to human. However, the mode of potential transmission can be quite varied throughout different countries and by study with exposures ranging from visiting a wet market, preparing infected poultry for consumption, to swimming or bathing in ponds frequented by poultry. Several important data gaps remain in the understanding of the epidemiology of H5N1 in humans and limit our ability to interpret the results of the available H5N1 seroepidemiologic studies.
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Influenza Other Respi Viruses · Sep 2013
Mortality burden of the 2009-10 influenza pandemic in the United States: improving the timeliness of influenza severity estimates using inpatient mortality records.
Delays in the release of national vital statistics hinder timely assessment of influenza severity, especially during pandemics. Inpatient mortality records could provide timelier estimates of influenza-associated mortality. ⋯ Modeling inpatient mortality records provides useful estimates of influenza severity in advance of national vital statistics release, capturing both the magnitude and the age distribution of pandemic and epidemic deaths. We provide the first age- and cause-specific estimates of the 2009 pandemic mortality burden using traditional 'excess mortality' methods, confirming the unusual burden of this virus in young populations. Our inpatient-based approach could help monitor mortality trends in other infectious diseases.
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Influenza Other Respi Viruses · Sep 2013
Neuraminidase inhibitor susceptibility surveillance of influenza viruses circulating worldwide during the 2011 Southern Hemisphere season.
Neuraminidase (NA) inhibitors (NAIs) are currently the only antivirals effective against influenza infections due to widespread resistance to M2 inhibitors. ⋯ This study summarizes NAI susceptibility of influenza viruses circulating worldwide during the 2011 Southern Hemisphere (SH) season, assessed using the NA-Fluor™ Kit. Despite low resistance to NAIs among tested influenza viruses, constant surveillance of influenza virus susceptibility to NAIs should be emphasized.
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Influenza Other Respi Viruses · Sep 2013
Observational StudyFactors promoting the prolonged shedding of the pandemic (H1N1) 2009 influenza virus in patients treated with oseltamivir for 5 days.
The duration of viral shedding is an important determinant of infectivity and transmissibility and provides vital information for effective infection prevention and control. However, few studies have evaluated viral shedding in patients admitted to hospital with 2009 H1N1 influenza and treated with oseltamivir. ⋯ The presence of major comorbidities, a delay in initiating antiviral treatment, and continuing respiratory symptoms after 5 days of antiviral treatment are associated with prolonged shedding of the 2009 H1N1 influenza virus.