Recovery rates of influenza virus subjected to the aerosol collection procedure.

<p>Prepared impactor plates were spiked with 10²–10³ pfu of PN99 (green) or IN11 (orange) influenza virus and were placed at a designated environmental condition as shown on the x-axis while air was pulled through them for 15 minutes (A) or 5 minutes (B). Experiments were performed in duplicate and the percentage of recovered RNA was determined by real time RT-PCR using M gene primers and infectious virus recovery was based on plaque assays. Each shaded section represents the proportion of the total amount of input virus that was recovered.</p

Volume of aerosols exhaled by naïve and influenza virus inoculated ferrets.

<p>Aerosol volumes were measured from ferrets during 15 minutes of normal breathing (NB) or 5 minutes of sneezing stimulation (SZ). Data collected from naïve animals, n = 6 (A), and data collected from inoculated animals (normalized to each ferret’s naïve level of aerosol shedding), n = 3, on 2, 4 and 6 dpi were combined and compared between PN99 and IN11 virus groups for aerosols <5 μm and ≥5 μm (B,C). Ferrets were housed under controlled environmental conditions as indicated. Data are presented + standard deviation.</p

Influenza virus in aerosol samples exhaled by infected ferrets based on recovery rates.

<p>Three ferrets each were housed under the designated environmental conditions and were presented with 10^3.8–10^5.5 pfu of PN99 (green) or IN11 (orange) virus by aerosol inhalation. Aerosol samples were collected from ferrets on 1, 3, and 5 dpi for 15 minutes of normal breathing (A) and 5 minutes of sneezing stimulation (B). Total plaque forming units (pfu) collected from infected ferrets were normalized based on the recovery rates of known amounts of infectious virus using our aerosol collection procedure. Total pfu exhaled by infected ferrets in both size ranges combined and at each time point are presented. Each dot represents a single animal at a single time point. Scatter dot plots show the distribution of data with the horizontal line representing the grand mean for all samples collected under the designated condition.</p

Influenza virus detection in aerosol samples exhaled by infected ferrets.

<p>Three ferrets each were housed under the designated environmental conditions and were presented with 10^3.8–10^5.5 pfu of PN99 (green) or IN11 (orange) virus by aerosol inhalation. On 1, 3 and 5 dpi, aerosol samples were collected from ferrets for 15 minutes of normal breathing (A) and 5 minutes of sneezing stimulation (B) and were segregated based on size (0.65–4.7 μm or >4.7 μm) and then assayed for the presence of infectious influenza virus. Total plaque forming units (pfu) from individual ferrets, n = 3, is shown with the grand mean for each sampling condition.</p

Estimated number of seropositive individuals and age-standardized population seroprevalence to influenza A(H1N1)pdm09, at the MN ≥ 1:40 and HI ≥ 1:20 thresholds, for the age range of the survey.

<p>Estimated number of seropositive individuals and age-standardized population seroprevalence to influenza A(H1N1)pdm09, at the MN ≥ 1:40 and HI ≥ 1:20 thresholds, for the age range of the survey.</p

Number and proportion of the 1,484 participants who tested positive to influenza A(H1N1)pdm09 at the MN ≥ 1:40 and HI ≥ 1:20 thresholds, by quintiles of age.

<p>Number and proportion of the 1,484 participants who tested positive to influenza A(H1N1)pdm09 at the MN ≥ 1:40 and HI ≥ 1:20 thresholds, by quintiles of age.</p

Characteristics of 1,484 participants of the influenza A(H1N1)pdm09 serosurvey in blood donors; Mexico, June–September 2010.

<p>Characteristics of 1,484 participants of the influenza A(H1N1)pdm09 serosurvey in blood donors; Mexico, June–September 2010.</p

Location of confirmed HPAI H5N1 virus poultry farm outbreaks during December 2007-June 2009 and suspected HPAI H5N1 outbreaks in live bird markets in 2009, Bangladesh.

<p>Location of confirmed HPAI H5N1 virus poultry farm outbreaks during December 2007-June 2009 and suspected HPAI H5N1 outbreaks in live bird markets in 2009, Bangladesh.</p

Seroprevalence of Antibodies against Highly Pathogenic Avian Influenza A (H5N1) Virus among Poultry Workers in Bangladesh, 2009

<div><p>We conducted a cross-sectional study in 2009 to determine the seroprevalence and risk factors for highly pathogenic avian influenza A (H5N1) [HPAI H5N1] virus antibodies among poultry workers at farms and live bird markets with confirmed/suspected poultry outbreaks during 2009 in Bangladesh. We tested sera by microneutralization assay using A/Bangladesh/207095/2008 (H5N1; clade 2.2.2) virus with confirmation by horse red blood cell hemagglutination inhibition and H5-specific Western blot assays. We enrolled 212 workers from 87 farms and 210 workers from three live bird markets. One hundred and two farm workers (48%) culled poultry. One hundred and ninety-three farm workers (91%) and 178 market workers (85%) reported direct contact with poultry that died during a laboratory confirmed HPAI H5N1 poultry farm outbreak or market poultry die-offs from suspected HPAI H5N1. Despite exposure to sick poultry, no farm or market poultry workers were seropositive for HPAI H5N1 virus antibodies (95% confidence interval 0–1%).</p> </div