Spatial, temporal, and species variation in prevalence of influenza A viruses in wild migratory birds

Although extensive data exist on avian influenza in wild birds in North America, limited information is available from elsewhere, including Europe. Here, molecular diagnostic tools were employed for high-throughput surveillance of migratory birds, as an alternative to classical labor-intensive methods of virus isolation in eggs. This study included 36,809 samples from 323 bird species belonging to 18 orders, of which only 25 species of three orders were positive for influenza A virus. Information on species, locations, and timing is provided for all samples tested. Seven previously unknown host species for avian influenza virus were identified: barnacle goose, bean goose, brent goose, pink-footed goose, bewick's swan, common gull, and guillemot. Dabbling ducks were more frequently infected than other ducks and Anseriformes; this distinction was probably related to bird behavior rather than population sizes. Waders did not appear to play a role in the epidemiology of avian influenza in Europe, in contrast to the Americas. The high virus prevalence in ducks in Europe in spring as compared with North America could explain the differences in virus-host ecology between these continents. Most influenza A virus subtypes were detected in ducks, but H13 and H16 subtypes were detected primarily in gulls. Viruses of subtype H6 were more promiscuous in host range than other subtypes. Temporal and spatial variation in influenza virus prevalence in wild birds was observed, with influenza A virus prevalence varying by sampling location; this is probably related to migration patterns from northeast to southwest and a higher prevalence farther north along the flyways. We discuss the ecology and epidemiology of avian influenza A virus in wild birds in relation to host ecology and compare our results with published studies. These data are useful for designing new surveillance programs and are particularly relevant due to increased interest in avian influenza in wild birds

Somatostatin in human pancreatic and gastric juice

Considerable amounts of IRS are secreted after secretin injection in human pancreatic juice collected during endoscopic retrograde cholangiopancreatography. The mean IRS levels in the pancreatic juice of non-diabetic patients were 79+/-10 (SE) pg/ml. The IRS levels in NIDDM were considerably higher, the mean value being 1635+/-313 (SE) pg/ml. The mean IRS level in IDDM were 312+/-151 (SE) pg/ml. In IDDM, those patients whose blood glucose levels were well controlled by insulin showed low pancreatic juice IRS ranging from non-detectable to 46 pg/ml. On the other hand, those with uncontrolled hyperglycemia showed IRS levels ranging from 452 to 1047 pg/ml. Gel-filtration profiles of IRS in pancreatic juice extracts were not consistent in all cases. Some showed IRS peaks eluting with SS14 and SS28, while others contained IRS species that were eluted in more retarded fractions. The retarded IRS fraction exhibited biological activity indistinguishable from that of SS14 as indexed using a quantitative cytochemical method.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24539/1/0000818.pd

Outbreak of Neisseria meningitidis capsular group W among scouts returning from the World Scout Jamboree, Japan, 2015

The 23rd World Scout Jamboree was held in Japan from 28 July to 8 August 2015 and was attended by over 33,000 scouts from 162 countries. An outbreak of invasive meningococcal disease capsular group W was investigated among participants, with four confirmed cases identified in Scotland, who were all associated with one particular scout unit, and two confirmed cases in Sweden; molecular testing showed the same strain to be responsible for illness in both countries. The report describes the public health action taken to prevent further cases and the different decisions reached with respect to how wide to extend the offer of chemoprophylaxis in the two countries; in Scotland, chemoprophylaxis was offered to the unit of 40 participants to which the four cases belonged and to other close contacts of cases, while in Sweden chemoprophylaxis was offered to all those returning from the Jamboree. The report also describes the international collaboration and communication required to investigate and manage such multinational outbreaks in a timely manner

Recommendations for and compliance with social restrictions during implementation of school closures in the early phase of the influenza A (H1N1) 2009 outbreak in Melbourne, Australia

Background Localized reactive school and classroom closures were implemented as part of a suite of pandemic containment measures during the initial response to influenza A (H1N1) 2009 in Melbourne, Australia. Infected individuals, and those who had been in close contact with a case, were asked to stay in voluntary home quarantine and refrain from contact with visitors for seven days from the date of symptom onset or exposure to an infected person. Oseltamivir (Tamiflu®) was available for treatment or prophylaxis. Methods We surveyed affected families through schools involved in the closures. Analyses of responses were descriptive. We characterized recommendations made to case and contact households and quantified adherence to guidelines and antiviral therapy. Results Of the 314 respondent households, 51 contained a confirmed case. The prescribed quarantine period ranged from 1-14 days, reflecting logistic difficulties in reactive implementation relative to the stated guidelines. Household-level compliance with the requirement to stay at home was high (84.5%, 95% CI 79.3,88.5) and contact with children outside the immediate family infrequent. Conclusions Levels of compliance with recommendations in our sample were high compared with other studies, likely due to heightened public awareness of a newly introduced virus of uncertain severity. The variability of reported recommendations highlighted the difficulties inherent in implementing a targeted reactive strategy, such as that employed in Melbourne, on a large scale during a public health emergency. This study emphasizes the need to understand how public health measures are implemented when seeking to evaluate their effectiveness

Effects of infection-induced migration delays on the epidemiology of avian influenza in wild mallard populations

Wild waterfowl populations form a natural reservoir of Avian Influenza (AI) virus, and fears exist that these birds may contribute to an AI pandemic by spreading the virus along their migratory flyways. Observational studies suggest that individuals infected with AI virus may delay departure from migratory staging sites. Here, we explore the epidemiological dynamics of avian influenza virus in a migrating mallard (Anas platyrhynchos) population with a specific view to understanding the role of infection-induced migration delays on the spread of virus strains of differing transmissibility. We develop a host-pathogen model that combines the transmission dynamics of influenza with the migration, reproduction and mortality of the host bird species. Our modeling predicts that delayed migration of individuals influences both the timing and size of outbreaks of AI virus. We find that (1) delayed migration leads to a lower total number of cases of infection each year than in the absence of migration delay, (2) when the transmission rate of a strain is high, the outbreak starts at the staging sites at which birds arrive in the early part of the fall migration, (3) when the transmission rate is low, infection predominantly occurs later in the season, which is further delayed when there is a migration delay. As such, the rise of more virulent AI strains in waterfowl could lead to a higher prevalence of infection later in the year, which could change the exposure risk for farmed poultry. A sensitivity analysis shows the importance of generation time and loss of immunity for the effect of migration delays. Thus, we demonstrate, in contrast to many current transmission risk models solely using empirical information on bird movements to assess the potential for transmission, that a consideration of infection-induced delays is critical to understanding the dynamics of AI infection along the entire flyway.<br /

Prevalence of Coxiella burnetii in clinically healthy German sheep flocks

<p>Abstract</p> <p>Background</p> <p>Current epidemiological data on the situation of <it>Coxiella (C.) burnetii </it>infections in sheep are missing, making risk assessment and the implementation of counteractive measures difficult. Using the German state of Thuringia as a model example, the estimated sero-, and antigen prevalence of <it>C. burnetii </it>(10% and 25%, respectively) was assessed at flock level in 39/252 randomly selected clinically healthy sheep flocks with more than 100 ewes and unknown abortion rate.</p> <p>Results</p> <p>The CHECKIT™ Q-fever Test Kit identified 11 (28%) antibody positive herds, whereas real-time PCR revealed the presence of <it>C. burnetii </it>DNA in 2 (5%) of the flocks. Multiple-locus variable number of tandem repeats analysis of 9 isolates obtained from one flock revealed identical profiles. All isolates contained the plasmid QpH1.</p> <p>Conclusions</p> <p>The results demonstrate that <it>C. burnetii </it>is present in clinically inconspicuous sheep flocks and sporadic flare-ups do occur as the notifications to the German animal disease reporting system show. Although <it>C. burnetii </it>infections are not a primary veterinary concern due to the lack of significant clinical impact on animal health (with the exception of goats), the eminent zoonotic risk for humans should not be underestimated. Therefore, strategies combining the interests of public and veterinary public health should include monitoring of flocks, the identification and culling of shedders as well as the administration of protective vaccines.</p

Influenza-A Viruses in Ducks in Northwestern Minnesota: Fine Scale Spatial and Temporal Variation in Prevalence and Subtype Diversity

Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July – October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. Prevalence of AIV peaked in late summer. We detected 27 AIV subtypes during 2007 and 31 during 2008. Ten hemagglutinin (HA) subtypes were detected each year (i.e., H1, 3–8, and 10–12 during 2007; H1-8, 10 and 11 during 2008). All neuraminidase (NA) subtypes were detected during each year of the study. Subtype diversity varied between years and increased with prevalence into September. Predominant subtypes during 2007 (comprising ≥5% of subtype diversity) included H1N1, H3N6, H3N8, H4N6, H7N3, H10N7, and H11N9. Predominant subtypes during 2008 included H3N6, H3N8, H4N6, H4N8, H6N1, and H10N7. Additionally, within each HA subtype, the same predominant HA/NA subtype combinations were detected each year and included H1N1, H3N8, H4N6, H5N2, H6N1, H7N3, H8N4, H10N7, and H11N9. The H2N3 and H12N5 viruses also predominated within the H2 and H12 subtypes, respectively, but only were detected during a single year (H2 and H12 viruses were not detected during 2007 and 2008, respectively). Mallards were the predominant species sampled (63.7% of the total), and 531 AIV were isolated from this species (80.5% of the total isolates). Mallard data collected during both years adequately described the observed temporal and spatial prevalence from the total sample and also adequately represented subtype diversity. Juvenile mallards also were adequate in describing the temporal and spatial prevalence of AIV as well as subtype diversity

Hampered Foraging and Migratory Performance in Swans Infected with Low-Pathogenic Avian Influenza A Virus

It is increasingly acknowledged that migratory birds, notably waterfowl, play a critical role in the maintenance and spread of influenza A viruses. In order to elucidate the epidemiology of influenza A viruses in their natural hosts, a better understanding of the pathological effects in these hosts is required. Here we report on the feeding and migratory performance of wild migratory Bewick's swans (Cygnus columbianus bewickii Yarrell) naturally infected with low-pathogenic avian influenza (LPAI) A viruses of subtypes H6N2 and H6N8. Using information on geolocation data collected from Global Positioning Systems fitted to neck-collars, we show that infected swans experienced delayed migration, leaving their wintering site more than a month after uninfected animals. This was correlated with infected birds travelling shorter distances and fuelling and feeding at reduced rates. The data suggest that LPAI virus infections in wild migratory birds may have higher clinical and ecological impacts than previously recognised