Influenza Research and Treatment
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Open Access journal
ISSN (Print) 2090-1380 - ISSN (Online) 2090-1399
Published by Hindawi [333 journals]
- Barriers Associated with Seasonal Influenza Vaccination among College
Abstract: Influenza can spread rapidly on college campuses because of high-density living conditions and frequent social interactions. However, seasonal influenza vaccination rates on college campuses are low. The purpose of this study is to identify barriers associated with receipt of the seasonal influenza vaccination. Questionnaires were completed by a convenience sample of 383 undergraduate students in January 2014. Data were analyzed to identify barriers associated with receiving the seasonal influenza vaccine. Only 20.6% of students reported receiving the vaccine within the last 6 months. Among students who did not receive the vaccine, 47.8% believed they would get influenza from the vaccine, 41.6% believed the vaccination may have dangerous side effects, and 39.6% believed they were not at risk for contracting influenza. The majority of nonvaccinated students did not believe cost of the vaccine or access to the vaccine were barriers. Many college students are not receiving the seasonal influenza vaccine, representing an important area for improvement. Understanding potential barriers associated with receipt of this vaccine is important for identifying and creating effective public health education programs and campaigns. There is a need for enhanced vaccination education efforts among college students, particularly with respect to the safety and importance of this vaccine.
PubDate: Thu, 24 Mar 2016 15:37:51 +000
- Serological Survey for Avian Influenza in Turkeys in Three States of
Abstract: Since the first outbreak of avian influenza (AI) in Nigeria in 2006, there has been continuous monitoring of the disease in chickens with little attention given to turkeys. As part of on-going surveillance for AI in southwest Nigeria, we used a competitive ELISA to detect anti-AI virus antibodies in 520 turkey sera obtained from poultry farms in Oyo, Osun, and Ondo states while haemagglutination inhibiting antibodies against low pathogenic AI viruses (LPAIVs) were detected using H3N8 and H5N2 subtype-specific antigens. The overall seroprevalence obtained by ELISA was 4.4% (23/520). Of the 23 ELISA-positive samples, 18 were positive for anti-AIV H3N8 antibodies only and four were positive for both anti-AIV H3N8 and H5N2 antibodies indicating a mixed infection, while five were negative for antibodies to either of the two AIV subtypes. Considering that turkeys have been implicated as a mixing vessel for generating influenza virus reassortants of human and avian origin, the detection of antibodies to LPAIV H3N8 and H5N2 in these turkeys is of public health concern. We advocate further studies to determine the potential role of turkeys in the zoonotic transmission of AIVs in Nigeria. Additionally, the practice of rearing turkeys with chickens should be discouraged.
PubDate: Tue, 17 Nov 2015 09:25:47 +000
- Passive Broad-Spectrum Influenza Immunoprophylaxis
Abstract: Influenza is a perennial problem affecting millions of people annually with the everpresent threat of devastating pandemics. Active prophylaxis by vaccination against influenza virus is currently the main countermeasure supplemented with antivirals. However, disadvantages of this strategy include the impact of antigenic drift, necessitating constant updating of vaccine strain composition, and emerging antiviral drug resistance. The development of other options for influenza prophylaxis, particularly with broad acting agents able to provide protection in the period between the onset of a pandemic and the development of a strain specific vaccine, is of great interest. Exploitation of broad-spectrum mediators could provide barricade protection in the early critical phase of influenza virus outbreaks. Passive immunity has the potential to provide immediate antiviral effects, inhibiting virus replication, reducing virus shedding, and thereby protecting vulnerable populations in the event of an impending influenza pandemic. Here, we review passive broad-spectrum influenza prophylaxis options with a focus on harnessing natural host defenses, including interferons and antibodies.
PubDate: Mon, 22 Sep 2014 08:26:45 +000
- Avian Influenza Surveillance in the Danube Delta Using Sentinel Geese and
Abstract: Highly pathogenic avian influenza (HPAI) H5N1 virus incursions from migrating birds have occurred multiple times in Romania since 2005. Beginning in September 2008 through April 2013, seasonal sentinel surveillance for avian influenza A viruses (AIVs) using domestic geese (Anser cygnoides) and ducks (Anas platyrhynchos) in the Danube Delta was established by placing 15 geese and 5 ducks at seven sites. Tracheal and cloacal swabs, and sera collections (starting in 2009) were taken monthly. We studied a total of 580 domestic birds and collected 5,520 cloacal and tracheal swabs from each and 2,760 sera samples. All swabs were studied with real-time reverse transcription polymerase chain reaction (rRT-PCR) for evidence of AIV. Serological samples were studied with hemagglutination inhibition assays against avian H5, H7, and H9 influenza viruses. From 2009 to 2013, 47 swab specimens from Cot Candura, Enisala, and Saon screened positive for AIV; further subtyping demonstrated that 14 ducks and 20 geese had cloacal evidence of H5N3 carriage. Correspondingly, 4 to 12 weeks after these molecular detections, sentinel bird sera revealed elevated HI titers against H5 virus antigens. We posit that domestic bird surveillance is an effective method to conduct AIV surveillance among migrating birds in delta areas.
PubDate: Tue, 25 Mar 2014 09:10:37 +000
- Effect of the PB2 and M Genes on the Replication of H6 Influenza Virus in
Abstract: H6 subtype influenza viruses are commonly isolated from wild aquatic birds. However, limited information is available regarding H6 influenza virus isolated from chickens. We compared the viral genome segment between A/chicken/Hong Kong/W312/97 (H6N1), which was able to grow in chicken trachea, and A/duck/Shantou/5540/01 (H6N2), which was isolated from wild aquatic duck, to explore the factors for effective replication in chicken. When chickens were inoculated with reassortants (W312 background), the replication of viruses with PB2 and M genes derived from the duck strain was significantly reduced. Chimeras of PB2 and M proteins, encoding the C-terminal region of the PB2 protein and the M2 protein from W312, were required for efficient replication in canine-derived (MDCK) cells and in chicken trachea. These results indicate that host range may be determined by some types of internal proteins such as PB2 and M2, as well as by surface glycoprotein like hemagglutinin.
PubDate: Tue, 18 Feb 2014 13:13:57 +000
- Detection and Isolation of Airborne Influenza A H3N2 Virus Using a Sioutas
Personal Cascade Impactor Sampler
Abstract: The air we breathe contains microorganisms that can cause infectious respiratory diseases. After two occupants of an apartment were diagnosed with influenza in February of 2013, efforts were made to detect and isolate airborne influenza virus using two different types of active air samplers: a Sioutas Personal Cascade Impactor Sampler (PCIS) and an SKC BioSampler. The PCIS collects size-fractionated particles by impaction on polytetrafluoroethylene filters, whereas the SKC BioSampler collects airborne particles in liquid media. Influenza H3N2 virus was collected by both types of air samplers. The PCIS collected a range of particle sizes containing influenza virus near one of the sick individuals but only ultrafine particles when the samplers were positioned farther away. Viable virus was present in the liquid collection media of the SKC BioSampler and some PCIS filters. These findings suggest that influenza patients produce ultrafine aerosol particles that contain viable virus.
PubDate: Thu, 10 Oct 2013 15:58:36 +000
- 3D Molecular Modelling Study of the H7N9 RNA-Dependent RNA Polymerase as
an Emerging Pharmacological Target
Abstract: Currently not much is known about the H7N9 strain, and this is the major drawback for a scientific strategy to tackle this virus. Herein, the 3D complex structure of the H7N9 RNA-dependent RNA polymerase has been established using a repertoire of molecular modelling techniques including homology modelling, molecular docking, and molecular dynamics simulations. Strikingly, it was found that the oligonucleotide cleft and tunnel in the H7N9 RNA-dependent RNA polymerase are structurally very similar to the corresponding region on the hepatitis C virus RNA-dependent RNA polymerase crystal structure. A direct comparison and a 3D postdynamics analysis of the 3D complex of the H7N9 RNA-dependent RNA polymerase provide invaluable clues and insight regarding the role and mode of action of a series of interacting residues on the latter enzyme. Our study provides a novel and efficiently intergraded platform with structural insights for the H7N9 RNA-dependent RNA Polymerase. We propose that future use and exploitation of these insights may prove invaluable in the fight against this lethal, ongoing epidemic.
PubDate: Wed, 25 Sep 2013 17:28:56 +000
- Comparative Serological Assays for the Study of H5 and H7 Avian Influenza
Abstract: The nature of influenza virus to randomly mutate and evolve into new types is an important challenge in the control of influenza infection. It is necessary to monitor virus evolution for a better understanding of the pandemic risk posed by certain variants as evidenced by the highly pathogenic avian influenza (HPAI) viruses. This has been clearly recognized in Egypt following the notification of the first HPAI H5N1 outbreak. The continuous circulation of the virus and the mass vaccination programme undertaken in poultry have resulted in a progressive genetic evolution and a significant antigenic drift near the major antigenic sites. In order to establish if vaccination is sufficient to provide significant intra- and interclade cross-protection, lentiviral pseudotypes derived from H5N1 HPAI viruses (A/Vietnam/1194/04, A/chicken/Egypt-1709-01/2007) and an antigenic drift variant (A/chicken/Egypt-1709-06-2008) were constructed and used in pseudotype-based neutralization assays (pp-NT). pp-NT data obtained was confirmed and correlated with HI and MN assays. A panel of pseudotypes belonging to influenza Groups 1 and 2, with a combination of reporter systems, was also employed for testing avian sera in order to support further application of pp-NT as an alternative valid assay that can improve avian vaccination efficacy testing, vaccine virus selection, and the reliability of reference sera.
PubDate: Sun, 15 Sep 2013 13:41:48 +000
- A Time Off Incentive Was Not Associated with Influenza Vaccination
Acceptance among Healthcare Workers
Abstract: Objectives. The national influenza vaccination rate among healthcare workers (HCWs) remains low despite clear benefits to patients, coworkers, and families. We sought to evaluate formally the effect of a one-hour time off incentive on attitudes towards influenza vaccination during the 2011-2012 influenza season. Methods. All HCWs at the Philadelphia Veterans Affairs (VA) Medical Center were invited to complete an anonymous web-based survey. We described respondents’ characteristics and attitudes toward influenza vaccination and determined the relationship of specific attitudes with respondents’ acceptance of influenza vaccination, using a 5-point Likert scale. Results. We analyzed survey responses from 154 HCWs employed at the Philadelphia VA Medical Center, with a response rate of 8%. Among 121 respondents who reported receiving influenza vaccination, 34 (28%, 95% CI 20–37%) reported agreement with the statement that the time off incentive made a difference in their decision to accept influenza vaccination. Conclusions. Our study provides evidence that modest incentives such as one-hour paid time off will be unlikely to promote influenza vaccination rates within medical facilities. More potent interventions that include mandatory vaccination combined with penalties for noncompliance will likely provide the only means to achieve near-universal influenza vaccination among HCWs.
PubDate: Wed, 26 Jun 2013 11:44:05 +000
- Mortality Associated with Influenza in Tropics, State of São Paulo,
Brazil, from 2002 to 2011: The Pre-Pandemic, Pandemic, and Post-Pandemic
Abstract: The impact of the seasonal influenza and 2009 AH1N1 pandemic influenza on mortality is not yet completely understood, particularly in tropical and subtropical countries. The trends of influenza related mortality rate in different age groups and different outcomes on a area in tropical and subtropical climate with more than 41 million people (State of São Paulo, Brazil), were studied from 2002 to 2011 were studied. Serfling-type regression analysis was performed using weekly mortality registries and virological data obtained from sentinel surveillance. The prepandemic years presented a well-defined seasonality during winter and a clear relationship between activity of AH3N2 and increase of mortality in all ages, especially in individuals older than 60 years. The mortality due to pneumonia and influenza and respiratory causes associated with 2009 pandemic influenza in the age groups 0–4 years and older than 60 was lower than the previous years. Among people aged 5–19 and 20–59 years the mortality was 2.6 and 4.4 times higher than that in previous periods, respectively. The mortality in all ages was higher than the average of the previous years but was equal mortality in epidemics of AH3N2. The 2009 pandemic influenza mortality showed significant differences compared to other years, especially considering the age groups most affected.
PubDate: Wed, 12 Jun 2013 08:31:50 +000
- Point-of-Care Testing as an Influenza Surveillance Tool: Methodology and
Lessons Learned from Implementation
Abstract: Objectives. Disease surveillance combines data collection and analysis with dissemination of findings to decision makers. The timeliness of these activities affects the ability to implement preventive measures. Influenza surveillance has traditionally been hampered by delays in both data collection and dissemination. Methods. We used statistical process control (SPC) to evaluate the daily percentage of outpatient visits with a positive point-of-care (POC) influenza test in the University of Utah Primary Care Research Network. Results. Retrospectively, POC testing generated an alert in each of 4 seasons (2004–2008, median 16 days before epidemic onset), suggesting that email notification of clinicians would be 9 days earlier than surveillance alerts posted to the Utah Department of Health website. In the 2008-09 season, the algorithm generated a real-time alert 19 days before epidemic onset. Clinicians in 4 intervention clinics received email notification of the alert within 4 days. Compared with clinicians in 6 control clinics, intervention clinicians were 40% more likely to perform rapid testing () and twice as likely to vaccinate for seasonal influenza () after notification. Conclusions. Email notification of SPC-generated alerts provided significantly earlier notification of the epidemic onset than traditional surveillance. Clinician preventive behavior was not significantly different in intervention clinics.
PubDate: Thu, 11 Apr 2013 10:41:29 +000
- Monoclonal Antibody Targeting Neutralizing Epitope on H5N1 Influenza Virus
of Clade 1 and 0 for Specific H5 Quantification
Abstract: H5N1 influenza viruses cause high mortality in avian and mammalian species, including humans. Antigenic drift in H5 sequence poses challenges in the development of vaccine and therapeutic antibody. In this study, a monoclonal antibody 11G12 was produced from inactivated H5N1 immunized mice. Results from IFA, ELISA, HI, and virus neutralization indicated that Mab 11G12 can specifically recognize and neutralize H5 type hemagglutinin from clade 1 and 0 without any cross-reaction to any other clades of H5N1 viruses. Mab 11G12 was used to differentiate and quantify the expression of H5N1 strain A/VietNam/1203/04 from a trivalent vaccine mix in ELISA. Sequencing of escape mutants identified that Mab 11G12 targets a major neutralizing epitope of influenza H5 hemagglutinin. The study indicated that some major neutralizing epitopes in H5s of early strains were mutated due to antigenic drift.
PubDate: Tue, 05 Mar 2013 13:25:52 +000
- Comparing Deaths from Influenza H1N1 and Seasonal Influenza A: Main
Sociodemographic and Clinical Differences between the Most Prevalent 2009
Abstract: Background. During the 2009 spring epidemic outbreak in Mexico, an important research and policy question faced was related to the differences in clinical profile and population characteristics of those affected by the new H1N1 virus compared with the seasonal virus. Methods and Findings. Data from clinical files from all influenza A deaths in Mexico between April 10 and July 13, 2009 were analyzed to describe differences in clinical and socioeconomic profile between H1N1 and non-H1N1 cases. A total of 324 influenza A mortality cases were studied of which 239 presented rt-PCR confirmation for H1N1 virus and 85 for seasonal influenza A. From the differences of means and multivariate logistic regression, it was found that H1N1 deaths occurred in younger and less educated people, and among those who engage in activities where there is increased contact with other unknown persons (OR 4.52, 95% CI 1.56–13.14). Clinical symptoms were similar except for dyspnea, headache, and chest pain that were less frequently found among H1N1 cases. Conclusions. Findings suggest that age, education, and occupation are factors that may be useful to identify risk for H1N1 among influenza cases, and also that patients with early dyspnea, headache, and chest pain are more likely to be non-H1N1 cases.
PubDate: Sun, 30 Dec 2012 16:09:27 +000
- Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian
Influenza Viruses with Allele A and B Nonstructural Gene in Northern
Pintail (Anas acuta) Ducks Wintering in Japan
Abstract: The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR*GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR*GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in pintail wintering in Japan.
PubDate: Tue, 25 Dec 2012 13:46:15 +000
- Myocarditis Associated with Influenza A H1N1pdm2009
Abstract: Acute myocarditis is a well-known complication of influenza infection. The frequency of myocardial involvement in influenza infection varies widely, with the clinical severity ranging from asymptomatic to fulminant varieties. The worst cases can result in death due to impaired cardiac function, although such fulminant myocarditis associated with influenza infection is rare, as shown by previous papers. Following the 2009 influenza pandemic, we reported on the clinical features of a cohort of 15 patients in Japan with H1N1pdm2009 myocarditis. In our subsequent survey of the literature for case reports or series of patients with myocarditis associated with H1N1pdm2009, we identified 58 detailed cases. We discuss here the high prevalence of fulminant myocarditis (36/58, 62%) among patients reported to have myocarditis associated with H1N1pdm2009. Mechanical circulatory support was required in 17 of the patients with fulminant myocarditis, 13 of whom recovered. We stress the need for increased awareness of influenza-associated myocarditis; such knowledge will facilitate earlier diagnosis and treatment of this fatal complication during future influenza pandemics.
PubDate: Mon, 17 Dec 2012 09:15:21 +000
- Factors Affecting Medical Students’ Uptake of the 2009 Pandemic
Influenza A (H1N1) Vaccine
Abstract: Background. Pandemic influenza vaccination rate amongst healthcare workers in England 2009/2010 was suboptimal (40.3%). Targeting medical students before they enter the healthcare workforce is an attractive future option. This study assessed the H1N1 vaccine uptake rate amongst medical students and factors that influenced this. Methods. Anonymised, self-administered questionnaire at a medical school. Results. The uptake rate amongst 126 medical students offered the vaccine was 49.2% and intended uptake amongst 77 students was 63.6%. Amongst those offered the vaccine, the strongest barriers to acceptance were fear of side effects (67.9%), lack of vaccine information (50.9%), lack of perceived risk (45.3%), and inconvenience (35.8%). Having a chronic illness (OR 3.4 (95% CI 1.2–10.2)), 4th/5th year of study (OR 3.0 (95% CI 1.3–7.1)), and correct H1N1 knowledge (OR 2.6 (95% CI 1.1–6.0)) were positively associated with uptake. Non-white ethnicity was an independent negative predictor of uptake (OR 0.4 (95% CI 0.2–0.8)). Students who accepted the H1N1 vaccine were three times more likely (OR 3.1 (95% CI 1.2–7.7)) to accept future seasonal influenza vaccination. Conclusion. Efforts to increase uptake should focus on routine introduction of influenza vaccine and creating a culture of uptake during medical school years, evidence-based education on vaccination, and improving vaccine delivery.
PubDate: Wed, 28 Nov 2012 09:53:04 +000
- Factors Affecting Acceptance and Intention to Receive Pandemic Influenza A
H1N1 Vaccine among Primary School Children: A Cross-Sectional Study in
Abstract: UK pandemic influenza strategy focused on vaccination of high risk groups, although evidence shows that school-age children have the highest infection rates. Vaccination of children might be an additional strategy. We undertook a cross-sectional study amongst 149 parents of primary school children aged 4–7 years in Birmingham, UK to quantify intention to accept pandemic influenza vaccine and identify factors affecting uptake. Ninety-one (61.1%, 95% CI 52.8, 68.9) had or would accept vaccine for their child. The most common reasons for declining vaccine were concerns about safety (58.6% reported this), side effects (55.2%), or believing their child had already had swine flu (12.1%). Parents of nonwhite ethnicity (OR 2.4 (1.1, 5.0)) and with asthmatic children (OR 6.6 (1.4, 32.1)) were significantly more likely to accept pandemic vaccine, as were those whose children had ever received seasonal vaccine and those who believed swine flu to be a serious threat (OR 4.2 (1.9, 9.1)). Parents would be more likely to accept vaccination if they received a letter of invite, if the government strongly encouraged them, if it were administered at school, and if it were more thoroughly tested. Accurate media portrayal of safety of the vaccine during future pandemics will be essential.
PubDate: Wed, 17 Oct 2012 09:41:41 +000
- Persistence of Avian Influenza Viruses in Various Artificially Frozen
Environmental Water Types
Abstract: Background. This study investigates the viable persistence of avian influenza viruses (AIVs) in various types of artificially frozen environmental water and evaluates the feasibility of similar occurrence taking place in nature, and allowing for prolonged abiotic virus survival, with subsequent biotic viral recirculation. Methods. Fresh, brackish, and salty water, taken in Japan from aquatic biotopes regularly visited by migratory waterfowl, were seeded with AIVs. We monthly monitored the viability of the seeded viruses in the frozen state at −20°C and −30°C, for 12 months. We also monitored virus viability following repeatedly induced freezing and thawing. Results. The viruses exhibited considerable viable persistence all along that period of time, as well as during freezing-thawing cycles. Appreciable, yet noncrucial variances were observed in relation to some of the parameters examined. Conclusions. As typical waterborne pathogens of numerous northerly aquatic birds, AIVs are innately adapted to both the body temperature of their hosts (40°C to 42°C) and, presumably, to subzero temperatures of frozen lakes (down to −54°C in parts of Siberia) occupied and virus-seeded by subclinically infected birds, prior to freezing. Marked cryostability of AIVs appears to be evident. Preservation in environmental ice has significant ecophylogenetic and epidemiological implications, potentially, and could account for various unexplained phenomena.
PubDate: Thu, 04 Oct 2012 13:21:55 +000
- Pediatric Influenza-Associated Deaths in New York State: Death Certificate
Coding and Comparison to Laboratory-Confirmed Deaths
Abstract: Introduction. Surveillance for laboratory-confirmed influenza-associated deaths in children is used to monitor the severity of influenza at the population level and to inform influenza prevention and control policies. The goal of this study was to better estimate pediatric influenza mortality in New York state (NYS). Methods. Death certificate data were requested for all passively reported deaths and any pneumonia and influenza (P&I) coded pediatric deaths occurring between October 2004 and April 2010, excluding New York City (NYC) residents. A matching algorithm and capture-recapture analysis were used to estimate the total number of influenza-associated deaths among NYS children. Results. Thirty-four laboratory-confirmed influenza-associated pediatric deaths were reported and 67 death certificates had a P&I coded death; 16 deaths matched. No laboratory-confirmed influenza-associated death had a pneumonia code and no pneumonia coded deaths had laboratory evidence of influenza infection in their medical record. The capture-recapture analysis estimated between 38 and 126 influenza-associated pediatric deaths occurred in NYS during the study period. Conclusion. Passive surveillance for influenza-associated deaths continues to be the gold standard methodology for characterizing influenza mortality in children. Review of death certificates can complement but not replace passive reporting, by providing better estimates and detecting any missed laboratory-confirmed deaths.
PubDate: Tue, 25 Sep 2012 19:18:58 +000
- Situation-Based Survey of Avian Influenza Viruses in Possible “Bridge”
Species of Wild and Domestic Birds in Nigeria
Abstract: The highly pathogenic avian influenza (H5N1 subtype) recurred in Nigeria after 9 months period of no reported case. A critical look at possible sources of the re-occurrence was desirable. The objective of this study was to determine whether avian influenza viruses were present at reasonably detectable levels (0.5%) in possible “bridge” species of wild and domestic birds. The study was conducted in 8 Nigerian states. A total of 403 birds from 40 species were sampled. Virus isolation was done in embryonated chicken eggs according to standard protocols. The test results were all negative for avian influenza viruses. The overall confidence interval (CI) calculated in R using the exact binomial confidence interval function was 0–0.007406. Tawny Eagle (Aquila rapax) was the lowest sampled 0.3% (1/403) and Red-billed Firefinch (Lagonosticta senegala) the highest 11.7% (47/403). The limitations of the sample size and possibly designing effects on the study, as to make concrete conclusions were acknowledged. Species of wild birds, so identified in the study could be useful in future surveys. Furthermore, multidisciplinary and community oriented approach, blending targeted and passive surveillances was suggested. This approach was envisaged to bring about wider coverage of “bridge” species and clearer insight of their possible roles in avian influenza re-occurrences and spread in Nigeria.
PubDate: Sun, 02 Sep 2012 08:26:04 +000
- Influenza-Associated Mortality in Georgia (2009–2011)
Abstract: We analyzed data from NCDCPH Georgia where samples from outpatients with influenza-like illness (ILI) and inpatients with severe acute respiratory syndrome (SARI) are referred for testing on influenza virus using PCR analysis. During 2009-2010 and 2010-2011 influenza pandemics total number of the laboratory-confirmed influenza cases were 1286 with 33 deaths (all of them influenza type A) and 1203 (51.4% type A) with 44 deaths, respectively. At least one underlying medical condition was reported in 70.7% (for pandemic influenza strain) and 96% (for influenza type B) of deaths. Predominating preexisting condition was coronary heart disease.
PubDate: Wed, 15 Aug 2012 12:52:02 +000
- Comparison of Human-Like H1 (ð›¿-Cluster) Influenza A Viruses in the
Abstract: Influenza A viruses cause acute respiratory disease in swine. Viruses with H1 hemagglutinin genes from the human seasonal lineage (ð›¿-cluster) have been isolated from North American swine since 2003. The objective of this work was to study the pathogenesis and transmission of ð›¿-cluster H1 influenza viruses in swine, comparing three isolates from different phylogenetic subclusters, geographic locations, and years of isolation. Two isolates from the ð›¿2 subcluster, A/sw/MN/07002083/07 H1N1 (MN07) and A/sw/IL/00685/05 H1N1 (IL05), and A/sw/TX/01976/08 H1N2 (TX08) from the ð›¿1 sub-cluster were evaluated. All isolates caused disease and were transmitted to contact pigs. Respiratory disease was apparent in pigs infected with MN07 and IL05 viruses; however, clinical signs and lung lesions were reduced in severity as compared to TX08. On day 5 following infection MN07-infected pigs had lower virus titers than the TX08 pigs, suggesting that although this H1N1 was successfully transmitted, it may not replicate as efficiently in the upper or lower respiratory tract. MN07 and IL05 H1N1 induced higher serum antibody titers than TX08. Greater serological cross-reactivity was observed for viruses from the same HA phylogenetic sub-cluster; however, antigenic differences between the sub-clusters may have implications for disease control strategies for pigs.
PubDate: Sun, 03 Jun 2012 11:49:04 +000
- Influenza Vaccine Coverage among Pregnant Women in a Public Hospital
System during the 2009-2010 Pandemic Influenza Season
Abstract: The purpose of this study was to compare influenza vaccination rates of pregnant women in a public safety-net health system to national coverage rates during the 2009-2010 pandemic influenza season. A chart review of a random sample of deliveries was undertaken to determine rates of coverage and predictors of vaccine coverage of women who obtained prenatal care and delivered in our health system. Rates were calculated from deliveries from when the vaccine was first available through April 30, 2010. Coverage rates were 54% for the seasonal influenza vaccine and 51% for the H1N1 vaccine. Race/ethnicity, insurance status and language spoken did not predict the receipt of either vaccine. When we included only births which occurred through March 12, 2010, as was done in a large population-based study, the rates were 61% and 59%, respectively. Our rates are about 10% higher than the rates reported in that study. Our comprehensive strategy for promoting vaccine coverage achieved higher vaccination rates in a safety-net health system, which serves groups historically less likely to be vaccinated, than those reported for the pregnant population at large.
PubDate: Mon, 07 May 2012 14:18:43 +000
- Clinical and Epidemiologic Characteristics of Hospitalized Patients with
2009 H1N1 Influenza Infection
Abstract: Objective. 2009 H1N1 virus is a new virus that was firstly detected in April 2009. This virus spreads from human to human and causes a worldwide disease. This paper aimed to review the clinical and epidemiological properties of patients with 2009 H1N1 influenza who were hospitalized and monitored at Eskisehir Osmangazi University Faculty of Medicine Hospital. Setting. A 1000-bed teaching hospital in Eskisehir, Turkey. Patients-Methods. Between 05 November 2009–01 February 2010, 106 patients with 2009 H1N1 influenza, who were hospitalized, were prospectively evaluated. Results. Out of 106 patients who were hospitalized and monitored, 99 (93.4%) had fever, 86 (81.1%) had cough, 48 (45.3%) had shortness of breath, 47 (44.3%) had sore throat, 38 (35.8%) had body pain, 30 (28.3%) had rhinorrhea, 17 (16%) had vomiting, 15 (14.2%) had headache, and 14 (13.2%) had diarrhea. When the patients were examined in terms of risk factors for severe disease, 83 (78.3%) patients had at least one risk factor. During clinical monitoring, pneumonia was the most frequent complication with a rate of 66%. While 47.2% of the patients were monitored in intensive care unit, 34% of them required mechanical ventilation support. Conclusion. Patients with 2009 H1N1 influenza, who were hospitalized and monitored, should be carefully monitored and treated.
PubDate: Mon, 23 Apr 2012 10:47:54 +000
- Influenza Vaccination in the Face of Immune Exhaustion: Is Herd Immunity
Effective for Protecting the Elderly'
Abstract: At the start of the 21st century, seasonal influenza virus infection is still a major public health concern across the world. The recent body of evidence confirms that trivalent inactivated influenza vaccines (TIVs) are not optimal within the population who account for approximately 90% of all influenza-related death: elderly and chronically ill individuals regardless of age. With the ever increasing aging of the world population and the recent fears of any pandemic influenza rife, great efforts and resources have been dedicated to developing more immunogenic vaccines and strategies for enhancing protection in these higher-risk groups. This paper describes the mechanisms that shape immune response at the extreme ages of life and how they have been taken into account to design more effective immunization strategies for these vulnerable populations. Furthermore, consideration will be given to how herd immunity may provide an effective strategy in preventing the burden of seasonal influenza infection within the aged population.
PubDate: Sun, 29 Jan 2012 08:19:38 +000
- A Novel Vaccine Using Nanoparticle Platform to Present Immunogenic M2e
against Avian Influenza Infection
Abstract: Using peptide nanoparticle technology, we have designed two novel vaccine constructs representing M2e in monomeric (Mono-M2e) and tetrameric (Tetra-M2e) forms. Groups of specific pathogen free (SPF) chickens were immunized intramuscularly with Mono-M2e or Tetra-M2e with and without an adjuvant. Two weeks after the second boost, chickens were challenged with 107.2 EID50 of H5N2 low pathogenicity avian influenza (LPAI) virus. M2e-specific antibody responses to each of the vaccine constructs were tested by ELISA. Vaccinated chickens exhibited increased M2e-specific IgG responses for each of the constructs as compared to a non-vaccinated group. However, the vaccine construct Tetra-M2e elicited a significantly higher antibody response when it was used with an adjuvant. On the other hand, virus neutralization assays indicated that immune protection is not by way of neutralizing antibodies. The level of protection was evaluated using quantitative real time PCR at 4, 6, and 8 days post-challenge with H5N2 LPAI by measuring virus shedding from trachea and cloaca. The Tetra-M2e with adjuvant offered statistically significant (ð‘ƒ
PubDate: Thu, 12 Jan 2012 08:18:48 +000
- A Time Course for Susceptibility to Staphylococcus aureus Respiratory
Infection during Influenza in a Swine Model
Abstract: Bacterial superinfections following influenza A virus (IAV) are predominant causes of morbidity in humans. The recent emergence of methicillin-resistant Staphylococcus aureus (MRSA) and highly virulent IAV strains has reduced treatment options. Development of an appropriate animal model to study secondary S. aureus infections may provide important information regarding disease pathogenesis. Pigs are natural hosts to both IAV and S. aureus and have respiratory physiology and immune response comparable to humans. To establish a time course of susceptibility to S. aureus after IAV infection, nursery pigs infected intranasally with IAV were challenged with MRSA at different time points. Lung pathology scores and MRSA CFU were evaluated in dual-infected animals after IAV infection. Flow cytometric analysis of bronchoalveolar lavage fluid indicated differences between treatments. These results demonstrate the appropriateness of an intranasal challenge model in nursery pigs for studying the pathogenesis of IAV and S. aureus coinfection and provide insights into the timeframe for susceptibility of IAV-infected pigs to secondary S. aureus infection.
PubDate: Wed, 11 Jan 2012 16:20:59 +000
- Experiences after Twenty Months with Pandemic Influenza A (H1N1) 2009
Infection in the Naïve Norwegian Pig Population
Abstract: Pandemic (H1N1) 2009 influenza A virus was detected in Norwegian pigs in October 2009. Until then, Norway was regarded free of swine influenza. Intensified screening revealed 91 positive herds within three months. The virus was rapidly transmitted to the susceptible population, including closed breeding herds with high biosecurity. Humans were important for the introduction as well as spread of the virus to pigs. Mild or no clinical signs were observed in infected pigs. Surveillance of SIV in 2010 revealed that 41% of all the Norwegian pig herds had antibodies to pandemic (H1N1) 2009 virus. Furthermore, this surveillance indicated that pigs born in positive herds after the active phase did not seroconvert, suggesting no ongoing infection in the herds. However, results from surveillance in 2011 show a continuing spread of the infection in many herds, either caused by new introduction or by virus circulation since 2009.
PubDate: Tue, 03 Jan 2012 10:22:54 +000
- Clinical Impact of Infection with Pandemic Influenza (H1N1) 2009 Virus in
Naïve Nucleus and Multiplier Pig Herds in Norway
Abstract: The Norwegian pig population has been free from influenza viruses until 2009. The pandemic influenza outbreak during the autumn 2009 provided an opportunity to study the clinical impact of this infection in an entirely naïve pig population. This paper describes the results of a case-control study on the clinical impact of pandemic influenza (H1N1) 2009 infection in the nucleus and multiplier herds in Norway. The infection spread readily and led to seroconversion of 42% of the Norwegian nucleus and multiplier herds within a year. Positive and negative herds were identified based on surveillance data from the Norwegian Veterinary Institute. Telephone interviews were conducted with pig herd owners or managers between November 2010 and January 2011. Pigs with clinical signs were reported from 40% of the case herds with varying morbidity and duration of respiratory disease and reduced reproductive performance. Clinical signs were reported in all age groups.
PubDate: Thu, 22 Dec 2011 08:56:49 +000
- Pathological Findings and Distribution of Pandemic Influenza A (H1N1) 2009
Virus in Lungs from Naturally Infected Fattening Pigs in Norway
Abstract: The Norwegian pig population was considered free from influenza A virus infections until the first case of porcine pandemic influenza A (H1N1) 2009 virus infection in October 2009. Human to pig transmission of virus was suspected. Unusual lung lesions were observed in fattening pigs, with red, lobular, multifocal to coalescing consolidation, most frequently in the cranial, middle, and accessory lobes. The main histopathological findings were epithelial degeneration and necrosis, lymphocyte infiltration in the epithelial lining and lamina propria of small bronchi and bronchioles, and peribronchial and peribronchiolar lymphocyte infiltrations. Infection with pandemic influenza A (H1N1) 2009 virus was confirmed by real-time RT-PCR and immunohistochemical detection of influenza A virus nucleoprotein in the lesions. This investigation shows that natural infection with the pandemic influenza A (H1N1) 2009 virus induces lung lesions similar to lesions described in experimental studies and natural infections with other swine-adapted subtypes of influenza A viruses.
PubDate: Tue, 20 Dec 2011 08:59:43 +000