Volume 14, Issue 41 - 15 October 2009 - Eurosurveillance

More documents

Recommendations

Info

children develops at least four weeks after vaccination and would occur too late in the pandemic to make a significant difference to the number of infected in that age group. The cost benefit analysis involved in devising a pandemic influenza vaccination campaign is extremely complicated, especially due to the ever evolving nature of the pandemic. What we learn from the successes and mistakes of vaccination programmes developed during the current H1N1 influenza pandemic will greatly aid us in decision making during future influenza pandemics. Acknowledgements The authors wish to gratefully acknowledge the partial support of this research by the National Science Foundation via grant DMS-0719697.* *Authors’ correction: On request of the authors, the following corrections were made on 14 January 2010: The population of the US used in the studies was 305,000,000, not 350,000,000 as originally written. The assumed initial number of infective individuals was I0=1, not I0=1/N. β 0 and β 1 are expressed in units of gamma. An acknowledgement was added. References 1. Questions and Answers: Seasonal Influenza. Atlanta: Centers for Disease Control and Prevention. [accessed 2009 Oct 2]. Available from: http://www. cdc.gov/flu/about/qa/disease.htm 2. FluView: 2008-2009 Influenza Season Week 38 ending September 26, 2009. Atlanta: Centers for Disease Control and Prevention. [accessed 2009 Oct 2]. Available from: http://www.cdc.gov/flu/weekly/fluactivity.htm 3. Influenza-like illness in the United States and Mexico. Geneva: World Health Organization; 22 April 2009. Avaliable from: http://www.who.int/csr/ don/2009_04_24/en/index.html 4. Dushoff J, Plotkin JB, Levin SA, Earn DJ. Dynamical resonance can account for seasonal influenza epidemics. Proc Natl Acad Sci USA. 2004;101(48):16915-6. 5. Colizza V, Barrat A, Barthelemy M, Valleron A-J, Vespignani A. Modeling the worldwide spread of pandemic influenza: baseline case and containment interventions. PloS Med. 2007;4(1):e13. 6. Orders for Live Attenuated Influenza Vaccine. Washington: US Department of Health and Human Services [accessed 2009 Oct 2]. Available from: http:// www.flu.gov/individualfamily/vaccination/orders.html 7. Hannoun C, Megas F, Piercy J. Immunogenicity and Protective Efficacy of Influenza Vaccination. Virus Res. 2004 Jul;103(1-2):133-8. 8. Clark TW, Pareek M, Hoschler K, Dillon H, Nicholson KG, Groth N, et al. Trial of influenza A (H1N1) 2009 monovalent MF59-adjuvanted vaccine -preliminary report. N Engl J Med. 2009;361. DOI: 10.1056/NEJMoa0907650. 9. Fraser C, Donnelly CA, Cauchemez S, Hanage WP, Van Kerkhove MD, Hollingsworth TD, et al; WHO Rapid pandemic Assessment Collaboration. Pandemic potential of a strain of influenza A (H1N1): early findings. Science. 2009;324(5934):1557- 61. 10. King JC Jr, Haugh CJ, Dupont WD, Thompson JM, Wright PF, Edwards KM. Laboratory and Epidemiological Assessment of a Recent Influenza B Outbreak. J Med Virol. 1988;25(3):361-8. 8 www.eurosurveillance.org
R a p i d c o m m u n i c a ti o n s R e s i s ta n c e o f t u R k e y s t o e x p e R i m e n ta l i n f e c t i o n w i t h a n e a R ly 2 0 0 9 i ta l i a n h u m a n i n f l u e n z a a ( h 1 n 1 ) v v i R u s i s o l at e C Terregino 1 , R De Nardi 1 , R Nisi 1 , F Cilloni 1 , A Salviato 1 , M Fasolato 1 , I Capua (icapua@izsvenezie.it) 1 1. OIE/FAO and National Reference Laboratory for Avian Influenza and Newcastle disease, OIE Collaborating centre for infectious diseases at the human-animal interface, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), Legnaro, Italy This article was published on 15 October 2009. Citation style for this article: Terregino C, De Nardi R, Nisi R, Cilloni F, Salviato A, Fasolato M, Capua I. Resistance of turkeys to experimental infection with an early 2009 Italian human influenza A(H1N1)v virus isolate. Euro Surveill. 2009;14(41):pii=19360. Available online: http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=19360 We performed an experimental infection of 21- and 70-day-old meat turkeys with an early human isolate of the 2009 pandemic H1N1 influenza virus exhibiting an α-2,3 receptor binding profile. Virus was not recovered by molecular or conventional methods from blood, tracheal and cloacal swabs, lungs, intestine or muscle tissue. Seroconversion was detected in a limited number of birds with the homologous antigen only. Our findings suggest that in its present form, the pandemic H1N1 influenza virus is not likely to be transmitted to meat turkeys and does therefore not represent an animal health or food safety issue for this species. Introduction Following the emergence of the human pandemic influenza A(H1N1)v virus in spring 2009, questions about the circulation of this virus in an animal reservoir were raised by international organisations. In particular, three aspects appeared to be of relevance, namely implications on animal health, aspects of food safety, and epidemiological aspects related to animals being infected with a human virus and perpetuating a parallel channel of infection in the animal reservoir. Turkeys (Meleagris gallopavo) are highly susceptible to type A influenza virus infection and have been infected in the past with viruses of swine origin [1-4]. In August 2009, infection of two turkey flocks in Chile with the human influenza A(H1N1)v virus was reported [5]. The genetic profile of the virus appeared to be closely related (similarity ranging between 99.7% and 100%) to the strain that was circulating in the human population in Chile at the time [6]. The aim of this experiment was to establish the susceptibility of turkeys of different ages to infection with the human virus and to assess whether it would be detectable in the blood or in tissues of meat birds following administration of a high viral dose. Materials and methods Animals Commercially available turkeys were used in this study. The birds originated from a flock that was serologically negative for all avian influenza subtypes, including influenza A(H1N1)v, by agar gel immunodiffusion test (AGID) and enzyme-linked immunosorbent assay (ELISA) and negative for influenza A virus by real-time reverse transcription-PCR (RRT-PCR) on cloacal and tracheal swabs [7]. All animals were identified by means of wing tags and received feed and water ad libitum. Birds were housed in negative pressure, high efficiency particulate air (HEPA) filtered isolation cabinets for the duration of the experimental trial. Challenge virus and protocol Challenge of turkeys was carried out with the influenza A virus isolate A/Italy/2810/2009(H1N1). The virus was isolated from a human case detected in Verona, Italy, in specific pathogenfree (SPF) embryonated hens’ eggs via the amniotic cavity and was characterised according to chapter on swine influenza in the World Organisation for Animal Health (OIE) Manual of Diagnostics Tests and Vaccines for Terrestrial Animals [8]. The number of virus passages in SPF embryonated hens’ eggs was limited to the minimum (two) in order to limit laboratory manipulation and adaptation. The haemagglutinin (HA) and neuraminidase (N) genes of the virus obtained from nasal swabs of the patient and the HA of the virus obtained from the allantoic fluid after the second passage in eggs, were genetically analysed and sequences were deposited in the EpiFlu database of the Global Initiative on Sharing Avian Influenza Data (GISAID), accession numbers EPI181386, EPI181387 and EPI211620. The A/Italy/2810/2009(H1N1) virus isolate has 99.6% homology with influenza A/California/4/09. The HA gene of the strain grown in eggs, which was used for the infection, contains arginine (Arg) instead of glutamine (Gln) at position 226. This substitution is associated with a receptor binding affinity to α-2,3 sialic acid receptors which are typical of avian viruses and thus bind preferably to avian cells [9]. For viral titration, 100 µl of 10-fold diluted A/Italy/2810/2009 virus was inoculated into five SPF embryonated hens’ eggs and the median embryo infectious dose (EID 50 ) was calculated according to the Reed and Muench formula [10]. Molecular tests Extraction of RNA Viral RNA was extracted from 200 µl of blood using the commercial kit ’NucleoPsin RNA II’ (Macherey-Nagel) and from 200 µl of phosphate-buffered saline (PBS) suspension of cloacal and tracheal swabs and homogenised organs using the ‘High Pure RNA Isolation Kit’ (Roche ® ) commercial kit. www.eurosurveillance.org 9
Page 1 and 2: Rapid communications EUROPEAN CENTR
Page 3 and 4: for individuals 2-64 years old were
Page 5 and 6: in mitigating the pandemic as it re
Page 7: our seasonally forced SIR model by
Page 11 and 12: 5. ProMED-Mail. Chile finds swine f
Page 13 and 14: providing immunostimulatory signals
Page 15 and 16: (VAESCO) are developing complementa
Page 17 and 18: conditions will be difficult in cou
Page 19 and 20: S u rve i ll a n c e a n d o u t b
Page 21 and 22: Clinical symptoms in the primary ca

Volume 14, Issue 41 - 15 October 2009 - Eurosurveillance

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?